Clinical performance of chairside monolithic lithium disilicate glass‐ceramic CAD‐CAM crowns

Abstract

Objectives To evaluate the clinical performance and the effect of various patient and provider‐related factors on the longevity of chairside monolithic posterior lithium disilicate glass‐ceramic (LDGC) computer‐aided design (CAD)‐computer‐aided manufacturing (CAM) crowns provided by predoctoral students. Materials and Methods A sample of posterior LDGC CAD‐CAM crowns was evaluated. Crown preparations were milled chairside using the CEREC Omnicam system and cemented with Rely‐X Unicem or Calibra Universal resin cements. Clinical assessment of the crowns and supporting periodontal structures was performed using the modified California Dental Association (CDA) criteria. Intraoral photographs as well as radiographs were taken for further assessment by two evaluators. Kaplan‐Meier survival analysis was performed. Results A total of 40 crowns were inserted in 32 patients and evaluated for 4 years. Three complications were observed (two‐technical and one‐biological). No chipping or fracture of crowns was observed. No significant association was found between age, sex, periodontal condition, tooth type, tooth vitality, cement type, and longevity. The 4‐year cumulative survival and success rates were 95.0 and 92.3%, respectively. Conclusion Chairside LDGC CAD‐CAM crowns exhibited a high survival rate after 4 years in function and were shown to be a viable and reliable treatment option for posterior teeth. Clinical significance The high survival rate of chairside CAD‐CAM crowns observed in this study suggests the likelihood of predictable performance in the predoctoral setup.

Resistance to Fracture of Lithium Disilicate Feldspathic Restorations Manufactured Using a CAD/CAM System and Crystallized with Different Thermal Units and Programs

“…In this study, the resistance values of the three groups of crowns were within the established ranges required in international standards for single restorations, agreeing with the statement that they can be used even in posterior sectors [27,28]. Likewise, with these antecedents, the clinical success of restorations made with this material could be substantiated [29]. Specimens in the form of anatomical crowns with a thickness of at least 1.84 mm, could withstand the initial load of the cell used, depending on an adaptation of tests used to measure fracture toughness, and this could be recommended as the ideal thickness [30].…”

Marginal and internal fit of full ceramic crowns milled using CADCAM systems on cadaver full arch scans

“…Restoration longevity is not compromised with marginal gaps up to 120 μm for conventional restorations luted by polycarboxylate cement [42] and the marginal gaps above 200 μm for CADCAM or heatpressed all-ceramic crowns cemented by adhesive technique [43]. Notwithstanding the lack of direct evidence for a relationship between the marginal gap and restoration longevity, the CADCAM restorations had good clinical success [43][44][45]. Therefore, some authors [2,46] question the necessity of the cement film thickness is less than 120 μm.…”

Is the bond strength of zirconia-reinforced lithium silicate lower than that of lithium disilicate? - A systematic review and meta-analysis

“…Currently, chairside restorations are fabricated in a monolithic manner using glass ceramics [4], mainly lithium disilicate (LD). LD has been widely used for anterior and posterior single-unit restorations because of its excellent esthetic and physical properties [5][6][7][8]. However, to date, no clinical evidence has presented satisfactory long-term outcomes when LD is used for fixed dental prostheses (FDPs) [9].…”