Endodontic surgery seminar/ dental implant courses by Indian dental academy

ENDODONTIC SURGERY

SEMINAR BY Dr. N.Upendra Natha Reddy Postgraduate Student

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CONTENTS Page No INTRODUCTION/HISTORY

1

CLASSIFICATION

6

INDICATIONS

7

CONTRA-INDICATIONS

9

PRE-OPERATIVE ASSESSMENT/ PRE-MEDICATION

9

SURGICAL KIT

12

FLAP DESIGNS

15

TECHNIQUES OF ENDODONTIC SURGERY

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 INCISION AND DRAINAGE

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 TREPHINATION

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 APICAL CURETTAGE AND BIOPSY

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 APICOECTOMY

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 ROOT END CAVITY PREPARATION

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 ROOT END CAVITY OBTURATION

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 ROOT END FILLING MATERIALS

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 CORRECTIVE SURGERY

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 REPLACEMENT SURGERY

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 IMPLANT SURGERY

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SUTURING

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POST-OPERATIVE INSTRUCTIONS

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POST-OPERATIVE SEQUELAE

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SUCCESS AND FAILURE

87

REFERENCES

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INTRODUCTION According to the strictest definition of the word surgery, most endodontic treatment falls into the category of a surgical procedure, since removal of tissues, such as vital pulp, necrotic debris, or dentin, is involved. However, as commonly used, the term endodontic surgery refers to the removal of tissues other than the contents of the root canal space to retain a tooth with pulpal and/or peri-apical involvement.

HISTORY Endodontic surgery was first recorded 1500 years ago when Aetius.S., Greek physician-dentist, excised an acute apical abscess with a small scalpel. Later the procedure was redefined and popularized, although one may question whether Hullihen’s contribution in 1839 was a refinement over Aetius. “Make an incision through the gum, along the entire length of the fang”, stated Hullihen, “then apply a roasted fig or bruised raisins to the gum”. Farrar (1884), Rhein (1897), and G.V.Black (1886) described root amputation techniques, and in 1919, Garvin demonstrated retrofillings radio graphically.

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Currently, endodontic surgery falls into more than one domain.

Many general practitioners and most oral surgeons routinely perform various types of endodontic surgery. Endodontists should be able to perform peri-apical surgery on any root in the dental arch, including mandibular molars. Periodontists may become involved in the endodontic surgery, peri-apical or amputational, when a tooth requiring periodontal surgery has a peri-apical problem of pulpal origin in addition.

Currently endodontic surgery is a predictable and integral part of comprehensive endodontic services. Schilder, as president of the American Association of Endodontists, editorialized that endodontic surgery

has

advanced

and

currently

plays

a

major

role

in

“retreatodontics�. However, the surgical approach to endodontics can be badly misused. For some, periradicular surgery automatically follows root canal obturation and at times is performed in lieu of filling the root canal. Others refuse to perform or recommend endodontic surgical procedures. Both groups lack an appreciation of comprehensive dental care. There are two major areas of endodontic surgery at this time: periapical and amputational. The two have certain basic similarities but have considerable differences as well.

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For many years the term conservative treatment has been used as a synonym for non-surgical treatment. Chivian correctly protested that using conservative to mean “without surgery” would indicate that surgery is radical treatment. Since peri-apical surgery usually saves a tooth that could not be retained by other methods, it too is conservative.

Weine also agrees that peri-apical surgery should not be considered radical therapy, in contrast, tooth retention by any method is conservative.

For

years,

many

dentists

unaccountably

have

separated

endodontists into two divisions: conservative and surgical. This classification inappropriately implies that surgery is a radical approach.

Surgical treatment should be considered an extension of therapy, a means of preserving teeth that otherwise would have to be extracted, and is therefore no less conservative than what we consider to be routine, nonsurgical root canal treatment.

The definition of conservative, “tending to preserve existing conditions”, supports this position. How did the erroneous perception of surgery as a radical and last -resort treatment originate? Apparently this idea began in 1884, when Farrar described “radical and heroic treatment of alveolar abscess”. In outlining a plan of treatment, Farrar used the term 5

radical. In a perusal of the endodontic literature of the past 100 years, the term conservative is used to describe non-surgical treatment. This archaic terminology is still found in current textbooks and journal articles.

However, because a surgical endodontic approach is often the only method of salvaging otherwise hopeless teeth, it is indeed conservative.

Other important factors that have enhanced the success and increased the applications of surgery are research and education. Through experimental investigations, surgical approaches and outcomes are better understood.

Advanced

endodontic

programs

have

increasingly

emphasized surgical training in response to the need for this treatment approach.

Endodontic surgery encompasses surgical procedures performed to remove the causative agents of radicular and peri-radicular disease and restore these tissues to functional health.

With the recent advent of magnification and illumination, coupled with ultra-sonic root end canal preparations and sealing with new retrograde filling materials, the success of surgical endodontic treatment will provide the answer to solving myriad problems that were once considered hopeless. The expanded scope of surgical endodontics includes apical 6

curettage, apicoectomy, root end filling, root resections, hemisections, replantation, transplantation, and guided tissue regeneration, with more advances on the horizon. This gives the clinician a wide range of choices in this conservative approach.

Root canal treatment is a relatively successful procedure if diagnosis and technical aspects are carefully performed. Most pulpal and peri-apical disease is best managed nonsurgically. There is a common belief that if root canal treatment fails, surgery is indicated for correction.

This is not necessarily true, as most failures are best corrected by retreatment. There are however, situations in which surgery is necessary to retain a tooth that would otherwise be extracted.

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CLASSIFICATION OF ENDODONTIC SURGERY It can be classified as follows:

1. Surgical drainage  Incision  Trephination (fistulative surgery) 2. Radicular surgery A. Apical surgery.  Curettage and biopsy (peri-radicular surgery).  Apicoectomy.  Retro filling.

B. Corrective surgery.

1. Perforative repair.  Mechanical.  Resorptive.

2. Periodontal repair.  Guided tissue regeneration.  Resection.

3. Replacement surgery.

A. Replant surgery  Intentional  Post traumatic.

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B. Endosteal implants surgery.  Endodontic  Osseo-integrated (endosseous)

INDICATIONS FOR ENDODONTIC SURGERY 1. Surgical Drainage A. Necessity for drainage 1. Elimination of toxins 2. Alleviation of pain 2. Apical surgery A. Irretrievable root canal fillings 1. Obviously inadequate filling 2. Apparently adequate filling B. Calcified canals C. Procedural errors 1. Instrument fragmentation.

2. Nonnegotiable ledging.

3. Over instrumentation and apical fracture.

4. Symptomatic overfilling.

D. Presence of dowels E. Anatomic variations F. Apical cyst G. Biopsy 9

H. False indications.

1. Presence of an incompletely formed apex, making hermetic sealing of the apex impossible.

2. Marked overfilling.

3. Persistent pain.

4. Failure of previous treatment.

5. Extensive destruction of peri-apical tissue and bone involving one third or more of the root apex.

6. Root apex that appears to be involved in a cystic condition.

7. Presence of crater shaped erosion of the root apex, indicating destruction of apical cementum and dentin.

8. Inability to gain negative culture.

9. Internal resorption.

10.Extreme apical curvature.

11.Fracture of root apex with pulpal death.

3. Corrective surgery A. Root anomalies B. Perforating carious and resorptive defects C. Periodontal-endodontal defects  Guided tissue regeneration.  Root resection, hemi section, bisection.  Correction, radicular gingival groove.

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4. Replacement surgery A. Replant surgery  Intentional.  Post-traumatic.

B. Implant surgery  Endodontic.  Endosseous.

CONTRA-INDICATIONS TO ENDODONTIC SURGERY

1. Indiscriminate surgery.

2. Poor systemic health.

3. Psychological impact.

4. Local anatomic factors  Short root length.  Poor bony support.  Site of surgery.

PRE-OPERATIVE ASSESSMENT The quality of endodontic surgery, and in many respects the final successful out is dependent on proper patient assessment, diagnosis and treatment planning. It is during this process that the facts surrounding the 11

case in question must be obtained and integrated into a meaningful diagnosis and treatment plan. Contraindications involving the patient’s psychological or systemic makeup can be identified as well as patient acceptance of, and cooperation with, the anticipated surgical procedure.

Often this will include procedures to minimize stress with patients who are particularly susceptible to pain and anxiety. Oral soft- and hard tissue conditions, including patient compliance with oral hygiene practices, can be ascertained and reinforced.

Local patient factors focus on the nature of the previous root canal treatment, if any, and the ultimate management of both soft and hard tissues during surgical entry and wound closure.

These include the

potential need to remove previous dental restorations, which are failing, and to attempt non-surgical pretreatment as part of overall management.

The removal of leaking crowns, restorations with deep decayed margins, poorly adapted inter proximal restorations and root fillings of silver comes or pastes is common. Favoring results have been obtained when root canal systems are retreated prior to surgical management.

Radiographic examinations are also essential, using prior radiographs if available, along with additional films exposed at the consultation visit.

When posterior teeth are involved it is common to 12

take several radiographs from different angles, identifying the number, curvature and angle of the roots requiring surgery. Likewise, anatomical structures, which may impair surgical or visual manipulation of the surgical site, are identified, such as the mental foramen, zygomatic process, anterior nasal spine and external oblique ridge.

Crucial to the success of the surgical procedure will be communication with the patient concerning the need for surgery, the prognosis, the use of preoperative medication or mouth rinses, the actual procedures to be performed, the potential for postoperative discomfort, the use of postoperative palliative procedures, the need for suture placement and removal, follow-up care and long-term assessment. It is recommended that the following pretreatment regimens be considered.

1. A periodontal examination should be performed prior to surgery and, if necessary, scaling and/or root planing performed.

The

patient’s oral hygiene practices should be assessed and reinforced.

2. Patients can be placed on chlorhexidine rinses 1 day before surgery, to continue for 2-3 days afterwards.

3. Patients can begin taking a non-steroidal anti-inflammatory medication 1 day before surgery, or at the latest one dose 1 h beforehand.

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4. Patient should be advised to refrain from smoking.

5. If sedative pre-medication is to be used the patient must bring an accompanying person, who will be responsible for escorting home and compliance with postoperative instructions.

General Medical Conditions Hypertension

Coronary artherosclerotic disease

Stable angina

Myocardial infarction

Infective endocarditis

Chronic obstructive pulmonary disease

Asthma

Cerebrovascular accident

Epilepsy

Diabetes

Adrenal insufficiency

Steroid therapy

Organ transplant

Impaired hepatic or renal function

SURGICAL KIT Basic instruments for surgical intervention have changed little in the past century. Many manufacturers have attempted to duplicate or enhance these instruments, but few major changes exist. The clinician must be familiar with the different types of instruments, and how and why they are beneficial in the performance of endodontic surgery. It is well accepted that there is more than one way to achieve high quality in the delivery of surgery. Therefore, instruments must be chosen which 14

best allow the surgeon to perform as well as possible. Instruments must be sharp, undamaged and permit total control of the surgical site. Backup instrument support for indispensable items must also be considered.

