Caries risk assessment associated with 10-year outcomes of CAD/CAM all-ceramic restorations in endodontically treated teeth: a retrospective cohort study

Caries risk may affect the long-term performance of CAD/CAM all-ceramic restorations in endodontically treated teeth, yet its definitive association with long-term restorative outcomes remains unclear. This retrospective cohort study aimed to examine the relationship between caries risk assessment and 10-year restorative outcomes. This retrospective cohort study included 206 CAD/CAM all-ceramic restorations placed in 186 patients with endodontically treated teeth at the School & Hospital of Stomatology, Wuhan University between 2015 and 2016, all of whom completed a 10-year follow-up. Caries risk status at follow-up was assessed using the American Dental Association Caries Risk Assessment Tool. Two calibrated independent examiners evaluated restorations at follow-up; inter-examiner agreement was excellent (Cohen’s κ = 0.792). Associations between potential associated variables and restoration failure were analyzed using the chi-square test or logistic regression. A two-tailed P < 0.05 was considered statistically significant. The overall 10-year success rate was 85.92% (177/206). Success rates were 89.19% (33/37) in the low-risk group, 89.34% (109/122) in the moderate-risk group, and 74.47% (35/47) in the high-risk group. Among the 29 failed restorations, 34 failure events were recorded; secondary caries (13/34, 38.24%) and debonding/dislodgement (12/34, 35.29%) were the most frequent failure modes. High caries risk was significantly associated with poorer 10‑year restorative clinical outcomes compared with moderate caries risk. Age ≥ 65 years, frequent between-meal sugary intake, history of chemotherapy and/or radiotherapy, exposed root surfaces, and the presence of dental/orthodontic appliances were associated with failure. At the 10‑year recall visit, high caries‑risk status was associated with poorer clinical outcomes for CAD/CAM all‑ceramic restorations on endodontically treated teeth relative to moderate caries‑risk status. Secondary caries was the leading mode of failure. These findings suggest that caries risk status at recall is associated with restoration status and warrants further investigation in prospective studies using baseline risk assessment.