11 June 2023

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Dental erosion and ultrathin CAD-CAM glass-ceramic and composite resin occlusal veneers

By Lorenzo Breschi and Diego D’Urso

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Thanks to modern technology, an alternative to traditional onlays and complete coverage crowns for dental erosion exists in ultrathin bonded posterior occlusal veneers (OVs). In June 2022, Schlichting et al. conducted a randomized clinical trial to evaluate the influence of computer-aided design and computer-aided manufacturing (CAD-CAM) restorative materials on the clinical performance of ultrathin occlusal veneers bonded to worn posterior teeth.

Materials and methods 

Eleven participants with worn dentition were included in the study. 

The following materials were used for the fabrication of the OVs: lithium disilicate ceramic (e.max CAD; n=24) and composite resin (Lava Ultimate; n=36). The teeth were selectively reduced with tapered diamond rotary instruments. 

An average occlusal clearance of 0.4 to 0.6 mm (central groove) to 1.0 to 1.3 mm (cusp tips) was generated for the ultrathin OVs. Under dental dam, all areas of exposed dentin were immediately sealed using a 3-step etch-and-rinse dentin bonding system and a temporary restoration was placed. 

The diagnostic waxing and the prepared teeth were scanned. Tooth preparations were airborne particle abraded and etched for 30 seconds with 37.5% phosphoric acid, rinsed and air-dried. Adhesive resin was applied to restoration and tooth, left unpolymerized and protected from direct light. The luting material was preheated to 68 °C and applied to the tooth and then the OVs were seated. Minimal or no occlusal adjustments were necessary. Researchers used the United States Public Health Service (USPHS) criteria for the evaluation at baseline and over a period of three years. 

Results

After the follow-up period, no failures were identified among groups, with no differences between the restorative materials. Only composite resin showed chipping of the restorations and higher incidence of surface degradation was observed when compared to the ceramic group. The chipping of the resin composite OVs was easily repaired, and the survival of the restorations was guaranteed until the end of the follow-up. 

Conclusions 

The findings of this medium-term clinical trial suggest favorable performance of ultra-thin bonded OVs. Researchers did not detect differences in survival rate between ceramic and resin composite restorations. 

Schlichting LH, Resende TH, Reis KR, Raybolt Dos Santos A, Correa IC, Magne P. "Ultrathin CAD-CAM glass-ceramic and composite resin occlusal veneers for the treatment of severe dental erosion: An up to 3-year randomized clinical trial." J Prosthet Dent. 2022 Aug;128(2): 158.e1-158.e12. Epub 2022 Jun 21. PMID: 35750501.