A comparative study of sliding wear of nonmetallic dental restorative materials with emphasis on micromechanical wear mechanisms.

The purpose of this study is to investigate the in vitro tribological behavior of modern nonmetallic restorative materials. Specimen prepared of IPS e.max Press lithium disilicate glass ceramic, IPS Empress Esthetic leucite-reinforced glass ceramic, Everest ZS Blanks yttria-stabilized zirconia and Lava Ultimate composite were subjected to wear using a wear machine designed to simulate occlusal loads.

Interfacial shear strength of titanium implants in bone is significantly improved by surface topographies with high pit density and microroughness.

Surface structure of implants influences bone response and interfacial shear strength between implants and bone. The aim of this study was to find topographical parameters that correlate with the interfacial shear strength. Two groups of sand-blasted titanium screws were implanted in 17 sheep tibia, each for 2-52 weeks: (A) acid pickled with HF/HNO(3); (B) acid etched with HCl/H(2)SO(4).