INDIAN DENTAL ACADEMY Leader in continuing dental education www.indiandentalacademy.com
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Introduction History Properties of Orthodontic wires Classification Indications Advantages Disadvantages Design Components Commonly Used Appliances Soldering and Welding Conclusion www.indiandentalacademy.com
Weinstein has said
“There is only one disease that is malocclusion. The medicine is force and there are number of ways of applying this force�
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HISTORY Victor Hugo Jackson chief proponent of removable appliances in the US
Charles Hawley
Introduced Hawley’s appliance in 1908
Martin Schwartz In mid 20th century developed a variety of split plate appliances
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Philip Adams Modified arrowhead clasp into ‘Adams Crib’ Became the basis for English removable appliances Still the most effective clasp for orthodontic purpose George Crozat In early 1900s developed a removable appliance entirely in precious metal Effective clasps on I molars modified from Jackson’s design Heavy gold wires as framework Lighter gold finger springs for desired tooth movement www.indiandentalacademy.com
At the beginning of the twentieth century • • •
•
vulcanite baseplate that covered the palate molars and premolars capped for retention. Although the materials changed, removable appliances remained the principal appliance for orthodontic treatment in UK and Europe for the next 70 years. In contrast, it had little impact on American orthodontics, which at that time was dominated by Edward Angle. www.indiandentalacademy.com
Development of Removable Appliances in Europe 1.
2.
3.
Angle’s dogmatic approach to occlusion, with its emphasis on precise positioning of each teeth had less impact on Europe Social welfare systems developed much more rapidly in Europe- providing limited treatment for large number of patients Precious metals for fixed appliances were less available in Europe www.indiandentalacademy.com
In the UK, the establishment of the National Health Service in 1948 favoured use of removable appliances. • only ten specialist orthodontists • so the vast majority of orthodontic treatment was provided by general dental practitioners. • Department of Health, and the then Dental Estimates Board, were of the view that the near exclusive use of removable appliances was the most cost effective way of providing UK orthodontic care.
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1970s: The length of postgraduate orthodontic training increased from one to two years 1980s: to three years. Postgraduates were able to complete supervised treatment of multibanded cases before they qualified. A series of technical advances • Prewelded, preformed orthodontic bands • Directly bonded attachments • Pre-adjusted edgewise bracket reduced the need for complex individually formed archwires. www.indiandentalacademy.com
Measurements of treatment outcome
The quality of outcome not as high as with fixed appliances Higher discontinuation of treatment associated with the use of removable appliances Dental practitioners now refer their patients on to specialist orthodontists. Specialist orthodontists favour the use of fixed appliances due to the ability to precisely position teeth www.indiandentalacademy.com
Scope of removable appliances The use of removable appliances still varies widely between clinicians, but it is possible to achieve adequate occlusal improvement with these appliances, provided suitable cases are chosen. It is vital to emphasize that cases suitable for removable appliance treatment are those that require simple tipping movements only, and surprisingly few malocclusions will fall into this category.
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Properties of Orthodontic wires 1) 2) 3) 4) 5) 6) 7) 8) 9) 10) 11)
Esthetics Kusy, AO 1997 Stiffness Strength Range Springback Formability Resiliency Friction Biohostability Biocompatibility Weldability www.indiandentalacademy.com
1) Esthetics: -desirable property -no compromise on mechanical properties -composite wires 2) Stiffness/Load deflection rate: -Magnitude of force delivered by the appliance for a particular amount of deflection. LDR=Load/Deflection www.indiandentalacademy.com
FÎą Edr4 d Îą l3 l3 r4 E- Modulus of elasticity d- Deflection r- Radius l- Length Doubling radius = Increases force 16 fold Doubling length = Reduces force 8 fold
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L3 α d
(2l)3 α 8d
1α d r4
1 α 16d (r/2)4
