Clinical performance of access flap surgery in the treatment of the intrabony defect. A systematic review and meta-analysis of randomized clinical trials.

Aim: To systematically review the literature and to determine the clinical performance of conservative surgery (CS) for the treatment of intrabony defects (ID). Methods: RCTs on ID treatment with 12 months of follow-up were identified through electronic databases and hand-searched journals. Primary outcomes were tooth survival, clinical attachment (CAL) gain, probing depth (PD) reduction and gingival recession increase (REC). Weighted means and forest plots were calculated for each outcome variable 12 months after surgery. Long-term stability was explored with RCTs of at least 24 months of follow-up. Subgroup analysis was performed according to the type of flap. Results: Twenty-seven trials reporting 647 subjects and 734 defects were identified. Twelve months after CS, tooth survival was 98% (IQ: 96.77-100), CAL gain 1.65 mm (95% CI: 1.37-1.94; p < 0.0001), PD reduction 2.80 mm (CI: 2.43-3.18; p < 0.0001) and REC increase 1.26 mm (CI: 0.94-1.49; p < 0.0001). Longer follow- up showed similar findings. CI of CAL gain were 1.44-3.52 for recently introduced papilla preservation flaps and 1.25-1.89 mm for access flaps. Conclusions: The treatment of intrabony defect with CS is associated with high tooth retention and improvement of periodontal clinical parameters. Clinical performance may vary according to the type of surgical flap used.