Surface Characterization of Current Dental Ceramics Using Scanning Electron Microscopic and Atomic Force Microscopic Techniques

Abstract

Dental ceramics is a highly esthetic material and its surface properties can impact its roughness, bonding properties, as well as strength and wear. The aim of the study is to analyze the surface characteristics by the determination of the roughness parameters of three dental ceramics used in computer-aided design/computer-aided manufacturing (CAD/CAM) technique: lithium disilicate (LS2), zirconium oxide-reinforced lithium silicate (ZLS), and zirconium oxide (ZrO2), prepared using two different processing techniques, polishing (self-glaze) and glazing with three different glazes. Both glass ceramics, pre-crystallized LS2 and crystallized ZLS, were cut into disks, and the surface was ground and polished. Crystallization was performed for LS2 samples, while ZrO2 samples were fabricated using CAD/CAM and sintered. Then, the glaze was applied and the samples were reheated as per the manufacturer’s instructions. The contact surface topographies of the tested ceramics were measured by atomic force microscopy (AFM) and the roughness parameters: average surface roughness (Ra), root-mean-square roughness (Rq), and surface area difference (SAD) were evaluated. Changes in the morphological characteristics of the tested ceramics were examined by scanning electron microscopy (SEM), and the surface chemical composition was determined by attenuated total reflection Fourier-transform infrared spectroscopy (FT—IR). In the spectroscopic analysis, a characteristic signal for ZrO2 was obtained for ZLS samples. A significant decrease in surface roughness was observed after glazing in all tested ceramics (p < 0.05). The abstract should be an objective representation of the article and it must not contain results that are not presented and substantiated in the main text and should not exaggerate the main conclusions.