In-Vitro Wear Analysis of Current Chairside CAD/CAM Materials

Objectives: The advancement of CAD/CAM materials has revolutionized esthetic and functional dentistry. Monolithic materials in particular have become established in chairside technologies, but data on their long-term wear behavior is limited. The aim of this study was therefore to evaluate the wear behavior of current CAD/CAM materials under long-term conditions.
Methods: Six materials, including polymer-infiltrated ceramic networks (PICN, VITA ENAMIC [VE]), lithium disilicate glass-ceramics (CEREC Tessera [CT], IPS e.max CAD, [IE]), nanohybrid composite (Grandio blocs, [GB]), hybrid resin (Varseo Smile Crown plus, [VC]) and PMMA (Telio CAD, [TC]), were each used to fabricate eight identical single-tooth crowns for a standardized prepared tooth stump 16 using CAD/CAM. After final cementation, the specimens were digitized using ATOS III Triple Scan (GOM GmbH). In a CS-4.2-chewing simulator (SD Mechatronik GmbH), 2.4 million chewing movements were performed to simulate a 10-year clinical load, followed by further digitization of the test objects. Surface changes were quantified and visualized after virtual superimposition of the corresponding data sets before and after chewing simulation using Atos Professional 2018 software (GOM GmbH).
Statistical analyses were performed applying the Kruskal-Wallis test and pairwise Mann-Whitney U tests, using Benjamini-Hochberg corrected p-values with a significance level of 0.05.
Results: TC exhibited the highest mean material loss (-0.191mm), while VE demonstrated the lowest wear (-0.106mm), followed by CT (-0,122mm), GB (-0.127mm), IE (-0.131mm) and VC (-0.159mm). Statistically significant differences were observed for TC in comparison to all other materials, except for VC (p ≤ 0,031).
Conclusions: PICN materials achieve the highest wear resistance, which is an advantage for single-tooth restorations.
Lithium disilicate glass-ceramics and composites offer high wear resistance and are suitable for long-term, high-load restorations.
PMMA and printed materials exhibit higher abrasion values and should be limited to temporary restorations.
The variability of the results highlights the clinical importance of wear resistance as a key factor in material selection, which should be adapted to individual mechanical and esthetic requirements.