Treatment of gingival recession using a collagen membrane with or without the use of demineralized freeze-dried bone allograft for space maintenance

Background: Studies utilizing collagen membranes for guided tissue regeneration (GTR)-based root coverage procedures have reported promising results. However, creating and maintaining space underneath the membrane remains a challenge. Therefore, the purpose of this clinical trial was to determine whether the addition of bone graft (i.e., demineralized freeze-dried bone allograft [DFDBA]) significantly affects the outcome of collagen membrane GTR-based root coverage procedures. Methods: Twenty patients participated. One Miller's Class I or 11 recession defect per patient was treated with a collagen membrane covered by a coronally positioned flap. Half of the patients also had DFDBA placed under the membrane. Clinical parameters recorded included: recession depth, recession width, width of keratinized tissue, clinical attachment level, and probing depth, measured to the nearest 0.5 mm. Presurgery and postsurgery (6-month) data were compared using Student's paired t test for parametric data and the Wilcoxon matched pairs test for non-parametric data. Results: Guided tissue regeneration with collagen (COLL) and collagen + DFDBA (COBA) both resulted in statistically significant (P <0.05) reductions in recession depth (2.1 +/- 0.9 mm and 2.5 +/- 0.5 mm), recession width (1.5 +/- 1.7 mm and 2.2 +/- 1.6 mm), increase in keratinized tissue (0.7 +/- 0.8 mm and 1.2 +/- 1.0 mm), and gain of clinical attachment level (2.1 +/- 1.0 mm and 3.0 +/- 1.0 mm), when comparing 6-month data to baseline. Mean root coverage was 68.4 +/- 15.2% with COLL and 74.3 +/- 11.7% with COBA. However, there were no statistically significant differences between groups for recession depth, recession width, width of keratinized tissue, clinical attachment level, and probing depth. Conclusions: Both techniques are effective in attaining root coverage. Although root coverage tended to be better with the addition of DFDBA, the difference was not statistically significant. Further studies with a larger. sample size are needed to determine whether adding DFDBA to GTR-based procedures using collagen membranes is of any benefit.