Clinical evaluation of coronally advanced flap with acellular dermal matrix graft or connective tissue graft in the treatment of gingival recession with thin periodontal phenotype: study protocol for a split-mouth randomized controlled trial
Authors: Zhan Yalin , Wang Miaozhen , Cao Xiaojing , Liu Feng 
Published: October 2020

Abstract
BackgroundAmong all mucogingival deformities, gingival recession is one of the most prevalent conditions that demand surgical correction. Accordingly, root coverage procedures are essential parts of plastic periodontal surgeries. It is undeniable that autogenous tissue grafts remain the gold standard for root coverage procedures. Substantial evidences have identified that the connective tissue graft (CTG) combined with coronally advanced flap (CAF) achieves favorable root coverage of recession. Nevertheless, there are some noticeable disadvantages of harvesting autogenous tissue, such as postoperative bleeding, pain, or discomfort at the donor site, restricted tissue supply, increased morbidity, and longer operative duration. In order to overcome the drawbacks of autogenous tissue harvesting, several non-vital substitutes have been produced as alternative options for replacing connective tissue graft. Acellular dermal matrix (ADM) is an allograft derived from human skin, which has been used extensively in various areas of dental practice over the last two decades. ADM exhibits undamaged collagen and elastin matrices that has been used as a substitute for connective tissue for root coverage procedures. Although its clinical efficacy has been discussed in several reviews, conclusions about the application of this material are still unclear and controversial. Moreover, the level of evidence on the clinical outcomes and patient-reported outcomes relevant to ADM graft (ADMG) is low. Therefore, the objective of this split-mouth; randomized, controlled, clinical study is to compare the long-term clinical efficacy of ADMG combination with CAF on root coverage, aesthetics and patient satisfaction with CTG combination with CAF for gingival recession with thin periodontal phenotype, hoping to provide some reference to dentists.Methods/designForty participants with bilateral Miller Class I/II gingival recession randomly received ADMG (test group) on one side and CTG (control group) on the contralateral side in conjunction with CAF. Gingival recession depth (GRD), gingival recession width (GRW), keratinized tissue width (KTW) are measured at baseline, 2, 4, 12, 24, 48 and 96 weeks. Mean root coverage (MRC), complete root coverage (CRC), root coverage aesthetic score (RES), color change (∆E), and patient satisfaction are assessed in postoperative follow-up.DiscussionCAF combined with CTG has been shown as a predictable technique in root coverage. At present, there is limited long-term data evaluating ADM on root coverage, aesthetics and patient satisfaction for the treatment of gingival recession with thin periodontal phenotype. The result of this split-mouth randomized controlled clinical studies is performed to evaluate the long-time efficacy of ADM, particularly when compared to the “gold standard” (CTG), contributing to an advanced treatment strategy of gingival recession with ideal clinical outcome. Trial registrationInternational Clinical Trials Registry Platform (ICTRP), ID: ChiCTR2000033230. Registered on 25 May 2020, http://www.chictr.org.cn/showproj.aspx?proj=54052