“In Vitro Investigation of CAD/CAM Ceramic and Hybrid Composite Materials in Simulated Parafunctional Activity”

Abstract

This in-vitro study was designed to test the wear of restorative materials against enamel in wear simulation of dental bruxism. The aim of this study was to evaluate the amount of wear generated from the use of recent CAD/CAM materials in wear simulation of parafanctional habits. Both the antagonist and sample wear were analysed. Samples were prepared and embedded in cold curing acrylic resin. Antagonists were made of natural human enamel, prepared from premolar teeth with the use of specially designed diamond bur for standardisation. Samples and antagonists were subjected to microhardness testing, optical coherent tomography and flatness tolerance testing using a laser profilometer. Bose Enduratec Electroforce wear testing machine was used in our study to simulate chewing under different loads. Two loads were used 80N and 120N with the higher load simulating parafunctional bruxing load. The study samples were divided into eight groups where four groups were subjected to attrition only under the two loads and the other four groups were subjected to erosive wear using Citric acid at the 80N load and Hydrochloric acid at 120N load, representing extrinsic and intrinsic acids respectively. True Defintion 3M ESPE intraoral scanner was used to scan the wear scar, after powdering with Titanium Oxide, which were then exported to Geomagic® software for superimposition and then surface metrology software Mountains Map® for step height analysis. Data was calculated, tabulated and analysed. Statistical analysis was done using Kolmogorov-Smirnov and Shapiro-Wilk tests to assess data normality