Restorations in Pediatric Dentisty. Dr. Sami Malik Abdulhameed B.D.S.; M.Sc.

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1 Restorations in Pediatric Dentisty Dr. Sami Malik Abdulhameed B.D.S.; M.Sc.

2 Objectives of the lecture To review the ideal dental office setup To review the moisture control and isolation To review the restorative materials used in pediatric dentistry To review the Matrices & bands To review different cavity preparation techniques and some modifications To review crown restorations for posterior & anterior teeth

3 Restorative Goals Relief pain & Cease disease process Restore function Improve esthetics Preserve space for permenant dentition

Moisture Control In Restorative Pediatric Dentistry

5 Introduction Objective: Maintain an environment that keeps the operating field free of excess water, saliva, blood, tooth fragments, and excess dental materials. Copyright 2003, Elsevier Science (USA). All rights reserved.

6 Oral Evacuation Systems The process of removing excess fluids and debris from the mouth. Two systems: Saliva ejector High-volume evacuator (HVE) Copyright 2003, Elsevier Science (USA). All rights reserved.

Saliva Ejector Small, strawlike oral evacuator used during less invasive dental procedures. Indications for use: Preventive procedures such as a prophylaxis or fluoride treatments.

7 Saliva Ejector Small, strawlike oral evacuator used during less invasive dental procedures. Indications for use: Preventive procedures such as a prophylaxis or fluoride treatments. Helps control saliva and moisture accumulation under the dental dam. For the cementation of crown or bridge. During an orthodontic bonding procedure. Copyright 2003, Elsevier Science (USA). All rights reserved.

HVE Used for most dental procedures, especially when the dental handpiece is in use. Indications for use Keep the mouth free of saliva, blood, water, and debris.

8 HVE Used for most dental procedures, especially when the dental handpiece is in use. Indications for use Keep the mouth free of saliva, blood, water, and debris. Retracts the tongue and cheek away from the field of operation. Reduces the bacterial aerosol caused by the high-speed handpiece. Copyright 2003, Elsevier Science (USA). All rights reserved.

9 HVE- cont d Oral evacuation tips Operative suction tips Designed with a straight or slight angle in the middle. Beveled working end. Made of durable plastic or stainless steel. Surgical suction tips Much smaller in circumference. Made of stainless steel. Copyright 2003, Elsevier Science (USA). All rights reserved.

Grasping the HVE Thumb-to-nose grasp Pen grasp Right hand

13 Objectives of Ideal Isolation Provide optimum visibility and access to operative site. Prevent moisture contamination of teeth. Retract and control soft tissue of tongue, lip, and mucosa. Protect patient against aspiration of dental instruments and materials. Provide patient comfort. Be easily and rapidly accomplished.

Dry-Angles A triangular absorbent pad placed over the Stensen's duct blocks the flow of saliva

The Dental Dam A thin stretchable latex material becomes a barrier when appropriately

17 Rubber Dam Application

18 Types of Dental Materials F release material ( Glass Ionomer) Resin Modified Glass Ionomer Composite Amalgam Stainless Steel

19 Fluoride-Releasing Materials Glass Inomer & Resin Modified Glass Inomer

20 Glass Inomer Cement loses and gains water easily: Early moisture contamination leads to increased solubility and poor esthetics, (protect for first 7 minutes). Later desiccation causes shrinkage and crazing, (maybe even months later).

21 GIC - Fluoride Release halo effect around restoration ~ 3 mm. Level around restoration ~ 10 ppm. Level in saliva of average patient ~ 0.08 ppm. Fluorine release from GIC does not lead to restoration breakdown.

22 Classification OF GI ADA Classification Type I: luting agents (Ketac-Cem, Fuji I) Type II: restorative material a = tooth-colored (Ketac-Fil, Fuji IX) b = reinforced (Ketac-Silver, Miracle Mix ) Type III: fast-set liners and bases (Ketac-Bond)

23 GIC Physical Properties Strengths: Ionic exchange leads to adhesion to tooth structure (chemical bond). Fluoride release and rechargeable.

24 GIC Physical Properties Weaknesses Moisture sensitivity. Lack of command cure, i.e. doesn t cure with light. Esthetics. Not recommended for stress-bearing areas. Difficult handling.

