Indian Journal of Dental Research

: 2020  |  Volume : 31  |  Issue : 2  |  Page : 209--216

Treatment of miller type I and II gingival recession defects using three-dimensional porcine collagen matrix with coronally advanced flap: A randomized clinical split-mouth trial (a 1-year follow-up)

Haydar Barakat, Suleiman Dayoub 
 Department of Periodontology, Dental Faculty, Damascus University, Damascus, Syria

Correspondence Address:
Dr. Haydar Barakat
Almazehh Street, Damascus


Introduction: The main goal of periodontal plastic surgery is obtaining complete root coverage (CRC) and an optimal appearance. Aim: The aim of this study was to evaluate the effectiveness of a three-dimensional porcine collagen matrix (PCM) with coronally advanced flap (CAF) in treating of Miller type I and II gingival recession (GR). Materials and Methods: Twenty patients were enrolled in this study, presenting 40 Miller type I and II GR. Patients were randomized into test group (PCM + CAF) and control group [connective tissue graft (CTG + CAF)]. Clinical parameters such as recession depth (RD), probing depth, clinical attachment level (CAL), and width of keratinized gingiva (WKG) were evaluated at baseline and 12 months later. Root coverage percentage (RC%) and CRC were assessed at 12 months post surgically. Statistical analysis was performed using independent t-test for intergroup comparison. Statistical significance was set at 0.05. Results: The mean RD at 12 months was 0.20 mm for the test group and 0.12 mm for the control group, whereas the mean RC% was 94.22% for PCM + CAF and 96.48% for CTG + CAF. CRC was higher in CTG + CAF with 80%. CAL gain was 2.05 and 2.07 mm in the test and control sites, respectively. The gain of WKG was 1.35 and 1.30 mm in the test and control sites, respectively. Patient esthetic satisfaction at 12 months post surgically in both groups was equivalent. Conclusion: Within the limits of this study, using of PCM + CAF in treating GR is a successful and effective treatment option and could serve as an alternative to CTGs.

How to cite this article:
Barakat H, Dayoub S. Treatment of miller type I and II gingival recession defects using three-dimensional porcine collagen matrix with coronally advanced flap: A randomized clinical split-mouth trial (a 1-year follow-up).Indian J Dent Res 2020;31:209-216

How to cite this URL:
Barakat H, Dayoub S. Treatment of miller type I and II gingival recession defects using three-dimensional porcine collagen matrix with coronally advanced flap: A randomized clinical split-mouth trial (a 1-year follow-up). Indian J Dent Res [serial online] 2020 [cited 2020 Jul 11 ];31:209-216
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Full Text


Gingival recession (GR) is defined as the displacement of the gingival margin apical to the cementoenamel junction (CEJ).[1] The main goal of esthetic periodontal surgical procedures is to achieve complete root coverage (CRC) and an optimal esthetic appearance.[2]

GR defects have been treated by several techniques, some of those were using repositioned periodontal flaps alone or combined with auto- or allografts, or membranes.[3],[4] Till now, the predominant choice for treatment of GR is by coronally advanced flap (CAF) with an autogenous connective tissue graft (CTG) obtained from the patient's palate,[5] but patient's discomfort, avoiding the second surgery, and reducing the surgical time prompted researchers to investigate alternative materials to CTG such as enamel matrix derivative (EMD) or Alloderm to match the effectiveness of CTG + CAF in obtaining CRC.[6]

Recently, a new three-dimensional (3D) porcine collagen matrix (PCM) (Mucograft collagen matrix; Geistlich Pharma, Wolhusen, Switzerland) has been used for soft tissue regeneration. According to the manufacturer, it has two layers and is approximately 2.5 mm thick. The outer layer is compact and placed facing the oral cavity or the inner layer of the flap; it consists of a denser collagen, which promotes wound healing and allows cell ingrowth. This layer provides optimal suture pullout strength. The inner layer is composed of thick and porous collagen that promotes regeneration of the tissue and is placed facing the host tissue to promote vascular regeneration and encourage immediate blood clot stabilization and soft tissue growth [Figure 1];[7],[8] the advantages of this collagen matrix are its thickness, which makes it easier to work with and more resistant to masticatory forces,[9] and it acting as a 3D scaffold, allowing the ingrowth of fibroblasts and epithelium from the surrounding tissues;[7] due to these functions, it has been investigated as an alternative material to free gingival graft and CTG in mucogingival surgery so as to increase the width of keratinized gingiva (WKG) around teeth[10] and implants[11] and treat GR defects.[12],[13],[14],[15] In 2013, a systematic review[16] evaluated the clinical outcomes of xenogeneic collagen matrix (XCM) compared with other mucogingival procedures and found that CRC ranged between 42% and 72% in the XCM group and between 81% and 85% in the CTG group when compared with XCM and CTG. Another systematic review by Cairo et al.[17] evaluated the periodontal plastic surgery procedures in the treatment of localized GRs, which suggested that the collagen matrix may improve the efficacy of CAF. We aim in this research to compare the PCM + CAF with CTG + CAF in the treatment of Miller type I and II GR defects.{Figure 1}

