GINGIVAL TISSUE MANAGEMENT INTRODUCTION An objective of restorative dental procedures is the placement of dental materials to restore teeth to proper form and function. The form and function must be in harmony with the periodontium for a restoration to become an integral component of total oral complex. Management of the periodontium is always delegated to the periodontists. However with certain restorative procedures the dentist must combine his knowledge of periodontics to provide optimal treatment for patients. The purpose of this seminar is to blend the microgingival retraction methods with the principles of restorative dentistry to establish a sound biologic approach. Therefore efforts can be made to define gingival tissue management as “The procedure of temporary eversion or resection of gingiva away from the tooth surface or deepening of gingival sulcus to expose the cervical portion of tooth in order to have proper marginal finish to the restoration or by establishing a good cervical cavosurface margin to the tooth preparation.
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Indications 1. Presence of SUBGINGIVAL CARIES. 2. Cervical ABRASION and EROSION. 3. Subgingival TOOTH FRACTURES . 4. Subgingival FINISH LINE. 5. Elastic IMPRESSION methods. 6. Decreased CROWN : ROOT ratio. 7. Gingival POLYP. 8. Severely ATTRITED TEETH requiring cast restoration. Contra indications 1. POOR oral hygiene. 2. Presence of GINGIVAL DISEASE . 3. GINGIVAL RECESSION. 4. BONE LOSS.
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Pre-requisites 1)
The periodontium should be sound or undergoing HEALING
2)
prior to tooth preparation. The CREST of FREE GINGIVA should be at its normal
position relative to the tooth surface with no recession. ↓
This may necessitate removal of any hyperplastic tissue if present.
3)
The dimensions of free gingiva should be TEMPORARILY REDUCED
to allow ↓
Exposure of the gingival termination of the preparation for final adjustments.
For reproduction of details.
This should be done in a way so that the free gingiva will regain its dimensions to normal level. 4)
CREVICULAR FLUID and BLEEDING should be arrested in order ↓
Maintain VISIBILITY . 3
MANIPULATION .
Proper REPRODUCTION OF DETAILS
5)
A temporary TROUGH should be made in the gingival crevice that is free of fluid, readily accessible and which exposes all the details of the circumferential tie as well as the portion of the unprepared tooth surface apical to it.
These objectives should be accomplished without detaching the apically located epithelial attachment and periodontal ligament. -
They should not cause any irreversible damage to the gingiva / periodontium.
-
Should not cause any hazard to the distant tissues or organs orally, para-orally or systemically.
CLASSIFICATION I] According to MARZOUK A] PHYSICO-MECHANICAL MEANS -
Temp restorations like ZnOE / Periodontal pockets.
-
Rolled cotton or synthetic cords.
-
Heavy weight rubber dam.
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B] CHEMICAL MEANS Impregnated by -
Cords
Vasoconstrictors
-
Drawn cotton rolls
Fluid coagulants
-
Cotton pellets layer coagulants
C] ELECTROSURGICAL MEANS -
By using ELECTRODES in Cutting Coagulation Fulgeration Dessication
D] SURGICAL MEANS -
Gingivectomy
II] According to TYLMAN A] MECHANICAL -
Copper band
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Surface
B] MECHANICAL – CHEMICAL -
Cords impregnated with chemicals
C] SURGICAL -
Electrosurgery
-
Gingitage
Coming to each technique individually dividing them mainly into 3 major headings i.e.:
-
Mechanical
-
Chemical
-
Surgical.
MECHANICAL 1)
This constitutes mechanically forcing the gingiva away from the tooth surface laterally and apically. Mechanical methods are more frequently indicated in patients
having: a) Absolutely HEALTHY GINGIVAE . b) Good VASCULAR SUPPLY. c) Definite zone of ATTACHED GINGIVAE apical to the free gingiva to be displaced.
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d) Adequate dimension of BONE SUPPORT without any resorption.