Pre-surgical assessment  Mirror and curved explorer  Straight and curved periodontal probes

Soft-tissue incision, elevation and reflection  Sharp scalpels – numbers 15, 15c, 11 and 12  Broad-based periosteal elevator  Broad-based periosteal retractor  Tissue forceps  Surgical aspirator  Irrigating syringes and needles

Peri-radicular curettage  Straight and angled bone curettes  Small endodontic spoon curette  Periodontal curettes  Fine, curved mosquito forceps  Small, curved surgical scissors

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Bone removal and root-end resection  Surgical length round and tapered fissure burs  Straight hand piece  Contra-angled hand piece/slow and high

Root-end preparation/placement of root-end filling/finish of resected root end  Miniature contra-angle or ultrasonic unit; sonic hand piece  Burs-very small inverted cone or round; angled ultrasonic or sonic tips

Root-end filling material  Haemostatic agent (avoid bone wax)  Miniature material carriers and condensers  Small ball burnished  Paper points or fine aspirator tip  Citric acid 10-50% and sterile cotton pellets  Small, fine explorer

Suturing and soft-tissue closure  Surgical scissors  Hemostat or fine needle holders 16

 Various suture types and sizes (3-0 to 5-0)  Sterile gauze for soft-tissue compression

Miscellaneous (or readily available)  Adequate aspiration equipment  Additional light source  Magnification  Root canal filling materials  Anaesthetic syringes and anaesthetic.

FLAPS- FUNCTION AND DESIGN FUNCTIONS OF A FLAP The most important function of a flap is to raise the soft tissue overlying the surgical site to give the best possible view to the operator and sufficient exposure of the area to be operated on. Since the free and attached gingiva and the underlying mucosa have considerable vascularity attempting to work through them would lead to increased blood loss and obstructed view.

Endodontic surgery has had a great advantage over gingivectomy gingivoplasty and push back procedures – methods of periodontal surgery that were in vogue for some time until recently. These types of surgery 17

left raw, bleeding tissues in addition to uncovered bone in some cases.

They were characterized by considerable postoperative pain and required surgical pack placement. In endodontic surgery the overlying tissue was stripped back and could be replaced after the procedure to give the best possible covering to the surgical site. Therefore the second important function of a flap is to provide healthy tissue that will cover the area of surgery, decrease pain by eliminating bone exposure, and aid in obtaining optimal healing.

It is no wonder that sophisticated periodontal surgery has incorporated the use of flaps, and most operations now involve that type of approach. The split thickness flap, apically repositioned flap, sliding flap and others have been found invaluable in the treatment of periodontal disease. Any of the new improvements in endodontic flap design and methods of flap retraction have been gleaned from the experience of Periodontists.

Whenever endodontic surgery is to be performed an

extremely careful periodontal evaluation must be ascertain the most desirable flap.

Additionally when the site is opened for endodontic

surgery, the operator should concomitantly perform any periodontal surgery necessary in the area. In many cases the exposure afforded by flap retraction for endodontic surgery exposes periodontal defects that would otherwise remain undetected.

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Requirements of an ideal flap  Making sure base is widest point of flap  Avoiding incision over a bony defect  Including the full extent of the lesion  Avoiding sharp coroners  Avoiding incision across a bony eminence  Guarding against possible dehiscence  Placing a horizontal incision in the gingival sulcus or keeping it away from the gingival margin  Avoiding incisions in the mucogingival junction  Avoiding improper treatment of periosteum  Taking care during reaction.

TYPES OF FLAPS • Semi lunar flap, • Full vertical flaps  Double vertical incisions  Modified envelope flaps •

Palatal flaps

• Ochsenbein Luebke flaps.

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1. Semilunar flap (Refer Fig.1) The semilunar flap has been used for many years in endodontic surgery. The chief advantage of this flap is its simplicity, requiring merely a straight, horizontal incision firmly through the soft tissues to the underlying bone. Because the incision is placed away from the gingival margin, the semilunar flap does not cause the uncovering of gingiva from the gingival margin of crown restorations or disturb the healing of gingiva after periodontal surgery. It is referred to as semilunar because the horizontal incision is slightly modified to have a dip toward the incisal aspect in the center of the flap, giving resemblance to a half-moon.

The disadvantages of this flap have caused it to be replaced by types of vertical incisions. Among these disadvantages are the following.  Considerable lateral extension is required to expose sufficient area at the surgical site.  If sufficient lateral extension is not provided, the incision may tear at the edges during retraction and create areas that heal poorly and with considerable scar formation.  If minimal attached gingiva is present, the flap may encroach on the sulcus depth of the teeth to the flapped.

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 Since the edges to be sutured are held apart during surgery, the healing is not as rapid as healing with other flaps and may result in considerable scar formation.  If the lesion is larger than anticipated, the incision may end up being over the surgical defect.  When the cuspid or adjacent tooth is involved in the surgery, the cuspid eminence is violated by the incision.  This flap usually originates in or is placed in the mucogingival junction, often leading to retarded healing and scar formation.

Indications for use of the semilunar incision are situations in which the contour and shape of the marginal gingiva must be preserved, as in patients with complete jacket crowns in the area or for use after periodontal surgery.

This type of flap is contraindicated where deep periodontal pockets are present, where minimal attached gingiva is present, when a very large lesion is anticipated, and when other types of flaps are deemed to be more desirable.

It is especially important that the gingival sulcus of all teeth involved in a semilunar flap be explored with a periodontal probe before the incision is made. The horizontal incision must be made a minimum of 2mm from the greatest sulcus depth.

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2.Vertical flaps (Refer Fig.1) Although referred to as vertical flaps because of the vertical incisions made to aid in the raising of the tissues, these flaps are always made in conjunction with a horizontal incision. The horizontal incision is usually placed in the gingival sulcus. Cutting the epithelial attachment around the necks of the teeth and across the interdental papillae develops this portion of the incision. When pushed back by a periosteal elevator, the gingival edge of the flap has a scalloped border. When periodontal surgery is to be performed in addition to the endodontic surgery a reverse bevel may be used to remove the diseased gingival tissue around the necks of the teeth and to return more healthy tissue to that area during closure.

If one vertical incision is used, the flap is referred to as a single vertical whereas the term double vertical implies the use of two vertical incisions. The vertical incisions greatly aid in the retraction of the tissue overlying the defect and have been recommended for use by periodontics.

If the Ochsenbein Luebke incision is considered to be a vertical type, which it truly is, vertical flaps have taken over almost completely as the most desirable type in endodontic surgery.

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The chief advantages of vertical flaps are that are optimal healing usually occurs, since no edges of the flap are manipulated during surgery, and the visualization of the surgical site is excellent because of the maximal uncovering of the area.

In addition, any necessary minor

periodontal surgery may be performed at the same time.

The

disadvantages are that the gingival areas of many teeth are uncovered, the possibility of opening a dehiscence is present, careful flap design must be adhered to in order to avert having the base too small, and sharp corners may be present at the junction with the horizontal portion of the incision.

The only contraindication for the use of vertical flaps are the cases in which the shrinkage that may occur during gingival healing might lead to the uncovering of gingival margins of crowns of cases in which gingival tissues are still healing after periodontal surgery. If the possibility of a dehiscence is present, the gingival portion of the flap may be prepared to be a split thickness flap leaving the periosteum covering undisturbed. Since vertical flaps are much more complicated o prepare and reflect than semilunar flaps, only those familiar with periodontal and surgical techniques should utilize them during the initial attempts at endodontic surgery. As greater experience and confidence are gained, improved results may accrue with the use of the vertical flaps.

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In the typical flap double vertical incision are used when anterior teeth are treated. The incisions are placed to the farthest edge of each tooth adjacent to the tooth to be treated. If the defect is expected to be very large or if the terminal end of the incision would normally approximate an attachment to be avoided, the vertical incisions may be placed two teeth over from the surgical site. In the posterior areas, generally only one vertical incision is used, located mesially to the tooth one or two teeth anterior to the one to be treated.

In mandibular molars a scalloped incision is developed around the necks of the adjacent teeth, extending anteriorly to the first bicuspid or cuspid in which a short, single vertical incision is placed to relax the flap and aid in visualization of the area of defect.

Some vertical flaps suggested for use are designed with an extremely wide base compared to the edge of the flap. This is to ensure that there will be sufficient blood circulating to all portions of the flap, which may be a problem if a vertical flap is not correctly designed. The base extends the width of two adjacent teeth, with two vertical incisions coming down at an oblique diagonal angle to the mesial and distal edges of only the tooth with the defect. Although this method does minimize the area of bone uncovered during the surgery, it may prove to be too 24

restrictive if the bone defect is larger than anticipated. This type of flap is often referred to as an envelope flap since it resembles the back of an envelope.

3. Palatal flaps (Refer Fig.1) The use of a flap to retract the palatal tissues of the maxilla may be needed in certain cases. These include reverse filling, perforation repair, apicoectomy or root amputation of the palatal root of a maxillary bicuspid or molar, and perforation or resorption repair of the palatal surface of anterior teeth. As in any flap, all rules for flap design must be satisfied for best results. However, the rich vascular supply of the palatal area provides for excellent healing in most instances.

The typical palatal flap is prepared with a scalloped incision around the gingival margins. Normally at least two teeth to the mesial and to the distal aspects of the tooth that is to be operated on must be included in the flap retraction for desirable visualization.

Relaxing

incisions are best placed between the first bicuspid and cuspid to diminished the change for severance of the palatal blood vessels and resultant hemorrhage problems.

The blood vessels from the incisive

canal and greater palatine foramen anatomize in this area are not as large as they are farther anteriorly or posteriorly.

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The bone topography in the posterior area of the palate is inclined to be pebblier than the labial or buccal surface of either the maxilla or mandible. This makes periosteum elevation more difficult as the elevator strikes humps or peduncles of bone during retraction. The scalpel may be used to partially dissect the tissue for a modified split thickness flap in these cases. Even with the mucosa retracted, examination of the surgical site with a palatal flap is difficult.

Even with assistance it is very

complex to retract the flap, use a mouth mirror for visualization of the area, and use a hand piece or hand instrument for preparation, curettage or filling. Therefore it is wise to obtain retraction by placing a suture at the edge of the flap and tying it tightly to the teeth on the opposite side of the arch. This tissue on the opposite side need not be penetrated, but the suture material is merely tied around the gingival margin of the bicuspid or molar. When the surgery is completed, the suture is cut and routine replacement afforded to the flap.

4. Ochsenbein Luebke flap (Refer Fig.1) Developed by a Periodontist and an Endodontist, this flap has been designed to combine the advantages of the vertical flaps with those of the semilunar flaps. Since the horizontal portion of this flap is placed a minimum of 2mm from the depth of the gingival sulcus, those gingival tissues covering jacket crowns or healing after periodontal surgery are 26

unaffected. The site of surgery has excellent exposure and yet less tissue is reflected, since the flap does not extend to the marginal gingiva. The exact width of the flap may have greater variability, since the flap does not have to terminate at a particular edge of any tooth. The edges of the flap are not manipulated during the surgery; therefore the blood supply to the area of suture margins remains excellent. Suturing is easier than when the horizontal incision lies in the gingival sulcus. There is no chance of opening a dehiscence.