25 GIC Indications High caries risk patient Atrumatic Restorative Treatment (ART) Pediatric dentistry Class V lesions Liners & bases & sandwich technique Luting agents Core buildups??? Maybe if > 2/3 of tooth structure remains Orthopedics (bone substitute material)

26 Steps of Clinical Use of Glass Inomer 1. Mechanical retention in preparation advised (no bevels).

27 Steps of Clinical Use of Glass Inomer 2. Dentin conditioning (10 % polyacrylic acid for seconds). 3. Inject into preparation. Overfill the preparation.

28 Steps of Clinical Use of Glass Inomer 4. Trim excess with finishing bur (wet, with very light pressure as the cement material cuts easily!) and polish (if necessary). Be cautious not to over-reduce, the material is softer than composite resin. 5. Dry the surface and paint on a thin layer of lightcured unfilled resin (smoothes the surface and prevents desiccation but lowers fluoride release. (optional)

29 Glass Ionomers Advantages Bond to tooth structure Physical properties similar to dentin Moisture tolerant Release fluoride (5 years) Fluoride rechargable Less microleakage

30 Glass Ionomers Disadvantages Not as strong Poor wear Increased setting time Not as esthetic as composite

31 Glass Ionomer Indications Smooth surface lesions Small anterior proximal lesions i.e. areas of low stress High caries risk patients Sealants Base underneath deep carious lesions Good cement for stainless steel crowns and brackets and bands Interim Therapeutic Restorations

32 Resin Modified Glass Ionomer Mixture of glass, an organic acid, and resin polymer that harden when light cured

$Resin Modified Glass Ionomer Advantages Increased wear and fracture toughness Some fluoride release Comand cure$

33 Resin Modified Glass Ionomer Advantages Increased wear and fracture toughness Some fluoride release Comand cure Increased esthetics Disadvantages Not as strong as composite or amalgam Less fluoride release than glass ionomer

34 Amalgam mixture of mercury (43%-54%) and powdered alloy (silver, tin, zinc and copper) Once mixed sets automatically

35 Amalgam Advantages Quick and easy manipulation Less moisture sensitive Microleakage decreases with time Good mechanical properties economical

$fracture Wide isthmus Rounded line angles Poor esthetics Dental amalgam$

36 Amalgam Disadvantages Non bonding Bulk for strength Proper preparation to prevent fracture Wide isthmus Rounded line angles Poor esthetics Dental amalgam controversy

37 Composite Mixture of powdered glass and plastic resin Polymerization reaction initiated by light Various level of filler particles can change esthetics, mechanical properties, and viscosity

38 Composites Advantages Micromechanical Bond Esthetic and polishable Conservative preparation Preventative Sealants

39 Composites Disadvantages Moisture sensitive Technique sensitive Multiple steps Time consuming Polymerization shrinkage leads to microleakage

40 Composite Indications Small pit and fissure caries Class I, II, III, IV and V restorations in primary and permanent teeth

41 Anterior Strip Crowns Anterior Restorations Primary anterior crown forms

42 Stainless Steel Pre-fabricated Full coverage restoration Pre-crimped with 6 sizes Adapted to tooth

43 Stainless Steel Advantages Strongest Preventative Can be adapted for space maintainer Disadvantages Poor esthetics Post op discomfort

44 Stainless Steel Indications Pulpotomy Extensive caries Fractured teeth Hypoplastic molars

45 Stainless Steel Crown Indications Space Maintainer Distal Shoe / loop High caries risk children Patients that require general anesthetic for dental treatment

46 Stainless Steel Crown Crown and loop Placed on tooth that has extensive decay with space maintenance needs

47 Anterior Stainless Steel Crowns Anterior SSC with windows Flowable composite Acid etched Micromechanical and mechanical retention

Matrix Systems for Restorative Dentistry Copyright

49 Introduction A matrix system provides and takes the place of the proximal tooth surface that was removed to restore the proximal contours and contact to their normal shape and function. Copyright 2003, Elsevier Science (USA). All rights reserved.

50 Types of Matrices w Tofflemire does not fit contour of primary tooth well difficult to fit multiple matrices W T-band w Spot welded allows for multiple matrix placement requires a spot welder chairside w Automatrix - costly

51 Posterior Matrix System Universal retainer Also referred to as the Tofflemire retainer. This device holds the matrix band in position. The retainer is positioned most commonly from the buccal surface of the tooth being restored. Copyright 2003, Elsevier Science (USA). All rights reserved.