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Low stiffness or LDR implies i. Low forces will be applied ii. Forces more constant as appliance deactivates iii. Greater ease & accuracy in applying a given force -For active components low LDR -For retentive components high LDR ‘Variable Cross-section Orthodontics’-Burstone ‘Variable Modulus Orthodontics’ NiTi ≤ TMA ≤ ss wire www.indiandentalacademy.com
3)
4)
5)
Strength: Force required to activate an archwire to a specific distance- Kusy Shape and cross-section of wire have an effect Range: Distance to which an archwire bends elastically, before permanent deformation occursProffit Springback: The extent to which the wire reverses its shape after permanent deformation. Wire can be activated to a large extent hence fewer activations will be needed www.indiandentalacademy.com
6)
7)
Formability: Ability to bend wire in desired configuration. Resiliency: Amount of energy stored in a body. www.indiandentalacademy.com
8)
9)
10)
11)
Friction: While closing spaces in continuous archwire technique, involves relative motion of bracket over wire. Excess friction- loss of anchor - binding Least amount of friction desired Biohostability: Ability of a wire to accumulate, or be a site of accumulation of bacteria, spores or viruses Biocompatibility: Resistance to corrosion and tissue tolerance to elements in the wire. Weldability: Ease by which a wire can be joined to other metals by actually melting the 2 metals in the area of the bond www.indiandentalacademy.com
1meter = 39.37in 1.0mm = 0.3937in 1mm = 40 thousandths of an inch 1mm = 0.040in
mm
inch
1.5 1.25 1.0 0.9 0.8 0.7 0.6 0.5
0.059 0.049 0.039 0.035 0.032 0.028 0.024 0.020
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thou of gauge an inch 60 50 40 36 32 28 24 20
19 20 21 22 23 24
Definition: Mechanical Orthodontic Appliances are instruments which apply pressure or offer resistance to the teeth for the purpose of stimulating alveolar bone change bringing about changes in the position of teeth.
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Classification
Appliances that affect actual tooth movement through adjustment of springs or attachments within the appliance- ACTIVE PLATE
Appliances that stimulate reflex muscle activity which in turn produces desired tooth movementFUNCTIONAL APPLIANCES www.indiandentalacademy.com
II. 1. 2. 3.
III. 1. 2. 3.
According to site of appliance placement Extraoral Intraoral Combination According to plane of movement Transverse Saggital Vertical www.indiandentalacademy.com
IV. 1. 2. 3.
Based on method of curing Heat cure Self cure Light cure
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Indications Minor tooth movement technique may be considered o Malposition limited to relatively few teeth o Desired movement not more than few mm o Adequate space between adjacent teeth to permit entry of teeth to be moved o Allowable axial inclination corrected by tipping forces o Correctable etiologic factors o Favorable periodontal and periapical prognosis o Absence of contraindications www.indiandentalacademy.com
• • • •
• •
Excessive flaring of maxillary anterior teeth Diastima closure Crossbite correction Anterior crowding Preprosthetic Closing of spaces Uprighting of teeth
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Preventive Periodontic Migration of mandibular incisors
Correction of Speech Defects Facilitation of Oral Surgical Procedures Retention after corrected malocclusion
•
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Procedural To gain space
Preventive and interceptive orthodontics
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Advantages
Disadvantages
1.Tipping movement 1.Only simple malocclusion can be 2.Can be removed corrected -for cleaning of teeth & appliance 2.Multiple rotations cannot -if in pain be corrected -on socially sensitive occasion 3.Uncooperative patients may 3.Less conspicuous leave out the appliance4.Can be undertaken by general prolongs treatment practitioner with adequate 4.Multiple tooth movement training - one at a time- prolongs Rx duration 5.Manufactured in lab 5.Lower appliance not well tolerated -less chair side time 6.Cases other than I premolar -more patients can be treated extraction cannot be treated easily 6.Inexpensive
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Components of removable appliances
Retentive Components Baseplate Active components
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Retentive Components Retention: Means whereby displacement of appliance is resisted. Clasp: any hook or band attached to a natural tooth and used to anchor a partial denture or an orthodontic appliance.
