Wear behaviour of lithography ceramic manufactured dental zirconia

ObjectiveThe study aims to evaluate the wear surface using 3D surface roughness and other material characterization of zirconia fabricated using photopolymerization based Lithography-based Ceramic Manufacturing (LCM).MethodLCM technology was used to fabricate zirconia specimens of size 10 x 10 x 2mm(3). Scanning Electron Microscope, 3D-profilometer, X-ray Diffraction, and hardness test characterized the samples before and after wear and Coefficient of friction (COF) was monitored.ResultThe COF was around 0.7 and did not differ much between the horizontally and vertically printed specimens. However, the surface roughness after wear for horizontally printed specimen was 0.567 +/- 0.139 mu m, while that for vertically printed specimen was 0.379 +/- 0.080 mu m. The reduced valley depth and the dale void volume were low for the vertically printed zirconia specimen, indicating lesser voids and low fluid retention. In addition, it was observed that the hardness value of the vertically printed sample was better. The scanning electron microscopic images and 3D surface profiles of the zirconia specimens depicted the surface topography and revealed the wear track.ConclusionThe study shows that zirconia fabricated using LCM technology possesses surface roughness of about 0.5 mu m with no machining scars that are usually associated with CAD/CAM dentistry and also indicating agreement with clinically acceptable values for minimal surface roughness of dental restorations. Dental restorations using LCM fabricated zirconia redues the requirement of post-processing work flow that is part of CAD/CAM dentistry.