In-vitro study of the sliding-wear of CAD/CAM dental composite materials

Polymer-ceramic composites are widely employed in dental prostheses. However, due to low hardness values, their lifetime is often limited by wear. Here, the wear of commercially available dental CAD/CAM composites is explored through in-vitro tests involving extended sliding contact with a zirconia antagonist. The predominant wear mode is abrasion, with specific mechanisms including plastic deformation at the asperity level and microcracking. The extent of damage exhibits significant variability as a function of materials’ microstructure, resulting in wear volume differences of up to two orders of magnitude. The findings are analyzed within the framework of tribology and contact fracture mechanics. Strategies for enhancing durability are discussed, emphasizing potential microstructural engineering approaches—increasing hardness, improving particle-matrix adhesive strength, and optimizing particle aspect ratio.