 Material and Methods

Study design

This study was a randomized clinical split-mouth trail of GRs in two sites. The study protocol was registered with clinical with a registration number: NCT02986191.

A total of 22 patients (11 male and 11 female) were enrolled in this study from those attending the Department of Periodontology at the Faculty of Dentistry in the period between October 2016 and October 2017, after they fulfilled the following criteria: (1) age ranging from 20 to 45 years with the ability to demonstrate a good oral hygiene and (2) periodontally and systemically healthy and who presented GRs type I or II of Miller. Only 20 patients (11 male and 9 females) were available for follow-up after 12 months [Diagram 1].[INLINE:1]

The exclusion criteria were as follows: patients who were smokers (more than 20 cigarettes a day), patients suffering from systemic diseases or periodontal diseases, patients under orthodontic treatment, patients who cannot maintain a good oral hygiene, or patients who had previous surgical treatments to cover the recession in the chosen area, in case of pregnancy or lactating, or in case of presence of restorative materials in the chosen area. The study was conducted in accordance with the Declaration of Helsinki of 1975, as revised in 2000, and was approved by the internal Ethical Committee of Damascus University, Damascus, Syria. A written informed consent was obtained from all subjects who participated in the research study. Subjects were randomized to test or control treatment by a computer-generated randomization list (SPSS v 22 for win, IBM, Chicago, IL, USA) by the researchers. Twenty GR defects were selected to be treated in the test group by PCM + CAF and 20 defects in the control group by CTG + CAF.

Sample size

The sample size was determined based on the null hypothesis, which states that the test group (PCM + CAF) and the control group (CTG + CAF) were not equal, based on previous studies[12],[13] with the equivalent of inclusion and extrusion criteria. The confidence level was determined by 95%, the desired sample power was 95%, the G power (version 3.1.2) was used, and the required sample size was 20 subjects. The selected study sample was increased by two persons, with the possibility of dispensing the results of some subjects. The sample size was 22 persons.

Clinical parameters

The primary parameter was the clinical attachment level (CAL). The secondary parameters were recession depth (RD), probing depth (PD), and WKG. These clinical parameters were recorded by the clinical researcher using calibrated UNC-15 probes (PCP UNC-15; Hu Friedy, Chicago, IL, USA) which were made to the nearest 0.5 mm at baseline and 12-month post surgically. In addition, we took into consideration the other parameters as follows:

Root coverage percentage (RC%) was evaluated at 12 months post surgically.Patient esthetic satisfaction at 12 months post surgically and it was recorded on a 11-point scale (insufficient – poor – unsatisfied – sufficient –neutral – agreed – satisfied – as requested –harmonic – highly satisfied – perfect) according to Funk.[18]Pain assessments (no pain to extreme pain) according to numeric rating scale at 1, 2, and 4 weeks after the surgery.[19]

Surgical procedures

All enrolled subjects received a preperiodontal treatment (scaling and root planing) before 2 weeks of surgery. On the day of surgery, the patients were prepared with a preoperative rinse of 0.2% chlorhexidine for 1 min. Both sites were treated in the same surgical session by the clinical researcher. A full-thickness CAF was elevated in both sites with an intracervical incision and two vertical incisions and freed from tension, and then a deepithelization of the adjacent papillae was performed.