Components of a Universal Retainer Copyright

The larger circumference of the band is the occlusal edge and is always placed toward the occlusal surface.

53 Posterior Matrix Systemcont d Matrix bands Matrix bands are made of flexible stainless steel and are available in premolar, molar, and universal sizes and thicknesses. The larger circumference of the band is the occlusal edge and is always placed toward the occlusal surface. The smaller circumference of the band is the gingival edge and it is always placed toward the gingiva. Copyright 2003, Elsevier Science (USA). All rights reserved.

55 Automatrix System The automatrix system is an alternative to a universal retainer. There is no retainer used to hold the band in place. Bands are already formed into a circle and are available in assorted sizes in both metal and plastic. Each band has a coil like autolock loop. A tightening wrench is inserted into the coil and turned clockwise to tighten the band. When finished, the tightening wrench is inserted into the coil and turned counterclockwise to loosen the band. Removing pliers are used to cut the band. Copyright 2003, Elsevier Science (USA). All rights reserved.

Fig. 49-9 Automatrix system. (Courtesy of Dentsply Caulk.

58 Matrix Systems for Primary Teeth The T-band is a T-shaped copper band. When formed, the top portion of the T allows the straight portion to adjust and fit the circumference of the primary molar. Copyright 2003, Elsevier Science (USA). All rights reserved.

60 Additional Matrix Systems for Primary Teeth A spot-welded band is a form-fitted band placed around a prepared tooth, then removed and placed in a smaller form of a welder that fuses the metal together to make a custom band. Copyright 2003, Elsevier Science (USA). All rights reserved.

61 Spot Welded Matrix w Cut matrix and spot weld ends 3/16 wide and thin (..002 ) matrix w Form a loop w Hold ends in spot welder w Weld at low setting Copyright 2003, Elsevier Science (USA). All rights reserved.

63 Matrices for Composite Restorations A plastic matrix, also referred to as a celluloid matrix or mylar strip, is used for class III and IV restorations in which the proximal wall of an anterior tooth is missing. Copyright 2003, Elsevier Science (USA). All rights reserved.

64 A clear matrix system. (Courtesy of Premier Dental Products.) Copyright 2003, Elsevier Science (USA). All rights reserved. Copyright 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved.

The Use of a Clear Matrix The matrix is placed interproximally before the etching and priming of a tooth. This protects adjacent teeth from these materials.

65 The Use of a Clear Matrix The matrix is placed interproximally before the etching and priming of a tooth. This protects adjacent teeth from these materials. After placement of composite material, a matrix is pulled tightly around the tooth to help reconstruct its natural contour. The clear plastic matrix allows the curing light to penetrate the material and complete the curing process. Copyright 2003, Elsevier Science (USA). All rights reserved.

66 Sectional Matrices A thin polished palodent-type band and a tension ring produce a tight anatomic contact for composite resin materials for class II restorations. Copyright 2003, Elsevier Science (USA). All rights reserved.

68 Sectional matrices. (Courtesy of Garrison Dental Solutions.)

69 Wedges A wedge is either triangular or round and made of wood or plastic. The wedge is inserted into the lingual embrasure to position the matrix band firmly against the gingival margin of the preparation. Copyright 2003, Elsevier Science (USA). All rights reserved.

71 Restorative Dentistry for Children BY DR SAMI MALIK ABDULHAMEED.

72 Cavity Preparation Dr. Sami malik abdulhameed

73 Objectives wto be able to identify and distinguish morphologic differences between primary and permanent teeth. To apply the knowledge of morphology in clinical procedures for pediatric patients

74 Morphological Considerations in the Primary Dentition w The crowns of primary teeth are shorter have a narrower occlusal table have a more pronounced cervical constriction have thinner enamel and dentin layers

75 Morphological Considerations in the Primary Dentition w The crowns of primary teeth have enamel rods that run in a slightly occlusal direction from the DEJ have broad flat contact areas between primary molars have nearly the same mineral content as permanent teeth have a lighter, more homogeneous color

76 Contact Area Point contact Broad, flat contact

Morphological Considerations in the Primary Dentition w The pulps of primary teeth are larger than that of the permanent tooth in relation to crown size are closer

77 Morphological Considerations in the Primary Dentition w The pulps of primary teeth are larger than that of the permanent tooth in relation to crown size are closer to the outer surface of the tooth the mesial pulp horn is pronounced occlusally more closely follow the surface of the crown usually have a pulp horn under each cusp

78 Comparison of Pulps

79 Influences of Primary Tooth Morphology w Tooth Preparations Need to take into account tooth size, pulp size and enamel and dentin thickness

80 Instrumentation w Utilize a # 245 bur w Tip - measure width and length of cutting shank w High speed w Minimal use of hand instruments

Class I Amalgam Preps w Pulpal Floor Depth -.5-1 mm into dentin primary molars - 1.25 to 1.

