Long-term clinical outcomes of periodontal regeneration of intrabony defects: A systematic review and meta-analysis.

Abstract

This systematic review and meta-analysis aimed to evaluate the long-term clinical outcomes of regenerative procedures compared with access flap surgery for the treatment of intrabony defects, with a minimum follow-up period of 5 years. A systematic review protocol following PRISMA guidelines was conducted. Both electronic and manual searches were conducted to identify randomized clinical trials (RCTs) on regenerative treatment of deep intrabony defects (≥3 mm) with a follow-up of at least 5 years. Primary outcome variables were probing depth (PD) reduction, clinical attachment level (CAL) gain, recession depth (REC) and tooth loss. Meta-analyses and meta-regressions were performed using random-effects models. Seventeen RCTs published from 2004 to 2022, accounting for 501 defects, with follow-ups ranging from 5 to 20 years, were included. Thirteen studies with some concerns and four with high risks of bias were identified. Meta-analyses revealed that after ≥5 years of follow-up, guided tissue regeneration (GTR) on the intrabony defect resulted in significant CAL gain (3.27 mm; 95% CI: 2.90-3.65) and PD reduction (4.04 mm; 95% CI: 3.69-4.38) compared with baseline. After ≥5 years, regenerative procedures with biologics, bone grafts, or both showed significant improvements in CAL gain (3.21 mm; 95% CI: 2.72-3.70) and PD reduction (3.92 mm; 95% CI: 3.39-4.44). GTR on the intrabony defects obtained higher long-term CAL gain (1.52 mm; 95% CI: 0.06-3.10) and PD reduction (0.89 mm; 95% CI: 0.22-1.99) than OFD (open flap debridement); however, none of the outcomes reached statistical significance (p = 0.06; p = 0.115). Meta-regression identified significant associations between outcomes and factors, such as follow-up time, surgical technique, membrane type, and baseline measurements. The certainty of evidence was low for CAL and PD outcomes, but high for REC. Long-term studies indicate that regenerative procedures for the intrabony defects, particularly GTR, provide significant improvements in clinical parameters compared with baseline. However, the evidence does not conclusively demonstrate the superiority of regenerative approaches over OFD in the long term.