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Circumferential Clasp
• •
Fabricated using wire 0.9mm -Also known as ‘C’ clasp or Three Quarter Clasp Simple clasp used to engage buccocervical undercut Cannot be used in partially erupted teeth www.indiandentalacademy.com
Jackson’s Clasp
- Fabricated using 0.9mm wire - Also known as Full clasp or ‘U’ clasp - Engages both buccocervical undercuts Simple design Offers adequate retention Inadequate retention in partially erupted teeth www.indiandentalacademy.com
Triangular Clasp
-Fabricated using 0.6mm wire -used between adjacent posterior teeth -Indicated for additional retention
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Adam’s Clasp -Also known as Liverpool Clasp, Universal Clasp, Modified Arrowhead Clasp Parts Bridge Arrowhead Retentive arms
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Advantages: Small, neat, unobtrusive, occupies minimum space Rigid, offers excellent retention Used on any tooth in the arch If broken can be repaired by soldering Permits modifications in design Extensive wire bending incorporates stresses in the wire
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Modifications Adams clasp with single arrowhead: Adams clasp with J hook Adams clasp with helix Adams clasp with additional arrowhead Adams clasp with soldered buccal tube www.indiandentalacademy.com
Adams clasp with distal extension
Double clasp on maxillary central incisors
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Schwarz Clasp
Designed by C. M. Schwarz Oldest & for a considerable amount of time most generally used Adj: Arrowhead bent towards papilla to engage undercuts Can be used in deciduous or permanent teeth Skill to fabricate Can be used only on posterior teeth www.indiandentalacademy.com
Duyzings Clasp
-Simple design -engages buccal undercut of molars -half clasp can also be constructed Adj: Bending towards the tooth or undercut area
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Eyelet Clasp
-similar to triangular clasp -used as single eyelet or multiple eyelet clasp -eyelets placed in embrasures Adj: Bending eyelet interdentally towards the tooth No sharp bends, breakage unlikely Does not interfere with eruption of teeth On single tooth does not have firm grip www.indiandentalacademy.com
Delta Clasp
Designed by William J. Clark • Similar to Adams clasp in principle • Engage interdental undercuts Adj: -hold retentive loop and twist inwards -bending towards interdental undercut as it emerges from acrylic •
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Southend Clasp
-0.7 mm wire -spans two adjacent margins of anterior teeth Adj: readapting into interdental area ďƒź Esthetically more pleasing www.indiandentalacademy.com
Ballend Clasp
• • •
Wire having a knob or ball like structure on one end utilizes interdental undercuts Indicated when additional retention required www.indiandentalacademy.com
Baseplate Greatest portion of removable appliance 1-2mm thick 3 main purposes 1. Act as vehicle to carry all parts of the appliance 2. Serve as anchorage 3. Become an active part of appliance itself
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ANCHORAGE Anchorage resists forces of reaction generated by active components. Thus, sites of anchorage must be equal in magnitude but opposite in direction to those generated by active components. Simple Anchorage: Teeth which offer greater resistance to movement, used as anchorage for movement of lesser resistance www.indiandentalacademy.com
Usually made of Acrylic • As thin as possible(1-2mm) • Closely adapted • Extend as far as necessary to obtain anchorage • Lower baseplate- U shaped, relatively thicker • Shallow lingual sulcus reinforced with ss wire or bar Heat cure Self cure Light cure Biocryl: Biostar pressure molding machine •
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BASEPLATE
Anterior
Upper
Parallel to occ plane
Posterior
Lower
Inclined to occ plane
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Anterior biteplane -Platform behind upper incisor teeth -Height enough to separate posterior teeth by 1.5-2mm -Reduce overbite of anterior teeth -‘opening the bite’ -Height of plane gradually increased Proclination of upper incisors *Placement of labial bow *Sved biteplane www.indiandentalacademy.com
Sved Biteplane -Introduced by Sved in 1944 -Covers incisal edges of upper anteriors -Pressure transmitted axially -Retention questionable -Ideal in growing individuals
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Posterior Biteplane
• •
displacing activity of mandible unilateral posterior crossbite
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wide enough to contact buccal & palatal cusps occlusion disengaged equal on both sides after correction appliance acts as retainer www.indiandentalacademy.com
Lower Inclined Plane • • • •
•
Catlan more than 200 yrs ago Anterior crossbite 45 degrees to occ plane Upper incisors guided into correct position labially indicated when incisors are in early stage of eruption If used for more than 6wksanterior open bite results May need frequent cementation www.indiandentalacademy.com
