Wear Behavior of Ceramic CAD/CAM Crowns and Natural Antagonists

Abstract

Objective: Evaluation of wear behavior of computer-aided design/computer-aided manufacturing (CAD/CAM) crowns from various restorative materials and natural antagonists. Method: Full CAD/CAM crowns fabricated with nanoceramic resin (Lava Ultimate (LU)), a glass ceramic in a resin interpenetrating matrix (Vita Enamic (VE)) and a lithium silicate reinforced ceramic enriched with zirconia (Vita Suprinity (VS)) were cemented on human molars. The crown and antagonists were subjected to simulated chewing. 3D data sets, before and after the chewing simulation, were generated and matched. Occlusal surface roughness, vertical and volume loss of the crowns and antagonists were analyzed. Results: Crown roughness was significantly different between the LU and VE groups after chewing simulation. Crown vertical loss differed in all groups. The highest crown volume loss was found in the LU group, and the lowest in the VE group. Comparisons between the LU and VE groups and the LU and VS groups were significantly different. The highest antagonist volume loss was reached in the VE group, the lowest was in the LU group. Conclusion: Roughness increased after chewing simulation. LU crowns are the most natural antagonist-friendly; these were the most susceptible to vertical and volume loss. Of the tested materials, the VE crowns are the most stable regarding occlusion.

Effect of different storage media on the microhardness and wear resistance of resin‐matrix ceramics

“…When the effects of storage media on wear were examined, the present study found none of the tested materials to show any significant differences in two‐body wear rates following storage in different media. Because previous studies evaluating wear resistance and other mechanical properties of resin‐matrix ceramic materials were conducted with only one type of storage media, no comparisons can be made regarding the effects of different storage media on the wear of resin‐matrix ceramics. While both Lava Ultimate and Paradigm MZ100 have been shown to be susceptible to roughening under acidic conditions due to the hydrolysis of the methacrylate ester bonds in their polymer matrixes, whether there is a direct correlation between the surface roughness and wear rates of these materials has yet to be investigated.…”

Reinforced Glass-ceramics: Parametric Inspection of Three-Dimensional Wear and Volumetric Loss after Chewing Simulation

“…1A) and superimposed ( Fig. 1B) from the baseline using a 3D digital parametric inspection software (GOM Inspect, Braunschweig, Germany) (9). This software generated a colorimetric map of each specimen and then aligned the models to detect the geometric changes that illustrate the wear caused by the antagonist (Fig.…”

“…A methodology that simulates a longitudinal evaluation is the wear resistance of restorative materials (9,10). A material with good resistance to wear will not modify the patient's vertical dimension, nor the restoration shape and its consequent aesthetics.…”

“…Moreover, the parametric inspection of the scanning files before and after the wear simulation can enable verifying the volume loss and the depth of the generated defects. In the proposed method, the specimen is verified as a whole and not just a single area, as in the case of the analysis by profilometry or surface roughness (9).…”

Effects of polishing vs. glazing on dental ceramic wear: A comparative in vitro study

“…Dental wear is a complex process that results in irregular loading on the occlusal surface, loss of the tooth surface substance, and changes in masticatory functions. Many factors influence the surface roughness and wear of the restorative materials and the antagonist tooth, including the quality of the finishing and the polishing or glazing of the occlusal surface of the dental ceramic [5]. Finishing and polishing techniques have been identified that create surfaces comparable to or better than those of glazed porcelain [14].…”