Evaluation of marginal fit and internal adaptation of zirconia copings fabricated by two CAD - CAM systems: An in vitro study

Abstract

Statement of Problem:Three main factors which determine the success of an All-ceramic restoration are esthetic value, resistance to fracture and third being the marginal fit. Marginal fit and internal adaptation are crucial factors in increasing the longevity of the restoration. Newer and economical CAD CAM systems have been introduced claiming better marginal fit and adaptation of All ceramic crowns. CAD CAM systems involves scanning of the die or the tooth preparation and milling of the restoration, which may have variations among the systems available.Aim of the Study:Our study intended to check the marginal fit and internal adaptation of commonly used CAD CAM systems namely CERAMILL and CEREC -In Lab MC XL.Materials and Methods:Two groups of typodont teeth (n = 10) were prepared using a standardized protocol to receive All ceramic copings. 10 samples of Group A were used for fabrication of copings using CERAMILL system and 10 samples of Group B were used for fabrication of copings using CEREC -In Lab MC XL system. They were then luted with glass ionomer cement under mild finger pressure. Samples were embedded in resin and sliced longitudinally. They were then viewed under stereomicroscope and readings were measured along 15 points using ImageScope software. The P value was set at 0.05 at 95% confidence interval with 80% power. The data were checked for normality and unpaired t-test was used to evaluate the results of the two groups.Results:The overall internal adaptation was 61.5 ± 5.2 μm for CERAMILL and 56.9 ± 5.7 μm for CEREC -In Lab MC XL (P < 0.05). The marginal fit for CERAMILL was 83 μm and for CEREC -In Lab MC XL was 68 μm (P < 0.05).Conclusion:The marginal adaptation of CEREC -In Lab MC XL (68 μm) was found to be superior to CERAMILL (83 μm) (P < 0.05). Both the CEREC -In Lab MC XL and CERAMILL copings demonstrated internal adaptation and marginal fit within acceptable discrepancy range. When corroborating both the internal adaptation and marginal fit, CEREC -In Lab MC XL was found to be better than CERAMILL.

An in vitro evaluation of marginal fit zirconia crowns fabricated by a CAD-CAM dental laboratory and a milling center

“…However, this study made use of an Etkon milling center and a traditional silicone impression technique rather than an intraoral scanner. Studies that compared marginal fit of zirconia coping found that the CEREC inLAB system showed smaller MD values compared to other CAD-CAM systems [15, 16, 22]. Rajan et al compared the marginal fit of zirconia coping produced by CEREC inLAB with that of the CERAMILL system and found significant differences, whereby CEREC inLAB copings had better adaptation than CERAMILL.…”

“…Rajan et al compared the marginal fit of zirconia coping produced by CEREC inLAB with that of the CERAMILL system and found significant differences, whereby CEREC inLAB copings had better adaptation than CERAMILL. For both CAD-CAM systems, a digital scanner was used [22]. Marginal fit for CERAMILL was 83 μm and for the CEREC InLAB MC XL was 68 μm [22].…”

“…For both CAD-CAM systems, a digital scanner was used [22]. Marginal fit for CERAMILL was 83 μm and for the CEREC InLAB MC XL was 68 μm [22]. Saab et al compared marginal fit of zirconia coping with four different CAD-CAM systems: CEREC inLAB, CERCON, CERAMILL, and LAVA milling unit.…”

“…Studies that have compared the marginal fit of zirconia copings to other ceramic restorations show higher accuracy for zirconia [20]. The marginal fit of zirconia copings produced using different CAD-CAM system has also been investigated [15, 16, 21, 22]. The marginal fit of monolithic zirconia crown was studied with regard to different preparation designs and sintering techniques [17, 18].…”

Accuracy and reproducibility of 3D digital tooth preparations made by gypsum materials of various colors

“…However, in view of the fact that the experimental procedure was the only part of all the production process for actual restoration, these resultant data only reflected the degree of deviation between virtual reference object and prepared tooth test datasets in this study. Thus, the methodology of this study was different from many previous literatures, 23 24 25 26 27 28 which described the adaptation of prostheses was the gaps between the real restoration and the abutment tooth.…”