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The methods are: 1)
Use of CUSTOM TEMPORARY RESTORATION where the gingival ends are blunted and are covered with bulky temporary cements like
- ZnOE
- Non-surgical perio pack ↓ In this method results cannot be observed for 24 hours. 2)
Use of ROLLED COTTON or SYNTHETIC CORDS which are forcibly introduced into the gingival sulcus. ↓ Results are seen within 30 minutes
3)
Use of Heavy Weight Rubber Dam ↓ Immediate results
Disadvantages: Full arch impressions are difficult with this technique. - Only single tooth or quadrant impressions can be taken. 4)
COPPER BANDS Oversized copper bands are contoured to the gingiva and
restricted towards the cavity margin when gently seated over the tooth.
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The band should be about 2.0mm wider than the MD width of tooth.
The gingiva is trimmed and contoured inward so that the band clears the preparation margin during the imp technique.
The band is vented for escape of excess elastomeric impression material.
A resin or compound plug is placed on tip of the band for stability.
Some other literatures also suggest usage of: -
Rubber rings.
-
Leather rings.
-
Aluminium bands.
-
Stainless steel bands.
CHEMICAL These methods use retraction cords, drawn cotton rolls and cotton pellets impregnated with chemicals for stoppage of bleeding and seeping of crevicular fluid.
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A variety of chemicals are available and constitute 3 major categories as suggested by Marzouk. (a)
VASOCONSTRICTORS These physiologically restricts the blood supply to the area by
decreasing (↓) the size of the blood capillaries. ↓ which -
Decreases haemorrhage.
-
Decreases tissue fluid seepage.
-
Decreases size of gingiva consequently.
Most commonly used agents are: RACEMIC EPINEPHRINE (8% in conc.). NON-EPINEPHRINE Contraindications 1) Cardiac arrhythmias. 2) Severe cardiovascular diseases. 3) Diabetes. 4) Uncontrolled hyperthyroidism. 5) Patients receiving drugs such as: -
β-blockers.
-
Antidepressants. 10
-
Rowolfia drugs.
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(b)
FLUID-COAGULANTS Biologic fluid coagulants coagulate blood and tissue fluids locally. ↓ Thus creating a surface layer that is an efficient SEALANT against
blood and crevicular fluid seepage. These are safe agents in regards to systemic effects. E.g.: - 100% ALUM - 15-25% ALUMINIUM CHLORIDE - 10% ALUMINIUM POTASSIUM SULPHATE - 15-25% TANNIC ACID 100% Alum is used most commonly instead of epinephrine. (c)
SURFACE TISSUE LAYER COAGULANT These coagulates surface layer of sulcular and free gingival
epithelium as well as seeped fluid. ↓ Creating a temporary impenetrable film for underlying fluids including blood.
Disadvantages: Ulceration. Local necrosis. Changes in dimensions and location of free gingiva. 12
These can result if the chemicals are in excessive concentration or excessive time application of the agents. E.g.: 8% Zinc chloride, Silver nitrate. These chemicals can be carried to the field of operation in one of the 3 ways. Cords Drawn cotton rolls Cotton pellets
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Oversized copper band should be about 2.0mm wider than the M-D width of the tooth
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The gingiva is trimmed and contoured inward to allow the band to just clear the preparation margin during the impression
Tucking the cord in mesial side (A)
Stabilizing it by tucking in distal side (B)
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Tucking force is applied towards the already placed cord to avoid displacing of cord (A)
If force is applied directed away from the area previously packed the cord placed will be pulled out (B)
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1) RETRACTION CORD Retraction cord is used for the isolation and retraction in direct procedures of treatment of cervical lesion. -
Facial veneering.
-
Indirect
procedures
involving
gingival
margin.
These are available in 2 types: - Ready made cotton. - Synthetic woven cords. ⇒
Some cords have a
- Metallic wire.