83 Class I Amalgam Preps w Pulpal Floor Depth mm into dentin primary molars to 1.50mm w Intercuspal width - 1/3rd w Rounded internal line angles w B-L walls slightly undercut w M-D walls flare at marginal ridges

84 Mandibular Molars Outline Form

85 Maxillary Molars Outline Form

87 Internal Form of a Class I Prep w 1) depth.5-1mm into dentin w 2) angle of floor and walls is rounded w 3) slightly rounded pulpal floor Avoids pulp w 4) sharp cavosurface angle

88 General Considerations w Adhere to GV Black s principles with respect to outline, resistance, retention and convenience form and finishing of enamel walls.

89 Class II Cavity Prep - Mandibular

90 Class II Cavity Preps - Maxillary

91 Class II Amalgam Preps w Accomplish occlusal outline form w Extend proximal box into self cleaning area leave 90 degree cavosurface margins isthmus width 1/3 w Proximal box in an occlusal gingival direction is parallel to the long axis of the tooth

92 Class II, continued w B-L walls of box should converge occlusally w Gingival floor should be beneath the contact, at, or just beneath the gingival tissue w Axial wall should follow the contour of the tooth 1 mm in width

93 Cross-sectional View of Class II w 1a) gingival floor position 1b) box is perpendicular to long axis w 1c) rounded angles

94 Common Errors - Class II s

95 Modifications B View from distal surface of primary 1st molar L w Concave pulpal floor and gingival seat w Rounded internal line angles both decrease stress in the restoration

96 Modifications w Relatively wider isthmus width one-third the intercuspal distance w Conservative proximal extensions you can see light, but cannot pass an explorer tip through

97 Modifications w No proximal grooves w No reverse curves

98 Class 2 slot preparation

99 Class V Restorations A class V restoration is classified as a smooth surface restoration. These decayed lesions occur at: The gingival third of the facial or lingual surfaces of any tooth. The root of a tooth, near the cementoenamel junction. Copyright 2003, Elsevier Science (USA). All rights reserved.

100 Condensation and Carving w Back to back condensation of Class II s w Carving described as hill and valley w Polishing procedure is same as taught for permanent teeth

101 Condensation and Carving w Back to back condensation of Class II s w Carving described as hill and valley w Polishing procedure is same as taught for permanent teeth

102 Polishing!

103 Failures of Amalgam Restorations w Fracture of the isthmus of a Class II due to insufficient bulk of amalgam w Marginal failure in proximal box area due to excessive flare of the cavosurface margin w Recurrent caries failure to extend preparation adequately

104 Class III Cavity - Incisors What type of spacing would make a patient more susceptible?

105 Class III Cavity - Cuspids Dovetail is placed on lingual of maxillary cuspids and the facial of mandibular cuspids. Proximal box is placed perpendicuar to a line tangent to the surface on which the dovetail is placed.

106 Restoration of Proximal-Incisal Caries in Primary Anterior Teeth Esthetic Resin Restoration Stainless Steel Crown Open-Face Steel Crowns Direct Resin Crowns

107 Composite (Strip) Crowns

108 Preventive resin restoration

109 OBJECTIVES: PREVENTIVE RESIN RESTORATION (PRR) 1. List the indications and contra-indications for PRR for primary and permanent teeth. 2. Describe the PRR materials. 3. Describe the clinical procedures for PRR. 4. Identify the advantages of using PRR and their cost effectiveness.

110 Preventive resin restorations were first described a long time ago in paediatric dentistry. Today the technique is still very pertinent, and has been extended to include teenagers and adult patients. New flowable composites have made it possible to extend the indication area for preventive resin restorations. Although mostly considered as a base material for posterior restoration, flowable composites are now proving very useful for many different types of minimally invasive cavity preparations such as carious fissures

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allowing the retention of healthy tissue to be maximised.

