## 4 Discussion
However, the connective tissue graft demonstrated a more uniform pattern compared to the collagen matrix, which displayed a secondary increase in blood flow at the 14-day mark. Alternative materials, like those derived from porcine or bovine sources, may occasionally be utilized instead of autogenous tissue [37]. Collagen matrices are often employed when patient preferences or clinical conditions preclude the use of autogenous grafts [38]. Improved patient satisfaction can be achieved through the use of collagen matrix, which reduces surgical discomfort and increases soft tissue thickness [39]. The utilization of collagen matrices frequently leads to improved patient comfort, as they typically involve only one surgical site, thereby obviating the need for multiple incisions and associated postoperative discomfort [40]. Although effective in supporting new tissue growth, studies generally indicate that collagen matrices might offer slightly lower root coverage percentages compared to subepithelial connective tissue grafts [41]. In order to ensure the safe and effective use of collagen matrices, it is crucial to investigate potential side effects such as infection, bleeding, pain, and discomfort [42]. The outcomes of this study demonstrated that subepithelial connective tissue generally exhibits superior performance. Additionally, follow-up treatment studies may be required to address any discomfort and generalize the application of collagen for improving root coverage and increasing soft tissue thickness. The specific type of collagen matrix utilized in the studies is detailed below. The use of a xenogeneic collagen matrix (Geistlich Mucograft(r): Geistlich Pharma, AG, Wolhusen Switzerland) has been proposed as an alternative treatment for obtaining promising results in comparison with coronally advanced flap alone in achieving greater root coverage and keratinized tissue [19; 21; 43; 44]. In another study, an acellular sterilized collagen matrix product (Mucoderm, Botiss Dental, Zossen, Germany) derived from porcine dermis and consisting of collagen Types I and III and elastin, was used for the treatment [20; 22; 23; 27; 45]. Acellular dermal matrix (LifeCell, Branchburg, NJ, USA) has also been used for root coverage purposes [46]. It is a type of dermal substitute obtained by special treatment of allogeneic dermis to remove its cellular components [47]. Due to its nonimmunogenic features, good osteogenic properties, encouragement of seed cell adhesion, and maintenance of stem cell characteristics, decellularized extracellular matrix has attracted a lot of interest as a bioactive scaffold material [48]. Allogeneic dermal grafts and collagen matrices are two connective tissue substitutes that have steadily acquired acceptance in the clinical setting for lowering patient morbidity [49]. The results of this research indicate that the decision to employ a flap or tunnel technique is significant when utilizing a collagen matrix for root coverage in periodontal surgery [50]. The flap technique involves making incisions to expose the bone and reflect a flap of tissue away from the root surface, thereby providing direct access [51]. A collagen matrix can be placed under the flap to facilitate coverage of the denuded root and to function as a scaffold for the growth of new tissue. In contrast, the tunnel technique is a minimally invasive approach that utilizes specialized instruments to create a tunnel under the gingival tissue, without the need for incisions or the reflection of a flap. The collagen matrix can be inserted into the tunnel to promote root coverage. There is a potential for less postoperative pain with the tunnel technique compared to the flap technique. Nevertheless, it can be surmised that the collagen matrix in the tunnel technique is more likely to be exposed to the oral environment than in the flap technique. In a prior report, the matrix was augmented by 3 mm beyond the bone, and the flap was shifted coronally, subsequently being secured beyond the matrix [46].