A Randomised Controlled Trial of Postoperative Sensitivity after Class II Restoration with Bulk-Fill vs Conventional Composites.

Introduction: Bulk-fill composites may simplify posterior restorations, saving time and reducing technical complexity. Post-operative sensitivity is a risk of posterior composites; bulk-fill composites could mitigate this. This single centre, double-blinded, parallel groups randomised controlled trial compared postoperative sensitivity following restoration of class II carious lesions with bulk-fill or conventional, layered composite.

Null hypothesis: there will be no difference in post-operative sensitivity between the two materials.

Methods: Participants requiring class II restoration of posterior teeth were randomised to bulk-fill (FU) (Coltene Fill-UpTM) or conventional, layered (BE) (Coltene Brilliant Everglow) composite. Allocation was concealed during cavity preparation. Only the operating dentist knew allocation. The outcome was 24 h post-operative sensitivity.

Results: 41 patients were randomised (20/group). Two patients from FU group were excluded from analysis (factors unrelated to intervention). There was no difference in postoperative sensitivity at 24 h nor any time point. Only participant age and baseline sensitivity scores significantly impacted post-operative sensitivity. One restoration debonded in FU group at 10 days, with no other adverse effects. No difference in time taken to place restorations was seen.

Conclusions: Within the study's limitations, post-operative sensitivity after class II posterior restorations was no different in bulk-fill restorations compared with conventional, incrementally cured composite.