140 The patient presented with infiltration of the fissures an eroded amalgam The decayed fissures were opened using special burs, allowing the retention of healthy tissue to be maximised. The amalgam restoration was removed.the dentine was properly cleaned of carious tissue.

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142 ATRAUMATIC RESTORATIVE TREATMENT A.R.T

143 INTRODUCTION Atraumatic restorative treatment (ART) is a procedure that involves removal of carious substance from the tooth using hand instruments and restoring with adhesive restorative material. This is being developed for less industrialized communities in special groups such as refugees and people living in financially deprived communities who are unable to obtain a restorative dental care. ART has broken many barriers and allowed delivery of dental restorative treatments possible despite unavailability of electricity or communities that can not afford dental treatment.

144 CONTINUED Glass Ionomer is the material of choice for ART that can be applied to early stages of caries development that would halt or slows the caries progression due to the slow release of fluoride. It is important to understand that ART is only a branch of oral health care that need to start with health promotion messages, healthy diet and good oral hygiene. With ART one attempts to conserve as much tooth structure as possible to prevent further decay to achieve the goal of Teeth for Life.

145 CONTINUED Instrument needed for ART is very convenient to carry around by bus or bicycle in a bag. In addition delivering this treatment oral care workers travel to rural communities for oral health education. ART is a very friendly procedure to patients that could be utilized to be effectively used on children and fearful adults. For this reason, ART is widely used even in industrialized countries because it supports minimal intervention and minimal invasion of the patient.

146 Interim Therapeutic Restorations Removing carious tissues using hand instruments only Less traumatic No need for electricity Conservation of tooth structure Low cost Glass Ionomer Bonds to tooth Releases fluoride

147 ART Applications Great technique for root caries Good alternative in field conditions Excellent for fearful children Good alternative in medically compromised patients Good alternative in mentally compromised

148 Quality of restorations depends on: Material Operator Patient

149 RESEARCH ART was pioneered in mid 1980s in Tanzania. In 1991 community field trial was started in Thailand comparing the difference between ART with traditional portable drilling equipment and amalgam. In 1993 another community field trial in Zimbabwe was set up based on experiences in Thailand. This showed that careful application yielded 85% of one surface fillings in permanent dentition survived for 3 years. In 1995 in Pakistan, a community field trial showed that pain is rarely experienced with this approach.

150 PRINCIPLES OF ART 2 main principles of ART are: 1. Removing carious tooth tissues using hand instruments only 2. Restoring the cavity with a restorative material that sticks to the tooth. Why GIC? It bonds chemically to both enamel and dentine, it is fluoride releasing and it does not inflame gingiva or pulp.

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152 INDICATION AND CONTRAINDICATIONS Indications: There is a cavity involving dentine Able to access the cavity with hand instruments. Contraindications: Presence of infection (abscess or fistula) Pulp is exposed Chronic inflammation of pulp Cavity is inaccessible with hand instruments.

153 PREPARING THE CAVITY Place a cotton roll and dry the working tooth. Use the dental hatchet to gain access and excavators to remove soft caries and unsupported enamel. It is very important that: 1. All soft caries is removed at enamel-dentine junction. 2. To avoid exposure of pulp in deep cavities, leave a small portion of affected dentine near pulp region.

154 CLEANING THE PREPARED CAVITY The purpose of cleaning the cavity walls is to improve chemical bonding of GIC to tooth structure. Cavity could be cleaned by: 1. Dentine conditioner (10% Polyacrylic acid) 2. The liquid supplied by GIC itself. With dentine conditioner clean the cavity walls for seconds and dry with cotton wool pellets. Repeat the procedure if contaminated by blood or saliva.

155 RESTORING THE CAVITY After cavity is washed and dried, start mixing GIC powder and liquid. Insert in small amounts using applier/carver to avoid air bubbles and build the restoration slightly high on occlusal surface. Insert material into corners and unsupported enamel first. With petroleum jelly on the gloved index finger press the soft material into the cavity, this is called the press-finger technique. Do not disturb the restoration during hardening phase.

156 CONTINUED After 1-2 minutes check the occlusion. If the ART restoration too high, remove the stained portion of restoration with a carver blade. Ask the patient not to eat for an hour.