In test sites, the 3D PCM (Mucograft collagen matrix; Geistlich Pharma) was cut to fit the size of the recipient area and sutured (Vicryl 5-0; Johnson and Johnson LLC, Piscataway, NJ, USA), and then CAF was sutured coronally to the CEJ (Silk 0-4; ACUFIRM, Dreieich, Germany) [Figure 2]. The control sites were treated as the same by elevating a full-thickness CAF and a CTG was harvested from the subject's palate using trap-door technique [one horizontal incision was made 3 mm below the gingival margin, then two vertical incisions were made at the end of the horizontal incision creating a door, then the door was undermined and opened, the connective tissue was then harvested using a periosteal elevator, and the door was then sutured using Silk 0-4 (ACUFIRM)]. The connective graft was sutured to the recipient site with (Vicryl 5-0; Johnson and Johnson LLC), and then the CAF was coronally repositioned and sutured (Silk 0-4; ACUFIRM) [Figure 3].{Figure 2}{Figure 3}

Following surgery, the patients were given instruction on a written paper, included to rinse twice daily with chlorhexidine rinse 0.2% and to avoid tooth brushing for a month in the surgical area. The patients consumed antibiotic amoxicillin/clavulanate potassium (625 g three times daily for 6 days) and nonsteroidal analgesic diclofenac potassium (50 mg, twice a day for 6 days). The patients were told to come 2 weeks after surgery to remove the sutures. All patients were followed up at 1, 3, 6, and 12 months.

Statistical analysis

The values were entered into a database, and SPSS statistical package v22.0 was used for analyzing data. For the descriptive analysis of quantitative variables, dispersion measures (mean, standard deviation, and variance) were used. For both test and control groups, data were analyzed using paired t-test at baseline and 12 months. Independent t-test was used for intergroup comparisons. Statistical significance was set at 0.05.


Twenty patients (11 male and 9 female) with mean age 27.25 ± 4.90 years were enrolled in this study. Forty Miller type I or II were treated (20 with CAF + PCM) and (20 with CAF + CTG). The clinical parameters were evaluated at baseline and 3, 6, and 12 months of follow-up, and intragroup comparison is as shown in [Table 1]. [Table 2] reports the mean values with standard deviation and 95% confidence interval for the test and control groups at baseline and 12 months and intergroup comparison [Diagram 2].{Table 1}{Table 2}[INLINE:2]

Primary outcome: in the test sites, the mean CAL changed from 3.90 to 1.97 mm in 3 months, 1.89 mm in 6 months, and 1.85 mm in 12 months; in control sites, the mean CAL changed from 3.62 to 1.75 mm in 3 months, 1.67 mm in 6 months, and 1.55 mm in 12 months.

Secondary outcomes: the mean of RD in control sites was 0.19, 0.14, and 0.12 mm at 3, 6, and 12 months, respectively. While in test sites, the mean RD was 0.24, 0.21, and 0.20 mm at 3, 6 and 12 months, respectively. The percentage of root coverage at 12 months was 96.48 ± 7.49 for the control group and 94.22 ± 10.99 for the test group [Table 3]. CRC was obtained in 70% and 80% in both the test and control groups, respectively. The change in GR was statistically significant (P < 0.05) in both the test and control groups [Table 1].{Table 3}

[Table 4] reports the patient esthetic satisfaction at 12 months post surgically in both groups, and the outcomes were equivalent. [Table 5] represents the pain assessment during the first weeks and the patients presented no pain in 4 weeks in both sites. In 2 weeks, the pain was concentrated on the donor sites.{Table 4}{Table 5}


The main goal of mucogingival plastic surgery is obtaining complete, predictable, and esthetic root coverage. To achieve this goal, many procedures have been used. In this study we evaluated the benefit of the use of 3D collagen matrix (PCM) with CAF for the treatment of GR compared with CTG + CAF. In 2010, McGuire and Scheyer[12] were the first who investigated collagen matrix CM + CAF compared with CTG + CAF in treatment of GR in a randomized split-mouth design with 6–12 months of follow-up. The percent of root coverage was greater for the CTG group (99.3%) when compared with the PCM group (88.5%); also in addition, WKG gain was equivalent in the PCM and CTG groups (1.34 and 1.26 mm). For aesthetic satisfaction and assessment of pain, no significant difference was found among subjects in both groups. Color scores were also equivalent in both groups. After 5-year follow up,[20] 17 patients were available for recall, and the mean of RC% for the PCM group was 77.6% and it was 95.5% for the CTG group. The WKG averaged over 3 mm for both test and control sites, and tissue color match with the surrounding tissues remained similar to both groups.

In 2012, Cardaropoli et al.[13] studied the use of PCM + CAF when compared with CTG + CAF in a randomized clinical trial, of 12 months of follow-up; 22 gingival defects were randomized into test group (11 defects) and control group (11 defects). The mean of GR at 12 month was 0.23 mm for PCM sites and 0.09 for control sites; the percent of root coverage was 94.32% in the PCM group and 96.97% in the CTG group. The WKG gain was 1.23 mm in the PCM group and 1.27 mm in the CTG group.