- Resin wire. Around them for:
⇒
- Compactness. -
Immobility
-
Non-shredding property
Available
in
different
size
and
numbers
arbitrarily given by the manufacturers. ⇒
May be supplied as already impregnated with the chemical or the chemical may be added before insertion of the cord of after insertion while the cord is within the sulcus.
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Advantages: They are fairly non-adhesive to the affected tissues because of its compactness. Disadvantage: It is difficult to insert it within sulcus. METHOD OF USING RETRACTION CORD 1) Anesthetize all sensory nerves to the region, apply cotton rolls and place saliva ejector to have a dry operating place. Profound anesthesia reduces salivation and allows tissue retraction without patient discomfort. 2) Select a cord of appropriate diameter. The length of the cord should be slightly longer than the length of the gingival margin. 3) Grasp the ends of cords between the thumb and forefinger, holding the cord taut, twist the ends to produce a tightly wound cord of small diameter. Forming it in a U-loop place it around the tooth with the thumb and forefinger applying tension slightly in apical direction. 4) Start always packing at one end of the cord systematically going to the other end.
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5) The packing instrument should be blunt, with definite corners, latchet or hoe-shaped preferably with serrations. 6) Start the placement of the retraction cord by pushing it into the sulcus on the mesial surface of the tooth. It should also be tucked lightly into the distal aspect to hold the cord in position while it is being packed.
7) Slide the cord gingivally along the preparation until finish line is felt in impression making procedures. If the instrument is directed totally in an apical direction, the cord will rebound off the gingiva and roll out of sulcus. 8) Cutoff the length of cord protruding near the interdental papilla leaving 2-3mm of cord tag for removal after the procedure.
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MODIFICATIONS IN TEETH a) Sometimes when the gingival margin is deep it is helpful to insert a 2 nd cord of same diameter or larger diameter over the 1 st cord. b) If sulcus is narrow ďƒ a cord of small diameter can be obtained by separating the double strands material into 2 strands. c) If the packed material does not interfere with the reproduction of circumferential tie and tooth surface immediately apical to it, and if it is immobile, it can be left in its place during an impression or direct wax patterns or any other restorative procedures. Time: The cord should remain for atleast 5 minutes. When excessive bleeding is present the cord should be placed for 10 minutes. 9) Removal of retraction cord should be done in hydrous field so that the moisture will act as a lubricant between the cord and sealing film made by the chemicals. It should be removed gently
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and lightly because rough handling can disturb the chemical film and start profuse bleeding. 10) After reproducing the details or restorative work, curette the field and create a fresh blood clot for better healing. 2) DRAWN COTTON ROLLS Soft loose cotton rolls can be readily rolled to a desired diameter. ↓ to be introduced into the sulcus already impregnated or to be impregnated with chemicals. Advantages: Because of its looseness, it can be compacted in the sulcus easier than the cords. Disadvantages: part of the coagulated surface layer may get deeply incorporated in cotton. ↓ when cotton is removed, the coagulated sealing membrane may be pulled out. ↓ initiating bleeding and fluid seepage called as “ COTTON ROLL BURN ”.
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Drawn cottons are used subsequently to cords after the treated cords create this coagulated sealing membrane. ďƒ The cotton rolls are very efficient in widening the trough and generating more shrinkage within the gingiva therefore they can accommodate more chemicals than cords. 3) COTTON PELLETS -
These are used to carry the chemicals to the already compacted, inserted cords or drawn cotton rolls. If they are allowed to remain on top of the cord/cotton they
provide a continuous source of chemical. ELECTROSURGICAL MEANS Sometimes even if the general condition of the gingiva in the mouth is healthy, areas of inflammation or granulation tissue may be encountered around a given tooth as a result of: -
Space created because of physiologic tooth movement.
-
Caries resulting in cavitation which cannot be successfully handled by retraction methods.