Pre-treatment
Post-treatment
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Active components
Labialbow Springs Elastics Screws
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LABIAL BOWS May have 2 functions 1) Serve as active element for movement of teeth 2) Hold the plate in place & retain the teeth
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Labial Bow with ‘U’ loop
• • •
0.7 mm wire flexibility depends on vertical height of ‘U’ loops Only minor overjet reduction or incisor alignment required www.indiandentalacademy.com
Adj: Compressing of ‘U’ loop Displaced palatally by only 1mm www.indiandentalacademy.com
Long Labial Bow
• • •
Used to close space between canine and premolar Can control the canine Used for retention
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Split Labial Bow
flexibility increased • incisor retraction Adj: at the ‘U’ loop •
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Labial Bow with Reverse Loop
Prevents buccal drifting of canine Adj: Done in 2 stages 1) Vertical loop opened by compressing with plier 2) This lowers the bow in incisor region compensating bends at the base of the loop •
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Mills Bow /Extended Labial Bow
Made of 0.7mm wire • Extensive loops- flexibility greatly increased Indications -Reducing large overbites -Alignment of irregular incisors Flexible, lighter forces, long range of action In mixed dentition when canines not erupted www.indiandentalacademy.com Due to extensive loops less comfortable •
High Labial Bow with Apron Spring Heavy base arch of 0.9mm wire • Apron spring 0.3-0.4mm Adj: Bent towards the teeth •
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Retraction of teeth with severe proclination Light forces Longer range of action Not well tolerated by the patient Time consuming to fabricate Cannot be used inwww.indiandentalacademy.com patients with shallow sulcus
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Roberts Retractor
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Flexible bow constructed of 0.5mm wire Steel tubing to give support Coil placed at the point of emergence from the tubing Ajd: Vertical limb below the coil www.indiandentalacademy.com
Fitted Labial Bow • • •
0.7 mm wire Adapted closely to labial surface of anterior teeth Used for retention Time consuming
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Beggs Retenton Bow
• •
0.7mm wire extends till last erupted molar ’U’ loops made between I & II premolars Allows settling of occlusion If not constructed well retention may not be good www.indiandentalacademy.com
SPRINGS Most commonly used active elements Requirements: springs should deliver optimum force should possess high degree of elasticity should have long range of action
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Force systems delivered depend on Intrinsic properties- cannot be altered by operator -modulus of elasticity -yield strength Extrinsic properties- operator can exercise control -length of wire -thickness of wire Small changes in diameter and length have a profound impact on the force delivered www.indiandentalacademy.com
Effect of wire diameter on force delivered -amount of activation 0.5mm- 3mm activation 0.7mm- 1mm activation- little margin of error Effect of wire length Coil- increase length of spring Lower force with same amount of activation
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Classification of Springs Based on direction of tooth movement 1. Springs for mesio-distal tooth movement 2. Spring for labio-lingual tooth movement 3. Springs for expansion of arches II. Based on nature of support 1. Self supported springs 2. Guided springs 3. Auxiliary springs III. Based on presence of loop or helix I.
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Single Cantilever Spring active arm Parts coil retentive arm • 0.5-0.6mm wire • coil with internal diameter of 3mm • used to move teeth labio-lingually or mesio-diatally
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Double Cantilever Spring / Z spring Constructed using 0.5 or 0.6 mm wire • Spring perpendicular to palatal surface of tooth • Indicated where incisors are to be proclined Activation: Opening both coils If not perpendicular to palatial surface of teeth, it tends to intrude teeth. •
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‘T’ Spring Constructed using 0.5 mm wire • Buccal movement of premolars and molars Activation: Pulling spring away from the baseplate •
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Coffin Spring
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• •
Described by Walter.H.Coffin in 1881 Made in 2 segments, large enough to make contact with all teeth to be moved Made of 1.25 mm wire Spring stands 1 mm away from the soft tissues www.indiandentalacademy.com
Indications: Transverse arch expansion – Unilateral crossbite with lateral mandibular displacement Advantage over screw – Differential expansion can be obtained.
Unless expertly made and adjusted, tends to be rater unstable.
