Abstract
OBJECTIVE: Bi-layer zirconia-based posterior fixed dental prostheses (FDPs) have reportedly a high incidence of veneering ceramic fractures. The CADon technique employs zirconia frameworks veneered with milled lithium disilicate glass-ceramic to overcome these shortcomings but long-term clinical studies are missing. This study evaluated the clinical efficacy of posterior 3-unit CADOn FDPs over a 5-year period. MATERIALS AND METHODS: A total of 25 patients, 16 male and 9 female with a mean age of 55.6 years, received a total of 25 posterior three-unit CADOn FDPs. Patients were recalled for baseline and for follow-up visits at 6, 12, 24, and 60 months. Parameters evaluated were fracture, marginal adaptation, marginal discoloration, wear, polish, color match, surface staining, and retention of these restorations as well as secondary caries of the abutment teeth. RESULTS: A total of 21 FDPs evaluated at 60-months revealed a 100% survival rate. All evaluated clinical parameters were satisfactory (alpha or bravo) and there was no statistically significant difference at different time points, except for surface staining, which was also worse at 60 months compared to baseline (p ≤ 0.001). CONCLUSIONS: CADOn three-unit posterior FDPs demonstrate excellent fracture resistance after 5 years of clinical function. All evaluated clinical parameters were satisfactory, except for surface stain, which also increased over time. CLINICAL SIGNIFICANCE: Conventionally veneered bi-layer zirconia-based posterior FDPs have limited clinical success. Based on this study, alternative methods such as zirconia frameworks veneered with milled lithium disilicate glass-ceramic provide a viable alternative with excellent long-term clinical outcomes.