Frontiers in Dentistry Use of Mucograft Collagen Matrix® versus Free Gingival Graft to Augment Keratinized Tissue Around Teeth: A Randomized Controlled Clinical Trial Amirreza Rokn1,2, Hadi Zare3, Pardis Haddadi3* 1. Dental Implant Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran 2. Department of Periodontics, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran 3. Department of Periodontics, Faculty of Dentistry, Lorestan University of Medical Sciences, Khorramabad, Iran Article Info A B S T R A C T Article type: Objectives: This study aimed to evaluate the mucograft collagen matrix (CM) to Original Article increase keratinized tissue around teeth compared to free gingival graft (FGG). Materials and Methods: The present double-blind, randomized, controlled clinical trial studied 12 patients who had 2 mm or less keratinized gingiva bilaterally around mandibular premolars. The 6-month width of keratinized tissue, periodontal Article History: parameters (preoperatively and 1, 3, and 6 months postoperatively), color match, Received: 16 Jul 2019 pain, and total surgical time were measured. Accepted: 17 Dec 2019 Published: 8 Mar 2020 Results: The mean dimensional change of keratinized gingiva 6 months postoperatively was 4.1±0.7 mm for FGG and 8±1.7 mm for CM. Periodontal parameters were not affected in the two groups. The CM group had a significantly lower pain, experienced less surgery time, and gained better aesthetics compared to * Corresponding author: the FGG group. Department of Periodontics, Faculty of Dentistry, Lorestan University of Medical Conclusion: CM appears to be a suitable substitute for FGG in procedures designed Sciences, Khorramabad, Iran to increase keratinized tissue around teeth. It has remarkable benefits, such as acceptable keratinized tissue gain, less pain, less surgical chair time, and better Email: [email protected] aesthetics. Keywords: Gingiva; Mucograft; Tissue Transplantation Cite this article as: Rokn AR, Zare H, Haddadi P. Use of Mucograft Collagen Matrix® Versus Free Gingival Graft to Augment Keratinized Tissue Around Teeth: A Randomized Controlled Clinical Trial. Front Dent. 2020;17:5. doi: 10.18502/fid.v17i1.3965 INTRODUCTION gingival augmentation procedures may be The width of keratinized gingiva differs in indicated when patients experience different individuals and even in different discomfort during tooth brushing and/or teeth [1]. The rationale of mucogingival chewing due to interference from a lining therapy has been primarily based on the fact mucosa or when orthodontic tooth that a minimum width of gingiva is critical for movement is planned and the buccal position maintaining gingival health and preventing of teeth can result in alveolar bone gingival recession [2]. However, today, it is dehiscence. An increase of the gingiva may believed that gingival health can be also be considered when subgingival maintained independently of its dimensions restorations are placed in areas with a thin [3,4]. As a result, narrow gingiva alone cannot marginal tissue [5]. justify surgical intervention. However, Various techniques have been invented for Copyright © 2020 The Authors. Published by Tehran University of Medical Sciences. This work is published as an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (http://creativecommons.org/licenses/by-nc/4). Non-commercial uses of the work are permitted, provided the original work is properly cited. Mucograft for Keratinized Tissue Augmentation increasing the width of keratinized gingiva. The present double-blind, randomized, Since the late 1960s, clinicians have controlled clinical trial (IRCT registration corrected insufficient keratinized tissue and number: IRCT2013052813501N1) was insufficient vestibules by placing autogenous conducted according to the guidelines of the free gingival grafts (FGGs), free connective Helsinki Declaration of 1975 (revised, 2000). tissue grafts, and surgically releasing the The Ethics Committee of the Dental Research vestibular area (vestibuloplasty) [6]. One of Center of Tehran University of Medical the earliest and most common gingival Sciences approved the research protocol augmentation procedures involves FGG in (Ethical code: 91-04-10-18791-78324). which the graft is harvested from the The study population consisted of patients patient’s palate. This technique has more referring to the Department of Periodontics, predictable results but it has some School of Dentistry, Tehran University of disadvantages. First, the palate is healed by Medical Sciences, Tehran, Iran, who had less secondary intention and requires a dressing than 2mm of attached keratinized gingiva for 10 to 14 days, which is uncomfortable for bilaterally on the buccal aspect