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Keeping this in mind a treatment modality using a high frequency electrical current of 1.0MHz (million cycles per second) or more to produce controlled tissue destruction to achieve a surgical result was thought of: d'Arsonval in 1891 demonstrated in his experiment that electricity at high frequency would pass through a body without producing a shock/pain but producing an increase in the internal temperature of the tissue which was used as a basis for electrosurgery. The electrosurgical unit is a high frequency oscillator or radotransmitter which uses either a vacuum tube or a transmitter. The concept is similar to diathermy or a microwave. Current flows from a small cutting electrode which produces ↓
-
-
High current density.
-
Rapid temperature rise at the contact point. The cells directly adjacent to the electrode
are volatilized by increased temperature. -
The current concentrates at point and bends therefore cutting electrodes are designed to take advantage of this property.
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CURRENTS There are 4 main types of currents used for electrosugery depending on the type of machine and circuit. (a)
UNRECTIFIED, DAMPED CURRENT
Characterized by recurring peaks of power which diminish rapidly.
Gives
rise
to intense
dehydration and
necrosis.
Considerable coagulation.
Healing is slow and painful.
Not routinely used.
(b)
PARTIALLY RECTIFIED DAMPED
Waveform with damping in second half of each cycle
Advantage: Good coagulant and hemostasis.
Disadvantage: lateral penetration of heat and slower healing.
(c)
Tissue destruction is more. FULLY RECTIFIED CURRENT
Continuous flow of energy
Advantages: -
Good cutting characteristics.
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(d)
-
Hemostasis is achieved.
-
Better gingival enlargement is observed.
FULLY RECTIFIED FILTERED
Continuous wave.
Excellent cutting.
Histologically healing was not as better as the fully rectified current.
The whole circuit is grounded by a ground electrode. ELECTRODES USED Selection of electrodes vary depending on the -
tooth
-
arch position
-
form of action
Example: 1) Cutting electrodes
diamond loop round loop
used for planing tissue
small loop small continuous loop straight wire – tungsten wire variable tip Posner’s AP 1½
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2) Coagulating electodes Small ball
Large ball Bar electode
4 types of action can be produced at the electrode end: (i) CUTTING also called Electrosection/Electrotomy / Acusection This procedure is
- Extremely precise - bloodless - minimal tissue involvement - requires unipolar electrode
There are different electrode tips used for this purpose: The most commonly used ones are the: -
diamond loop
-
small loop
-
straight wire
-
variable tip
-
Posner’s AP 1½
After using a diamond or a continuous loop electrode a small amount of tissue tag remains which can be removed by a straight single wire tip or variable tip. 27
-
Variable tip electrode wire can be adjusted to a desired length.
-
Posner’s AP 1½ indicates that the working tip extends 1½ mm beyond the insulation. This offers a precise, uniform depth of sulcus which is adjustable too.
-
The
angle
of
working
electrode
is
kept
approximately 15-20 degrees. Holding it more angled results in loss of gingival height. -
Whereas in anterior quadrant where the gingiva is thin, the angle of working electrode is nearly parallel to long axis of tooth.
Note:
The depth of tissue removal is determined by the morphology of the tissue and biologic width. The tissue trough should extend 0.3-0.5mm below the finish line.
It is always better to remove the inner wall of sulcus rather than the crest of gingiva to prevent recession.
Cutting
of
attached
gingiva
result
in
permanent destruction of gingival height because it is
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important to know the difference between anatomic crown height and clinical crown height, especially in anterior quadrant where esthetics is of prime importance. (ii) Coagulation It causes coagulation of surface tissues -
Fluids
-
Blood (hemostasis)
Destroys necrotic tissues.
Used to remove granulation tissue.
Electrodes used are:
Bar Small ball Large ball
It is caused due to thermal energy introduced by electrode tips.
Partially rectified, partially damped output is used.
Overuse of tip causes carbonization of tissues creating a sealing film on the tissues.
(iii) Fulgeration
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-
has greater energy because it can be used in deeper tissues.
-
Always accompanied by carbonization.
