Coronally positioned flap procedures with or without a biodegradable membrane in the treatment of human gingival recession. A 6-year follow-up study

BACKGROUND: Short-term data have indicated that treatment of gingival recession type defects by coronally positioned flap procedures with or without biodegradable membranes may result in similar treatment outcome. The aim of this study was to compare 12-month and 6-year follow-up results for these two treatment approaches. METHODS: Twenty patients with buccal bilateral Miller Class I or Class II gingival recession defects in cuspids or bicuspids were treated randomly by coronally positioned flap alone (20 sites) or in combination with a biodegradable membrane (20 sites). Clinical measurements at baseline, 6, 12 months and 6 years included apical extent of gingival recession, width of the defect at the cemento-enamel junction (CEJ), width of keratinized tissue, as well as attachment level and probing depth. Eleven patients were available for the 6-year evaluation. RESULTS: At 12 months (20 sites), both treatments resulted in significant gain of root coverage (p<0.001), stable probing depth, and increased attachment level (p<0.001). The 6-year evaluation (11 sites) showed a significant gain of root coverage for the non-membrane group only (p<0.05). No significant between-group differences were detected for any other treatment variable regardless of smoking status (p>0.05). Compared with baseline, the 6-year results showed that seven membrane sites gained root coverage, three were unchanged and one lost root coverage. For the 11 non-membrane sites, eight gained root coverage, and three were unchanged. The five membrane and the 10 non-membrane sites exhibiting complete root coverage at 6 months were reduced to two and one, respectively, at the 6-year evaluation. CONCLUSIONS: The coronally positioned flap procedure offers a simple and reliable treatment alternative as a root coverage procedure in Class I and Class II recession type defects. Placement of a biodegradable membrane underneath the flap does not seem to improve neither the short- nor the long-term results. Long-term outcome stability seems to be critically dependent on a continuous follow-up program with re-instruction in non-traumatic brushing habits.