WITHDRAWN: Comparative evaluation of internal and marginal fit of interim crowns fabricated by CAD/CAM milling and two different 3D printing systems - An in vitro study

Abstract

The aim of the present study is to compare and evaluate the internal and marginal fit of interim crowns fabricated by CAD/CAM milling and two different 3D printing systems. Fabrication of the metal master model was done by Selective Laser Melting Unit after preparing and scanning a typhodont tooth. A designing software was used to design crowns onto the metal master model after scanning it. The STL (Stereolithography) file of designed crowns is then sent to CAD/CAM milling machine and two different 3D printing systems namely Stereolithography (SLA) and digital light processing (DLP) for fabrication of 15 crowns each. Internal and marginal fit was measured with the help of silicon replica technique and obtained data was analysed with one way ANOVA which was followed by Tukey’s post-hoc analysis test for verifying the statistical significance. The smallest discrepancy of 96.7 μm was observed in DLP 3D Printing group followed by 131.1 μm in SLA 3D printing group and lastly CAD/CAM group stood with the discrepancy of 179.6 μm. A significant difference was seen for discrepancy values of the 3 groups and it was observed that DLP 3D Printing was able to manufacture crowns with better marginal and internal fit than SLA 3D Printing and SLA 3D Printing was better than CAD/CAM Milling group.