Clinical Performance of Monolithic Lithium-disilicate Glass-Ceramic CAD/CAM Crowns

The clinical success of the monolithic Lithium-disilicate Glass-ceramic (LDGC) crowns manufactured with computer-aided design (CAD) / computer-aided manufacturing (CAM) technology provided by predoctoral students was not investigated. Thus, the purpose of this study was to evaluate the clinical performance of laboratory and chairside fabricated monolithic anterior and posterior LDGC CAD/CAM crowns performed by predoctoral students at the University of Toronto and the effect of different patient and provider-related factors on their longevity and to compare them to the metal-ceramic (MC) crowns. A sample of LDGC CAD/CAM crowns (IPS e.max, Ivoclar Vivadent) provided by predoctoral students was evaluated. Crown preparations were made according to the specific criteria and were milled in-house using the CEREC bluecam and Omnicam systems. Crowns were cemented with Rely-X Unicem (3M/ESPE) and Calibra Universal (Dentsply Sirona) resin cements. Clinical assessment of the crowns and supporting periodontal structures was performed following the modified California Dental Association (CDA) criteria. Intra-oral photographs, periapical and bitewing radiographs were taken for further assessment by two evaluators. Two-hundred and fifty-one patients with 275 crowns were examined with a follow-up period of up to 6 years. Part 1 evaluated the performance of laboratory-fabricated LDGC CAD/CAM crowns. Part 2 evaluated the performance of chairside LDGC CAD/CAM crowns. Forty crowns were evaluated. Part 3 evaluated the performance of LDGC CAD/CAM and MC crowns using split-mouth design. A total of 25 patients and 50 crowns (25 crowns for each group) were examined.