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Activation
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Canine Retractors • •
I. II. III.
Type of spring used to move canine in distal direction CLASSIFICATION Based on location -buccal -palatal Based on presence of helix or loop Based on mode of action -push type -pull type www.indiandentalacademy.com
Buccal Self Sopported Canine Retractor
• •
•
0.7 mm wire buccally placed canine is to be moved palatally and distally coil just distal to long axis of tooth
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Activation: by 1mm Distal -closing the loop Palatal -anterior limb is bent towards the tooth after it emerges from the coil ďƒť ďƒť
Uncomfortable to patient Stability increased- flexibility compromised www.indiandentalacademy.com
Supported Buccal Canine Retractor
identical in design to self supported retractor • 0.5mm wire supported in tubing Activation: by 2mm •
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Reverse Loop Canine Retractor
can be used in shallow sulcus Activation: 1mm i. cut off 1mm from the free end & readapt it ii. opening the coil •
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‘U’ Loop Buccal Canine Retractor
can be used in sallow sulcus Activation: free end is cut by 1mm & readapted Requires frequent adjustment •
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Palatal Canine Retractor
-canine placed palatally requiring distal buccal movement -coil of 3mm placed between the initial & final position of canine www.indiandentalacademy.com
Boxing & Guarding
• • •
Boxing to protect from damage Spring lies in the recess between baseplate &mucosa Guard to prevent distortion during removal
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-often cranked Activation: 1-2mm by opening the coil -should not be bent where it merges from the baseplate
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Dr.Safeena
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Screws Used for moving individual teeth or group of teeth Types of screws 2 types of expansion screws Skeletal expansion screw Dental expansion screw
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Types of Screws Maxillary expansion Mandibular expansion Bilateral expansion Sectional expansion Radial expansion Expansion in three directions www.indiandentalacademy.com
Activation Screw is turned 90 degrees Will drive the parts of the plate apart by 0.2 mm Narrows periodontal membrane by 0.1 mm on each side Ideal orthodontic condition for transformation of bone
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Uses : Baseplate divided into sections driven apart by one or more screws
1)
Split along midline – Bilateral crossbite and minor crowding of incisors
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2)
Split into a larger and a smaller part
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Pretreatment
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Post-treatment www.indiandentalacademy.com
3)
Lingually locked and crowded upper central incisor tipped forward using springs after space provided by moderate expansion
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4)
Expansion and reduction of overjet
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5)
Y-Plates – For alignment of crowded canines by saggital and lateral expansion
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Elastics Resembles rubber band Made of latex rubber Available in various diameters – force applied depends on their diameter Colour coded for easy identification Uses : For movement of singe teeth and groups of teeth For intermaxillary traction www.indiandentalacademy.com
Molar intrusion with removable a appliance Giuilio Alessandri Bonatti, Daniela Giunta JCO Aug 1996
CASE 1
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After 4 months
Prosthetic replacement
CASE 1 www.indiandentalacademy.com
CASE 2
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CASE 2
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Soldering Soldering is the joining of two metals by the use of filler metal which has a substantially low fusion temperature than that of the metal parts being joined Fusion temperature of filler metal ≤ 450°
Brazing Fusion temperature of filler metal ≥ 450°
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Dental solders Dental solders are alloys used as intermediary or filler metals to join two or more metallic parts. Composed of gold, silver, copper, zinc, tin, nickel Requisites of a solder 1. Good tarnish & corrosion resistance 2. Fusion temperature should be lower than that of parts being joined. (50째-100째 less) 3. Should be free flowing and adequately wet the metal parts for good adhesion 4. Strength of solder comparable to metals being joined 5. Colour of solder should match with parts being soldered www.indiandentalacademy.com
Flux: in Latin means ‘flow’ • Removes oxide coating to increase flow of the molten solder • Dissolves any surface impurities • Prevents oxidation of metals • Reduces melting point of dental solder Flux used commonly Borax Glass- 55% Boric acid- 35% Silica- 10% Fluoride fluxes- Boric acid : Potassium fluoride(1:1) www.indiandentalacademy.com
Antiflux Material used to confine the flow of molten solder over metals being joined Graphite
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1)
2) 3)
Stainless steel is difficult to solder No union between solder & steel under conditions of stress & strain in the mouthJoint failure Heating to temperature required for soldering anneals- useless for spring purpose Passive surface film of chromium protects it from further oxidation- inhibits flow of solder Good design Accurate control of heat distribution Use of fluoride containing flux www.indiandentalacademy.com
Soldering technique
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• • • • •
• •
Miniature butane blow lamp Jet of fine needle flame 1cm long Reducing zone of flame Twisting one wire around the other Overheating-burning of wire and solder –rough pitted surface on soldering. Soldering to be performed in one heating if possible. Localization of heat to the site of solder.
