Background: The aim of this study was to compare the effects of guided tissue regeneration (GTR) using 2 different bioabsorbable barriers (control: polylactide acetyltributyl citrate; test: polydioxanon). The polydioxanon barrier is an experimental membrane for GTR therapy that consists of a continuous occlusive barrier that has a layer of slings on the side that is meant to face the mucoperiosteal flap. Methods: In 21 patients with 22 pairs of similar contralateral defects (30 intrabony and 14 Class II furcation lesions), each defect was randomly assigned for treatment with either control (c) or test (t) devices. At baseline and 12 months after surgery, clinical measurements, plaque index (PI) gingival index (GI), probing depth (PD), and vertical and horizontal clinical attachment loss (CAL-V; CAL-H) and standardized radiographs were obtained. Results: Barrier exposure was commonly observed in both groups. Four weeks after surgery 61% of all barriers were exposed to some extent. However, both treatments revealed a significant GI reduction (P < 0.005), PD reduction (-3.08 +/- 2.29 mm [t]; -3.52 +/- 2.67 mm [c]; P < 0.001) and CAL-V gain (2.44 +/- 2.29 mm [t], 2.80 mm +/- 2.21 [c]; P < 0.001) 12 months after surgery in all defects. Within the intrabony defects significant bony fill (2.03 +/- 1.70 mm [t]; 1.91 +/- 1.20 mm [c]; P = 0.001), and within the furcations a significant but small CAL-H gain (0.79 +/- 0.68 mm [t]; 1.13 +/- 1.44 mm [c]; P < 0.05), was observed, Conclusions: Regarding GI and PD reduction as well as CAL-V and CAL-H gain, this study failed to reveal statistically significant or clinically relevant differences between test and control 12 months postsurgically. Thus, the use of both bioabsorbable barriers in GTR therapy may be recommended.
