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Preparation for Full & Partial Veneer Crowns. 가천의대 길병원 치과센터 보철과 김연휘. Preparations for Partial Veneer Crowns. Advantages. Preservation fo tooth structure Good accessibility Less gingival irritation More easily seated completely during cementation
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Preparation for Full & Partial Veneer Crowns 가천의대 길병원 치과센터 보철과 김연휘
Advantages • Preservation fo tooth structure • Good accessibility • Less gingival irritation • More easily seated completely during cementation • More easily verified by direct observation • Accessible when EPT
Disadvantages • Retention • But!!! • Single Cr./ Short-span Br. 의 retainer로서는 적당!!!
Lingual lock Resistance Free enamel Too lingual : 금속 두께 부족
Contents • Mx. Post. ¾ Crowns • Post. Partial Veneer Variations • Ant. ¾ Crowns • Pin-modified ¾ Crowns
Mx. Post. ¾ Crowns • 심미적 요구 : 중증도 • 일상 대화중에는 금속 노출
Mx. Post. ¾ Crowns occlusobuccal line angle넘어 0.5mm까지 1.5mm 1.0mm 1.5mm Occlusal reduction : Round-end tapered diamond & #171 L bur Functional cusp bevel : Round-end tapered diamond & #171 L bur Lingual axial reduction and finishing : Torpedo diamond bur
Mx. Post. ¾ Crowns Gingivofacial angle: 충분히 연장 가능한 facial 쪽으로, Chamfer로부터 0.5mm Axial finishing : Torpedo bur Proximal axial reduction and finishing : Short needle and Torpedo diamond bur Proximal grooves : #171 L bur
Mx. Post. ¾ Crowns Groove 단계별 형성171L bur groove outline Utility wax로 bur 고정 • Groove 형성 시 원칙 • facial surface를 undermine하지 않는다. • 가능한 facial에 위치한다. • 구치의 장축과 평행하게 한다
Mx. Post. ¾ Crowns 1.0mm 0.5mm for marginal integrity Occlusal offset : #171 L bur Proximal flares : Flame diamond & bur Buccal bevel : Flame diamond and #171 L bur
prox. caries shoulder가 offset역할 DB caries Proximal box가 있는 상악 3/4 하악 대구치 3/4 상악 대구치 7/8 상악 처럼 occlusal offset 90도 회전된 ¾ Cr. 하악 대구치 reverse 3/4 기울어진 하악 대구치 proximal half
Ant. ¾ Crowns • 적응증 • 수복물/우식증 없는 short-span Br. • 지대치 조건 • 배열 양호 • 순설면 치질 두께 충분 • 단점 • 금속 노출
Ant. ¾ Crowns 0.7mm 이상 45° Incisal 2/3와 평행 Lingual reduction : Small wheel diamond Incisal reduction Lingual axial reduction : Torpedo diamond • 삭제 되지 않은 절단면의 경사와 평행 • Labioincisal line angle을 약간만 침범 • 0.7mm깊이
Ant. ¾ Crowns Axial finishing : Torpedo bur Proximal axial reduction : Long needle and Torpedo diamond Proximal grooves : #169L & 170L burs
Ant. ¾ Crowns 최대한 apical & labial Proximal flares : Flame diamond and bur Incisal offset : #171 L bur Incisal bevel : Flame diamond and # 170 L bur 설측으로 기울임
Pin-modified ¾ Crowns • 적응증 • 심한 lingual abrasion을 가진 전치 • 금기증 • small/thin teeth • large pulp • malposition
Retentive pin • 한 단계씩 작은 것!! • pin의 길이가 중요!! 0.6mmdrillnylon bristleiridioplatinum pin
Pin-modified ¾ Crowns 0.7mm 이상 Incisal 2/3와 평행 최대한 순측으로 Lingual reduction : Small wheel diamond Proximal axial reduction : Long needle and Torpedo diamond Lingual axial reduction : Torpedo diamond 너비 : 1.5mm
Pin-modified ¾ Crowns Contact에서 충분히 설측으로 Axial finishing : Torpedo bur Proximal grooves : #169L & 170L burs Proximal flares : Flame diamond and bur 무치악 부에 2개
Pin-modified ¾ Crowns Ledge Incisal bevel : Flame diamond and bur Ledge, offset & trough :#170L burs Pin holes : # ½ bur and 0.6 mm drill Offset/Trough
Pin hole형성 순서 Tapered fissure bur Small round bur Twist drill