The main disadvantage of this flap is that extreme care must be exercised so no sharp points occur at the junction of the vertical and horizontal incisions. There are only a few contraindications to this type of flap. If minor periodontal surgery is to be performed around the gingival sulcus, the double or single vertical incision is to be placed across a prominent eminence, vertical incisions avert the problem. If minimal attached gingiva is present, the horizontal incision may approach the mucogingival junction.

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Fig. 1. Flap designs

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Fig. 2. Flap designs

Triangular tissue flap design with single vertical releasing incision.

The vertical releasing incision can be performed in different ways. Either (A) the incision leaves the interdental papilla intact or (B; insert) the incision includes the interdental papilla. In

Rectangular tissue flap design with double vertical releasing incisions. As with the triangular flap design, variations can be used with the vertical incisions (A and B); a

description has been included.

either case the incision line should meet the tooth at 90°.

Trapezoidal tissue flap design. Note vertical releasing incisions are angled towards the base of the flap.

Horizontal tissue flap design. No vertical releasing incisions are used initially but they can be added later to enhance surgical access if necessary.

Luebke – Ochsenbein (Submarginal) tissue flap design. This flap may have one or two vertical releasing incisions, or may be limited to a horizontal incision, only if sufficient surgical and visual access can be obtained.

Semilunar tissue flap design. Note that the scope of this flap limits extension if necessary.

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TECHNIQUES OF ENDODONTIC SURGERY

I. Surgical Drainage Surgical drainage usually involves emergency procedures and acute lesions. Both require patience in diagnosis and kindness in treatment.

Incision And Drainage (Refer fig.3) Incision And Drainage (I & D) is the standard method to drain apical abscesses. Although the technique is relatively easy, two problems always accompany an I & D. First, is the problem of timing—the optimal time to intervene. Second is the problem of obtaining adequate local analgesia.

Learning the correct moment for surgical intervention is gained by experience. Ideally, the immediate area to be incised, the “pointed” area should feel soft and fluctuant under the examiner’s fingertips. The apex of the swelling may appear whitish or yellowish. This is the ideal time at which to anesthetize, incise and drain.

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Obtaining local analgesia is difficult because: 1. It is difficult to establish profound analgesia for an inflamed and abscessed area.

2.There is some reluctance to inject into the area. Not only is it initially very painful to increase the fluid pressure by injecting into the region, but it is also unwise to risk spreading the infection by the pressure of the injection.

Order of operation after anesthesia is as follows: A. Arrange the instruments.

B. Place the gauge sponges to catch the flow.

C. Swab the area with disinfectant.

D. Test the dept of anesthesia with the end of the swab stick.

E. Perform a sweeping vertical incision with a No:11 scalpel through the pointed area down to the bone and irrigate copiously with anesthetic solution.

F. Have assistant aspirate immediately.

G. Open the incised area widely by following out the tract with a hemostat. Spread the handles of the hemostat to separate the beaks.

More irrigation with anesthetic solution washes out the toxic elements and reduces remaining sensitivity.

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H. Place a “T” drain with the bar of the “T” inside the incision.

Placement of a drain is optional because the initial epithelial and connective tissue bridging break down under moderate pressure.

I. Suture the drain in position if necessary.

Figure -3

Fig. 3. Incision and drainage of acute apical abscess. A. Good level of anesthesia is established. B. Sweeping incision made. C. Scalpel carried through to bone. D. curved hemostat used. E. Positioning of “T-drain”. F. If drain not in place it may be sutured.

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TREPHINATION (Refer fig.4) This surgical form is used to secure drainage and alleviate pain when exudate in the cancellous bone is dammed up behind the cortical plate. The tremendous pressure leads to the excruciating pain of an intraosseous acute apical periodontitis or apical abscess. The intraosseous pressure can be released and the area decompressed through trephination, which provides a pathway to empty pus and other acid exudates.

• A mini vertical incision provides adequate access and landmark visualization.

• The focal area of the lesion is pin pointed by examination. Working through the retraction of the soft tissue, the overlying cortical plate of bone is grossly removed with No: 8 bur to identify the involved root apex.

• The bone is then penetrated at the apex with a No:4 bur. In certain cases entrance can be made through the cortical plate with a file because of the resorptive activity of the periradicular lesion.

One must be careful to avoid structures, such as inferior alveolar nerve, mental foramen or the roots of non-affected teeth in that area. A lead shot, a broken bur head, or a pellet of gold foil in the incision is an excellent way to pinpoint by radiograph the proper location for entrance.

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Figure –4

Fig. 4. Surgical trephination of intact labial cortical plate.

II. Radicular Surgery Radicular surgery involves root structures and may be divided into apical surgery and corrective surgery. Apical surgery is a procedure designed to modify and curette the apex and peri-radicular tissues. Most cases require filling of the root end following a 3 mm (±) apical resection.

Corrective surgery involves the repair of the perforated root structure per se.

Four basic steps are common to apical and corrective surgery, whether one stops at curettage or proceeds to perform an apicoectomy, a retro filling, a root repair, or a resection.  Adequate flap design  Exposure of surgical site  Curettage of inflammatory tissue  Closure of the flap 34

TECHNIQUES

1. The two-step or filling first method 2. Post-resection filling technique

A. Two –step or Filling-First Technique Two cases require canal filling prior to periapical surgery 1. Failing case with a canal filling that may be removed.

2. A case where the need for surgery had become apparent during the course of routine therapy before the filling appointment.

Retreatment: A heavy condensation technique will give important additional information helpful during the surgery. Such disclosures include:  Position of apical foramen  Existence of significant lateral canals  Resorptive defects  Bifurcated canals  The proper time for this filling is either immediately before the surgery or during the surgical exposure.

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B. Post-resection filling technique Currently as a result of the reports of Dorn and Gartner and Frank et al, one no longer employs amalgam as a material for canal reverse filling.

Indications for Reverse Filling 1. Teeth with clinical and/or radiographic symptoms and no negotiable canal.

2. Presence of a well fitting post and core that might cause root fracture during removal.

3. Presence of a sectioned silver point.

4. Presence of an irretrievable broken instrument or filling material with lack of apical seal.

Any of these situations may occur without clinical or radiographic evidence of damage being present

Disadvantages 1. The time spent with the tissue reflected and bone uncovered is greater than with the two-step technique, since both canal filling and curettage are performed after the flap is opened.

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2. Since the degree of pain and edema is usually proportional to the time the flap is retracted, this method would appear to cause greater post-operative problems.

3. The presence of blood from the per-apical tissues can interfere with the condensation of the cones.

4. The final filling is usually less dense, as there is no solid dentinal matrix to pack against.

5. The additional information derived form viewing the radiograph of the canal filling is not available.

6. Since no rubber dam is placed, it is possible for the patients to taste any of the canal irrigants.

7. The possibility of swallowing or aspirating a file or reamer is present.

Advantages 1. Time for total procedure is lessened because no immediate

disinfection is performed, no application of rubber dam is necessary, and no master gutta-percha cones need to be verified radiographically.

2. It is easier to locate a difficult –to- find apex, since a large

instrument may be placed through the canal and into the peri-apical tissue as a landmark.

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3. If an instrument or filling material is broken off in the apical

portion of the canal or partially into the per-apical tissues, the fragment may be surgically removed before canal filling.

Removal of diseased soft tissue (peri-radicular curettage) and Biopsy This procedure can often be performed before or in conjunction with root-end resection. The purpose is to remove the bulk of the soft tissues, which may be present at various root canal orifices on the root surface. This adverse tissue response has been described as reactive or protective. Therefore, omitting to remove every remnant of soft tissue will not lead to failure, as the tissue elements in the periphery of these lesions are often productive in nature and contain fibroblasts, vascular buds, new collagen and bone matrix. In those cases in which the softtissue mass is exposed upon flap reflection or initial bone removal upon flap reflection, curettage can proceed prior to root-end resection. In other cases resection is necessary to gain access to most of the tissue.

Straight and angled surgical bone curettes are necessary, along with angled periodontal curettes. At times it may be necessary to inject 0.5 ml of anesthetic solution to control haemorrhage and ensure patient comfort if the lesion is extensive. Initially the bone curettes are used to peel the soft tissue from the lateral borders of the bony crypt. This is accomplished with the concave surface of the curette facing the bony 38

wall, applying pressure only against the bone. Care must be taken to avoid penetration of the soft tissue, which may share the tissue, server the vascular network, and increase local haemorrhage. Once the tissue is freed along the lateral margins, the bone curettes can be turned and used in scraping fashion along the deep walls of the crypt. This will detach the soft tissue from its lingual or palatal base. Once loosened, tissue forceps are used to grasp gently the tissue, which is teased from its position with a bone curette. The tissue sample is placed directly into a bottle of 10% neutral buffered formalin for biopsy. In those cases, which require rootend resection prior to curettage, one must make sure that the root structure is sufficiently exposed to minimize shredding of the soft tissues during resection.

In the presence of large lesions, care must be exercised during curettage of the lateral surfaces of the bony crypt to avoid exposure of adjacent roots and their pulpal vasculature.

Pre-surgical radiographs

should reveal this possibility, and tissue in these areas may need to be left in position. Caution must also be exercised when close to the maxillary antrum, mental foramen or mandibular canal to prevent damage to vital structures. When soft tissue is adherent either lingually to the root or in the furcation region, periodontal curettes are essential for thorough removal.

39

Whilst retention of root structure is necessary for tooth stability and strength, rarely should peri-radicular surgery be limited to just curettage. Therefore root-end resection is usually needed.

APICOECTOMY (Refer fig.5) The term root-end resection refers specifically to the removal of the apical portion of the root. There are many indications for resection of the root end during peri-radicular surgery, each designed to eliminate aetiological factors and to enhance the sealing of the root canal at the resected root surface. These indications vary from case to case, but support the stated purpose.

Syngcuk Kim used the HESS model of root anatomy to find out the incidence of lateral canals and apical ramifications when resection was performed at 1, 2 and 3 mm. The incidence of lateral canals was found to be 52, 78 and 98% respectively.

Until early 1990’s bevel angle of 45° was taught in all schools of dentistry with the following reasons for its use.

1. Gain visual and operating access for root tip resection, 2. Ease of placing retrofilling materials, 3. Ease of inspection.

40

In recent years 45° bevel angle was found to have no biological basis.

Resection at 90° was found to eliminate 98% of the apical

ramifications and 93% of lateral canals. Hence root resection must be done perpendicular to long axis of the root whenever possible. However, a 10° bevel is allowed where perpendicular bevel may not be possible.

Massimo Gagliani et al (1998) evaluated the apical root resection angle and cavity made by ultrasonic retrotips and its influence on apical seal, They found that 90 angle showed less dye leakage for dentin than 45 angle and that a 3mm or more apical cavity produces a safe and effective seal.

