###### Abstract  
Background: This study aimed to conduct a meta-analysis to assess the differences in the performance of root coverage between collagen matrix and subepithelial connective tissue. Methods: A comprehensive search using a combination of controlled vocabulary (MeSH) and free-text terms was undertaken by two reviewers to identify published systematic reviews. Three major electronic databases (Medline via PubMed, Cochrane database, and Embase) were searched up to October 2023. Results: Initially, five hundred and seventy-six articles were identified, but only nine studies met the criteria for inclusion in the meta-analysis. Meta-analysis showed that the pooled mean difference in mean root coverage of collagen matrix compared with subepithelial connective tissue was \(-0.48\) (95% confidence interval of \(-0.69\) to \(-0.26\)). The relative risk of complete root coverage of collagen matrix compared with subepithelial connective tissue was \(0.68\) (95% confidence interval, \(0.49\) to \(0.94\)). The pooled mean difference in width of keratinized tissue of collagen matrix compared with subepithelial connective tissue was \(-0.75\) (95% confidence interval of \(-1.25\) to \(-0.26\)). Conclusions: The outcomes of this study revealed that subepithelial connective tissue generally exhibited superior performance. Nonetheless, the utilization of the coronally advanced flap with collagen matrix may yield comparable results in terms of the percentage of complete root coverage. collagen; root coverage; subepithelial connective tissue +
Footnote †: journal: Medical  
Root coverage can be used for the patient's esthetic needs, tooth hypersensitivity, and cervical abrasion [4]. Over the past few decades, various surgical techniques on the root surface have been used to enhance root coverage/periodontal regeneration. Techniques for root coverage can be broadly categorized as advanced flap, pedicle soft tissue graft, and free soft tissue graft [5]. Free soft tissue grafting can be further categorized into free gingival grafting and subepithelial connective tissue grafting. Subepithelial connective tissue grafting was described previously and used subepithelial connective tissue grafting to cover the exposed root [6]. The advantages of subepithelial connective tissue grafting include relatively little postoperative pain in the donor area, dual blood supply to the graft from the overlying flap and periosteum in the recipient area, good blood supply, and a good prognosis due to low graft resorption [7; 8]. In addition, it has the advantage of being able to be applied to multiple gingival recessions with excellent esthetics due to its color harmony with adjacent tissues [9]. Furthermore, because of its high success rate and pleasing color, coronally advanced flap with subepithelial connective tissue grafting can be regarded as a standard treatment [10]. Usually, subepithelial connective tissue is obtained from the palatal side [11]. Minimally invasive surgical techniques have been developed to address the surgical limitations of limited autologous harvest and collagen, a tissue graft substitute, has been suggested to overcome the limitations associated with autogenous tissue transplantation [1]. In preclinical and clinical studies, treatment concepts should be based on a biological basis that takes into account not only the use of regenerative materials but also the patient's innate healing potential, which is why we want to apply root coverage utilizing collagen, which has a decisive influence on periodontal wound healing and regeneration [12]. A previous report evaluated the efficacy of a cross-linked xenogenic volume-stable collagen matrix in treating gingival recessions and in addition to the fact that the treatment significantly reduced oral hypersensitivity, reasonably high patient-reported pleasure and esthetics were connected with the treatment outcomes [13].