A Cheap Adjunct That Cut Post-Op Pain — Pilot RCT on Local Insulin

Local application of biomaterials alongside conventional periodontal surgery is an active area of research for boosting regenerative outcomes in intrabony defects. This pilot randomized controlled trial compared two candidate adjuncts — insulin and hyaluronic acid (HA) — each delivered via an absorbable collagen sponge (ACS), during single flap approach (SFA) surgery for periodontal intrabony defects. Twenty-one patients with periodontitis and intrabony defects were randomized into three groups of seven: SFA plus insulin plus ACS, SFA plus HA plus ACS, and SFA plus ACS alone as control. The primary outcome was clinical attachment level (CAL) at baseline and 6 months; secondary outcomes included probing pocket depth (PPD), postoperative pain (VAS at 24 and 48 hours), and radiographic linear defect depth and bone density.

All three groups showed significant improvement in PPD and CAL over the 6-month follow-up, with no significant differences between groups — meaning insulin and HA did not outperform the collagen sponge alone on these core periodontal measures in this small sample. Where the adjuncts did show an edge was postoperative comfort: VAS pain scores were significantly lower in both the insulin and HA groups than in controls at both 24 and 48 hours, with insulin producing the lowest pain scores. Radiographically, defect depth decreased significantly in all groups, with HA+ACS showing a somewhat greater reduction than insulin or control at 6 months; bone density increased significantly in the insulin and HA groups but not in the ACS-alone group.

The study is registered (NCT05746676) and clearly labeled as a pilot, and its small group sizes (n=7) limit how much weight the between-group comparisons can bear. Still, for clinicians looking for low-cost, accessible adjuncts to periodontal regenerative surgery, the signal is that local insulin — an inexpensive, widely available biomaterial — produced favorable clinical and radiographic changes and reduced postoperative pain, positioning it as a promising candidate worth testing in larger trials. HA remained the stronger radiographic performer on defect fill. Neither result should yet change standard practice, but both merit follow-up in adequately powered studies.