The ideal root end preparation according to Peter Gillheany and associates should be:  Parallel to the long axis of the root,  3 mm deep and centered.

The optimum depth of the retrograde cavity should be 3mm, because as the depth increased the leakage decreased. This was attributed to the occlusion of the apical tubules by the retrofilling material (Massino Gaglianiet al 1998).

41

The root end can be resected and beveled tin one of two ways.

Once the root end has been exposed, the bur (narrow or constringe) is positioned at the desired angle and the root is shaved, beginning from the apex, cutting caronally. The bur is moved from mesial to distal at the desired angle, shaving the root smooth and root outline. The approach allows for continual observation of the root end during cutting.

The second technique of resection is to predetermine the amount or root end to be resected. This approach, however, may remove more root structure than is necessary. The bur and hand-piece are positioned at the chosen angle and cutting through the root from mesial to distal resects the apex. Once the apex is removed, the root face is gently shaved with the bur is smooth the surface and ensure complete resection and visibility of the root face. This technique works well when an apical biopsy is desired or to gain access to significant amounts of soft tissue located lingual to the root.

Figure – 5

Fig. 5. Two ways of performing apicoectomy 42

The appearance of the root face following root-end resection will vary, based upon the type of bur used, the external root anatomy, the anatomy of the canal system exposed at the particular angle of resection, and the nature and density of the root canal filling material. Various types of burs have been recommended for root-end resection, such as round burs, straight fissure burs, diamond burs, and cross-cut fissure burs.

Each will leave a characteristic anatomical imprint on the root face from rough-grooved and gouged to regularly grooved and smooth. To date, no study has clearly defined the advantages of one type of bur over the other, although for year’s clinical practice as favoured a smooth flat root surface.

The extent too which the removal of the root end should occur will be dictated by the following factors.

• Access and visibility to the surgical site.

• Position and anatomy of the root within the alveolar bone.

• Anatomy of the cut root surface relative to the number of canals and their configuration.

• Need to place a root-end filling into sound root structure.

• Presence and location of procedural error, e.g. perforation. Presence of an intra-alveolar root fracture.

43

• Presence of any periodontal defects. • Anatomical considerations, e.g. proximity of adjacent teeth, or level of remaining crestal bone. • Presence of significant accessory canals; roots with such anatomical aberrances would be likely to receive more extensive resection.

Only when 3 mm of the apex is resected are lateral canals reduced by 93%. Additional resection reduced the percentage insignificantly. A root resection of 3 mm at a 0-degree bevel angle removes the majority of anatomic entities that are potential causes of failure. Any remaining lateral canals are sealed during retrograde filling of the canal. Therefore removing the apex beyond 3 mm is of marginal value and compromises a sound crown / root ratio.

Regardless of the rationale for the extent of root-end removal, there is no reason to resect to the root to the base of a large peri-radicular lesion, as was previously advised. Likewise, resection to the point where little (<1mm) or no crestal bone remains covering the buccal aspect of the root may very well doom the tooth to failure. On the other hand, failure to remove sufficient root structure to be able to inspect the resected root surface and establish an apical seal may also contribute to failure. In this

44

case, root canals may be missed, or they may be so extensive that they cannot be properly managed within the confined space.

The complete root face must be identified and examined subsequent to resection. The examination is done with a fine, sharp probe, e.g. DG 16, guided around the periphery of the root and the root canal. The external root anatomy will determine the ultimate shape of the cut root end, ad oval, round, dumbbell shaped, kidney shaped, or teardrop shaped. Outlines will vary depending on the tooth, angle of the bevel and position of the cut on the root. Once cut, however, the entire surface must be visible. If visibility or access is impaired, or the root possesses an unusual cross-sectional outline, 1% methylene blue dye can place on the root surface to help identify the periodontal ligament that surrounds the root. A small cotton pellet containing dye is wiped over the root face for 5-10s. Subsequently the area is flushed with sterile water or saline.

The dye will stain the periodontal ligament dark blue, highlighting the root outline. A potential drawback to the technique may be deposition of cotton fibres on the resected surface or on bone. Residual remnants of cotton fibres have been shown to induce a foreign-body reaction in healing tissues.

45

The shape of the exposed canal system will very depending on the angle of the bevel and the canal anatomy at the level of the cut. Canal systems will generally assume a more elongated and accentuated shape as the angle of the bevel is increased buccally. Often, canal systems will be irregular and extend further than anticipated.

Also visible on most resected root ends is the presence of the root canal filling material. Variations in quality of the filling will be seen in both type of filling material, e.g. gutta percha, silver cones, pastes, and the nature of the obturation technique, e.g. lateral condensation, vertical condensation or thermoplastic filling.

Likewise, the different burs

advocated for resection will create discrepancies in the surface of the filling material and adaptation to the canal walls. For example Coarse diamond burs will tend to rip and tear at the gutta-percha root canal filling, spreading the gutta-percha over the edge of the canal aperture and onto the resected root face. Invariably this will create gaps between the originally adapted gutta-percha and the root canal wall. Similar findings are noted with metal burs. In order to prevent this, surface finishing with an ultra fine diamond is recommended.

46

Figure â&#x20AC;&#x201C; 6

Fig. 6. A. Cleaning and shaping of the root canal with file tips through the resected root end. B. Condensation of the gutta-percha filling with the tip through the root-end. C. Removal of excess filling material and finishing of the root surface with an ultrafine diamond bur.

The presence of additional foramina anatomizes between foramina, fracture lines and the quality of the apical adaptation of the root canal filling must be checked on the resected root surface. If methylene blue has been used, it will also have a tendency to stain the periphery of the canal system and highlight fracture lines.

Nitromersol, a dental

disinfectant which strains reddish-brown, can also be used when examining the root face or a fibreoptic light can be aimed at or behind the root end to enhance visibility. If these methods do not work, it may be necessary to remove additional root structure to identify the canal system or, in the case of a fracture line, to enhance its direction and extent.

A major area of concern following root-end resection and dentinal tubule exposure is the possibility that these tubules may serve as a direct source of contamination from un-cleaned root canals into the peri47

radicular tissues, especially if there is coronal leakage.

Root ends

resected from 45o to 60o have a many as 28000 tubules/mm2 at a point immediately adjacent to the canal. At the dentinocemental junction, an area which may communicate with the root canal even in the presence of a root-end filling, an average of 13000 tubules/mm 2 are found. Likewise, due to angular changes in the tubules at the apex, there could be patent communication with the main canal if the depth of the root-end preparation the buccal aspect of the cavity is insufficient to compensate for these anatomical variations. Root-end resections in older teeth have shown less leakage than that seen in teeth from younger patients; this corroborates the findings of sclerosis and reduced patency in apical dentinal tubules. It has been suggested that, if the apical ramifications commonly found in young teeth are dismissed as a rationale for root-end resection, then resection would be inadvisable due to the patency of the apical dentinal tubules.

Another concern following root-end resection is the presence of a contaminated smear layer, containing tissue debris and possibly microorganisms, over the resected root end. This may serve as a source of irritation to the peri-radicular tissues, primarily preventing the intimate layering of cementum against the resected tubules.

Cutting usually

creates a thicker smear layer without water spray than with a heavy air48

water spray, or by using coarse diamond burs than tungsten carbide burs.

Therefore it is recommended that root-end resection be performed under constant irrigation, which assists the partial removal of the dentinal smear layer from the surface. Also, if diamond burs are used to resect the root, medium grit is preferred, followed by a fine or ultra fine grit diamond. If there is a gutta percha root canal filling, resection without irrigation should be avoided as it may promote the lodging of dentine chips in the gutta-percha, which would serve as a source of irrigation if contaminated.

These chips may not be removable during the elimination of the smear layer with a dentinal cleanser.

ROOT END CAVITY PREPARATION (Refer fig.7) Various instruments are being used for retro-preparation like 1. Conventional slow speed handpiece, 2. Hi-speed handpiece, 3. Ultrasonics and 4. Sonics.

ď&#x201A;§ Conventional slow-speed handpiece and burs are bulky to handle, require excessive removal of bone and tooth structure and can result in shallow misaligned cavities.

49

The ideal root end preparation suggested by Cohen should be 3mm deep and centered.

One of the advancements in endodontic surgery that allowed greater efficiency was the adaptation of piezoelectric ultra-sonic for root end preparations. Ultrasonic tips are available in various configurations (Analytic Endo, Satelec / Amadent Co. and Spartan / Obtura Co.) to accommodate virtually all access situations.

Specially designed tips

produce smooth cutting with relatively little chatter when the tips are activated against the dental walls of the apical preparations. These micro tips are very a narrow in diameter (i.e., about one teeth the size of a conventional micro head hand piece).

The first ultrasonic tips for endodontics and endodontic surgery were the CT tips made of stainless steel (SS) and designed by Dr. Gary Carr. They were first available in early 1990. The CT tips were the most popular tips and have been widely used until recently. In 1990 KiS tips were introduced; these provided improvements in many areas, including cutting efficiency by coating the tip with zirconium nitride, more convenient angles, and relocation or irrigation port.

It shows a

comparison of the two tips: the CT tips are short more angled than the KiS tip. The location of the ultrasonic irrigation port, which is on the tip 50

rather than on the shaft, delivers maximum irrigation volume directly into the cutting site. KiS tips are also different from CT tips in terms of shaft angle, tip angle and length.

In summary, the advantages of ultrasonic tips over micro-head burs are:  Better access, especially in difficult-to-reach areas (e.g., a lingual apex)  More through debridement of tissue debris.  Conservative preparations tracing the long axis at a precise depth of 3 mm.  Precise isthmus preparations with parallel canal wall for better retention of filling materials.

Root End Preparation is accomplished under the microscope at low-tomid magnifications (4 × 16 ×). First, a number of appropriate tips are pre-selected, depending upon the location of each apex. Second, the resected root surface, stained with methylene blue, must be critically examined at high magnification (16 × to 25 ×) to see the microanatomy.

Third, at low magnification (4 × to 6 x), the selected ultrasonic tip is positioned parallel with the long axis of the root. To accomplish this the surgeon must examine the position of entire tooth at low magnification

51

(4 Ă&#x2014;), including the crown and root eminence and compare this with the position of the ultrasonic tip. Failure to make this comparison will risk an off-angle root end preparation or perforation. Fourth, the ultrasonic tip is activated and the apical canal is retro-prepared with copious water coolant to a depth of 3 mm. If an ultrasonic tip is pressed too firmly it is dampened to deactivation, thus a light sweeping motion using short forward-and-backward and up-and-down strokes is all that is needed for effective cutting action. Depending on the canal configuration, a typical 3 mm retro-preparation should take less than 1 minute with KiS tips.

Once the retro-preparation is completed, the cavity preparation is inspected with a micro-mirror at high magnification of 16 Ă&#x2014; to 25 Ă&#x2014;. A thorough inspection should include the interior canal walls for remnants of gutta percha, especially on the difficult-to-reach facial wall, and confirmation that the parallel walls are sharply defined and smooth.

