Marginal accuracy of lithium di-silicate monolithic veneers fabricated by different computer-aided design/computer-aided manufacturing systems

Abstract

Introduction The importance of precise marginal fit has been confirmed in many studies The increased marginal gap may lead to many unwanted side effects which affects fixed prosthodontics longevity and underling tooth integrity so several studies have investigated the effect of scanning and milling process of computer aided design/computer aided manufacturing (CAD/CAM) and its relation to the marginal adaptation of resulting restorations. Aim The aim of this in-vitro study was to evaluate the Marginal Accuracy of lithium di-silicate Monolithic Veneers when they are milled by Different CAD/CAM systems. Materials and methods A maxillary ready-made scannable model containing central incisor tooth with laminate veneer preparation was used to generate the design of the virtual master die and using CEREC in lab software the final design of the laminate veneer restoration was made and then was exported to the 2 tested milling machines MCX5 and Ceramill motion 2, the milled monolithic lithium di-silicate veneers was then cemented to their corresponding three-dimensional printed dies and was examined under Digital microscope for values of vertical marginal gap. Results There was statistically significant difference in marginal gaP values between the two studied groups (P < 0.05). Conclusion Veneers produced by both milling machines were with clinically acceptable marginal adaptation greater than 120 µm, However there was statistically significant difference in the vertical marginal gap values of the produced veneer between the two test groups CEREC MCX5 and Amangerbach Ceramill motion 2, with CEREC MCX5 milling machine having the advantage of milling veneer restoration with better marginal adaptation and less vertical marginal gap values.