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Why Carry Out Esthetic Bonded Restorations on Posterior Teeth?. Prevention 과 oral hygiene 이 잘 유지되고 있는 35세 환자의 caries free mouth. Traditional approach using amalgam : 증례(1). recurrent caries around old composite restoration on M & PM cavity prep & pin placement for amalgam
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Why Carry Out Esthetic Bonded Restorations on Posterior Teeth?
Prevention과 oral hygiene이 잘 유지되고 있는 35세 환자의 caries free mouth.
Traditional approach using amalgam : 증례(1) • recurrent caries around old composite restoration on M & PM • cavity prep & pin placement for amalgam • completed amalgam filling
Traditional approach using amalgam : 증례(2) • interproximal caries on #14,15 • intact occlusal surface • traditional approach • occlusal extension prep for amalgam • 술후 사진.
More conservative approach using adhesive technique • similar case above • maximum sound tissue preservative cavity form • direct composite restoration
Evolution of decayed tooth • a) “classical” approach • “natural caries decay”의 진행, 수복물의 변성, mechanical failure 발생 빈법 • (left arrow) unfavorable condition : mesiodistal fissure로 진행 - premature root canal tx.- protective crowning • (right arrow) onlay만으로 더 이상의 진행 prevention.
B) “ adhesive” approach • mechanical failure 발생 감소.
Fractured tooth :증례 (1) • sensitivity to pressure • intact on radiography • deep fractured fissure on mesial side • direct composite restoration으로 sealing & reinforce : sensitivity 감소
Fractured tooth : 증례(2) • frail & wide class 1 amalgam filling. ( No cuspal coverage) : spontaneous & pressure induced pain • 일차적으로 composite inlay수복으로 symptom완화 시도. • 술후 방사선 사진 : 와동형성을 심부까지 extension하지 않음.
Fractured tooth :증례 (3) • superficial class 2 : not visible defect but thermal change & pressure에 sensitivity • deep ,discolaorated fissure ( leakage ) • endodontic therapy • crown for prevent from further crack progression
prevention form의retoration은많은 양의 치질 삭제를 요한다.
Decmentation of gold inlay • 부적절한 marginal fit으로 severe secondary caries 발생.
rich blend color로natural anatomy와esthetic,optimal function을 만족시키고 있는 수복형태.
new esthetic material의만족 할만한long-term behavior • after 5-year • after 9-year
Bonded ceramic inlay • 구치부 심미 수복 중 most long lasting. But, 과정이 복잡하고 가격이 비싸다 • after 3-year • after 5-year
1) esthetic intracoronal restoration: not a modern concept (1) 1856prefabricated ceramic inlay sealed with gold foil (2) 1882fired ceramic inlay (Herbest, Germany)
(3) 1888fired ceramic inlays over platinum foil (Land) (4) 1895 ceramic inlay was introduced well before amalgam (5) 1905 resinous adhesive + porcelain etching (Nyman)
Low fusing ceramic inlay (Ducera)에 fatigue test (mechanical loading & thermocycling) : porcelain etching과 new adhesive에 의한 adhesion remain ( D:dentin LC:luting composite C:ceramic )
(6) 1871silicate cement : direct esthetic m.의 real development begin (Fletcher) (7) 1937 unfilled resin (8) 1938 development of epoxy molecule (Castan Swiss) (9) 1951 acid conditioning (Hager, Swiss) (10) 1952 “hybrid layer” first description
(11) 1955further development of enamel etchin (Buonocore) (12) 1962 Bowen’s Bis-GMA formulation에 의한 composite resin (Bowen) : moder adhesive dentistry의 beginning (13) 수년 전까지 posterior esthetic material은 amalgam이나gold filling과경쟁이 되지 않았다. Biological & physiochemical short comings
2-2a.b amalgam restoration의 satisfactory long-term behavior - amalgam over 20 year - free of recurrent decay
2-3a.b gold inlay의 excellent long term behavior - 24 year old gold inlay
(14) limitation of esthetic material의durabillity a. marginal degradation b. wear c. mechanical failure
<clinical finding> a. Recurrent decay b. pulpal injury c. loss of function
Bonded posteriorrestoration에 이용되는material의 기능에 의한 분류 • Liner • Base • Adhesive • Luting composite • Restorative material
Direct composite filling: enamel, dentin 각각에 대한adaptation비교 • Enamel : perfect adaptation • Dentin : separation
Dentin etching(phosporic acid, 10 sec) • exposure collagen fiber network • porius structure • <주의> No over etching! • Collagen fiber denaturation & weakening 으로 dentinal tubule collapse
Hybrid layer or interdiffusion zone • intertubular dentin과 peritubular dentin 사이로 resin tag형성.
Ceramic bonded inlay :1.5year loading (thermal & functional) • resist
Hybrid layer에 의한dentin bonding failure example • 원인 • Maybe spontaneous collagen collapse or compression during etching & dehydration
Liner application under Direct composite • deepest part에 pulp protection 위해 calcium hydroxide cement을 partial lining.
Base,liner application이 marginal seal에 미치는 영향 • Base,liner : fluorecent resin leakage • bonding agent : full surface adhesion
Prep for adhesive restoraion • PM : direct filling • M: compomer base로resin inlay위한 형태 형성. • Resin restoration volume감소.
Conventional glass ionomer cements : structure • developed by Wilson & Kent by 1972 • polycarboxylate cement liquid (polyacrylic acid) • + silicatecement liquid (aluminisilicate glass)
final state : 2 phase • Matrix : gelation of polyacid by metal ions from the glass during the initial acid attack • Filler • large particle : intact glass core sheathed by siliceous hydrogel • small particle : completely degraded in siliceous hydogel
Compomer 1: Dyrect의 structure • Resin과 유사한 matrix에 GI filler (aluminosilicate glass)첨가
Advantage • Ease of manipulation due to long working time and rapid set ( light activation) • Resistance to early contamination by water and to dehydration • Higher early strength and superior mechanical properties • Fluoride release
Compomer 2: temporary restoration & base • Delay the final steps of the restorative procedure
Ceramics 1“heterogeneous conventional dental porcelain” • 2 phase : glassy matrix & crystalline inclusion • after firing • after HF acid etching : imprints of leucite crystal • Reinforced heterogeneous porcelain : higher proportion of alumina & leucite
Ceramics 2“glass ceramic(Dicor)” • glassy matrix + crystalline inclusion • 1st step : casting of glass (amorphous glass) • after “thermal ceramization” : development of crystalline structure
Ceramics 3“slip casting (In Ceram) • crystalline matrix + infiltrated glass • 1st processing : sintering spinell crystals • infiltrated by a glass
Ceramics 4“low fusing ceramic (LFC,Ducera) • homogeneous porcelain • firing phase : melting glass particle • final stage : homogeneous glass react superficially with water & produce a reinforced hydroxylated layer.
Composite resin : polymerization • light activated • pore-free structure • homogeneity of activation • possibility of multilayer application • chemically cured • numerous void from hand mixing
Composite resin 1: monomodal heterogeneous microfilled composite • Prepolymerized complex with higher filler density • Filler : pyrolytic silica