FIG7

Fig.7. Root end cavity preparation

52

TYPES OF PREPARATION Two types of preparations have been in routine use for some time; the Class I and the slot, or Matsura, type. An additional preparation also has been described and is referred to as the figure eight type of reverse fill preparation.

Before any preparation is begun, the root to be reversing filled must be beveled. Placing a filling in an un-beveled apex is similar to placing a filling at the point of a pyramid. No flat table would be present to pack against, and the filling material would merely fall down the sides and not seal the tip. Using a fissure bur in the airotor or straight hand piece and cutting the root tip from mesial to distal surface at approximately a 45-degree obtain beveling on the tooth, allowing for visualization of the entire root face. Teeth that have a palatal or lingual inclination may require a greater angle of beveling for ease of preparation and filing placement.

Beveling of the root tip may be accomplished without significant reducing root length and thus retaining almost the same crown root ratio.

If the crown root ration is highly unfavorable, but the strategic importance of the tooth warrants its retention, the slot preparation should be made, which requires little, if any root length reduction.

53

After beveling, the outline of the root face will have one of two configurations, either oval or figure eight. The most common shape will be a slightly irregular oval, with the canal having a smaller oval shape in the approximate center. The ideal reverse fill preparation for this shape is similar to the typical Class I occlusal amalgam preparation of operative dentistry, only in miniature. It is prepared by using a no33½ bur or ultrasonic tip down into the canal for a minimum of 1mm but preferably at least 2 to 3 mm. It is important to remember that the bevel of the root face is at approximately 45 degrees and that if the preparation is made with the bur perpendicular to the root face, there is a good chance for perforation of the root lingually. Therefore the bur must come down along the long axis of the tooth and remain within the confines of the canal while the preparation is made. If insufficient room is available to come down the long axis, greater beveling of the root face or removal of periapical bone should be performed. If this is not desirable, the slot preparation should be utilized.

The other root face configuration developed after beveling is the figure eight shape with a long oval or slot canal in the center. This shape may be found when two canals are present in one root of a tooth, such as the mesio-buccal root of a maxillary first molar, maxillary and mandibular bicuspids and mesial roots of mandibular molars and 54

mandibular anterior teeth. When these roots have one canal in one root, the configuration of the root face after beveling will be oval.

The proper preparation for teeth having one root and two canals is the figure eight preparation. A no.33½ bur or ultrasonic tip is used and two round but touching preparations are made, with care taken to keep the bur along the long axis of the root. This type of preparation should be made in any one rooted tooth when it is suspected that two canals may be present, even if only one canal was previously filled.

The third type of preparation is the slot type, also referred to as the Mastura preparation, from the name of its early advocate. This should be used where it is inconvenient to utilize the other types of preparations that involve access along the long axis of the tooth. The slot preparation is made with the bur used perpendicularly to the long axis of the tooth and requires much less tooth and / or periapical bone removal. The most common needs for the slot preparation are in those teeth where removal of root structure will lead to an inadequate crown root ratio or removal of periapical bone sufficient to gain access will infringe on adjacent vital structures. Examples of the latter are maxillary bicuspids and molars near the maxillary sinus, mandibular molars near the mandibular canal, and maxillary anterior teeth near the nares. In addition, teeth with palatal or 55

lingual inclinations, such as maxillary lateral incisors and mandibular anterior teeth, may be easier to prepare and fill by using the slot preparation.

The preparation is made by using a no.700 bur in the straight hand piece or airotor makes the preparation. Starting at the apex of the tooth, the bur is brought toward the cervical margin approximately 2mm, leaving a trough of tooth structure missing. Then a no.33½ of 35 burs or ultrasonic tip is used to sharpen the corners of the preparation to afford undercuts for the retention of the filling material.

When a slot

preparation is used, much less root face beveling is required, since the retention is obtained in the undercut areas near the base of the preparation.

Micro-mirrors One of the key instruments in microsurgery is the micro-mirror.

The reflective surface is made of either highly polished stainless steel or sapphire.

The mirrors are small enough to fit into an osteotomy

measuring no larger than 4 to 5 mm in diameter. Inspection of root ends cannot perform thoroughly without the aid of micro-mirrors.

The

anatomy of the root surface is reflected in the micro-mirror into the viewing range of the microscope before and after the retro-preparation.

56

INSPECTION OF THE ROOT END PREPARATION For depth of field purposes, the root end is best prepared that lowto-mid magnification (8 × to 12 ×). However, the preparation must be inspected at high magnification (16 × to 25 ×). Uncommonly, retropreparations can also be inspected by direct view.

In addition to

examining the completed preparation for clean, sharply defined walls, it should also be examined one last time for important anatomic structures (e.g. accessory canals, micro-fracture) that may have escaped detection during the initial inspection.

DEPTH OF THE ROOT END PREPARATION The optimal depth of the root and preparation should be 3mm; however, depths of 1,2 and 4 mm have also been studied. Using the Hess model slides provided by Dr. N. Perrini, the incidence of lateral canals and apical ramifications in the natural apex have been studied; over 95% of these anatomic entities are found within the apical 3 mm. Although a retro-preparation deeper than 3 mm does not provide any greater benefits, a retro-preparation shorter than 3 mm may jeopardize the long-term success of the apical seal. The management of the apical 6 mm; 3 mm root resection perpendicular to the long axis of the root and retropreparation and retro-filling of 3 mm parallel the long axis of the root.

Each is essential to ensure an adequate seal of the root apex.

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ROOT END CAVITY OBTURATION To clean and obturate the root canal before root-end resection or to do it at the time of surgery has been controversial for many years. Some authors have found greater success when the canal is obturated in conjunction with surgery, less often when a previous root canal filling was left in place, and least often when the canal was filled immediately prior to surgery. On the other hand a better prognosis has been identified when the root is cleaned and filled prior to surgery. Favourable results with root canal obturation either before or during surgery have been demonstrated. In a recent evaluation of the surgical management of nonsurgical endodontic failures, cleaning, shaping and obturation of the root canal prior to surgery resulted in the highest rate of success. In the cases that could be managed this way the root end was not resected, and surgical procedures were limited to curettage. Cases in which root-end resection was performed and root-end filling placed resulted in a higher number of failures. What is important is that the canal system is cleaned and sealed as well as possible. In many respects this necessitates that old root canal fillings should be redone as well as possible. Under these circumstances many cases may be successful without the use of a rootend filling.

58

In some cases in which a radiolucency exists and time is a factor, or cases in which there are persistent exacerbations between visits or failing root canal treatment which has been treated non-surgically in an assumed optimal manner, canal re-preparation and refilling can be done at the time of surgery. A tissue flap is reflected, the root apex exposed and resected.

The canal preparation is performed with the file tips

protruding through the resected root end. Small aspirators can bleached next to the apical opening to present root canal irritant (0.5-2.5% sodium hypochlorite) entering the bony cavity. After adequate preparation, the canal is dried with paper points. Obturation should allow with guttapercha and sealer condensed from the coronal access apically.

Any

condensation technique is acceptable; however, the master gutta percha point should not be pulled through the apex, as point retraction may occur. The excess gutta-percha can be removed with an ultra fine bur, which usually creates a well-adapted root canal filling on the resected surface.

In these situations the placement of a root-end filling will

usually be unnecessary.

This is common with gutta percha fillings,

especially those placed immediately before or at the time of surgery. An ultra fine diamond bur can be run over the root surface with a sterile water or saline spray. If the canal is properly obturated the result will be a very smooth, well-adapted root canal filling. Paste fillings acceptable because of frequent voids, the irritating nature of most pastes and the 59

potential for paste dissolution. Metal fillings (e.g. silver points) are also unacceptable because of poor adaptation and the potential for corrosion.

When a root-end cavity is to be obturated it must be isolated to ensure moisture control.

This is usually done with a haemostatic

collagen-based agent, such as Hemofibrine or Hemocollagene, which can remain in the osseous cavity or be removed prior to closure. Also used is a solution of ferric sulphate, which must be removed from the bone cavity prior to tissue closure.

Presently there are no commercially available materials, which will provide a perfect seal, therefore the materials that are used must be carefully prepared and placed to ensure the best possible adaptation to the root cavity walls. Coupled with the attempt to seal the apical end off he canal system, attention must also be directed to the coronal end. It is illogical to place a filling material, which is imperfect at the root end of the tooth and neglect the potential for coronal leakage around root canal fillings, and coronal restorations with carious lesions, imperfect margins, or through exposed dentinal tubules in the cervical area.

60

Figure 8

Fig. 8. Step by step procedure of apical surgery. A. Pen grasp of scalpel is used to make vertical incision. Vertical and horizontal incisions of scalloped flap have been made and flap is retracted.

C. Sharp curette is used to test density of cortical plate. D. If cortical plate is solid # 8 bur is used.

E. Inflammatory tissue and bone are probed with sharp curette. F. Debridement of inflammatory tissue done, apex is beveled and lesion irrigated. G. Retro-preparation with ultrasonic tips.

H. Amalgam placed. I. Radiograph taken sutures placed.

ROOT END FILLING MATERIALS ď&#x201A;§ Materials

used:

Gutta-percha,

Goldfoil,

Amalgam,

Poly

carboxylate cements, Zinc oxide eugenol paste, Diaket, Cavit, Super-EBA Cement, Mineral trioxide aggregate, Bone cement etc. ď&#x201A;§ One of the major requirements of an ideal retrofilling material is its close adaptability to the cavity walls of the retro-preparation.

61

 However, when non-adhesive materials are used for apical sealing, a microscopic space always exists between the restoration and the tooth interface, which leads to microleakage (M Torabinejad 1995).  1962, Nicholls showed preference to zinc oxide eugenol cements, but these cements showed increased solubility and tissue irritation (Paul D Brent et 1999).  Super EBA was introduced by oynick and oynick in 1978 the strength of mixture.  Studies (Frank J Vertucci et al 1986) showed that the tissue response to super EBA in replanted teeth was less severe and less extensive when compared to amalgam.  This was attributed to the antibacterial action of eugenol, which may account for the success of endodontic surgery by killing the bacteria (A Rainwater et al 2000).  Adhesion to dentin is an interesting property of glass ionomer cement and therefore it has been advocated for use as a rootend filling material.  Several studies (Kamran Safavi et al 1999) have shown superior biocompatibility, fluoride release and marginal adaptation of glass ionomer cements and hence it has been incorporated in this study.

62

ď&#x201A;§ Recently newer materials like Mineral Trioxide Aggregate and Bone cement have been used for retrofilling. ď&#x201A;§ Mineral Trioxide Aggregate has been proven to be biocompatible, have good sealing ability, dimensionally stable, insensitive to moisture and promote tissue regeneration. ď&#x201A;§ Torabinejed et al 1995 reported that Mineral Trioxide Aggregate leaked significantly less than all the other materials like Amalgam, IRM and Super-Ethoxy Benzoic Acid.

MTA: Induces osteogenesis and cementogenesis.

Studies showing Amalgam causing more microleakage : Richard M Moodnik et al (1975), James T. Kimura (1982), Satoshi Inoue et al (1991), Rahmat A Barkhordar et al (1989).

