title: Marginal and internal fit of all-ceramic CAD/CAM crown-copings on chamfer preparations.
abstract: Evaluation of the marginal and internal fit of all-ceramic molar crown-copings hypothesizing that Computer Aided Design/Computer Aided Manufacturing (CAD/CAM) fabrication shows the same accuracy of fit as conventional techniques. A set of six individual crown preparations was duplicated 12 times yielding 72 plaster dies. Slip-cast (In-Ceram Zirconia), heat-pressing (Empress II) and CAD/CAM crown-copings (Cerec inLab, DCS, Decim and Procera) were seated on 12 dies each. Marginal and internal gap width was measured in the SEM at 120x magnification. Marginal gap of slip-cast (25 +/- 18 microm) was significantly (P < 0.05) smaller than that of Empress II (44 +/- 23 microm) copings. Procera (17 +/- 16 microm) and Decim (23 +/- 17 microm) did not differ (P > 0.05) from slip-cast (25 +/- 18 microm) but were smaller (P < 0.001/P < 0.01) than Empress II (44 +/- 23 microm) and Cerec inLab (43 +/- 23 microm) (P < 0.001/P < 0.05). DCS (33 +/- 20 microm) did not differ (P > 0.05) from any of the others. The internal mid-orobuccal gap width of Procera (136 +/- 68 microm) was larger (P < 0.001) than that of Decim (81 +/- 30 microm) and slip-cast (94 +/- 84 microm) (P < 0.05) while Empress II (105 +/- 53 microm), DCS (110 +/- 79 microm) and Cerec inLab (114 +/- 58 microm) did not differ significantly (P > 0.05) from Decim, Procera and slip-cast. Internal mesiodistal gap width was similar. The fit of conventional and CAD/CAM all-ceramic molar crown-copings covered the same range of gap width confirming the assumed hypothesis.
authors.affiliation: Division of Aesthetic and Computer Restorations, Department of Preventive Dentistry, Periodontology and Cariology, Center for Dental and Oral Medicine, University of Zurich, Zurich, Switzerland. andreas.bindl@zzmk.unizh.ch
authors.forename: A
authors.initials: A
authors.lastname: Bindl
authors.forename: W H
authors.initials: WH
authors.lastname: Mörmann
mesh_terms: D002516:Ceramics; D017076:Computer-Aided Design; D003442:Crowns; D018772:Dental Marginal Adaptation; D003776:Dental Porcelain; D017267:Dental Prosthesis Design; D006801:Humans; D016876:Metal Ceramic Alloys; D008855:Microscopy, Electron, Scanning; D014025:Titanium
chemical_list: D016876:Metal Ceramic Alloys; C077451:Procera; D003776:Dental Porcelain; C074543:Cerec; D014025:Titanium