Comparison of Vertical Marginal Fitness of Zirconia Overlay Fabricated Using Conventional and Two Digital Impression Technology: An In Vitro Study

Introduction: We aimed to compare the vertical marginal fitness measurement of indirect zirconia overlay restorations fabricated using conventional and two types of digital impression technologies. Methods: Thirty sound upper first premolar teeth were divided into three main groups ( n = 10) according to the type of impression method: group A impressions were taken using addition silicone; group B digital impressions were obtained using the Medit i700 digital scanner; and group C impressions were taken using Primescan scanner. After the indirect restorations were completed, the marginal fitness was assessed using a digital microscope at 200× and the Image J program, both before and after cementation. Results: There were statistically significant differences in vertical marginal fitness among the different impression methods ( P < 0.001) and before and after cementation ( P < 0.001). Nonsignificant differences were found among different tooth surfaces. Post hoc pairwise comparisons showed a significant difference among the three impression methods ( P < 0.001). Conclusion: The marginal gap instead of marginal fitness of indirect restorations fabricated using digital impressions was smaller than that of restorations fabricated using conventional impressions. The marginal fitness for overlays fabricated using the Primescan scanner was lower than that of overlays fabricated using the Medit i700 intraoral scanner.