-
It
has
less
after-effects
than
cutting
and
coagulation. -
It requires bipolar electrode.
-
The tip remains above tissue. Current sparks are sprayed to the tissue in circular motion till the tissue becomes blackened or carbonized.
-
Dehydration of tissue occurs.
(iv) Dessication This includes massive tissue involvement both in terms of depth - Bipolar electrodes
surface area
Disadvantages: 1) It is most unlimited and uncontrolled. 2) Tissue reactions are unpredictable. 3) 1800째 heat generated. 4) Deeply penetrates causing permanent deformation. Not frequently used.
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GENERAL RULES TO BE FOLLOWED DURING ELECTROSURGERY 1) OPERATION AREA Moist tissue cuts best because avoid complete drying highly dried tissue can be detrimental. 2) Use only FULLY RECTIFIED, UNDAMPED CURRENT with minimum energy output required for desired purpose.
If sparks appear electricity output is too much.
If tip drags and collects streads of tissue clinging output is too low.
3) For cutting use light pressure touch and rapid deft strokes with a 5 seconds lapse between two strokes. 4) Never involve:
free gingiva. Crest of gingiva (recession). attached gingiva (permanent separation).
Always keep cutting electrode in the internal wall of sulcus maintain biologic width. 5) Metallic restorations should not be touched ↓ Can create short circuit and damage surrounding structures.
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6) Always clean debris on the electrode tip with alcohol soaked gauge. 7) After the impression / restoration procedure create a blood clot with curetting. 8) It is contraindicated in patients with pacemaker. 9) ORINGER’S SOLUTION – after the procedure of making final impression or retraction during restorative procedures, a tincture of myrhh and benzoin (oringer’s solution) should be placed on surgical area and air dried – for 4-5 times. The healing is rapid and takes place within a weeks time – Oringer’s can be replaced by ORABASE. SURGICAL In other terms surgical means can be referred to as “GINGIVECTOMY”. Gingivectomy means exicision of the gingiva. It is done by using a cold shape knife called the Kirkland knife or the Bald-Parker blades No. –11 and 12 and a pair of scissors.
Indications: 1) Interfering or unneeded gingival tissue during any impression / restorative procedures. 32
2) In cases of gingival polyps seen in proximal caries. 3) In a Class V restorative procedures. 4) For crown lengthening during or cast restoration crown procedures.
5) For
apical repositioning of whole
periodontal attaching
apparatus to create a healthy, safely manipulated, easily retractable free gingiva. LASER GINGIVECTOMY Most commonly used lasers are the CO 2 and Neodymium; yttrium-aluminium garnet (Nd:YAG) in the infra-red range. ďƒ Healing is delayed. ďƒ Needs experience. CHEMOSURGERY Several techniques using chemicals like 5% paraformaldehyde or potassium hydroxide are used to remove gingiva. Disadvantages: -
depth of section cannot be controlled.
-
Healing cannot be predicted.
-
Epithelization and re-establishment of gingiva is doubtful because of the chemical action. 33
Not used generally.
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GINGITAGE /ROTARY CURETTAGE / DENTTAGE Dr. Fred Hansing in 1972-75 originally developed the techniques for gingival tissue management during cast, restoration fabrication by using high speed diamond instrument which he refined later and was called gingitage. It is also done with pencil shaped instrument at 7500rpm as given by Moskow 1964. Used to remove sulcular tissue. Healing is satisfactory. CONCLUSION: While making impressions of prepared teeth or restoring them it is necessary to expose the margins. Proper tissue management is a key factor in accurately duplicating subgingival margins. At the same time the health of the gingival tissues is crucial for success as opposed to inflamed redundant tissue as a liability. Therefore the dentist must recognize the importance of using a systematic approach right from diagnosis till completion of the restoration with adequate emphasis on correct handling of the gingival tissue.
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REFERENCES : -
Marzouk.
-
Shillingburg.
-
Tylman.
-
Glickman.
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