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Welding Welding is process by which surfaces of metal are joined by mixing, with or without use of heat Design of welder for orthodontic purpose Fred in 1938 Mc Keag in 1939 Principle design features- speed & power
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Cold welding- done by hammering or pressure. Hot welding- Heat of sufficient intensity to melt metals being joined. 3 methods of welding used in dentistry 1) Spot welding 2) Pressure welding 3) Laser welding
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Spot welding Convenient method of uniting pieces of metal of the same kind Clean, Quick, produces joints that are strong & reliable Basic Principles- Heat & pressure Electric current conducted through 2 copper electrodes Resistance offered generates very high temperature Copper electrodes simultaneously apply pressure on metals Metal melts at contact points and pressure squeezes metal into each other www.indiandentalacademy.com
ď Ž
Circuite diagram:
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Spot Welder
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Pressure Welding Metal parts placed together Sufficiently large force applied perpendicular to the surface- welding occurs Force applied should be sufficiently large Laser Welding High intensity pulse of light that can be focused Select duration & intensity of pulse- metal melts in small region without micro structural damage to surrounding areas www.indiandentalacademy.com
APPLIANCES Classification 1. 2. 3.
Retention Preventive & Interceptive Active tooth movement Transverse Saggital Vertical
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Hawley’s Appliance
Designed by Charles Hawley in 1908 Most frequently used retainer Short labial bow Adams Clasp on molars www.indiandentalacademy.com
Modifications : Long labial bow – Closing space distal to canine Labial bow soldered to bridge of Adams clasp – avoids risk of space opening due to cross over wire Fitted labial bow – Offers excellent retention Anterior bite plane – To retain or correct deep bite cases Expansion screw with split labial bow With tongue crib. With Z spring on second molars for lingual movement of molars www.indiandentalacademy.com
Alexander,s Retainer • •
‘C’ clasp on molars Anterior labial bow
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High Labial Retainer
• • • •
Harvey L. Lavitt JCO Jan1972
Control over each tooth seperately Springs for correction of rotation and uprighting Both active and retentive More esthetic
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A Removable CUSPID-TO-CUSPID Retainer DOUGLAS J. SHILLIDAY (JCO 1973)
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Begg’s Wraparound retainer Popularized by P.R.Begg. Bow extending till last erupted molar ďƒź No crossover wire, eliminates risk of space opening up
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Clip-on Retainer Wire runs labial to incisors, passes between canine and premolar Both labial and lingual wire segments embedded in strips of acrylic Brings out correction of rotation in lower anterior segments
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Van der Linden Retainer JCO May2003
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Kesling’s Tooth positioner Described by H.D.Kesling in 1945 Made of thermoplastic rubber like material Spans interocclusal space and covers clinical crowns and a small portion of gingiva No activation needed Difficulty in speech Risk of TMJ problems
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Essix Retainers- Fabrication and supervision for permanent retention John. J. Sheridan, Willaim Ledoux, Robert Mcmin JCO Jan 1993
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Wraparound cantilever retainer Timonthy J. Tremont JCO Feb- 2003 Ideal for a well finished case •Cantilever arm- middle of first bicuspid soldered to labial bow •Bow adjusted by giving a slight bend in the cantilever arm •
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Thermoplastic copolymer retainer • Thin, yet strong, cuspid-cuspid • Low cost & ease of fabrication • Brilliant appearance of teeth caused by light reflection • Thickness- .030”Space cut at distogingival margin to allow removal removal •
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•Pontic can be incorporated for missing anterior tooth
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Habit Breaking/Restraining Appliances
Tongue crib appliance Tongue crib anchored to oral cavity by clasps and labial bow Used for interception of habits like tongue thrusting and thumb sucking. www.indiandentalacademy.com
Oral Screen/Vestibular screen
• • • • •
Introduced by Newell in 1912 Shield of acrylic placed in the labial vestibule Designed to screen oral cavity Metal ring projecting between upper and lower lips Used to intercept habits like thumb sucking, tongue thrusting and mouth breathing. www.indiandentalacademy.com
