Performance of posterior 3D printed resin-matrix ceramic crowns fabricated in a fully digital workflow: a two-year prospective clinical study.

OBJECTIVES: To evaluate the survival and success rates, as well as mechanical and biological outcomes of posterior 3D-printed resin-matrix ceramic crowns in a fully digital workflow over a 2-year follow-up. MATERIAL AND METHODS: A prospective clinical trial was conducting involving 30 posterior crowns fabricated from a resin-matrix ceramic using DLP 3D-printing technology. Dental preparations were performed and scanned with an intraoral scanner by a single operator. All crowns were cemented using the same dual-curing resin cement. Clinical performance was assessed using California Dental Association (CDA) criteria. Periodontal parameters (plaque index, gingival index and probing depth) were evaluated with a periodontal probe at cementation and at 6-month, 1-year, and 2-year recall appointments on abutment teeth and contralateral or antagonistic uncrowned natural teeth used as controls. Data were analyzed using Wilcoxon signed rank test and Kaplan–Meier survival analysis. RESULTS: The 2-year survival rate was 93%, and the success rate was 87%. Two crowns debonded, and no biological complications were observed. All crowns remained within the satisfactory range after 2 years. A slight yellow shift was detected in 4 crowns, resulting in a significant color change at 2 years (p = 0.046), while all other CDA parameters remained unchanged. The margin remained stable throughout the observation period. Plaque index increased after one year in the abutment and control teeth. CONCLUSIONS: Within the limitations of this study, including the absence of a control group, 3D-printed resin-matrix ceramic crowns may represent a viable alternative for posterior teeth. Long-term studies are required to confirm these results. CLINICAL RELEVANCE: Posterior 3D-printed resin–matrix ceramic crowns within a fully digital workflow demonstrated satisfactory performance after two years, supporting their potential as a viable option for posterior restorations.