Others studies also

suggesting the same: John D Bramwell and M L Hicko (1986)

Studies suggesting MTA to be superior: Mahmoud Torabinejad et al (1995) several studies, James D Kettering and M Torabinejad (1995), Torabinejad and T R Pittford (1996)

Studies suggesting GIC to be superior: Noriyasu Hosoya et al (1995) than amalgam and heated gutta-percha.

63

Studies suggesting Super EBA to be superior: John T Biggs et al (1995) better than amalgam

Frank Gerhards and Wilfried Wagner (1996): Harvard cement, Diaket, Gold leaf, Ketac-Endo and, amalgam in human teeth. Ketac-Endo showed significantly less leakage compared with amalgam.

Harvard

cement and gold foil showed more leakage than amalgam and was no significant difference between Diaket, Amalgam, Gold foil and Harvard cement.

Postoperative radiographic assessment As previously indicated, a postoperative radiograph should be taken before closure of the surgical site. Mistakes can be rectified and procedures altered more easily at this point. In some cases, especially posterior teeth, several angled radiographs should be considered.

Radiographs taken with specific film-holding devices are preferred.

When review examination radiographs are taken with the same device, healing can be assessed more accurately. Some points for the clinician to consider are : 1. Is there scattered radiopaque material within the surgical site?

2. Are the correct root ends surgically obturated?

3. Do the root-end fillings appear adequate in depth and adaption?

64

4. Are the fillings well condensed?

5. Is there un-resected root structure, or have the wrong roots been inadvertently damaged?

6. Has root-end filling material been pushed into the maxillary sinus or mandibular canal?

7. Is there a fracture visible that was not seen clinically?

CORRECTIVE SURGERY Corrective surgery is categorized as surgery involving the correction of defects in the body of the root other than the apex. When the coronal and middle thirds of the root are involved, it is imperative to physically observe, diagnose, and repair the defect. A full flap, such as the single or double vertical design, must be utilized to gain adequate vision and access.

Reparative defects of the root and associated

procedures are classified as follows: I.

Perforation repair A. Mechanical B. Resorptive

II.

Periodontal repair A. Guided tissue regeneration B. Resection

65

PERFORATION REPAIR Mechanical.

Perforations generally occur when the dentist is disoriented as to the direction of the bur and its relationship to the anatomy of the pulp chamber or root. High potential areas for perforations are the furcal floor of molars and two-rooted maxillary premolars-roots that are narrow mesiodistally and broad bucco lingually with curved canals.

â&#x20AC;&#x153;Strippingâ&#x20AC;? of a canal is the overcutting of root structure resulting in a longitudinal opening that can all too easily occur on the furcal surface of mandibular molars or any narrow root. This lesion is often caused by overwidening a canal orifice through aggressive use of Peeso or Gates-Glidden drills. If the perforation that occurs at the present appointment is small and the bleeding is well controlled, the root canal filling can be condensed as the seal. Because large strippings are usually surgically inaccessible, a hemisection where restoratively indicated may save the case.

Midroot and apical third perforations should be immediately sealed if possible, or calcium hydroxide should be used prior to sealing. If the perforation is excessively large or long standing, a full vertical flap should be reflected and the area repaired with Super EBA. If the location 66

of the perforation is near the root apex, an apicoectomy is a more effective and efficient way of handling the case.

Resorptive Eventual repair of a defect on the root surface, from either internal or external resorption, depends to a large part on whether there is complete communication from the pulp to the oral cavity. If the lesion has destroyed an area of the root into the periodontal structures, but has not communicated with the oral cavity, it can generally be repaired by placing calcium hydroxide into the cleaned and prepared root canal to promote cementogenesis. One should expect new cementum and bone repair to follow, and finally the internal and external defects may be obturated by non-surgical root canal filling alone.

In the event cemetogenesis and new bone formation do not occur to serve as a matrix for the internal filling of the canal and defect, or in the event the lesion has broken through to communicate with the oral cavity and will not respond to cementogenesis, corrective radicular surgery is in order.

67

Periodontal Repair Guided Tissue Regeneration In the past, extensive periodontal defects required extraction or root amputation. Today, with techniques of guided tissue regeneration, many teeth can be saved without root resection. This concept is based on an inert barrier membrane, such as Goretex, providing the retention of blood clot in a relatively undisturbed environment of the walled off periodontal pocket. This allows the local undifferentiated cells of the periodontal ligament and surrounding bone to form new bone that bridges across the surgical wound with the potential of forming a new periodontal attachment, thereby blocking the down growth of epithelial migration. In the event this procedure proves ineffective, the root severely involved in periodontal disease may have to be amputated.

Root Amputation Root amputation procedures are a logical way to eliminate a weak, diseased root to allow the stronger to survive, whereas if retained together they would collectively fail.

Selected root removal allows

improved access for home care and plaque control wit resultant bone formation and reduced pocket depth.

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Indication for Root Amputation 1. Existence of periodontal bone loss to the extent that periodontal therapy and patient maintenance do not sufficiently improve the condition.

2. Destruction of a root through resorptive processes, caries, or perforations.

3. Surgically inoperable roots that are calcified, contain broken instruments, or are grossly curved.

4. The fracture of one root that does not involve another.

5. Conditions that guarantee that the surgery will be technically feasible to perform and that give evidence for a reasonable prognosis.

Teeth that do not fit these criteria are contraindicated for root amputations.

Contraindications for Root Amputation 1. Teeth not strategically located. These teeth are better served with a bridge.

2. Lack of necessary osseous support for the remaining root or roots, inadequate root structure, or a poor crown: root ratio.

3. Fused roots or roots in unfavorable proximity to each other.

4. Endodontically inoperable roots.

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5. Lack of patient motivation to effectively clean and maintain the furcal areas and follow through with proper restorative procedures.

Two different approaches to resection are available.

One approach is to amputate horizontally or obliquely the involved root at the point where it joins the crown, a process termed root amputation. The other approach is to cut vertically the entire tooth in half-from mesial to distal in maxillary molars and premolars, and from buccal to lingual in mandibular molars-removing in either case the pathologic root. This procedure is termed hemisection.

Bisection or â&#x20AC;&#x153;bicuspidizationâ&#x20AC;? refers to a division of the crown that leaves the tow halves, yet forms a more favorable position for the remaining segments that leaves them easier to clean and maintain. If the remaining roots are too close to each other, minor orthodontic movement may be necessary to property align them.

Amputation Technique for Mandibular Molars Treatment planning is critical when evaluating mandibular molars for root removal. If it is not a terminal tooth in the arch, and there are sound adjacent abutment teeth, a fixed bridge may be just as satisfactory, and possibly stronger and more economical.

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Some outstanding

successes, however, are seen involving three unit bridges. Anatomically, the mesial and distal roots are about the same length. The mesial root is slightly wider bucco-lingually, more curved, and its cross-section appears as a figure eight.

Hemisection is the most common method of removing a pathologically involved mandibular molar root.

A terminal second

mandibular molar is ideally suited for hemisection provided there are opposing teeth. The remaining root and crown structure is then restored as a premolar.

Technically, the preparation procedure is the same as that for the maxillary molars. The roots to be retained undergo endodontic therapy, and the pulp chamber is filled with amalgam. No filling material needs to be placed into the root to be removed, for that entire half of the tooth will be extracted.

A sharp cowhorn explorer or periodontal probe is used to identify the buccal and lingual furcations. By first placing the tip of a high-speed tapered fissure bur (No. 702 XL) in the furcation, the operator can effectively section the molar with accuracy. Sufficient proximal furcal floor should be left to establish a restorative finish line, as well as 71

sufficient crown for retention.

Again, the sectioning is done at the

expense of the part to be extracted. Care must be exercised not to gouge the remaining stump.

An elevator should be wedged between the two halves and slightly rotated to determine if the separation is complete. The pathologic half is then extracted with forceps or eased out with an elevator. The socket area is lightly curetted and packed with bone wax or gel foam while the remaining hemisected half is trimmed and smoothed with a blunt tapered diamond. The packing should be removed from the socket and followed by copious irrigation and debris removal with a 2” x 2” gauze sponge.

Bisection or “bicuspidization” is successful in molars in which periodontal disease has invaded the bifurcation. The type of cut is the same as that used in hemisecting, except the location is centered to evenly divide the crown at the center of the furcation. The furcal is then turned into an interproximal space where the tissue is more manageable by the patient.

Single root amputation in the mandibular arch may on occasion be indicated where a splint or bridge is in place. For the most part, however, an uneven exertion of occlusal forces tends to exert a force on the 72

remaining root, thereby causing a fracture.

Some cases are treated

successfully by single root amputation, and when economic factors dictate, it is indicated.

REPLACEMENT SURGERY Replant Surgery - Intentional Replantation The primary reason for intentional replantation is based on the inability to perform adequate non-surgical rot canal therapy on a tooth, as well as on the inadvisability of performing endodontic surgery.

Some teeth requiring root canal therapy are absolutely inoperable in situ. Mouths with such a small orifice that finger instrumentation of pulpless molar teeth is impossible are candidates for extraction and intentional replantation.

Roots with obstructed canals resulting from

calcification, silver points, posts, or separated instruments, although indicated for retrofillling, may need to be extracted and intentionally replanted be cause of an oversized external oblique ridge that blocks safe access.

Pulpless teeth have also been encountered with so many perforations or lateral aberrations of the canal that repair in site is impossible. If extraction appears to be the only alternative in these cases, 73

one is right to pose the question â&#x20AC;&#x153;What have we to loseâ&#x20AC;? reported survival periods of up to 22 years for replanted teeth and have also made recommendations for case selection.

Intentional replantation should be considered when it is the only alternative to extraction.

Steps in Intentional Replantation 1. The tooth should be extracted as atraumatically as possible and received in a sterile gauze sponge saturated with normal saline solution. It should be held in the moist sponge throughout treatment, and the roots and attached periodontal tissue should be frequently irrigated with saline.

2. If the canals are not blocked, standard access is made to the pulp chamber, and the canal or canals are prepared and filled; the coronal access sealed in hand as carefully as in site. A slight (1-to2-mm apicoectomy, prior to retrofilling, is done to reduce the hydrostatic pressure buildup during replacement.

3. Roots containing blocked canals are retrofilled in the usual manner.

4. Preparations in teeth with perforation or resorptive defects are similarly done. Root canal filling in these cases should be completed before the repair of defects.

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5. Before replantation, the alveolus should be gently curetted and irrigated with saline to remove the clot and â&#x20AC;&#x153;freshenâ&#x20AC;? the socket, being careful not to promote excessive bleeding or detach viable periodontal ligament attachment to the alveolar bone.

6. The tooth is replanted and stabilized with a splint if necessary.

Posterior teeth normally are well retained and do not need splinting.

Anterior teeth may be splinted with a coronal acid-etch technique using a direct bonding plastic.

IMPLANT SURGERY Two types of endosteal implants fall under the purview of endodontics-endodontic implants and ossointegrated implants, also called endosseous implants.

