Características teciduais prévias ao tratamento cirúrgico podem prever o sucesso do recobrimento radicular? Uma tomada de decisão em abordagens com enxertia para o tratamento de recessões gengivais unitárias

Abstract

Gingival recession (GR) is characterized as a mucogingival defect with high prevalence in clinical practice. Dentin hypersensitivity and/or esthetic discomfort when smiling are complaints that lead the patient to seek treatment. Currently, the gold standard for the treatment of single GR is the coronally advanced flap (CAF) associated with the use of connective tissue graft (CTG). Due to the postoperative discomfort caused by the presence of two surgical sites, as well as anatomical limitations in the palatal region, biomaterials have been developed with the aim of replacing ETC, such as the xenogenous acellular dermal matrix (CM) and xenogenous collagen matrices (XDM). Although these biomaterials still do not reach the performance of the autogenous graft, their clinical results are promising. Baseline characteristics of the site to be treated can influence the outcome obtained depending on the technique/graft selected. Therefore, the aim of the present study is to re-evaluate three randomized clinical trials (RCTs) and analyze tissue predictors in decision-making for grafting procedures to treat GR/RT1 type using the success or fail of root coverage (RC) as the dependent variable. Ninety-five patients with RG/RT1 were treated with CAF (n=23), CAF+CTG (n=25), CAF+CM (n=25) and CAF+XDM (n=22). Clinical parameters, such as probing depth (PD), clinical attachment level (CAL), gingival recession (GR), keratinized tissue height (KTW), keratinized tissue thickness (KTT), papilla height and width (PH/PW) and margin position in the immediate postoperative period (MPIP) were recorded. In addition, the success of therapy was evaluated 6 months postoperatively by recession reduction (RecRed), percentage of root coverage (%RC), and complete root coverage (CRC). Patients were divided into two categories, Category A (%RC from 100 to 80%) and Category B (%RC from 80 to 0%), to establish success/failure probabilities from tissue predictors at baseline. After comparative analysis, despite the improvement of these parameters in the intragroup analysis, there was a superiority of the CAF+CTG group in RecRed and a gain in KTT. Similarities were obtained in %RC and RRC between groups, except for CAF+XDM. Moreover, no difference was observed between KTW gain between CAF and CAF+CTG. From the multiple logistic regression using all the evaluated groups, it was found that every 1 mm of the KTW in the CAF+XDM group at baseline increases the probability of reaching a %RR>80% by 5.35x when compared to the gold standard. Similarly, every 1 mm of PW at the beginning of treatment increases the probability by 7.8x of the patient achieving successful root coverage (%RR>80%) regardless of the treatment chosen. From a model with only the grafting groups, there is an influence of KTW in the CAF+XDM group at 5.10x and a tendency in the CAF+CM group at 2.5x when compared to the CAF+CTG. After predictions using the present logistic models, there is a need for about 3.5-4 mm of KTW at baseline to reach %RR>80% when using CM and XDM, respectively. Additionally, regardless of the type of therapy used, a PW with at least 5 mm favors a high probability of achieving successful surgical therapy. Within the limits of the present data reanalysis, KTW is a tissue predictor in the decisionmaking of graft procedures for the treatment of GR/RT1. Besides, LP is reported as a predictor for procedures with and without grafting.