Coronally advanced flap associated to the xenogenous collagen matrix graft in the treatment of teeth presenting gingival recession associated with non-carious cervical lesion partially restored with composite resin. Randomized clinical trial

The aim of this study is to evaluate a new multidisciplinary protocol by means of a randomized controlled clinical trial. Were it selected 62 patients who will be randomly allocated to one of the following groups: Test group (n = 31), partial restoration of cervical lesion and surgery for root coverage with graft collagen matrix xenogenous (MCG + PR) and control group (n = 31), partial restoration of cervical lesion and surgery for root coverage without connective tissue graft (CAF + PR). The groups were compared as to bleeding on probing (BOP), biofilm accumulation (IP), relative gingival recession (RGR) clinical attachment level (CAL), decrease of dentin hypersensitivity (DH) and aesthetic evaluation (AE) for a period of 1 year. The parameters of height, width and depth of the cervical lesion (CLH, CLW and CLD) and height and thickness of keratinized tissue (KTH and KTT), were placed as independent variables in a multiple linear regression model to evaluate their influence on the final outcome of the procedures. Average percentage rates of root coverage for test and control group were 52.83% and 53.65%, respectively. No significant statistical difference between test and control was observed regarding root coverage. A statistically significant difference was observed when height and thickness of the keratinized tissue favored the group with mucograft. When the other parameters were compared between the two groups, no difference was found. Thus, it can be concluded that the two treatments resulted in a significant reduction of the combined defect, with no difference between the treatments, although additional benefit related to keratinized tissue height and thickness was observed when the xenogen matrix of collagen was used.