Endodontic Implants It makes great sense that, if a rigid implant can safely extend out the apex of the tooth into sound bone, and by so doing stabilize a tooth with weakened support, the patient is well served and perhaps has avoided a fixed bridge. Such is the reasoning behind the endodontic implant, many of which have proven quite successful.

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Placing endodontic implants is a technique-sensitive operation. A perfectly round preparation must be reamed through the tooth apex and into periradicular bone.

Unfortunately, there were three errors to

commission by those caught up in the “glamour” of this new innovation.

The worst was a failure to prepare a perfectly round preparation so that the extruding implant would perfectly seal the apex, much as a cork seals a bottle. Trying to prepare a perfectly round preparation in an ovoid canal caused tow problems, the most obvious being that the apical opening remained ovoid. Microleakage eventually developed because the apex was not properly “corked”.

The second problem was fractured roots. To “round out” the ovoid apex, larger and larger preparations were made, thus materially weakening the root. Then, when the tapered implant was forced into place, it acted as a wedge and a vertical fracture developed.

The third cause of failure was overlooked second canals, particularly in mandibular anterior teeth, and an error of omission was in not correcting or controlling the periodontal condition that led to the alveolar bone loss in the first place.

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Root Form Osseointegrated Implants A new option has opened for replacing teeth lost because of a hopeless prognosis. The osseointegerated root-form implant has now achieved a success rate approaching that of conventional endodntics.

Branemark’s 1985 definition of osseointegration – “the direct structural and functional connection between ordered, living, bone and the surface of a load-carrying implant”-trumpeted the advent of successful osseointegration, and the usage of implants skyrocketed.

Although Branemark”s paper of 1977, reporting on the first 10 years of implant research, dealt exclusively with mandibular anterior implants in the edentulous arch, subsequent usage has expanded to fixed and removable prosthesis abutments and single tooth replacement.

Although single tooth replacements are the most common indication in the endodontic environment, there are often indications for two or more replacements in an endodontic milieu. Endodontic graduate programs are now teaching osseointegerated implants.

Indications The patient who presents himself for endodontic treatment but has a non-treatable tooth that is a candidate for removal and an implant include: 77

1. Vertical root fractures.

2. Horizontal root fractures in the coronal 1/3 to ½ of the root.

3. Non-reparable resorption, either external or an extra-canal invasive resorption.

4. Non-treatable endodontic failures.

5. Non-treatable endo-perio lesions.

6. Non-treatable retained primary teeth.

7. Gross post-perforations.

8. Non-restorable teeth.

Contraindications for Placement of Implants 1. Lack of special training by the surgeon.

2. Uncontrolled or brittle diabetes mellitus.

3. Patient psychiatric factors.

4. Postmenopausal women on thyroid medication and without estrogen replacement therapy (according to a preliminary report).

There is an increased likelihood of failure (absence of integration of the implant) if the following six requisites for success are not observed: 1. The implant must be fabricated form an alloplastic biocompatible material such as titanium alloy, or hydroxyapatite.

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2. The preparation of the bony socket must be done with a gentle surgical technique. Electric handpieces that revolve at slow RPMs are designed specifically for implant surgery.

3. The implant must closely fit the precise bony preparation throughout its length.

4. The implant must be mechanically fixed to the bone, by either threads or a roughened surface on the implant.

5. The implant must remain unloaded during the healing phase of 3 to 9 months, depending on which jaw received the implant and the extent of bone grafting that was necessary.

6. The implant must be properly restored with an even distribution of occlusal forces, both working and balancing. The restoration must not overtax the system.

SUTURING Adequate well-placed sutures will aid in the healing process.

Improper, insufficient, poorly placed sutures will diminish the rate of healing and may lead to uncomfortable or unesthetic scar or keloid formation.

For placing sutures in the most desirable manner, the

following suggestions are made.

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1. Digitally press the flap before suturing.

After the surgery is completed, the flap is returned to its original position and firm but not overly forceful digital pressure is applied for 3 full minutes. This allows the fibrin network to begin its formation so that an adherence develops between the raised and underlying tissues.

2. Never be skimpy with sutures.

The function of a suture is to keep the edges of the flap in contact during the period immediately after the surgery. In this way the tissues attach across the lines of incision and optimal healing is gained. If the tissues are not apposed, granulation tissue will grow in, which is most undesirable. Also, the sutures prevent the underlying bone from being exposed to the oral environment and thereby lessen postoperative pain.

In order for these objectives to be accomplished enough sutures must be placed to keep the edges of the flap in apposition. It is almost impossible to place too many sutures, and it is much better to err on the side of too many than too few. If any question arises as to the need for additional sutures after the surgeon observes t initially sutured flap, the answer is to place more.

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3. Take deep bites with the needle into the tissue.

Placing the sutures close to the incision lines may cause problems. is difficult to avoid placing the knots over the lines of incision, and when the sutures are tightened one side or the other may pull through the tissue.

The answer is to take deep bites with the needle for enough from the lines of incision.

4. Do not pull the stitches too tightly.

When deep bites are taken to place each suture, care must be exercised in tying the knot so that the edges are brought just into contact with each other and that no further tightening is allowed. There is room to tighten more, but this will cause a bunching of the edges and may lead to decreased blood circulation in the area.

5. Avoid placing the knots over the lines of incisions.

The knots of each stitch should be placed close to either of the puncture sites in the tissue rather than in the center. Leaving the knot in the center will place it right over the line of incision. The bulk of the knot, when pushed by the lip or cheek, will cause additional irritation and delay healing in the already inflamed areas.

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If possible, the most desirable position for the knot is over the puncture site on the non-raised side of the incision, which is the most normal segment. If, after the suture is tied, it is noticed that the knot is over the line of incision, it can be moved easily. The knot is grasped by the teeth of the miniature hemostat and gently pulled toward the unflapped segment.

6. Do not leave sutures in place for too long.

Individuals heal with different speeds, and it is impossible to predict with any accuracy the rate in a particular case. However, leaving sutures in place for too long always causes a local inflammation and may lead to overgrowth of tissue., embedding the thread. Therefore 5 days after the operation seems to be the average and thus ideal time to remove sutures, with the maximum being 7 days postoperatively.

7. Be sure to schedule a suture removal appointment: As ridiculous as it seems, in the exhilaration of a job well done, the surgeon may forger to schedule an appointment for suture removal at 5 to 7 days after surgery. Many patients have had resorbable sutures used in other surgical procedures and are not aware that the same type is not used in dentistry.

Some weeks later the patient may call to complain of

irritation in the area of the surgery, and an embedded suture is discovered, 82

much to the chagrin of the surgeon. Similarly, the number of sutures placed must always be recorded on the patientâ&#x20AC;&#x2122;s chart so the surgeon can be certain that no stitches have been left behind.

8. Choose the type of suture material.

Many companies market packaged disposable presterilized suture material. There are a myriad of varying choices in thickness and type of material to replace the formerly used gut or silk material. Polyester fibers are woven and treated with a chemical that prevents oral fluids, bacteria and other contaminants from being absorbed by the thread. It appears that this foreign matter that accumulates within the suture material causes the local inflammatory response frequently noted. Suture material is also produced in a monofilament but is more difficult to tie.

Both new

materials, being so smooth, require the placing of three square knot ties to prevent unraveling.

Knots are no longer needed to attach the thread to the metal, but a traumatic needle is available so that a much smaller puncture hole is made. Individual packages are kept ready for the surgical procedure.

When needed the material is removed from its outer wrapper and dropped onto the surgical tray.

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9. Use a circumferential tie.

For use with vertical flaps, the circumferential tie, so named because of its similarity to the circumferential periodontal ligament fibers is a valuable.

After the vertical incisions are sutured, thee

circumferential tie is used to bring the scalloped gingival margin to place.

Postoperative patient instructions When the soft tissues are properly managed and surgical time is minimized, healing is generally uneventful.

Careful attention to

postoperative instructions, however is essential for patient comfort and tissue healing during the next few days. Postoperative instructions should be given verbally and supported in writing for the patientâ&#x20AC;&#x2122;s easy reference.

1. Strenuous activity should be avoided, along with drinking alcohol and smoking.

2. An adequate diet consisting of fruit juices, soups, soft foods and liquid food supplements should be consumed. Avoid hard, sticky or chewy foods.

3. Do not dug at or unnecessarily lift the facial tissues.

4. Oozing of blood from the surgical site is normal for the first 24h.

Slight and transient for the first 24 h. Slight and transient facial swelling and bruising may be experienced.

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5. Post-surgical discomfort is minimal but the surgical site will be tender and sore. The use of analgesics for 24-28 h will help to alleviate this occurrence.

Normally, continue with the analgesics given pre-

surgically.

6. For the first day place ice packs with form pressure directly on the face over the surgical site for 20 min and remove for 20 min. Repeat until retiring that evening.

7. The day following surgery and for the next 3-4 days, chlorhexidine rinses are used twice daily. Alternatively warm salt-water rinses are used every 1-2 h if possible (half a teaspoon of salt in a glass of water).

8. Sutures will be removed in 48-72 h.

9. Brushing of the surgical site is not recommended until the sutures are removed. Prior to that the surgical area can be cleaned using a large cotton puff or ball saturated with warm salt solution.

10.Telephone numbers are provided for your convenience should complications arise.

POSTOPERATIVE SEQUELAE Surgical sequelae include pain, swelling, ecchymosis, laceration, premature separation of sutures, infection, maxillary sinus perforation, and transient paresthesia. Calling the patient at home the evening after 85

surgery and the next day is always deeply appreciated. To minimize post-surgical sequelae, oral and written postoperative instructions must be given to the patient and the person accompanying the patient. Because of anxiety and nervousness, patients sometimes misunderstand or simply do not remember the verbal instructions; for this reason written instructions allay confusion or further anxiety.

Pain Pain is usually not a serious problem.

Long-acting anesthetic

agents, such as bupivacaine (i.e., Marcaine) or etidocaine (i.e., Duranest) can be injected postoperatively into the surgical site to control pain for a period of up to 8 hours. The reader is referred to Chapter 18 for the preventive ibuprofen or acetaminophen regimen that almost always ensures that any pain will be minimal and transient. Rarely are narcotic analgesics required.

Hemorrhage Postoperative hemorrhage is rare. To prevent it from occurring, two 2X2 sterile gauge pads are folded in half and moistened with chilled sterile water. This pack is placed over the sutured flap in the buccal fold and pressed by the surgery with moderate pressure for several minutes.

The patient is provided an ice pack to press lightly against the cheek or 86

jaw for at least 30 minutes to constrict the cut micro-vasculature, minimizes swelling and promotes initial coagulation.

Swelling Swelling is common surgical sequelae and is a major concern for the patient. Patients must be informed that the surgical site and face may swell regardless of the home care. Also, patients must be assured that the degree of swelling is not an indication of the success or failure of the surgery or the severity of the case. Intermittent application of ice packs, 10 minutes on and 5 minutes off, for the 2 days almost always minimizes swelling.

