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College of DentistryDivision of Pediatric Dentistry UKCD PDO 822 The use of preformed stainless steel crowns in primary molars June 8, 2016 Enrique Bimstein Professor of Pediatric Dentistry The use of SSC on primary molars Goal: You will acquire the basic knowledge required for the tooth preparation, adaptation and cementation of primary molar preformed stainless steel crowns. Topics 1. Introduction: crown types, definitions, rationale, indications and contraindications. 2. Characteristics, advantages and disadvantages. 3. Clinical procedures: tooth preparation, crown adaptation and cementation. 4. Summary and conclusions. Crown types for primary teeth Cast : Stainless steel: Strip crowns Zirconia crowns Lifelike™ CAD-CAM crowns Gold crowns occlusal anatomy trimmed contoured pre-veneered Composite Prefabricated Prefabricated In-office Stainless steel crowns • SSCs are an invaluable restorative material in the treatment of badly decayed primary teeth. eb eb eb Definition of SSC Full coverage metallic , definitive restoration for primary teeth. (Or temporary for permanent teeth) eb eb Characteristics of SSC Pre-veneered: metal with esthetic facing eb eb • Have a resin-composed facing bonded to Occ. and B. surfaces. • Expensive, require more tooth reduction, and allow only for minimal crimping. • Relatively low success rate. Pre-veneered: metal with esthetic facing Long-term clinical performance: at the 4 year evaluation all the esthetic crowns showed chipping of the esthetic facing, with poor esthetic appearance. eb Ram D et al. Pediatr Dent 25:582-4, 2003 eb Ceramic crowns - Zirconia CAD-CAM Definition of SSC Is a metal shell with preformed anatomy that can be adapted to the tooth, and still remain elastic. eb eb Characteristics of SSC Stainless steel crowns may be: With occlusal anatomy Trimmed Contoured Crimped Pre-veneered eb eb Unlock your mind and snap the crown! Characteristics of SSC 3M Stainless steel Shape ION Ni-Chro Size eb 3M Stainless steel ION Ni-Chro Length Cervical constriction/ contour eb Rationale for using a SSC Perio health # of visits Time Difficulty Lab required Cost Esthetics Good Several Hours Difficult Yes Expensive “Bad” Good One Minutes Easy No “Cheap” “Bad” Rationale for using a SSC Stainless steel crowns are used to restore primary molars in which the failure of an amalgam or composite restoration or recurrent caries is clear in your mind. Indications for using a SSC Extensive caries destruction. An adequate isthmus is difficult to obtain with a small occlusal surface a wide contact and large pulp . eb eb Indications for using a SSC No gingival floor possible for a proximal – occlusal restoration Indications for using a SSC Early childhood caries eb eb Indications for using a SSC Multi-surface restorations eb eb Indications for using a SSC Failure before the age of 8 years 1st primary molar One surface 70% restorations Two surface 75% restorations Stainless 12.8% steel crowns Dawson et al. ASDC J Dent Child 1981. 2nd primary molar 32% 71.4% 11.0% Indications for using a SSC eb eb Indications for using a SSC After endodontic treatment Pulpotomy Pulpectomy eb Indications for using a SSC Pulpotomized primary molars can be successfully restored with one surface amalgam if their natural exfoliation is expected within not more than 2 years. Holan et al. Success rate of formocresol pulpotomy in primary molars restores with stainless steel crowns vs amalgam. Pediatr Dent 24:212, 2002. Indications for using a SSC Delopmental abnormalities Enamel hypoplasia Enamel hypoplasia and caries eb Indications for using a SSC Compliance and behavior? eb Indications for using a SSC Space maintainer eb As an abutment for space maintainers or prosthetic appliances. eb Indications for using a SSC Fractured molars due to trauma eb eb Tejani Z, Johnson A, Mason C, Jane Goodman J. Multiple crown-root fractures in primary molars and a suspected subcondylar fracture following trauma: a report of a case. Dental Traumatology 2008; 24: 253–256. Contraindications for SSC Primary tooth close to exfoliation eb Contraindications for SSC Extensive dental caries there is not enough crown structure left, caries located to apical. eb eb eb Contraindications for SSC No restorability due to extreme mesial drift eb eb Contraindications for SSC Esthetics. Contraindications for SSC Allergy to nickel • Stainless steel crowns (Unitek and Rocky Mountain) crowns composition consist of 1719% chromium, 9-13% nickel and 0.08-0.1 carbon. • Nickel based crowns (Ion Ni-chro from 3M) composition consists of 76% nickel, 8% iron, 0.04 carbon and 0.35% manganese. MS Muthu- N Sivakumar. Pediatric Dentistry. Principles and practice. Elsevier 2009. eb Contraindications for SSC Pazzini CA, Pereira LJ, Marques LS, Generoso R, de Oliveira G Jr. Allergy to nickel in orthodontic patients: clinical and histopathologic evaluation. Gen Dent. 2010 Jan-Feb;58(1):58-61 Kolokitha OE, Chatzistavrou E. A severe reaction to ni-containing orthodontic appliances. Exposure to nickel-containing orthodontic appliances may cause intra- or extraoral allergic reactions. Nickel is the most typical antigen implicated in causing allergic contact dermatitis, which is a Type IV delayed hypersensitivity immune response. Angle Orthod. 