Clinical Performance of Bioactive Bulk-Fill Composite vs. High Viscosity Glass Ionomer in Head and Neck Radiotherapy Patients: A Randomized Controlled Trial

Aim: Patients undergoing head and neck radiotherapy (HNRT) face increased risks of dental caries. Bioactive restorative materials offer potential advantages, but clinical evidence in this high-risk cohort is limited. This randomized controlled study evaluated and compared the 1-year clinical outcomes of a new bioactive bulk-fill resin composite and a high viscosity glass ionomer cement (HVGIC) used in restoring occlusal carious lesions in patients undergoing (HNRT). Materials and Methods: Twenty-eight adult patients scheduled for HNRT, each with at least one posterior tooth requiring an occlusal restoration, were randomized (one: 1) to receive either a bioactive bulk-fill composite (Predicta™ Bioactive Bulk, n = 14) or an HVGIC (EQUIA™ Fil, n = 14). Restorations were evaluated at baseline, 3, 6, and 12-month by a blinded assessor using modified United States Public Health Service (USPHS) criteria. Primary outcomes included secondary caries and marginal adaptation. Statistical analyses involved Chi-squared tests, Cochran’s Q test, Kaplan-Meier survival analysis with log-rank test, and logistic regression ( P ≤ 0.05). (Trial registered: NCT05332041). Results: All 28 participants completed the 12-month follow-up. No statistically significant differences were observed between the Predicta™ Bioactive Bulk and EQUIA™ Fil groups for any of the modified USPHS criteria at any evaluation point ( P > 0.05). At 12-month, no secondary caries occurred in either group. For marginal adaptation, 92.9% of restorations in both groups scored alpha. For anatomic form, 100% of Predicta™ restorations scored alpha, versus 85.7% for EQUIA™ Fil ( P = 0.1495). Overall, restoration survival rates were high and not significantly different (Predicta: 92.8% alpha overall, EQUIA™ Fil: 85.7% Alpha overall; P = 0.5485 by log-rank test for any Bravo score as event). Conclusion: Within the 12-month evaluation period, both the bioactive bulk-fill composite (Predicta™ Bioactive Bulk) and the high viscosity glass ionomer (EQUIA™ Fil) demonstrated acceptable clinical performance for restoring occlusal carious lesions in patients undergoing HNRT. While Predicta™ Bioactive Bulk showed a non-significant trend toward better maintenance of anatomic form, neither material proved clinically superior overall in this challenging oral environment.