The impact of different milling machines on marginal fit discrepancies of lithium disilicate crowns

Abstract

The goal of this study was to determine the level of various discrepancies in all-ceramic IPS e. max - lithium disilicated crowns milled with three different milling machines. A 3D printed Geller model with a preparation for all ceramic crown was scanned, then the digital design was created and 24 lithium disilicate crowns were milled using three different milling machines: Plan mill 40S (Planmeca, Helsinki, Finland), Cerec MC XL (Sirona GmbH, Germany), and one laboratory milling machine Imes-Icore 650i (Coritec, Eiterfeld, Germany). Among the three groups, the highest marginal fit accuracy was displayed by crowns fabricated by laboratory milling machine Imes-Icore 650i, followed by chairside Plan mill 40S and Cerec MC XL. The results of our study shows that llithium disilicate crowns fabricated by a laboratory milling and 2 chair-side milling machines present marginal accuracy in the acceptable clinical range.