2009 Jan;79(1):186-92 Bruce GJ, Hall WB. Nickel hypersensitivity-related periodontitis. Compend Contin Educ Dent. 1995 Feb;16(2):178, 180-4; quiz 186 Ehrnrooth M, Kerosuo H. Face and neck dermatitis from a stainless steel orthodontic appliance. Angle Orthod. 2009 Nov;79(6):1194-6 Clinical procedures for SSC • Rationale. • Tooth preparation. • Crown selection. • Crown adaptation. • Complications. • Cementation. • Cleaning. Rationale for SSC tooth preparation and adaptation a. do not require the retention features that are incorporated in cavity design of cast crowns. b. The retention of SSC is based on the flexibility and elasticity of the thin, contoured and crimped crown margins, and its cementation. Rationale for SSC tooth preparation and adaptation The tooth preparation and crown adaptation of SSC in primary (and permanent) molars is based (among other) on the crown’s: Flexibility: easily bent or shaped. Elasticity: the tendency of a body to return to its original shape after it has been stretched. Rationale for SSC tooth preparation and adaptation eb • Preformed metal crowns are flexible and elastic (they snap). • The tooth cervical bulge is “surrounded” by the crown. Characteristics of SSC eb Rationale for SSC tooth preparation and adaptation Subgingival depth ≈ 1.5 mm C. E. J. eb Clinical procedures for SSC • Rationale • Tooth preparation. • Crown selection • Crown adaptation. • Complications. • Cementation. • Cleaning Armamentarium for adaptation eb eb eb 114 contour plier Crimping plier Sharp scaler eb Round scissors Check Occlusion before starting tooth reduction. eb Occlusal preparation (a) Create a “channel” ± 1.25 mm deep between the cusps (or use a football bur). Occlusal preparation (a) eb eb eb eb eb eb Occlusal preparation (b) Tooth preparation for SSC • Buccal and lingual surfaces a)Limited to occlusal 1/3 of the B & L surfaces at a 45º bevel. b)Round off all line angles. c)A large mesio-buccal or cervical bulge may require more buccal and lingual reduction. Buccal and lingual reduction. Prepare a slight bevel, at the occlusal 1/3 portion of the surface. eb eb Buccal and lingual reduction. Prepare a slight bevel, at the occlusal 1/3 portion of the surface. What’s next? Caries removal Pulp therapy (if required) Proximal surfaces Proximal surfaces Caries removal Pulp therapy (if required) Caries removal eb Apply a liner or perform pulp therapy if needed eb Tooth preparation for SSC Proximal surfaces a) 169L tapered fissure or thin tapered diamond bur. Tooth preparation for SSC Proximal surfaces a) 169L tapered fissure or thin tapered diamond bur. b) “Open ” the proximal contacts at appropriate depth in single sweeping motion (or gradually O G). c) With slight convergence in an occlusal and lingual/palatal direction. d) Feather-edge finish line; common error: ledge formation. Proximal surfaces eb eb eb eb Proximal surfaces eb eb Rounding angles. eb SSC selection & adaptation General considerations a)Place or “seat crown” from lingual to buccal. b)Push crown over the buccal buldge for a snap fit. c)Check margins for close cervical adaptation extending 1-1.5 mm subgingivally (temporary gingival blanching possible). Placing the crown SSC selection & adaptation Too small M-D eb SSC selection & adaptation Too big M-D eb SSC selection & adaptation Crowns which are to big M-D may prevent the adequate eruption of adjacent permanent tooth. eb eb SSC selection & adaptation eb SSC selection & adaptation Sharp scaler eb eb SSC selection & adaptation eb eb SSC selection & adaptation • Crown and Bridge Scissors eb Additional crown adaptation Polish the crown with a heath less stone. eb SSC selection & adaptation 114 Contouring Pliers eb eb eb SSC selection & adaptation eb eb SSC selection & adaptation Crimping Pliers eb eb eb SSC selection & adaptation Examine the occlusion. The occlusion should be the same before starting the procedure. eb WARNING ! eb WARNING ! Aspiration is possible eb eb Adewumi A. Kays DA. Stainless steel crown aspiration during sedation in pediatric dentistry. Pediatr Dent 30:59-62, 2006. eb SSC Cementation and cleaning eb eb