Effect of Locally-Applied Simvastatin on Clinical Attachment Level and Alveolar Bone in Periodontal Maintenance Patients
Condition: Periodontal Diseases
MeSH terms: Periodontal Diseases
Study type: Interventional
Phase: Phase 4

Summary: 
      The purpose of this study is to determine of local application of commericially-available,
      FDA-approved preparation of simvastatin is effective in increasing clinical attachment levels
      (primary outcome), as well as alveolar bone (secondary outcome) compared to standard
      mechanical therapy in patients on periodontal maintenance therapy (PMT). Subjects undergoing
      PMT at the UNMC College of Dentistry clinics will be recruited to participate in the
      randomized one-year clinical trial based on the following eligibility criteria: 1) diagnosis
      of chronic advanced periodontitis (generalized or localized), 2) participating in regular PMT
      visits (3-6) month intervals), 3) no systemic diseases or medication which significantly
      impact periodontal inflammation or bone turnover (e.g. steroids, bisphosphonates, > 325 mg
      aspirin/day and in good general health, 4) one experimental quadrant of the mouth with an
      inflamed 6-9 mm interproximal posterior periodontal pocket with history of bleeding on
      probing (BOP), 5) willingness to sign consent form. Subjects will be divided into two groups
      for additional therapy in a 6-9 mm interproximal periodontal pocket at baseline: 1) local
      anesthesia and mini-flap reflection with subgingival mechanical debridement plus application
      of the simvastatin-methylcellulose gel or 2) local anesthesia and mini-flap reflection with
      subgingival mechanical debridement plus application of methylcellulose gel alone.
      Samples/measurement will be obtained at the designated experimental site at baseline, 2
      weeks, 6 and 12 months during PMT: 1) digital radiographs (baseline and 12 months only; bone
      height measurements), 2) presence of explorer-detectable supragingival plaque, 3) 30-second
      gingival crevicular fluid (GCF) sample (markers of inflammation, bone turnover), 4) recession
      from the cemento-enamel junction, 5) probing pocket depth and bleeding on probing (BOP).
      Following the 12-month visit, the research-specific intervention and measurements in the
      experiment quadrant will be removed from routine PMT.
    

Detailed description: 
      Dental records of patients attending routine periodontal maintenance therapy visits at the
      UNMC College of Dentistry clinics are reviewed as part of the direct supervision by faculty,
      including investigators involved int his study. Assessment includes review of medical and
      dental histories and previous oral hygiene and periodontal charting. Subjects who appear to
      qualify (40-85 years old, diagnosis of advanced chronic adult periodontitis, one quadrant
      with at least 3 posterior teeth and one 6-9 mm periodontal pocket, no systemic diseases or
      medications which significantly impact periodontal inflammation and bone turnover) will be
      informed of the study, given an opportunity to ask questions, and given an informed consent
      form to take home. Once signed consent is obtained, subjects will be randomized to one of the
      two groups: 1) SRP + SIM or 2) SRP + methylcellulose.

      At the baseline visit, all women subjects will be given a urine pregnancy test. Once the
      pregnancy test is determined to be negative, the following sequence of procedures will be
      performed by the faculty investigator (AK, RR, RH): 1) assignment of the experimental site
      (6-9 mm pocket with previous bleeding on probing); 2) remove supraginigval plaque from the
      experimental tooth with explorer [record positive sites]; 3) insert paper strip into facial
      and lingual of experimental site sulcus for 30 seconds for gingival crevicular fluid (GCF)
      sample, remove and place into sterile vial, and freeze at -80º C for testing inflammation
      markers; 4) measure recession on experimental teeth and adjacent interproximal tooth at
      mesial-facial, mid-facial, distal-facial, mesial-lingual, mid-lingual and distal lingual with
      UNC 15 probe; 5) measure probing pocket depths at same surfaces as recession; 6) record sites
      that bleed within 30 seconds. After the faculty investigator (primary or secondary
      investigator) leaves, the participating personnel (LK) will; 7) take a baseline radiograph,
      administer local anesthesia to the experimental site via local injection, 9) surgical
      mini-flap reflection localized to the experimental site (papilla reflection), 10) remove most
      of the remaining interproximal soft tissue to allow access to the root and measure markers of
      inflammation, 11) scaling/root planing of site to remove supra- and subgingival bacterial
      plaque and calculus; 12) placement of SIM-methylcellulose gel, 13) repositioning of papilla
      to initial location and placement of intra-oral cyanoacrylate; 14) finish full-mouth
      measurement of probing depths and bleeding on probing; 15) perform full-mouth scaling to
      remove supra- and subgingival bacterial plaque and calculus; 16) review oral hygiene
      instructions.

      It is possible that steps 14, 15 and 16 could be completed prior to steps 1-13 on all teeth
      except experimental and adjacent teeth due to availability of faculty investigators at the
      time of the PMT appointment.

      It is also possible that steps 1-13 could be completed at a separate appointment.

      Subjects will return for postoperative visit in two weeks. Subjects will return for
      subsequent PMT visits after 3, 6, 9 and 12 months. Steps 14-16 will be completed at each
      visit as part of routine PMT. At 6 and 12 months, steps 2-6 will also be completed. At 12
      months, a radiograph will also be taken.

      Dental record data that will be recorded at each visit includes probing depths (PD),
      recession, bleeding on probing (BOP) and presence of plaque (+/-) at test site and adjacent
      interproximal sites.

      The expected amount of time for the baseline visit in 90-120 minutes. The expected amount of
      time for subsequent visits in 60-90 minutes.
    

Intervention name(s): Methylcellulose; Simvastatin-Methylcellulose
Intervention type(s): Other; Drug
Intervention description(s): Methylcellulose gel will be placed in a deep (6-9 mm) periodontal pocket.; Simvastatin-Methylcellulose gel will be placed in a deep (6-9 mm) periodontal pocket.
Other intervention name(s): Simvastatin
Intervention MeSH terms: Simvastatin
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary purpose: Treatment