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158 PROCEDURE FOR RESTORING MULTIPLE SURFACE CAVITIES Prepare the cavity in a dry cotton rolls. environment using Place a matrix strip between teeth with a wedge for support under the contact point and gum margin. Condition the cavity and fill it with GIC completely. Use the finger press technique Remove excess and wait for 1-2 minuets. Check the occlusion and it is important to have non occluding contacts with the opposing tooth.

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160 PRESS-FINGER TECHNIQUE

161 PRESS-FINGER TECHNIQUE

162 AFTER PRESSING

163 AFTER APPLYING WATERPROOFING

164 SURVIVAL OF GIC SEALANTS 3 year old glass-ionomer sealant

165 SURVIVAL OF GIC SEALANTS 2 year old glass-ionomer sealant

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167 MONITORING It is important to collect any information if any pain is being experienced and if ART restoration was accepted. Assess if the patient is satisfactory with the restoration within first 4 weeks. The clinical evaluation is planned annually or biannually depending on the risk statues and oral hygiene.

168 FAILED OR DEFECTIVE RESTORATION A restoration is no longer satisfactory when : 1. It is completely missing 2. Fractured restoration 3. Much of the restorative material is worn away. 4. Caries have developed at the restoration margin or else where on the tooth surface.

169 Stainless Steel Crowns Indications and Techniques Dr. Sami Malik Abdulhameed B.D.S.M.Sc.

170 Use of Stainless Steel Crowns u Introduced to pediatric dentistry by Dr. William Humphrey in 1950 prior to that orthodontic bands filled with amalgam were a last resort necessity is the mother of invention u Considered superior to large multisurface amalgam restorations and have a longer clinical lifespan than two or three surface amalgams (Dawson et al., 1981)

171 Objectives u The student should be able to: Describe the indications for stainless steel crowns. Understand the principles of preparation, adaptation, and cementation of a successful stainless steel crown. To properly prep a dentoform tooth for a SSC and properly adapt a crown to fit it.

172 Crowns vs. Class II Amalgams Crowns 90% successful from date of placement, regardless of age Majority of failures are related to pulp failure, not restoration failure (false failure) Not as esthetic however More expensive Class II Amalgams Success rate is highest when life expectancy of the tooth is less than 3 years Better looking than crowns Cheaper than crowns Approximately 50% failure rate when placed in children <4 y.o.

173 Indications Rampant Caries Caries involving three or more surfaces Recurrent caries Following pulp therapy Developmental defects Fractured teeth Severe bruxism Orthodontic appliance fabrication

174 Rampant Caries

175 Indications Rampant caries

176 .:Indications Three surface radiographic decay

177 Indications Non-ideal two surface, or 3 surface decay

178 .:Indications Recurrent caries

179 .:Indications Following pulp therapy

180 Indications Developmental Defects

181 Indications Developmental Defects Following indirect pulp therapy on permanent first molars Restoration of large developmental defects on permanent first molars

182 .:Indications Fractured amalgams

183 .:Indications Severe Bruxism

184 .:Indications Orthodontic Appliance Fabrication Distal Shoe Crown / loop

185 Contraindications u Esthetics u Teeth that are nearing exfoliation u Mechanical problems space loss caries beneath the level of the bone u Permanent restoration in the permanent dentition

186 Types of Crowns Rocky Mountain Unitek Ion

187 Types of Crowns First crown developed, originally by an orthodontist Must be trimmed Must be contoured Not crimped Rocky Mountain Rarely used today due to significant time to fabricate at chairside

188 Types of Crowns Second crown developed Pre-trimmed Must be contoured Must be crimped Unitek Primarily composed of chromium and steel, this is strongest of the three crowns

189 Types of Crowns Latest evolution Pre-trimmed Pre-contoured Pre-crimped Ion Softer metal, but designed to snap over prep without any alterations

190 What you will need u Burs and stones #169 heatless stone u Pliers and instruments contouring plier crimping plier u Polishing

191 Clinical Procedures Pre-treatment evaluation Prior to placing rubber dam, check occlusion Vertical space loss? Horizontal space loss? Soft tissue change? Mobility? Rubber dam is mandatory!!! Crowns are very slippery when wet with saliva Must have adequate anesthesia, particularly on the palate.

