Influence of Gingival Biotype on the Outcome of Open Flap Debridement
Condition: Chronic Periodontitis
MeSH terms: Periodontitis; Chronic Periodontitis
Study type: Interventional

Summary: 
      The influence of periodontal thickness has been documented in outcome of various periodontal
      interventions like non surgical periodontal therapy, mucogingival therapy, guided tissue
      regeneration (GTR), crown lengthening and implant dentistry. There is lack of study showing
      the influence of gingival biotype on outcome of surgical procedure. The present study is
      therefore undertaken to evaluate the influence of gingival biotype on the outcome of open
      flap debridement for treatment of chronic periodontitis.
    

Detailed description: 
      Periodontitis is inflammation of the periodontal tissues resulting in clinical attachment
      loss, alveolar bone loss, and periodontal pocketing. Chronic periodontal disease can be
      successfully treated by non-surgical or surgical mechanical therapy provided adequate plaque
      control is maintained during the supportive phase of treatment. Elimination of these pockets
      by the therapist is necessary to allow the patient better access for plaque control. The goal
      of periodontal therapy, therefore, should include the creation of an oral environment in
      which the patient can cleanse every surface of every tooth. Ideally, this would be best
      accomplished by complete regeneration of the lost attachment apparatus and reestablishment of
      a minimal depth of sulcus.

      It is seen that in pockets with shallow probing depths(1-3mm), there is reduction of pocket
      depth and loss of attachment by all the treatment modalities and more following surgical
      treatment. Lindhe et al. (1982) defined a critical probing depth below which the nonsurgical
      therapy is most likely to lead to loss of probing attachment In sites with moderate probing
      depth (4-6mm), there is more pocket reduction following MWF than subgingival curettage and
      SRP. Attachment gain is seen following all techniques and more following modified widman flap
      (MWF).

      Deep pockets(>7mm) have shown reduction in probing depth following all the treatment
      modalities but more reduction is seen following MWF. More gain in attachment is seen
      following MWF than subgingival curettage.

      Ramfjord observed an increase in pocket depth following periodontal treatment in shallow
      pockets. He also found loss of attachment with surgical therapy in moderate probing depth.

      Histological findings in humans have revealed that there is loss of crestal bone as a
      consequence of periodontal surgical treatment. The resorption pattern varied with thickness
      of connective tissue covering the bone and was modified by injury to bone due to contact or
      near contact during instrumentation. Measurement indicated resorption occurs if retained
      tissue is 0.45 mm or less.

      The influence of periodontal thickness has been documented in outcome of various periodontal
      interventions like non surgical periodontal therapy, mucogingival therapy, GTR, crown
      lengthening and implant dentistry.

      Studies have shown that sites with thin gingiva lost attachment while no attachment loss is
      seen in sites with thick gingiva following non surgical therapy. Gingival thickness ≥0.8mm is
      associated with better root coverage with coronally advanced flap. Less recession is seen
      after GTR in sites with gingival thickness >1mm than the sites with <1mm. Thick biotype is
      also correlated with greater tissue rebound following surgical crown lengthening. Greater
      tissue recession is seen around implant with thin biotype.

      Predictability of outcome following surgical procedures is of fundamental importance. Perusal
      of the available literature hints towards the need to further explore factors influencing the
      outcome of surgical procedures for the management of periodontitis. Periodontal biotype is
      one among such important factors.

      The present study is therefore undertaken to evaluate the influence of gingival biotype on
      the outcome of open flap debridement for treatment of chronic periodontitis.

      MATERIAL AND METHOD This study will be conducted in Department of Periodontics and Oral
      Implantology, Post Graduate Institute of Dental Sciences(PGIDS), Rohtak.

      STUDY POPULATION Patients will be screened from outpatient department of Periodontics and
      Oral Implantology. The study will be conducted in 36 chronic periodontitis patients who had
      undergone phase 1 periodontal therapy.

      Gingival biotype will be assessed by visibility of the periodontal probe through the gingival
      margin.

      Group 1: Patient with thin biotype (periodontal probe is visible) Group 2: Patient with thick
      biotype (periodontal probe is not visible)

      METHODOLOGY Periodontal examination Parameters recorded at baseline (on the day of surgery),
      at 3 months and 6 months follow up visit will be Plaque index (Silness and Loe) (PI) ;
      Gingival index (Loe and Silness) (GI); Bleeding on probing (BOP); Probing pocket depth (PPD);
      Clinical attachment level (CAL) and Gingival recession (REC). Probing pocket depth (PPD),
      Clinical attachment level (CAL). BOP will be assessed as a dichotomous measure (bleeding
      present or absent) within 15 seconds of probing. PPD will be recorded from gingival margin to
      base of pocket, and CAL from cementoenamel junction (CEJ) to base of pocket with university
      of North Carolina (UNC) 15 probe.

      Methodology Patients meeting eligibility criteria will receive phase1 periodontal therapy
      consisting of scaling and root planing (SRP). SRP will be completed with ultrasonic scaler
      (EMS Piezon 250 ,Switzerland), hand scaler and curettes (Hu-Friedy) within two visits.

      PERIODONTAL SURGICAL PROCEDURE After healing period of 8 weeks, clinical evaluation will be
      repeated and patients presenting atleast 4 residual periodontal pockets measuring ≥4 mm in
      maxillary or mandibular anterior segment will be subjected to surgical intervention. The
      study procedure will be explained to the patient in their own language. Written informed
      consent will be obtained from each patient.

      Modified Widman flap surgery will be performed in both groups as described by Ramfjord and
      Nissle.37,38 After meticulous debridement, root planning and thorough irrigation with normal
      sterile saline solution, mucoperiosteal flaps will be repositioned and secured by using 3-0
      black silk suture. Post operative instructions will be given.

      POST OPERATIVE CARE Patients will be given both verbal and written instructions about post
      operative care including mouthrinse with 0.12% chlorhexidine digluconate solution twice daily
      for two weeks. All patient will be prescribed Amoxycillin 500mg thrice daily for 5 days and
      Ibuprofen 400 mg thrice daily for two days. Sutures will be removed after 1 week.

      STATISTICAL ANALYSIS A minimum sample size of 18 patients in each group was calculated to be
      sufficient to detect a clinically important difference of 1mm gain in clinical attachment
      level with standard deviation of 1mm, 80% power of study and alpha level=0.05.To compensate
      for the expected dropouts in patient pool overtime, 20 patients will be involved in each
      group of this study.

      Data recorded will be processed by standard statistical analysis. All statistical analysis
      will be carried out using statistical software (SPSS, Version 25.0 for Windows, SPSS,
      Chicago, IL).The normality of distribution of the data will be assessed using the
      Shapiro-Wilk test. . If it is in normal distribution, intra group comparison will be done by
      paired T test between two time points and inter group comparison will be done by using
      Independent T test between two groups. If it is in non normal distribution, intra group
      comparison will be done by Wilcoxon signed rank test and inter group comparison will be done
      by Mann-Whitney U test.. Statistical analysis of BOP will be done by McNemar test in
      intragroup and Chi-square test for intergroup comparison. Correlation and association between
      predictors and dependent variables will be analyzed by correlation analysis and regression
      analysis. Statistical significance level will be set at P≤0.05.
    

Intervention name(s): open flap debridement
Intervention type(s): Procedure
Intervention description(s): Modified Widman flap surgery followed by meticulous debridement, root planning and thorough irrigation with normal sterile saline solution
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment