Use of second generation platelet derived growth factor in root coverage procedure

Phase 3

• Conditions: Other periodontal diseases,

• Registration Number: CTRI/2019/08/020857
• Lead Sponsor: Dr Ripu Singh

Brief Summary

**INTRODUCTION**

Gingival recession  is the exposure of the root surface by an apical shift in the position of  the  gingiva.(1) Loe et al. showed that the prevalence of  gingival recession in Norwegians was 60% at 20 years of age, and that it exceeded 90% at 50 years of age where as in the Sri Lankan cohort, it was more than 30% of individuals before the age of 20 years (confined to buccal surface), in 90% of individuals at 30 years of age (with recession mostly located at interproximal surfaces) and in 100% of individuals at 40 years of age. (2) The prevalence of gingival recession is 41.37%, 58.90 %, 77.41% and 86.79% in age groups of 20-29 years, 30-39 years, 40-49 years and ≥ 50 years respectively in rural Nepalese population. (3) Traumatizing toothbrushing and tooth malposition are the factors most frequently found to be associated with gingival recession. (4,5) Other local factors that have been associated with marginal tissue recession are alveolar bone dehiscence, high muscle attachment and frenal pull, plaque and calculus, and iatrogenic factors related to restorative and periodontal treatment procedures. A study done by Agudio (6) concluded that untreated gingival recessions show a negative prognosis over time in spite of good patient motivation, while the prognosis is improved after applying mucogingival procedures. However, mere presence of a narrow zone of gingiva cannot justify surgical intervention (7)

Surgical treatments like free gingival graft, pedicle flaps in different modifications or combined procedures are indicated when the gingival recession causes functional (i.e. dentinal hypersensitivity and root caries) or esthetic problems. The other indications for root coverage procedures are prevention or management of root caries and cervical abrasion, enhancement of restorative outcomes, and facilitation of plaque control efforts. Although all the proposed techniques have shown potential for root coverage, meta-analyses from several systematic reviews (8–13) showed the greatest potential for recession reduction and complete root coverage when applying coronally advanced flap or combined procedures (14) along with subepithelial connective tissue graft. The preference of pedicle grafts over the free soft tissue grafts is for the  preservation of vascularity of the flap as the studies suggest that one of the most important factors to achieve success in any type of mucogingival surgical procedure is the preservation of an adequate blood supply . (15) Coronally advanced flap (CAF) is one of the most widely used surgical technique indicated for the treatment of Miller’s class I and class II gingival recession defects. This coronally repositioned flap technique was first introduced by Brustein in 1970 and modified by Allen and Miller in 1989. (16) In 1999, Pini Prato et al. coined the term ‘Coronally Advanced Flap’. This procedure is based on the coronal shift of the soft tissues on the exposed root surface. (16,17) CAF may lead to excellent esthetic results, avoiding the need for a second surgical site, more over it is simple to perform. The other problem concerning with the use of free autogenous tissue grafting includes a limited amount of source material and an unaesthetic appearance, making the technique less than ideal in certain cases.

Based on the data from randomized controlled studies included in recent systematic reviews shows that on average about 70% root coverage may be expected (range 34–87%). (8,9) Complete coverage of the recession defect, which is the ultimate goal of the therapy, may be reached in approximately 35% of treated cases (range 15–60%). Based on Cochrane review on Root coverage procedures for the treatment of localized recession-type defects (9), mean root coverage varied from 64.7% (18) to 97.3% for  subepithelial connective tissue graft (SCTG) (19), 55.9 % (20) to 86.7% (21) for CAF. Treatment of multiple gingival recession with modified coronally advanced flap showed mean root coverage of 97% and 88% complete root coverage. (22) Based on the studies reviewed, the SCTG procedure remains the treatment of choice in terms of percent root coverage. Though, its application is limited due to tissue availability and patients’ preference to avoid a donor harvest site.

Various growth factors have shown to enhance wound healing as well as facilitate regeneration of periodontal tissues. Platelet rich fibrin (PRF) is a second generation platelet concentrate, which is a concentrated suspension of growth factors like platelet-derived growth factor (PDGF), transforming growth factor-β (TGF-β), insulin-like growth factor (IGF) found in platelets. It is prepared with simplified processing without requiring either anticoagulant or bovine thrombin. PRF was first developed in France by Choukroun (23) and is known to accelerate wound healing, as well as hard and soft tissue maturation when used in conjunction with various root coverage procedures. (24) Various studies have been performed comparing coronally advanced flap with and without the use of PRF. However, based on available literature, there appears large variability in the outcomes of those studies, some proving use of PRF being superior, some showing no additional effect and some even inferior outcomes with the use of PRF along with coronally advanced flap for the treatment of root coverage. This conflict in the results have led to the demand of further researches on this scope of periodontal plastic surgery treating gingival recession. Therefore, the aim of this study is to determine whether the use of an autologous platelet-rich fibrin membrane (PRF) to modified coronally advanced flap (MCAF) would provide additional benefit in root coverage compared to MCAF alone for the treatment of gingival recessions.

**RATIONALE OF STUDY**

The scientific rational behind the use of platelet preparations lies in the fact that it is the reservoir of many growth factors known to play a crucial role in hard and soft tissue repair. (25,26) Platelet rich fibrin has been claimed to enhance soft tissue healing, promote initial stabilization, revascularization of flaps and grafts in root coverage.  However, limited evidence is currently available verifying these claims. Therefore, this study is designed to investigate the effects of PRF on MCAF root coverage procedure. In the present study, the clinical outcomes will be evaluated over a period of 3 months, to evaluate the stability of the gingival margin after a MCAF.

This will be the first study of its kind evaluating the effectiveness of PRF when used in combination with coronally advanced flap in patient with Miller’s class I and class II recession in Nepalese population.

It is expected that performing this research will make it possible to;

·         better understand the effectiveness of using PRF in reduction vertical recession depth (VRD) and mean root coverage percentage (MRC%) after MCAF and MCAF + PRF procedures.

·         counsel the patients accordingly in Miller’s class I and class II recession defect for treatment with MCAF procedure alone or with addition of PRF membrane prepared from patients’ own blood.

  **REVIEW OF LITERATURE**

**Lang and Löe** (27) examined the width of the facial and lingual keratinized gingiva to determine gingival width "adequate" for the maintenance of gingival health. It was demonstrated that gingival health is compatible with a very narrow gingiva. However, in areas with less than 2 mm keratinized gingiva inflammation persisted in spite of effective oral hygiene. It is suggested that 2 mm of keratinized gingiva (corresponding to 1 mm attached gingiva in this material) is adequate to maintain gingival health.

**Bernimoulin** (15) first reported the coronally positioned graft succeeding grafting with a free gingival autograft. After increasing the width of the attached gingiva by free palatal mucosa transplants, 20 procedures with coronal flap repositioning were performed on 41 teeth with gingival recessions in 13 young adults. The amount of gingival recession and the clinical gingival sulcus depth were measured pre-operatively and 1, 6 and 12 months after surgery; the amount of osseous dehiscence was measured during surgery. No significant differences were found among reduction values of gingival recession by reattachment 1, 6 and 12 months post-operatively. Although a significant correlation was found between the degree of gingival recession preoperatively and 1 month post-operatively, non was found between the amount of alveolar bone dehiscence and gingival recession 1 month post-operatively.

**Maynard** (28) outlined the following requirements as criteria for success when using coronally positioned flaps: • The presence of shallow crevicular depths on proximal surfaces • Normal interproximal bone heights • Tissue height within 1 mm of the cemento-enamel junction of adjacent teeth • Six-week healing of the free gingival graft prior to coronal positioning • Reduction in root prominence • Adequate release of the flap during the second-stage surgery to prevent retraction during healing.

**Serino G et al.**(29) performed the cross-sectional and longitudinal analyses and showed that in subjects with a high standard of oral hygiene (i) buccal gingival recession was a frequent finding, (ii) the proportion of subjects with recession increased with age, (iii) the prevalence as well as the incidence of recessions within the dentition showed different patterns depending on age, (iv) sites with recession showed susceptibility for additional apical displacement of the gingival margin and (v) loss of approximal periodontal support was associated with gingival recession at the buccal surface.

**Fundac****Ìœ****ãoOdontoloÌgica de Ribeirão Preto** (30) published a study with 16 cases of localized gingival recessions varying from 3.5 to 10 mm (total recession) treated with a coronally positioned gingival autograft in conjunction with mechanical (root planing) and chemical (saturated citric acid) treatment of the exposed root surfaces. The results showed no significant change in sulcus depth, coverage of 72.17% of the exposed root surfaces, and a gain of 3.0 ± 1.4 mm in attached gingiva in areas where little or no attached gingiva had existed prior to treatment. A positive correlation between the bone level and total visible recession before treatment was also demonstrated. The study concluded that the coronally positioned gingival autograft is a highly predictable surgical technique for the treatment of large localized gingival recessions.

**Harris RJ, Harris AW** (31) used the coronally positioned pedicle graft with inlaid margins in the treatment of shallow recession areas. Utilizing the described technique, 20 isolated Class I defects were treated. Complete root coverage was obtained 95% of the time; the mean root coverage was 98.8%. The procedure resulted in a decrease in sensitivity, the final color and tissue contours of the grafts were excellent, and all patients were satisfied with the results. The coronally positioned pedicle graft with inlaid margins is a simple and predictable method to cover exposed root surfaces in shallow recession areas.

**Harris RJ** (32) examined 22 defects, in 19 patients, treated where less than complete root coverage was obtained at 4 weeks postoperative. Creeping attachment occurred in 21 of the 22 defects (95.5%), in 18 of the 19 patients (94.7%). Complete root coverage occurred in 17 of the 22 defects (77.3%), in 15 of 19 patients (78.9%). The mean creeping attachment obtained was 0.8 mm. Additionally, it was the goal of this study to see if any factor could be associated with creeping attachment. This study did not find any factors that could be associated with the amount of creeping attachment seen. Creeping attachment seems to occur commonly, but complete root coverage is not predictable.

**Serino G et al.** (17) performed a clinical controlled study to measure the tension of coronally advanced flap to treat shallow gingival recession and to compare recession reduction achieved in test group (flap with tension) 3months after surgery. The study showed that the minimal tension in the flap do not influence recession reduction after 3 months when shallow recession are treated by means of CAF. In test group (flap tension) statistical analysis suggests that higher the flap tension, lower the recession reduction.

[**Zucchelli G**](https://www.ncbi.nlm.nih.gov/pubmed/?term=Zucchelli%20G%5BAuthor%5D&cauthor=true&cauthor_uid=11022782)**,**[**De Sanctis M**](https://www.ncbi.nlm.nih.gov/pubmed/?term=De%20Sanctis%20M%5BAuthor%5D&cauthor=true&cauthor_uid=11022782)**.** (33) demonstrated that the proposed modified coronally advanced flap technique ( without vertical releasing incision) was very effective for the treatment of multiple gingival recessions affecting teeth in esthetic areas of the mouth and that these successful root coverage results could be achieved irrespective to both the number of recessions simultaneously treated during the surgical intervention and the presence, before surgery, of a minimal amount of keratinized tissue apical to the defects.

**J.** **Choukroun, A. Diss** (23) showed that Sinus floor augmentation with FDBA and PRF leads to a reduction of healing time prior to implant placement. From a histologic point of view, this healing time could be reduced to 4 months.

**de Sanctis M. and  Zucchelli G.** (19) treated forty isolated Miller class I or II gingival recessions in upper jaw with at least 1 mm of keratinized tissue apical to the defects with a modified approach to the coronally advanced flap and performed re-evaluation 1 year and 3 years post operatively. The main change in the surgical procedure consisted in the modification of flap thickness and dimension of surgical papillae during flap elevation. At the 1-year examination, the average root coverage was 98.6% of the pre-operative recession depth and 96.7% at 3 years. All changes of keratinized tissue were statistically significant. Hence, modified coronally advanced surgical technique was found to be effective in the treatment of isolated gingival recession in the upper jaw.

 **Santamaria et al.** (34)assigned nineteen subjects with bilateral Miller Class I buccal gingival recessions associated with non-carious cervical lesions to receive CAF or in combination with a resin-modified glass ionomer restoration (CAF+R) randomly. Bleeding on probing (BOP), probing depth (PD), relative gingival recession (RGR), clinical attachment level (CAL), non-carious cervical lesion height (CLH), and dentin sensitivity (DS) were measured at baseline; 45 days; and 2, 3, and 6 months postoperatively. Keratinized tissue width (KTW) and keratinized tissue thickness (KTT) were measured at baseline and 6 months. The height of the non-carious cervical lesion located on the root and crown were estimated, allowing calculation of root coverage. Both groups showed statistically significant gains in CAL and soft tissue coverage with no statistical significant differences.

**G. Zucchelli et al.** (33) compared root coverage and esthetic outcomes of the coronally advanced flap (CAF) with and without vertical releasing incisions in the treatment of multiple gingival recessions. Thirty-two systemically and periodontally healthy subjects with esthetic complaints due to the exposure of Miller Class I and II multiple (at least two) gingival recession defects affecting adjacent teeth of the same quadrant of the upper jaw were enrolled in the study. Sixteen patients (with 45 gingival recessions) were randomly assigned to the control group, and the other 16 patients (with 47 recession defects)were assigned to the test group. All recessions were treated with a CAF; vertical releasing incisions were performed in the control group, whereas an envelope-type flap was used in the test group. Clinical evaluation was done 1 year later. The study showed that the surgical time was significantly shorter in the envelope-type CAF group. No statistically significant difference was demonstrated between the two groups in terms of recession reduction and clinical attachment level gain. A statistically greater probability of complete root coverage and a greater increase in buccal keratinized tissue height were observed with the envelope type of CAF. The study concluded that envelope type of CAF was associated with an increased probability of achieving complete root coverage and with a better postoperative course. Keloid formation along the vertical releasing incisions was responsible for the worst esthetic evaluation made by an independent expert periodontist.

**Agudio** (6) performed a retrospective long-term split-mouth study to compare the periodontal conditions of sites treated with gingival-augmentation procedures to untreated homologous contralateral sites over a long period of time (10 to 27 years) and observed that the sites treated with gingival-augmentation surgery showed a tendency for coronal displacement of the gingival margin with a reduction in recession whereas the contralateral untreated sites showed a tendency for apical displacement of the gingival margin with an increase in the existing recessions. Thus, concluded that untreated gingival recessions show a negative prognosis over time in spite of good patient motivation, while the prognosis is improved after applying mucogingival procedures.

**Minkle Gulati et al.** (35) used coronally advanced flap (CAF) technique without vertical incisions using CAF brackets (CAF+B) for treating a patient presenting with class II gingival recession defects in relation to maxillary anteriors. Complete root coverage was observed, and the results were consistent even after 6 months. The current case report demonstrates good outcomes of the CAF + B technique without the use of any additional soft tissue grafts or vertical incisions, therefore, endorsing the promising potential of the CAF + B technique in multiple gingival recession cases.

Study showing superior effect on addition of PRF membrane to CAF when compared to CAF alone in terms of root coverage;

**A Sreedhar et al.** (36)enrolled 15 systemically healthy subjects presenting bilateral isolated Miller’s class I and II recession and randomly treated with a combination of CAF along with a platelet-rich fibrin (PRF) membrane on the test site and CAF alone on the control site. Recession depth (RD), clinical attachment level (CAL), and width of keratinized gingiva (WKG) were compared with baseline at 1, 3, and 6 months between test and control sites. Mean percentage root coverage in the test group after 1, 3, and 6 months was 34.58, 70.73, and 100, respectively. Differences between the control and test groups were statistically significant. This study also showed a statistically significant increase in WKG in the test group (2.94 ± 0.77 at baseline to 5.38 ± 1.67 at 6 months). The study concluded that CAF is a predictable treatment for isolated Miller’s class I and II recession defects. The addition of PRF membrane with CAF provided superior root coverage with additional benefits of gain in CAL and WKG at 6 months postoperatively.

In contrary to this study, some studies concerning single or multiple recessions showed no significant benefit with addition of PRF to CAF;

**Aroca S et al.** (37)studied on twenty subjects, presenting three adjacent Miller Class I or II multiple gingival recessions treating patient with MCAF on control side and combination of PRF on the test side Probing depth (PD), recession width, clinical attachment level (CAL), keratinized gingival width, and gingival/mucosal thickness (GTH) were measured at baseline and at 6 months post-surgery. Gingival recession was measured at baseline and at 1, 3, and 6 months post-surgery. The study concluded that MCAF is a predictable treatment for multiple adjacent Miller Class I or II recession-type defects. The addition of a PRF membrane positioned under the MCAF provided inferior root coverage but an additional gain in GTH at 6 months compared to conventional therapy.

**Thamaraiselvan, et al.** (38)performed a study to determine whether the addition of an autologous platelet rich fibrin (PRF) membrane to a coronally advanced flap (CAF) would improve the clinical outcome in terms of root coverage, in the treatment of isolated gingival recession. Materials and Methods: Systemically healthy 20 subjects each with single Miller’s class I or II buccal recession defect were randomly assigned to control (CAF) or test (CAF + PRF) group. Clinical outcome was determined by measuring the following clinical parameters such as recession depth (RD), recession width (RW), probing depth (PD), clinical attachment level (CAL), width of keratinized tissue (WKT), gingival thickness (GTH), plaque index (PI), and gingival index (GI) at baseline, 3rdand 6th month postsurgery. The root coverage was 65.00 ± 44.47% in the control group and 74.16 ± 28.98% in the test group at 6thmonth, with no statistically significant difference between them. Similarly, CAL, PD, and WKT between the groups were not statistically significant. Conversely, there was statistically significant increase in GTH in the test group. They concluded that addition of PRF to CAF provided no added advantage in terms of root coverage except for an increase in GTH.

**Gupta S et al.** (39) enrolled thirty isolated Miller class I or II sites in 26 subjects were randomly divided into test (15 sites- CAF+PRF) and control (15 sites- CAF alone) and evaluated periodontal parameters; probing depth (PD), recession depth (RD), clinical attachment loss (CAL), keratinized tissue width (KTW) and gingival tissue thickness (GTH) at baseline, 3 months and 6 months postoperatively. Both groups showed significant differences in all parameters at 3 and 6 months respectively except difference in gingival tissue thickness which was non-significant in control group at 3 months. The study concluded that combination of PRF to CAF procedure did not provide any added advantage in term of recession coverage in Miller class I and II recessions

Since, various studies have shown contradicting results with use of PRF along with CAF in terms of root coverage, this study has been designed to achieve the following objectives;

**OBJECTIVES**

**Primary Objectives**

Ø  To access and compare the postoperative change in vertical recession depth (VRD) after MCAF with and without PRF.

Ø  To compare the mean root coverage percentage (MRC%) in CAF with and without PRF at baseline with1 and 3 months.

**Secondary Objectives**

Ø  To compare the change in gingival thickness (GTH) and width of keratinized gingiva (WKG) after MCAF with and without PRF at baseline with1 and 3 months.

Ø  To access and compare the change in clinical parameters (PD, CAL) after MCAF with and without PRF at baseline with 1 and 3 months.

Ø  To access and compare the post-operative pain in MCAF procedure with and without PRF at 10 days.

**Research hypothesis (alternative)**

§  Addition of PRF membrane to MCAF provides superior root coverage when compared to MCAF alone.

**MATERIAL AND METHODS**

**Methods**:

**a. Instruments/questionnaire**: It is an instrument based study. The clinical periodontal examination will be carried out manually using UNC-15 probe (University of North Carolina-15 probe, it is 15 mm long with markings at each mm and color coding at 5th, 10th and 15th mm) and mouth mirror. Patients fabricated cast with dental stone will be used. Custom made acrylic occlusal stent with vertical groove placed at mid buccal region for precise alignment of probe will be used. Similarly, for preparation of PRF, 10 ml syringe to collect intravenous blood (by venupuncture of the antecubital vein) from the patient, will be transferred into a test tube and centrifuged immediately without the addition of anticoagulant at 3000 rpm in PRF machine. The fibrin clot will be formed in the middle part of the tube. The upper part will contain an acellular plasma, and the bottom part, the red corpuscles. The fibrin clot easily separated from the lower part of the centrifuged blood will be spread on a sterile dry gauze. The gauze will be folded over the PRF to squeeze out fluids from fibrin clot to obtain PRF membrane.

**b. Frequency and duration of intervention/follow up of subjects :**

Patients will be recalled at 10 days for suture removal, and 1 month and 3 months for reevaluation of clinical outcomes.

