Relative connective tissue graft size affects root coverage treatment outcome in the envelope procedure.

摘要

BACKGROUND: This study investigated the correlation between the connective tissue graft size and the percentage of root coverage. METHODS: Fifteen patients with Miller Class I or II recession defects (one tooth/defect per patient) were treated using an envelope connective tissue graft procedure. Clinical parameters including gingival recession depth (RD), clinical attachment level (CAL), keratinized tissue width (KW), and the probing depth (PD) were measured. Visible denuded area (VDA) and graft tissue area (GTA) were indirectly measured in mm2 using computer software. Graft tissue thickness (GTT) and graft tissue width (GTW) were also measured. All clinical parameters and VDA were recorded at baseline and 3 and 6 months. The RD, CAL, KW, PD, and VDA were evaluated by Friedman test. The correlation between the percentage of root coverage (PRC) and factors related to graft size were determined by Spearman rank correlation and nonparametric regression analysis. RESULTS: The percent of root coverage at 3 and 6 months postoperatively was statistically significantly associated with the GTA:VDA ratio (P<0.01); it did not correlate with GTA, GTT, or RD, and was inconsistently correlated to GTW and VDA. In patients who had 100% root coverage, the GTA:VDA ratio ranged between 10.92:1 and 21.95:1; in patients with <100% root coverage, the ratio was between 4.54:1 and 11.06:1. CONCLUSION: The GTA:VDA ratio should be at least 11:1, which is a significant factor for optimal root coverage result in the envelope procedure.