Long-term results of guided tissue regeneration therapy with non-resorbable and bioabsorbable barriers. II. A case series of infrabony defects

Background: The aim of this 5-year follow-up case series was to clinically and radiographically evaluate the long-term results after guided tissue regeneration (GTR) therapy of infrabony defects using non-resorbable and bioabsorbable barriers. Methods: In 12 patients with advanced chronic periodontitis 12 pairs of contralateral infrabony defects were treated. Within each patient one defect received a non-resorbable (expanded poly tetrafluoroethylene [ePTFE]; control: C) and the other a bioabsorbable (polyglactin 910; test: T) barrier by random assignment. At baseline and at 6 and 60 +/- 3 months after surgery clinical parameters and standardized radiographs were obtained. Gain of bone density within infrabony defects was assessed using subtraction radiography. Results: Eight of 12 patients were available for the 60-month reexaminations. Six and 60 +/- 3 months after GTR therapy statistically significant (P <0.05) vertical attachment (CAL-V) gain was observed in both groups (C6:2.6 +/- 1.4 mm; C60:1.6 +/- 1.5 mm; T6:3.0 +/- 1.7 mm; T60:3.0 +/- 0.7 mm). However at 60 months, 2 infrabony defects in the control group had lost all the attachment that had been gained 6 months after therapy and a clinically relevant but statistically insignificant mean CAL-V loss of 1.0 +/- 2.1 mm was observed from 6 to 60 months. The case series failed to show statistically significant differences between test and control regarding CAL-V gain 60 months after surgery. Also subtraction analysis failed to reveal statistically significant differences regarding density gain between both groups 6 and 60 months postsurgically (C6: 26.4 +/- 54.2, C60 62.8 +/- 112.7, T6:68.7 +/- 72.8, T60. 84.1 +/- 83.6). Conclusions: CAL-V gain achieved after GTR therapy in infrabony defects using both non-resorbable and bioabsorbable barriers was quite stable after 5 years in 14 of 16 defects.