**C.Procedure and Schedule:**

Patients with Miller’s class I and class II gingival recession diagnosed on the basis of clinical and radiographic features will be included in the study as per inclusion and exclusion criteria of study from Outpatient examination (OPE) on daily basis from Department of Periodontology and Oral Implantology, College of Dental Surgery, B. P. Koirala Institute of Health Sciences, Dharan, Nepal.

34 recession defects will be randomly assigned to two treatment groups by comuputer generated randomization.  The control group will include 17 defects which will be treated with CAF alone, whereas the test group with 17 defects will be treated with CAF with PRF. For all the enrolled patients routine radiographic and blood investigations will be done. The initial therapy will consist of nonsurgical periodontal therapy as indicated. Four weeks following phase I therapy, a periodontal re-evaluation will be performed. All clinical parameters will be recorded by a single examiner at baseline (BL), 1 and 3 months who will be masked about the treatment groups. The periodontal examinations will include periodontal parameters like vertical recession depth (VRD), mean root coverage percentage (MRC %), gingival thickness(GTH), width of keratinized gingiva (WKG), probing (PD), clinical attachment level (CAL), recorded at base line, 1 month and 3 months postoperatively using William’s periodontal probe. The RD will be measured at mid-facial region of the tooth from CEJ to the free gingival margin. The clinical attachment level will be measured from a fixed reference point (CEJ) to the base of the sulcus using customized stent. The WKG will be determined by subtracting the RD from the CEJ-MGJ (mucogingival junction). The percentage of root coverage will be calculated according to the following formula;

([RD preoperative - RD postoperative]/RD preoperative) × 100%.(40)

GTH will be measured 3 mm below the gingival margin at the attached gingiva or the alveolar mucosa using a #15 endodontic reamer with a silicone disk stop. The is reached. The silicone stop on the reamer will be slid until it is in close contact with the gingiva. After removal of the reamer, the distance between the tip of the reamer and the inner border of the silicone stop will be measured to the nearest 0.1 mm with calipers.

After local anesthesia, surgical operations in both groups (test and control) will be performed. Recession defects will be thoroughly scaled using Gracey curets. No root conditioning will be used. Modified Coronally Advanced Flap technique will be undertaken (22) using a modified suturing technique .In contrast to conventional technique, this Zucchelli’s modification of CAF procedure avoids need for vertical releasing incision. Hence, guarantees adequate blood supply, no unaesthetic scar along the incision line and also allows adequate coronal advancement as it is split-full-split thickness flap.(22)The flap design will be as follows: Oblique submarginal incisions will be made in the interdental areas connecting intracrevicular incisions at recession defects. The incisions will be extended to include one tooth on each side of the teeth to be treated to facilitate coronal repositioning of the flap. Split-full-split flap incisions will be performed in a coronal–apical direction. Gingival tissue adjacent to the root defect and the interproximal bone will be raised full thickness to provide maximum soft tissue thickness of flap to be positioned coronally over the denuded root, whereas the most apical portion of the flap will be split thickness to allow coronal repositioning of the flap without tension. All papillae will be deepithelialized to create a connective tissue bed.

In the test group, intravenous blood will be collected in 10-ml vial without anticoagulant and immediately centrifuged (i.e. within a minute) at 3,000 revolutions per minute for 10 minutes. The fibrin clot will be formed in the middle part of the tube. The upper part contained an acellular plasma, and the bottom part contained the red corpuscles. The fibrin clot will be easily separated from the lower part of the centrifuged blood and spread on a sterile gauze. Dry gauze will be folded over the PRF. At the test sites, the freshly prepared PRF membrane will be positioned over the recession defects, just below the CEJ. The gingival flap will be repositioned and secured with its margin 1-2 mm coronal to CEJ by horizontal suspensory sutures around the contact points on the test and control sides. Stabilization of the blood clot will be achieved by the application of gentle pressure for 3 minutes.

Patient will be recalled on 10th day and postoperative discomfort will be measured using visual analog scale (VAS) where 0 stands for no pain, 5 moderate pain and 10 an unbearable/ worst pain. Suture removal will also be done on 10th day. The postsurgical measurements of clinical parameters on 1 month and 3 months will be done by the same trained examiner blinded for the 2 groups. Change in clinical parameters will be determined by comparing the postsurgical measurements at each site with the baseline values.

