Guided Tissue Regeneration With Bioabsorbable Barriers. II. Long‐Term Results in Infrabony Defects

Background: The aim of this 5‐year randomized controlled clinical trial was to evaluate the long‐term results after guided tissue regeneration (GTR) therapy of infrabony defects using two bioabsorbable barriers. Methods: Fifteen pairs of contralateral infrabony defects in 15 patients with moderate to severe periodontitis were treated. Each patient received one polydioxanon (test: T) and one polylactide acetyltributyl citrate (control: C) barrier by random assignment. At baseline, 12, and 60 ± 3 months after surgery clinical parameters and standardized radiographs were obtained. Vertical bone levels (PBL‐V) were measured during surgery and 60 ± 3 months later by transgingival bone sounding. Results: Thirteen patients were available for the 60‐month examinations. Twelve and 60 ± 3 months after GTR, statistically significant ( P ≤0.001) vertical attachment (CAL‐V) gain was found in both groups (T12: 3.5 ± 1.5 mm; T60: 2.2 ± 1.8 mm; C12: 4.0 ± 0.9 mm; C60: 2.4 ± 1.0 mm). However, from 12 to 60 months after therapy both groups experienced significant CAL‐V loss ( P <0.05): two defects in the test group and three in the control group had CAL‐V loss >2 mm compared to the 12‐month reexamination. Twelve and 60 ± 3 months after surgery, statistically significant ( P <0.05) radiographic bony fill was found in both groups (T12: 1.2 ± 1.3 mm; T60: 1.5 ± 2.2 mm; C12: 0.9 ± 1.4 mm; C60: 1.0 ± 1.6 mm). Further, 60 months after surgery significant ( P <0.05) PBL‐V gain was found in both groups (test: 1.8 ± 2.3 mm; control: 2.2 ± 1.8 mm). The study failed to show statistically significant differences between test and control regarding CAL‐V and PBL‐V gain 60 months after surgery. Conclusion: CAL‐V gain achieved after GTR therapy in infrabony defects using both bioabsorbable barriers was stable after 5 years in 21 of 26 defects (81%). J Periodontol 2004;75:957‐965 .