In 2016, a randomized controlled trial (RCT) study was conducted by Cieślik-Wegemund et al.,[21] evaluating the use of XCM compared with CTG with a tunnel technique in treating of GR. At 6 months of follow-up, the mean RD was 0.21 in the test group (XCM) versus 0.39 in the CTG group, and the average root coverage was 95% in the CTG and 91% in the XCM group; CRC was 71.4% and 14.3% in the control and test groups, respectively. The mean of KTW increased in both groups.

In 2016, Moreira et al.[22] evaluated the outcomes of treatment of single GR type I/II of Miller with CAF alone or combined with PCM. The RC% was 77.2% in the test group (CAF + PCM) and 72.1% in the CAF group, and CRC was found to be 40% in CAF + PCM and 35% in CAF alone. Reino et al.[23] in 2015 compared two techniques (CAF and extended flap technique (EFT)) to treat GR using PCM, and the mean root coverage was higher in EFT + PCM group (81.89%).

In 2017, Sangiorgio et al.[24] investigated a xenogenic collagen matrix and/or EMD for treatment of GR type (I/II) by Miller in a randomized clinical trial. Patients were divided into four groups (CAF, CAF + CM, CAF + EMD, and CAF + CM + EMD), and at 6-month follow-up, CRC was higher in CAF + EMD group (70.59%) and then in CAF + CM group (52.94%). The gain in KG was significant in CM-treated groups from 2.58 to 2.93 mm. No significant differences were shown among groups in the outcomes of esthetic evaluation. Recently in 2017, Chevalier et al.[25] evaluated the XCM versus CTG of the treatment of GR in a split-mouth design case series. The mean of recession reduction was 2.00 mm with CTG and 2.00 mm with XCM. Likewise Jepsen et al.[3] in 2017 compared 6-month and 3-year outcomes for root coverage by CAF procedures in localized GRs. Eighteen patients with 36 GR types I/II of Miller were treated in a split-mouth design with CAF procedures or CAF + XCM. The mean of RC% in CAF + XCM group was 89.9% and 91.76% at 6 months and 3 years, respectively. While in the CAF group, RC% was 83.7% at 6 months versus 82.8% 3 years later. CRC was 61% for CAF + XCM versus 39% for CAF.

In this RCT study, periodontal clinical parameters (RD, PD, CAL, and WKG) were evaluated at baseline and 12 months later. Both surgical techniques (PCM and CTG) were effective in the treatment of gingival recession with significant root coverage at 12 months (94% and 96%, respectively). CRC was obtained in 70% of cases on the test group and 80% in the control group. These findings are comparable to other studies.[3],[13],[21],[23],[24] Our results outperformed the results obtained by McGuire and Scheyer[12] and Cieślik-Wegemund et al.[22]

This study demonstrated that there were no statistically significant differences in PD or CAL parameters between groups. The main gain of CAL in the test group was 2.05 mm and 2.07 mm in the control group, and that could be related to the new attachment to the root. Although there were no differences between the two groups, CTG + CAF provided better outcomes than PCM + CAF in treating GR type I and II by Miller.

For WKG, the gain of WKG at 12 months in the PCM + CAF group was 1.35 mm versus 1.30 mm in the CTG + CAF group with nonstatistical differences. These findings are in consistence with other studies,[12],[13],[21],[22],[23],[24] where the gain in WKG was equivalent in both groups. The increase in CTG group correlated with the ability of the connective tissue to induce keratinization of the epithelium,[26] and the gain in the PCM group could be explained by the acting of collagen matrix, which fabricated the pure type I and III collagen, as a 3D scaffold allows the cell ingrowth and repopulation of fibroblast and blood vessels and integrates with the surrounding tissue.[27]

Regarding esthetic satisfaction and pain assessment, the outcomes were equivalent and that leads to the fact that PCM + CAF is a viable alternative to CTG + CAF without the morbidity of graft harvest.


Within the limit of this study, the use of 3D PCM with CAF represents a clinically and esthetically treatment of GR defects. The percentage of root coverage and the gain in WKG and CAL at 12 months of follow-up were similar to the outcomes obtained from CTG + CAF technique. Besides, using PCM reduces the time of surgery and avoids the second surgery.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.


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