Five-year follow-up of regenerative periodontal therapy with enamel matrix derivative at sites with angular bone defects

Background: This prospective case series report aimed at analyzing the long-term (5 years) stability of clinical attachment level (CAL) gains following regenerative therapy with the use of enamel matrix proteins in intrabony defects. Methods: A total of 114 consecutively treated periodontal patients (mean age: 55.8 years) were initially included. Each subject exhibited at least one deep proximal intrabony defect with the inclusion criteria of 1) probing depth (PD) >= 5 mm, 2) clinical attachment loss >= 6 mm, and 3) radiographic evidence of a >= 3-mm intrabony component. A total of 146 defects met the criteria for inclusion. At least 6 months after the completion of an initial phase of mechanical infection control, a baseline examination was performed to characterize the experimental site. Reconstructive therapy with the use of enamel matrix proteins was subsequently performed. Experimental sites were reexamined 1 and 5 years after reconstructive surgery. Primary efficacy variables were considered to be changes in PD, CAL, soft tissue recession (REC) and radiographic defect depth (RDD). Stepwise regression analysis was employed for evaluation of predicting factors of CAL change between the 1- and 5-year reexaminations. Results: A total of 82 patients (102 defects) were included in the analysis. One year following the regeneratiue surgery, a mean CAL gain of 4.3 mm (P < 0.001), a mean PD reduction of 4.9 mm (P < 0.001), and a mean increase in REC of 0.6 mm (P < 0.001) were recorded. At the 5-year follow-up, a further mean PD reduction of 0.3 mm (P > 0.05), CAL gain of 1.1 mm (P < 0.01), and reduction in recession of 0.8 mm (P < 0.01) had taken place. Radiographs revealed that the bone defect had been reduced in depth with an average of 2.9 mm at 1 year (P < 0.001). No statistically significant alteration in defect depth was observed between 1 and 5 years of follow-up. The stepwise regression analysis identified the degree of REC and residual PD at 1 year as significant predictors of CAL change between 1 and 5 years. Conclusion: Results demonstrated long-term (5 years) stability of CAL gains following regenerative therapy with the use of enamel matrix proteins in intrabony defects.