192 Horizontal space loss: #E has shifted mesially into #D Vertical Space loss: U #E has palatal cusp erupted into L #E caries

193 Squares vs. rectangles (maxillary molars vs. mandibular molars) - Hint!!! - distal caries on a mandibular primary first molar will alter its shape to look more like a square! When this happens, choose a maxillary primary first molar crown from the opposite arch (I.e. - space loss on lower left primary first molar. Choose a crown from the upper right box!!!)

194 Managing Space Loss Another technique for managing space loss Using the Howe plier, grasp the Unitek crown on the marginal ridges and gently squeeze This causes the rectangular crown to become square. Doing this reduces the mesio-distal width of the crown, but inceases the buccolingual width Recontour and recrimp the crown.

195 Overview u Occlusal reduction u Proximal reduction u Buccal and lingual reduction u Beveling u Round all sharp line angles and corners

196 Crown preparation Key points to remember This is not a cast restoration. The crown does not rely on a precision fit. Retention relies on the natural undercuts, the adequacy of the crimp, and the luting material. This prep is completely different from that of a full gold crown prep Excessive buccal/linqual reduction may result in a non-retentive crown and an unplanned extraction!

197 Crown Preparation Armamentaria Burs --- No. 169L FG Tapered Diamond FG No. 6 or 8 RA No. 330 FG Heatless Stone Accessories--- Wire wheel No. 114 contour pliers No crimping pliers Howe pliers

198 Crown Preparation Occlusal reduction Occlusal beveling Interproximal reduction Line angle refinement

199 Crown Preparation Occlusal Reduction - prior to preparation

200 Crown Preparation Occlusal Reduction - using a 330FG or a round wheel diamond, remove approximately 1-1.5mm.

201 Crown Preparation Occlusal bevel - use 330FG or tapered diamond

202 Occlusal Reduction mm

203 Occlusal Reduction mm

204 Completed Occlusal Reduction u Check reduction with opposing arch

205 Crown Preparation Occlusal reduction completed - do not over-reduce the mesiobuccal aspect (high pulp horn)!!!

206 Proximal Reduction u Contact with adjacent teeth must be broken gingivally and buccolingually u proximal slices converge slightly toward the occlusal and lingual DO NOT OVER TAPER u The gingival margins should have a featheredge finish line u Adjacent tooth structure must not be damaged

207 Proximal Slices

208 Crown Preparation Interproximal reduction - tapered diamond used to avoid interproximal ledges which can prevent seating!!!

209 Crown Preparation Completed preparation - should be approximately mm below the plane of occlusion as judged by comparing adjacent marginal ridge height. Should be no sharp angles to prevent crown from seating Must not be ledged interproximally Margin should be approximately 1 mm below the marginal gingiva

210 Crown Preparation

211 Crowns for Guiding Teeth Ectopic Eruption Crown is indicated on a second molar AND the permanent first molar is hold-type ectopic

212 Crowns for Guiding Teeth Techniques Pulp treatment is completed in the usual manner Estimate amount of distal reduction required Carefully reduce so that first molar is not damaged Estimated reduction

213 Crowns for Guiding Teeth Technique (con t) Using perio probe, sound the mesial of the permanent molar Unitek crown is trimmed so that the distal margin extends below the mesial marginal ridge of the first molar. Solder???

214 Crowns as Space Maintainers The primary advantage of using a crown instead of a band is the increased stability. May be a one or two step procedure (usually two)

215 Angulation of Slices Proper slice Improper slice

216 Ledging u Proximal slice must be extended below tissue to to avoid leaving a ledge

217 Preserving the Outline u Remember: crown preparation if a significant part of the crown s retentive potential

Buccal-Lingual Reduction u Reduction is optional and is undertaken only if the buccal or lingual bulges are so prominent that the constricted

218 Buccal-Lingual Reduction u Reduction is optional and is undertaken only if the buccal or lingual bulges are so prominent that the constricted margin of the crown will not go over he height of contour when required, no more than.5-1mm should be removed reductions must end in a feather edge

219 Beveling u A bevel at an angle of degrees removes the sharp cusp tips and creates a gentle slope in the occlusal third of the lingual and buccal surfaces

220 Round Sharp Line Angles u The buccal and lingual proximal line angles are rounded by holding the bur parallel to the tooth s long axis and blending the surfaces togetherthe finished contour should conform to the internal contour of the stainless steel crown

221 Crown Adaptation u Mark gingival line with a scaler & trim 1mm beneath the mark using C&B scissorsmargins should be trimmed to lie parallel with the contour of the gingival tissue and consist of a series of curves without sharp angles

