Background: The aim of this study is to evaluate the long-term benefits of regenerative therapy and which factors (i.e., smoking, oral hygiene, radiographic angle, tooth, clinical center, and biomaterial) influence results.
Methods: A total of 120 infrabony defects were treated with guided tissue regeneration using bioabsorbable and non-resorbable membranes with grafts or enamel matrix derivative (EMD) proteins. At baseline, smoking, x-ray angle, probing depth (PD), recession, and clinical attachment level (CAL) were recorded. CAL was measured 1 year post-surgery and every 2 years for ≤16 years. The participation of patients in oral hygiene protocols was recorded.
Results: The mean ± SD baseline CAL was 8.5 ± 2.3 mm, baseline PD was 7.8 ± 2.1 mm, and baseline x-ray angle was 31.8° ± 8.9°. One year post-surgery, CAL gain was 4.1 ± 2.1 mm. EMD was used in 47 defects, bioabsorbable membranes with deproteinized bovine bone were used in 41 cases, non-resorbable membranes were used in seven defects, bioabsorbable membranes and autogenous bone were used in five defects, and a combination was used in 20 defects. A total of 10% of subjects were smokers, and 20% of subjects did not participate in an oral hygiene program. The average follow-up was 9 years. A total of 90% teeth survival was achieved at 13 years, and CAL gain was maintained at 82% for 11 years. Statistical analyses demonstrated that smoking and oral hygiene maintenance influenced long-term outcomes. The x-ray angle, tooth, clinical center, and biomaterials did not influence results.
Conclusions: Regenerative therapy provided a high percentage of long-term success. Smoking and non-participation in oral hygiene maintenance negatively influenced the prognosis, whereas other factors did not affect long-term results.