Ecchymosis Ecchymosis is the discoloration of facial and oral soft tissues because of the extravasation and subsequent breakdown of blood in the interstitial subcutaneous tissues. This is basically an esthetic problem. It is more prevalent in elderly patients with capillary fragility and patients with fair skin. Frequently, ecchymosis occurs below the surgical site because of gravity. For instance, the surgical site may be a maxillary premolar, but the ecchymosis may be found in the neck area. The patient should be assured that the ecchymosis has no bearing on the success or severity of case.

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Paresthesia When paresthesia occurs, it is when the mental nerve presents near the second premolar and first molar. However, transient paresthesia may occur even if the surgical site is far from the nerve.

Inflammatory

swelling of the surgical site may cause temporary impingement on the mandibular nerve causing transient paresthesia. If the nerve has not been severed, normal sensation generally returns within a few weeks. In rare instances, however, it may take a few months to regain normal sensation.

The patient should be assured of the probable return of sensation in the affected side; however, on rare occasions paresthesia can be permanent.

Maxillary Sinus Perforation Perforation of the Schneiderian membrane covering the sinuses may occur. If perforation of the sinus occurs, utmost care should be taken to prevent any material from entering the sinus.

The patient should be cautioned not to blow his or her nose and should be instructed to elevate the head during the night. Prophylactic antibiotic therapy with Augmentin 500mg every 6 hours along with Sudafed for 1week should be prescribed. The patient should return for a post-surgical checkup in 1 week.

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Postoperative examination and review Re-examination of the patient, both clinically and radiographically, is normally scheduled at 6 months and 1 year. In most cases osseous repair is virtually complete at 1 year. Evidence of this as well as clinical healing has been considered as a valid criterion for continued success.

Therefore, no additional follow-up may be necessary. Failure to observe complete repair or delayed healing should complete repair or delayed healing should warrant additional evaluation for as long as 4 years, until repair is evident, or signs and symptoms indicate failure.

Radiographic interpretation is highly variable and can easily be influenced by the quality and angulation of the film and processing irregularities. Therefore, the clinician should use a film-holding device for all follow-up radiographs. Likewise, familiarity with radiographic classifications of healing (success-failure) is essential. This will enable case outcomes to be based on a sound, logical and consistent decision making process.

Success and failure â&#x20AC;&#x201C; aetiology and evaluation Whilst many studies have attempted to determine success-failure rates for perpendicular surgery, none have been able to integrate fully all parameters of evaluation with techniques performed, materials used, 89

patient compliance and clinician expertise, variability and interpretative skills. Attempts at multivariate analysis have provided some trends and correlations, but even these findings may only be applicable to specifically controlled cases.

Success (complete healing) with peri-radicular surgery has been reported to range from 25% to 90% using mixed populations, less than ideal percentages of review examinations and minimal evaluation periods. Because of the significant variability in results, comparison of studies is not possible. However, the identification of factors that have contributed to the success or failure of peri-radicular surgery is essential, and these should be integrated into all phases of case assessment and treatment. Often the aetiology of failure may be difficult to identify and may encompass the integration of multiple factors. For peri-radicular surgery, most failures can be attributed to specific causes. At the same time, when failure cannot be explained, speculation may lead to uncertain aetiological factors and treatment. Table lists aetiological factors often cited as valid or uncertain in the failure of peri-radicular surgery.

Evaluation of success or failure following root-end surgery is limited to clinical and radiographic examinations. Clinical criteria for success or failure are most commonly used and are integrated with the 90

radiographic findings. Clinically patients are classified into one of three categories at the time of review examinations.

Patient assessment,

however, must be made after integrating both clinical and radiographic parameters of evaluation. If the only goal of peri-radicular surgery is to retain the tooth in adequate clinical function, then many cases can be classified as successful. Many factors, however, such as case selection, evaluator bias and patient factors, can skew levels of success or failure.

Likewise, many clinically symptom-free teeth may have histopathological changes at the root apices along with minimal or extensive radiographic changes. Even in the presence of an apparently normal radiographic appearance, a clinically symptom-free tooth may exhibit histo-pathological changes in the peri-radicular tissues. This is especially true adjacent to resected root surfaces which are difficult to assess radiographically.

Factors influencing success or failure of peri radicular surgery

Valid causes for surgical failure • Failure to debride the root canal space thoroughly • Failure to seal the root canal space three-dimensionally • Tissue irritation from toxic root canal or root-end fillings

91

• Failure to manage root canal or root-end materials properly • Superimposition of periodontal disease • Vertical root fracture • Recurrent cystic lesions • Improper management of the supporting periodontium

Uncertain causes for surgical failure • Infected dentinal tubules • Infected periradicular lesions • Failure to use antibiotics • Accessory or lateral canals • Loss of alveolar bone • Root resorption • Timing of root canal obturation (before or during surgery) • Type of root-end filling

Clinical success • No tenderness to percussion or palpation • Normal mobility and function • No sinusitis or par aesthesia • No sinus tract or periodontal pocket 92

• No infection or swellings • Adjacent teeth respond normally to stimuli • Minimal to no scarring or discoloration • No subjective discomfort

Clinical uncertainty • Sporadic vague symptoms • Pressure sensation or feeling of fullness • Low-grade discomfort on percussion, palpation or chewing • Discomfort with tongue pressure • Superimposed sinusitis focused on treated tooth

Clinical failure • Persistent subjective symptoms • Discomfort to percussion and/or palpation • Recurrent sinus tract or swelling • Evidence or irreparable tooth fracture • Excessive mobility or progressive periodontal breakdown • Inability to chew on the tooth.

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Re-treatment of surgical procedures Not all surgery is successful.

With astute case analysis the

aetiological factors may be identified and further surgery performed.

When this is not the case, some patients undergo this is not the case, some patients undergo multiple operations only to have persistent signs or symptoms of failure. Often these teeth will be extracted, or last-ditch efforts will be made with intentional replanation.

Radiographic evaluation of success and failure Radiographic success • Normal periodontal ligament width or slight increase • Normal lamina dura or elimination of radiolucency • Normal to fine meshed osseous trabeculae • No resorption evident

Radiographic uncertainty • Slight increase in periodontal ligament width • Slight increase in width of laminadura • Size of radiolucency static or slight evidence of repair • Radiolucency is circular or asymmetrical • Extension of the periodontal ligament into radiolucency • Evidence of resorption

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Radiographic failure • Increased width of the periodontal ligament and lamina dura • Circular radiolucency with limited osseous trabeculae • Symmetrical radiolucency with funnel shaped borders • Evidence of resorption

When a case has been identified as failing it is necessary to use all tests and information available to determine the cause before further surgery is undertaken.

Table lists some of the more common

unsuspected, anatomical and technical causes for failure. Not all of these causes are amenable to further surgery, and often a tooth may require extraction and prosthetic replacement.

Very few studies have evaluated the results of peri radicular surgery that was performed subsequent to previous surgical failure.

Success rates of surgeon have been 50% or less with little subsequent alteration in healing after 1 year. Even poorer results have been reported when the peri radicular lesion at the time of the first surgery was > 5 mm in diameter.

Causes of surgical failure • Unsuspected Root fracture not readily visible • Post – hole perforation, especially on the buccal or lingual surface

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• Instrument perforation coronal to the resected root end • Persistent infection in the apically resected tubules • Corrosion of previously placed amalgam root end filling

Anatomical • Fenestrations or dehiscence’s – loss of marginal bone • Aberrant root anatomy or canal space • Proximity of root of adjacent teeth • Proximity of maxillary sinus

Technical • Poor canal cleaning and obturation • Inadequate root end resection • Inadequate root end preparation and obturation • Toxicity of root end filling materials • Improper soft tissue management

The primary reason for failure following peri radicular surgery is the presence of necrotic tissue debris in uncleaned and obturated canal space.

The primary cause for failure with non-surgical root canal

treatment has been identified as coronal leakage due to poor quality of the

96

coronal restoration. Therefore, it is essential to access, clean and obturate as much of the canal space as possible and to seal thoroughly the coronal aspects of the root canal system before resorting to surgical intervention.

If this is not adhered to, failure will inevitably.

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REFERENCES

1. Massino Gagliani, Silvio Taschieu and Raffaella Molinaei.

Ultrasonic root end preparation. Influence of cutting angle on the apical seals. Journal of Endodontics. 1998; 24(11): 726-730.

2. M Torabinejad. Comparative investigation of marginal adaptation of Mineral trioxide Aggregate and other commonly used root-end filling materials. Journal of Endodontics. 1995; 21 (6): 295-299.

3. M Torabinejad, Hong, Pitt Ford, Kettering. Antibacterial effects of some root-end filling materials. Journal of Endodontics. 1995; 21(8): 403-406.

4. Ingle I.J., Leif K. Bakland. Endodontics, 4th Edn, William and Wilkins: 1994; 689-763.

5. M Torabinejad and T R Pitt Ford. Root-end filling materials. A review. Endod Dent Traumatol. 1996; 12: 161-178.

6. Peter A Gilheany, David Fidgor and Martin J Tyas. Apical dentin permeability and microleakage associated with root end resection and retrograde filling. Journal of Endodontics. 1994; 20 (1): 22-25.

7. Cohen. S, Burns RC. â&#x20AC;&#x153;Pathways of the Pulpâ&#x20AC;?, 7th Edn. St.Louis. The CV Mosby Company. 1997; 683-726.

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8. A Rainwater, B G Jeansonne and N Sarkar. Effects of ultrasonic root-end preparation of microcrack formation and leakage. Journal of Endodontics 2000; 26(2): 72-75.

9. Frank J Vertucci and Richard G Beatty. Apical leakage associated with retrofilling techniques: A dye leakage study, Journal of Endodontics. 1986; 12: 331.

10.Kamran Safavi, Reza Kazemi and Dudley Watkins. Adherence of enamel derivatives on root-end filling materials. Journal of Endodontics 1999; 25: 710.

11.T. R. Pittofrd, J O Andreason, S O Dorn and S P Kariyawasam.

Effect of IRM root-end filling on healing after replantation. Journal of Endodontics. 1994; 20: 381.

12.James D Kettering and M Torabinejad.

Investigation of

mutagenecity of MTA and other commonly used root-end filling materials. Journal of Endodontics. 1995; 21: 537.

13.Noriyasu Hosoya, Cugene P. Lautenschlager and Evan H Greener. A study of the apical microleakage of a Gallium Alloy as a retrograde filling material. Journal of Endodontics. 1995; 21(9): 456558.

14.Frank Gehards and Wilfried Wagner. Sealing ability of five different retrograde materials. Journal of Endodontics. 1996; 22(9): 463-466.

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15.Franklin S. Weine.

“Endodontic Therapy”.

5th Edn, Mosby

Company: 1996; 523-605.

16.Walton R.E, Torabinajed M. “Principles of Endodontics”, 2nd Edn, W.B. Saunders Company. 1989; 401-422.

17.T R Pitt Ford. “Harty’s Endodontics in Clinical Practice”, 2 nd Edn, Wright Publishers: 154-159.

18.Louis I Grossman.

“Endodontic Practice”. 11th Edn, Lea and

Febiger. 1991; 289-312.

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