The Wear Behavior of Various Monolithic Ceramics after Wear Simulation against Human Enamel.

Abstract
Purpose: To evaluate and compare the surface roughness (SR), weight loss and volume loss of three monolithic ceramics; monolithic zirconia functional explore (f.explore), lithium disilicate glass ceramic (IPS.e. max CAD), and lithium silicate (Obsidian) and their wear effect on the natural enamel.
Materials and Methods Twenty four ceramic disc and twenty four natural tooth antagonist were used. Samples were divided according to ceramic materials into 3 groups (n=8). Group I: f.explore, Group II: Obsidian, and Group III: IPS e.max CAD. SR, weight loss and volume loss of the discs and the enamel were verified before and after exposing the specimens to chewing simulator. Digital and Scanning electron microscopic evaluations were used.
Results: The roughness differences changes between all groups was non-significant. While Obsidian antagonist cusp recorded the highest roughness followed by f.explore, whereas, e.max recorded least value. The greatest mean weight loss of materials was recorded in e. max followed by f.explore, where the lowest was recorded for Obsidian significantly.The greatest mean weight loss for antagonist cusp was recorded for f.explore followed by obsidian with insignificant difference ,while the lowest weight loss significantly was recorded in e.max antagonist cusp . The greatest mean volume loss of materials was recorded in e. max followed by f.explore where Obsidian recorded least value significantly. The greatest mean antagonist cusp volume loss was recorded in f.explore followed by e.max , whereas obsidian recorded least value.
Conclusions: Obsidian is more wear resistant than e.max and f.explore and produced the least wear in opposing enamel.