of the most patients [7]. Other disadvantages mandibular premolar teeth. include the inability to harvest large grafts, The inclusion criteria were: 1) age over 18 high morbidity rates after surgery, and poor years, 2) good oral hygiene; O'Leary oral aesthetics due to differences in texture and plaque index < 15%, 3) no bleeding on probing color from adjacent areas [8]. In patients with (BOP) based on the Ainamo and Bay index difficult-to-control bleeding at the graft (1976), 4) the presence of an identifiable donor site, treatment of multiple sites would cementoenamel junction (CEJ), and 5) teeth in be a challenge [9]. need of prosthetic or orthodontic treatment. Possible alternatives to FGGs are xenografts Exclusion criteria were: 1) active carious and allografts [10]. The Mucograft® Collagen lesions or restorations or crowns at the CEJ, 2) Matrix (CM; Geistlich Pharma AG, Wolhusen, smoking, 3) systemic conditions precluding Switzerland) is a resorbable, three- periodontal surgery, 4) systemic conditions dimensional (3D) matrix that is designed affecting the periodontium; 5) high frenum specifically for soft tissue regeneration in the pull, 6) history of mucogingival surgery in the oral cavity. It is fabricated as a matrix of pure area, and 7) pathologic movement of the type I and III porcine collagen obtained with involved teeth. The sample size was standardized and controlled manufacturing predicated based on obtaining 80% power for processes without cross-linking or chemical testing the primary study endpoint, which treatment [8]. evaluated whether or not mucograft was Some previous studies have investigated the inferior to FGG in the generation of keratinized clinical outcome of CM for augmentation of tissue from the baseline to 6 months insufficient keratinized tissue [11-13]. These postoperatively. studies have shown favorable clinical results; This assumed a paired t-test of non-inferiority however, most of them have been conducted with a non-inferiority margin of 1.0 mm, a around dental implants and not around teeth. within-patient standard deviation (SD) of 1.0 In most cases, the design of the studies was mm, and a one-sided alpha of 0.05. Under not split-mouth; therefore, patient-related these assumptions and according to the below factors were not the same in the control and formula, a sample size of 10 was required to test groups. As a result, we decided to power the primary endpoint [13]. To account compare CM and FGG for the augmentation of for potential loss to follow-up, 12 patients keratinized gingiva around teeth in a split- were enrolled in the trial. The investigator mouth study. blinded to the details of the study and surgical protocols carried out randomization of the MATERIALS AND METHODS patients and their assignment to intervention Study design and participants: groups. Volume 17 | Article 5 | Mar 2020 2 / 8 Rokn AR, et al. Fig. 1. Gingival augmentation by free gingival graft (FGG) on the right side (a and b) and mucograft on the left side (c and d) The patients were numbered according to adjacent teeth. Recipient sites were slightly when they had presented to the department. larger than the CM and FGG grafts. The CM and After the patients' eligibility for enrollment in FGG grafts were 10×20 mm2. Vertical the study was confirmed, all the surgeries incisions were made on the mesial and distal were done according to the patients' numbers. aspects of the CM and FGG sites, extending Concealed allocation was performed by using apically as far as the vestibules allowed. The sealed, coded envelopes that were opened just mesial and distal incisions were then before surgery to determine the test connected apically. Muscle fibers were (Mucograft®) and control (FGG) groups. To removed with scissors, creating a clean allow for possible dropouts, 12 patients were periosteal bed. recruited. One experienced surgeon, who was The CM was placed dry (not pre-wet), and blinded to the randomization sequences, blood was allowed to soak into the matrix to performed all surgeries. form an initial stable clot. The FGG was Periodontal parameters: harvested from the randomly assigned palate Patients received oral hygiene instructions for donor site. The CM and FGG test and control two weeks before surgery, and professional materials were placed in direct contact with scaling and root planing (SRP) was carried out. the appropriate randomly assigned recipient A calibrated postgraduate student, who was bed and sutured in place with non-resorbable blinded to the study protocol, measured all 4-0 Cytoplast™ PTFE suture’s monofilament clinical parameters before and after surgery. construction that does not allow bacterial All measurements were made using a wicking