Long-term success and influencing factors of regenerative surgery for intra-bony defects: A retrospective cohort study.

Background: The composite outcome measure (COM) more comprehensively assesses the clinical efficacy of regenerative surgery than a single probing measurement. We aimed to assess long-term success defined by the COM (clinical attachment level [CAL] gain of ≥3 mm and postsurgery probing pocket depth [PPD] ≤ 4 mm) and influencing factors of regenerative surgery using bone substitutes and resorbable collagen membrane (RM) for intra-bony defects (IBDs).

Methods: We retrospectively collected data from patients who underwent regenerative surgery using deproteinized bovine bone mineral (DBBM) and RM for IBDs. CAL and PPD values were compared at baseline (preoperative), 1 year (short-term), and at the last follow-up (5-10 years). Multivariate logistic regressions were performed to identify factors influencing COM-based long-term success.

Results: Eighty-one defects in 75 teeth of 33 patients who completed follow-up (6.5 ± 1.4 years) were included. One tooth was lost. All defects with complete follow-up exhibited long-term average CAL gain (3.00 ± 2.00 mm, 95% confidence interval [CI]: 2.56-3.44 mm, p < 0.001) and PPD reduction (2.06 ± 1.91 mm, 95% CI: 1.64-2.49 mm, p < 0.001). Long-term success was achieved in 38.8% of IBDs. CAL and PPD values were comparable between 1 year and the last follow-up. Logistic regression analyses revealed that male sex (odds ratio [OR] = 0.23, 95% CI: 0.07-0.75) and bleeding on probing (BOP) during supportive periodontal therapy (OR = 0.96, 95% CI: 0.94-0.99) were risk factors for long-term success.

Conclusions: Regenerative surgery with DBBM and RM for IBDs can achieve some degree of long-term success defined by COM. However, within this study's limitations, male sex and higher BOP incidence postoperatively are negatively associated with optimal long-term success.

Clinical Trial Number: ChiCTR2300069016.