222 Guidelines u Resistance in seating without tissue blanching. Check for high spots on occlusal surface ledges u Resistance in seating with tissue blanching. Check for crown too wide (preliminary contouring) crown too long tissue caught in margin

223 Contour the Crown u Use contouring pliers, bend the gingival third of the crown s margins inward to restore anatomic margins and to reduce the marginal circumference ensuring a good fit

224 u With the crowncrimping plier (#118) crimp the margin Replace crown on tooth and check margins with an explorer Crimp the crown

remove small scratches and smoothpolish surface

225 Finishing and Polishing u Use heatless stone to smooth jagged edgesthen use a rubber wheel to remove small scratches and smoothpolish surface of crown to a high shine with tripoli and rouge

226 u Clean crown and tooth u Fill crown with zinc phosphate cementseat crown, expressing cement form all margins and press into occlusionremove excess cement when partially set Cementation Cross-sectional View

227 Post-op instructions? u Although a welladapted and cemented crown should not come off under these circumstances, patients and parents should be warned of the possibility

228 Managing Clinical Variations u Space Loss

229 Managing Space Loss u May need to increase the buccal and lingual reductionsmay need to compress crown form on mesial and distal with Howe pliers

230 Clinical Variations u Back-to-back chrome crowns First & Second primary molars

231 Composite Crowns BY DR. SAMI MALIK ABDULHAMEED

232 Objectives u To describe the indications for a composite crown on a primary incisor.to properly prepare a dentoform tooth for a composite crown.to properly adapt a crown form and to restore a dentoform tooth.

233 Restoration of Class IV Caries in Primary Anterior Teeth u u u u Esthetic Resin Restoration Stainless Steel Crown Open-Face Steel Crowns Composite Crowns

234 Anterior Stainless Steel Crowns u Esthetics - poor u Durability - very good u Time for placement - fastest u Selection criteria - severely decayed, esthetics of minimal importance, gingival hemorrhage not controlled, inadequate patient cooperation

235 Open Faced Stainless Steel Crown u Esthetics - okay u Durability - good, although facing may be dislodgedtime for placement - takes longest to place due to two-step procedureselection criteria - severely decayed teeth, durabilty needed, esthetics are a concern

236 Crown Form Selection u Select the appropriate crown form size from the mesio-distal measurement (mm) of the tooth s incisal edge, or by direct comparison

237 Tooth Preparation u Incisal reduction mm u Proximal reduction - parallel mesial and distal slices to break contact with the adjacent tooth and to allow enough bulk to give strength to the final restoration.5-1 mm

238 Utilize a fine diamond or a 699

239 Tooth Preparation u Buccal reduction - to allow the placement of the restoration within the normal buccal lingual width of the tooth restored.5-1 mm u Lingual reduction - to allow for the necessary bulk for the strength of the crown and to prevent for any occlusal interferences

240 Buccal Reduction

241 Lingual Reduction

242 Circumfrential Undercut Shoulder u Terminates at the crest of the gingiva u Shoulder depth should be.75-1 mm u Use inverted cone

243 Variation Cervical undercut on facial only Removal of caries may also provide undercuts

244 Crown Adaptation u Carefully trim off the cervical collar with curved festooning scissorstrim crown form so that when seated, it covers the shoulder but extends no more than 1 mm past tge shoulder

245 Trial Fitting of Crown Form u Try on trimmed crown form Incisal edges should line up Place hole in incisal edge of crown with an explorer to allow vent for composite to flow through during crown placement

246 Crown Placement u Etch tooth with phosphoric acid for 30 seconds u Thoroughly wash and dry etched surface u Apply bonding agent according to specifications

247 Crown Placement u Carefully pack the crown form resin to avoid entrapment of air bubbles

248 u u Position the filled crown form over the prepared tooth so it extends 1mm over the gingival marginremove excess resin from margins with an explorer before polymerizing Slice crown form

249 Minimal Finishing and Polishing u u u u Peel it away from composite crown Finish margins Adjust occlusion DO NOT FINISH the labial surface polymerization of the resin against the plastic provides the smoothest and most stain resistant surface

250

Stainless Steel Crowns

Stainless Steel Crowns Objectives Indications for use of stainless steel crowns Technique used in preparing and placing a stainless steel crown restoration on a primary molar. Indications for SSC Restoration