Root coverage of Millers Class I and II Gingival recession defects following non-surgical periodontal therapy: A prospective clinical study

The goal of periodontal therapy is to arrest inflammation and prevent further disease progression. This involves removing the subgingival biofilm through mechanical means and creating a favourable environment and microflora compatible with periodontal health. Successful treatment of chronic periodontal disease requires non-surgical or surgical mechanical therapy, provided that adequate plaque control is maintained during the supportive phase of treatment.1 Both non-surgical and surgical treatment modalities are used throughout the active phase of therapy to achieve these objectives. Nonetheless, non-surgical periodontal treatment remains the gold standard for managing periodontal patients.

Multiple therapeutic options are available for effectively addressing the issue of gingival recession, and these treatments exhibit a high success rate. Gingival recession can arise from various factors such as bacterial, anatomical, chemical, or mechanical trauma, but it is primarily driven by the presence of inflammation and bone loss.2 Patient phenotype also plays a role in influencing the development of gingival recession. Non-surgical periodontal therapy presents a promising solution for effectively managing gingival recession, as it addresses the underlying causes of the condition, promotes tissue healing, and has the potential to restore a healthier gingival margin.

Persistent dentinal hypersensitivity following topical use of antihypersensitivity medications and aesthetic concerns are the primary indications for surgical root coverage procedures. Hence recessions ≥2mm deep are treated by surgical approaches, while shallow recessions <2 mm do not receive any specific treatment. Nevertheless, shallow recessions are subject to progression.

The outcomes of periodontal therapy, whether surgical or nonsurgical, can vary due to the inherent variability in the healing process. Both types of therapy involve manipulating the affected tissues, creating wounds in an already inflamed periodontal environment.3 The disruption of the attachment between the epithelium and underlying tissues elicits an acute inflammatory response within the connective tissue. Following a brief delay of 12-24 hours, epithelial migration commences, accompanied by a gradual reduction in inflammation. Around the fifth day, the formation of new epithelial attachment commences, and over the subsequent 1 to 2 weeks, the residual rete pegs involute, resulting in the development of healthy-looking gingiva.4 While its main goal is to decrease inflammation and manage infection, nonsurgical therapy can also positively impact the width and thickness of keratinized tissue. Overall, it is through the intricate biological communication and the body’s healing capacity that nonsurgical periodontal therapy can bring about these beneficial effects.

Unfortunately, the subject of recession coverage after non-surgical periodontal therapy has not garnered substantial consideration thus far. At present, only a few studies have demonstrated successful root coverage via non-surgical modalities.5-8 Therefore, this study aimed to evaluate theeffect of non-surgical debridement on the healing of marginal tissue in terms of changes in recession height, width, keratinized tissue width, and thickness in patients with Miller’s class I & II recession over a 6-month period.

Materials and Methods

This prospective clinical study will include 95 patients aged between 19 and 60 years, who will present to Department of Periodontics, SCBDCH with Miller’s class I and II gingival recession. It will be conducted in accordance with the 1975 Declaration of Helsinki, as revised in 2000.  All the participants will sign an informed consent form and will be duly explained of all the relevant details and clauses prior to engagement in the study. The criteria for inclusion and exclusion were defined as follows:

a)     Inclusion criteria

·       Age range of 18 to 60 years

·       Subjects presenting with Miller’s Class I or II gingival recession defects on the anterior teeth or premolars, in either arch

·       Subjects having identifiable CEJ at the recession sites.

·      radiographic evidence of sufficient interdental bone (the distance between interdental crestal bone and cemento-enamel junction ≤2 mm)

·      difference in extension of gingival recession between left and right ≤1 mm

·       Tooth vitality and absence of malposition, cervical abrasions, caries, or restorations in the area to be treated

·       Patient willing to and fully capable of complying with the study protocol

b)    Exclusion criteria

·       Patients with systemic co-morbidities (uncontrolled diabetes mellitus, immunocompromised patient, psychological problems, radiotherapy to head and neck region in past 24 months etc.)

·       Individuals with deleterious habits like chronic alcoholism, smoking, and tobacco intake in any form

·       Patient under medications that may potentially impact treatment outcomes

·       History of prior periodontal surgical interventions in the affected sites

After power-analysis calculation to achieve 80% power with a 5% significance level and effect size of 0.5 in reduction of probing pocket depth, 95 patients are needed, and considering a loss of up to 10%, as reported in previous study, a final sample size of 105 was defined appropriate for this study.

All patients will receive full mouth non-surgical periodontal therapy (NSPT) which includes supragingival full mouth ultrasonic scaling, root planing and oral hygiene instructions. Patients will be instructed to employ a modified Bass brushing technique with a soft toothbrush and an unwaxed dental floss for interdental cleaning. These procedures will be maintained and monitored for the entire experimental period. Following the achievement of a full-mouth plaque score (FMPS) and a full-mouth bleeding score (FMBS) ≤ 20% score and the absence of plaque and bleeding at the selected sites, patients will be  enrolled in the study and will sign a written consent form approved by the Institutional Ethics Committee, SCB Dental college and hospital, Cuttack. Additionally, a rigid stent will be fabricated on the study model, including one tooth anterior and posterior to the concerned tooth. This stent will serve as a stable reference point for vertical measurements.

Clinical parameters, including Plaque Index score9 (PI), gingival index score10 (GI), calculus component of OHI-S11,recession height (RH), recession width (RW), width of keratinized tissue (KTW), and thickness of keratinized tissue (KTT) will be recorded at baseline (immediately prior to the commencement of initial treatment) and during subsequent follow-up appointments scheduled at intervals of 2 weeks, 1 month, 3 months, and 6 months post therapy. PI and GI will be measured at the four surfaces of each tooth namely labial, lingual/palatal, mesial and distal. RH and KTW will be scored at the mid-buccal aspect of experimental teeth and rounded to the nearest 0.5 mm. KTW will be calculated by gauging the distance between the gingival margin and the mucogingival junction. KTT will be recorded by means of a calliper to the nearest 0.1 mm at a mid-buccal location approximately 3 mm apically to the gingival margin with a number 20 endodontic K file.12 The file will be inserted perpendicularly to the mucosal surface, gently piercing through the soft tissue until a hard surface was felt. The silicone disk stop will be slid and placed in tight contact with the soft tissue surface by fixing with a drop of cyanoacrylate adhesive to ensure accurate measurement of thickness. All periodontal parameters, apart from KTT will be assessed using the UNC-15 probe.

Statistical Methods and Data Analysis

The data will be collected and entered in Microsoft Excel version 2007 (Windows) and imported to SPSS version 27 (IBM corporation) for further analysis. All the continuous variables will be expressed in terms of mean and standard deviation (S.D.). Normality of the continuous variables will be assessed using Kolmogorov-Smirnov test. Changes in continuous variables over time will be assessed using repeated measures ANOVA test. Post-hoc analysis for pair wise comparison will be done using LSD method. The association between calculus score and the amount of root coverage will be evaluated using an unpaired t-test. p value less than 0.05 will be considered statistically significant.