Modifications • For interception of tongue thrusting : • Additional screen placed in the lingual aspect, attached to the vestibular screen by means of a thick wire • For mouth breathing- when airways are open • Fabricated with a number of holes that are gradually closed. • Open bite in deciduous & mixed dentition • Mild disto-occlosion with premaxillary protrusion www.indiandentalacademy.com
Space Maintainers Space maintenance is a process of maintaining the space previously occupied by a tooth or several teeth before the eruption of permanent tooth. Classification  Functional- teeth incorporated to aid in mastication, speech and esthetics.  Nonfunctional- acrylic extension over edentulous area to prevent space closure www.indiandentalacademy.com
Class I: Unilateral maxillary posterior Class II: Unilateral mandibular posterior Class III: Bilateral maxillary posterior Class IV: Bilateral mandibular posterior
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‘C’ Space Regainer
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Tongue Blade Therapy
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Lip Bumper/ Lip Shield Extends into the vestibular sulcus to the labial fold No contact made between shield and incisors Eliminates persistent hyperactivity of mentalis muscle Class II div 1 malocclusion Class I flush terminal plane with large overjet Shield the lower lip away- used for interception of lip sucking habit To augment anchorage Distallisation of first molars As space regainers- early loss of deciduous molars www.indiandentalacademy.com
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Denholtz Appliance Lip bumper for the maxillary arch Design similar to madibular lip bumper
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Crozat Appliance Treatment of Buccal Crossbite JCO 2003, June Frank Marasa
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ACCO Acrylic Cervico Occipital anchorage • Margolis 1976 & Spengeman 1967 • Acrylic on labial bow • Auxiliaries- springs for posterior rotation - minimal anterior crowding - minimal distalization Jacobson splint- Used phase therapy or prefixed appliance guidance. Verdon combination appliance-When mandibular protraction desired www.indiandentalacademy.com •
Fixed Removable approach to presurgical Orthodontic Treatment H.S.Orton, P.M.Noble Lower full edgewise appliance JCO May 1990 Upper labial sectional edgewise appliance Expansion plate with dams clasp for fixation
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Design variation for class II div 2 cases Clasps on I premolar and I molar Palatal spring to intrude and procline upper incisors
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Bonding for Retention of Removable Appliances Leonard Gorelick, Arnold Geiger JCO 1986 JUNE Anatomic factors prevent adequate retention •Bell shaped posterior teeth •Teeth with abnormal axial inclination •High palatal vault- poor tissue adaptation of acrylic • Large tori that limit tissue support Bondable eyelet Composite bonding material www.indiandentalacademy.com
Bonded Composite Button for Removable Appliances JCO 2003 June Stephen Edward Grimm III Composite button made on lingual surface • Undercut made on the gingival side of the button • Prevents the spring from being displaced • Allows full force to act on the tooth •
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Instructions to patient • • • • • •
Discomfort Phonetics Increased salivation Cleaned after eating Initially full time wear except while eating for 6mts Later night time wear
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Conclusion “All you can do is push, pull or turn a tooth. I have given you an appliance and now for God’s sake use it” Edward.H.Angle
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References
Orthodontic treatment with removable appliances- W. W.J.B. Houston, K.G. Issacson The Design, construction and use or Removable Orthodontic Appliances – C. Philip Adams Removable Orthodontic Appliances- T.M. Graber, Bedrich Neumann Orthodontics Principles and Practice- T.M. Graber Contemporary Orthodontics- Proffit www.indiandentalacademy.com
References
Orthodontics. Post graduate dental hand book- Spiro. J. Chakonas An Introduction to Orthodontics- Laura Mitchell Removable Partial Prosthodontics - McCracken’s Dentofacial Orthopedics with Functional Appliances, Thomas. M. Graber, Thomas Rakosi, Alexandre G. Petrovic Removable Orthodontic Appliances. M.S.Rani
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References
High Labial Retainer Harvey.L.Levitt JCO Jan1972 A Removable cuspid-to-cuspid Retainer Doglus J. Shilliday JCO 1973 Crozat Princilples and Technique. Wendell H. Taylr. JCO June 1985 Crozat Appliance Treatment of Buccal Crossbite Frank Marasa. JCO June 2003 Essix Retainers- Fabrication and supervision for permanent retention John. J. Sheridan, Willaim Ledoux, Robert Mcmin. JCO Jan 1993 Van der Linden Retainer JCO May2003 www.indiandentalacademy.com
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