Comparative evaluation of internal fit and marginal fit of zirconia copings obtained from impression and die fabricated using cad-cam an in vitro study

Abstract

Aims: To evaluate and compare the internal fit and marginal fit of zirconia copings fabricated using CAD-CAM from impressions and model. Material and Methods: Using a standardized die, 15 impressions group 1and 15 models group 2 were made with standardized protocol. All impressions and models were scanned and virtual models were made. Using the CAD data, zirconia copings were fabricated and cemented using silicone under finger pressure and standardized sections of the silicone were made and thicknesses were measured at eleven specific points under stereomicroscope. Statistical analysis used: ANOVA Results: Mean Internal gap value of Group 1was 292.4µ ± 23.48 and Group 2 was 258.54 µ ± 22.83 µ, Mean Marginal Gap value of group1 was 252.64µ ± 11.86 µ and group2 was 232.18 µ ± 06.24 µ, ANOVA test showed statistical significance with p value >0.05 Conclusions: Within the limitations of the study, mean marginal gaps of both the groups were within clinically acceptable range. Group 2 copings demonstrated comparatively smaller values. Hence fit of the restoration is better in Group 2 (copings fabricated from scanned models).