**d. Dosage, formulations, schedules, duration of drug treatments/ surgical technique, suture;**

Patients will be prescribed analgesics for post-surgery discomfort;

Tablet Ibuprofen 400mg tid for 2 days then SOS.

0.2% chlorhexidine oral rinse for plaque suppression twice for two weeks.

Patients will be advised not to brush their teeth in the operated areas until after suture removal 2 weeks later. They will be instructed to rinse their mouth with a 0.2% chlorhexidine solution, two times a day for 1 minute, for 3 weeks. Fifteen days after surgical treatment, all patients will be reviewed and instructed in mechanical tooth cleaning in the operated areas using a soft toothbrush and a roll technique. All patients will be recalled for evaluation at 1 month and at 3 months after suture removal.

 **DATA MANAGEMENT AND STATISTICAL ANALYSIS**

a.             **Data handling:** The entire questionnaire will be checked for its accuracy in every month. Collected data will be entered in Microsoft excel 2007 and again checked on every 10 entries to avoid entry error.

b.            **Coding:** A coding list will be prepared. On the basis of coding data will be entered into computer.

c.             **Monitoring:** Supervision and monitoring will be done for entered data by guide and co-guide at regular interval

d.            **Statistical methods proposed****:**

The excel data will be converted into Statistical package for Social Science (SPSS, version 16) for statistical analysis. Percentage distribution of subjects with Miller’s class I and class II gingival recession will be tabulated in each group and with change in vertical recession depth (VRD) after periodontal surgery. Descriptive statistics will be used to explore characteristics of numeric data, calculation of mean, SD and range. Normalacy of variables will be checked. Student t-test or Mann Whitney U-test will be used to compare the clinical parameters in between two groups. Paired sample t-test or Wilcoxon’s signed rank test will be used to compare the variables into the same groups in each follow-up. Probability of significance will be set at 5% level.

**Calculation of the sample size**

According to a literature by **Sofia Aroca et al** in 2009(37), the mean ± SD of root coverage percentage as a clinical parameter among test and control groups have been reported as 80.7 ± 14.7 and 91.5 ± 11.4 respectively. Considering the minimum difference of 10.8 in root coverage percentage in between the groups and minimum standard deviation as 11.4, the sample size has been calculated for two means comparision. If each group are normally distributed, we need to enroll 17 defects in each group to be able to reject the alternate hypothesis that both the means are equal with 80% power and 95% confidence interval (CI).

**LIST OF ABBREVATIONS**

BL            : Baseline

CAF         : Coronally Advanced Flap

CAL         : Clinical Attachment Level

CEJ         : Cemontoenamel Junction

GTH         : Gingival Thickness

MCAF      : Modified Coronally Advanced Flap

MGJ        : Mucogingival Junction

MRC%    : Mean Root Coverage percentage

PD         : Probing Depth

PRF        : Platelet Rich Fibrin

RW          : Recession Width

VRD        : Vertical Recession Depth

WKG       : Width of Keratinized Gingiva

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Detailed Description

Not available

Study Timeline

• Study Start: 2019-05-09
• Last Update Posted: 2019-08-22

Recruitment & Eligibility

• Status: Not Applicable
• Sex: All
• Target Recruitment: 34

Inclusion Criteria

Patients with multiple Miller’s Class I and class II gingival recession Width of Keratinized Gingiva ≥ 3 mm Patients age between 20 to 50 years Patient with at least 20 natural teeth within both jaw.

Exclusion Criteria

inflammatory periodontal disease, PD (probing depth) >3mm, previous surgical attempt to correct gingival recession, patient with known systemic disease or severe immune deficiency, pregnancy, smokers, patients receiving treatment with any medications known to affect the periodontal health, malpositioned tooth.

Study & Design

• Study Type: Interventional
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
VRD (Vertical Recession Depth)	1,3 months
MRC % (Mean Root Coverage percentage)	1,3 months

Secondary Outcome Measures

Name	Time	Method
Gingival thickness,	Width of Keratinized Gingiva,

Trial Locations

Locations (1)

College Of Dental Surgery; 🇮🇳 Room, 7, CODS,BPKIHS, India

College Of Dental Surgery

🇮🇳Room, 7, CODS,BPKIHS, India

Dr Ripu Singh

Principal investigator

9843670496

drripusingh2017@gmail.com