ABSTRACT
PURPOSE: The aim of this study was to compare the precision of optical impression (Trios, 3Shape) versus that of conventional impression (Imprint IV, 3M-ESPE) with three different margins (shoulder, chamfer, and knife-edge) on Frasaco teeth. MATERIALS AND METHODS: The sample comprised of 60 zirconia half-crowns, divided into six groups according to the type of impression and margin. Scanning electron microscopy enabled us to analyze the gap between the zirconia crowns and the Frasaco teeth, using ImageJ software, based on eight reproducible and standardized measuring points. RESULTS: No statistically significant difference was found between conventional impressions and optical impressions, except for two of the eight points. A statistically significant difference was observed between the three margin types; the chamfer and knife-edge finishing lines appeared to offer better adaptation results than the shoulder margin. CONCLUSION: Zirconia crowns created from optical impression and those created from conventional impression present similar adaptation. While offering identical results, the former have many advantages. In view of our findings, we believe the chamfer margin should be favored.
Subject(s)
Crowns , In Vitro Techniques , Microscopy, Electron, Scanning , Shoulder , ToothABSTRACT
Objective@#To explore the influence of different cement spaces on the marginal adaptation of CAD/CAM zirconia inlay.@*Methods@#30 teeth extracted for orthodontic purpose were selected and divided into 3 groups (Group A 10 μm, Group B 30 μm, Group C 50 μm). The marginal spaces of inlays were recorded by the light-body Silicone impression material, and measured by microscope. The data were analyzed by SPSS 13.0.@*Results @# All the inlays fitted very well and all the marginal spaces were less than 120 μm. The shoulder of Group A was statistically lower than Group B and Group C (P < 0.05). The axial surface of Group B was statistically lower than Group C (P < 0.05).@*Conclusions @#CEREC zirconia inlay is satisfactory when the cement space is between 10-50 μm.