Surface roughness of monolithic ceramic and ceramic-like CAD/CAM materials.

The aim of this study was to compare surface roughness of three different types of chairside monolithic ceramic and ceramic-like CAD/CAM restorative materials finished and polished with two)stage diamond impregnated polishing disc systems. before- and after- clinician experience. For each test material such as: glass ceramic (VITA Mark II, VITA-Zahnfabric, Bad Sackingen, Germany), polymer infiltrated ceramic (VITA Enamic, VITA-Zahnfabric, Bad Sackingen, Germany), nano hybrid ceramic (Lava Ultimate, 3M-ESPE, Seefeld, Germany), 20 disc shaped specimens (radius=10mm, thickness=2mm) were prepared. Then each test groups were subdivided into two groups depending on operator’s experience. Finishing and polishing procedure was achieved before (n=10) and after (n=10) experience of operator, respectively. Average surface roughness (Ra) measurement were obtained using a surface profilometer. For each test group ten specimens were prepared and roughness was measured in five different positions using a profilometer with a traversing distance of 4 mm and a cut-off value of 0.8mm. The radius of the tracing diamond tip was 5µm and measuring force and speed was 4mN and 0.5 mm/s, respectively. The surface roughness of each individual disk was taken as the arithmetic mean of the Ra values measured in five different positions. It can be concluded that finishing and polishing of ceramic and ceramic-like CAD/CAM restorative materials are dependent both material structure and experience of operator. [ABSTRACT FROM AUTHOR]