48-month clinical performance of an Alkasite restorative material versus resin composite in class II restorations: a randomized controlled trial

Objectives: To evaluate the 4-year clinical performance of an alkasite restorative material (Cention N) compared with a posterior resin composite in Class II restorations. Methods: In this randomized, split mouth, double-blind clinical trial, 31 patients received 100 Class II restorations (n = 50 per group). Cavities were restored either with Cention N or with a posterior resin composite (G-ænial Posterior) applied using an universal adhesive with etch-and-rinse mode. Clinical evaluations were performed at baseline, 6, 12, 36 and 48 months according to modified USPHS criteria. Intergroup comparisons were conducted using chi-square tests. Changes over time were assessed using Cochran's Q and McNemar tests. Kaplan–Meier survival analysis was performed (95% CI: 0.434–5.455) (α = 0.05). Results: At 48 months, recall rate was 58% which may be considered relatively low. No statistically significant differences were observed between the materials in terms of marginal adaptation (p = 0.880), marginal discoloration (p = 0.526), surface texture (p = 0.175), color match (p > 0.05), postoperative sensitivity, or secondary caries incidence. Kaplan–Meier analysis showed comparable survival rates (83.6% for Cention N and 88.4% for resin composite; log-rank p = 0.49). Minor deterioration over time occurred in both groups in terms of marginal adaptation, marginal discoloration and surface texture. Conclusions: Cention N demonstrated clinical performance and survival comparable to the posterior resin composite used in Class II restorations. Clinical significance: Cention N may represent a clinically acceptable, simplified restorative alternative for posterior applications, showing mid-term outcomes comparable to a posterior composite resin. © 2026 Elsevier Ltd