Influence of different glaze firing protocols on the surface roughness of CAD/CAM ceramic blocks before and after simulated brushing

Abstract

The CAD/CAM system used in dentistry allows for indirect restorations, in a short period of time, to be cemented in the same clinical session, without the intermediation of the prosthesis laboratory. Ceramics is an option that meets the aesthetic, biological, mechanical and functional requirements of restorative material and today there is a wide variety of CAD/CAM ceramic blocks with different properties, composition, and indications. To ensure long-term aesthetics, surface roughness is a factor to be considered, as rough surfaces are more prone to food retention, favoring biofilm formation. Whatever material is used in a restoration, it is subject to wear and tear by various factors such as chewing and daily brushing. The objective of this study is to evaluate the effect of different glaze firing protocols (conventional and extended) on surface roughness (Ra) of CAD/CAM restorative materials, before and after simulated brushing. The following materials will be used: Feldspar Ceramics (Cerec Blocs, Dentsply Sirona); Leucite-reinforced feldspar ceramic (IPS Empress CAD, Ivoclar Vivadent); Ceramic Lithium disilicate (IPS e-max CAD, Ivoclar Vivadent). The specimens will be submitted to different glaze protocols: conventional (G) - application following the manufacturer's recommendations; extended (E) - extended glaze protocol; control (C) - no glaze. Surface roughness will be obtained before and after simulated brushing by means of contact roughness. The obtained data will be submitted to the appropriate statistical tests depending on their distribution. (AU)