title: Marginal and internal fit of all-ceramic crowns fabricated with two different CAD/CAM systems.
abstract: This study evaluated the accuracy of marginal and internal fit between the all-ceramic crowns manufactured by a conventional double-layer computer-aided design/computer-aided manufacturing (CAD/CAM) system and a single-layer system. Ten standardized crowns were fabricated from each of these two systems: conventional double-layer CAD/CAM system (Procera) and a single-layer system (Cerec 3D). The copings and completed crowns were seated on the abutments by a special device that facilitated uniform loading, and the marginal discrepancies were measured. Internal gaps were also measured using a low-viscosity silicone material. Marginal discrepancies of Procera copings were significantly smaller than those of Procera crowns and Cerec 3D crowns (p < 0.05), but Procera crowns and Cerec 3D crowns did not differ significantly from each other (p > 0.05). On internal gaps, Cerec 3D crowns showed significantly larger internal gaps than Procera copings and crowns (p < 0.05). Within the limitations of this study, the single-layer system demonstrated acceptable marginal and internal fit.
authors: Department of Prosthodontics, School of Dentistry, Kyungpook National University, 2-50 Samduk-dong, Jung-gu, Daegu 700-721, Korea.
authors: Kyu-Bok
authors: KB
authors: Lee
authors: Charn-Woon
authors: CW
authors: Park
authors: Kyo-Han
authors: KH
authors: Kim
authors: Tae-Yub
authors: TY
authors: Kwon
mesh_terms: D002516:Ceramics / Q000737:chemistry; D002858:Chromium Alloys / Q000737:chemistry; D017076:Computer-Aided Design; D003442:Crowns; D000044:Dental Abutments; D003722:Dental Alloys / Q000737:chemistry; D003760:Dental Impression Materials / Q000737:chemistry; D003776:Dental Porcelain / Q000737:chemistry*; D017267:Dental Prosthesis Design; D006801:Humans; D016876:Metal Ceramic Alloys / Q000737:chemistry; D003765:Models, Dental; D011145:Polyvinyls / Q000737:chemistry; D012828:Silicones / Q000737:chemistry; D012833:Siloxanes / Q000737:chemistry; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry; D019231:Tooth Preparation, Prosthodontic / Q000379:methods
chemical_list: D002858:Chromium Alloys; D003722:Dental Alloys; D003760:Dental Impression Materials; D016876:Metal Ceramic Alloys; D011145:Polyvinyls; C077451:Procera; D012828:Silicones; D012833:Siloxanes; C480691:aquasil; D003776:Dental Porcelain; C074543:Cerec; C036884:Rexillium III; D014025:Titanium