This study compared the results following treatment of gingival recessions by a coronally advanced flap procedure alone (CAF) or combined with a bioabsorbable membrane and a demineralized xenograft (GTRF). Sixteen nonsmokers with 20 Miller Class I or Class II buccal gingival recessions at canines or premolars were included in the study. Sites were randomly assigned to either CAF treatment (control, n = 10) or GTRF treatment (test, n = 10) and examined at baseline and at 6 months postoperatively. Both treatments resulted in a significant reduction in recession and gain in clinical attachment level; there was no significant difference between treatments. No differences were found in probing depths among or between the groups. The increase in keratinized tissue from baseline to 6 months was slightly greater for the GTRF group than for the CAF group, but without statistical significance. The test group experienced a statistically significant increase in gingival thickness from baseline to the 6-month evaluation, while little gain was detected in the control group; the between-group difference was statistically significant in favor of the test group. Both procedures offer a predictable, simple, and convenient means of root coverage in Miller Class I and II recession defects, but the GTRF-supported procedure resulted in more keratinized tissue and a significant increase in gingival thickness than the CAF-only approach.