Modified perforated membrane (MPM) is considered as a modality that could enable participation of periosteal cells and gingival stem cells which could improve the outcomes of guided tissue regeneration more than the use of the traditional occlusive membrane (OM). Simvastatin (SMV) modulates bone formation by increasing the expression of bone morphogenetic protein 2 and angiogenesis. Ethylenediaminetetraacitic acid (EDTA) found to be effective as low ph etchant for smear layer removal and exposing root surface collagen. The investigators compared the clinical and radiographic outcome of SMV gel combined with MPM to SMV gel combined with OM with and without an associated EDTA gel root surface etching for improving bone regeneration in intrabony defects in chronic periodontitis patients. Moreover, evaluation of SMV gingival crevicular fluid (GCF) levels availability for 30 days in cases with and without EDTA root surface etching was performed.

Forty patients with 40 intrabony defects having chronic periodontitis were randomly assigned into four equal groups to receive open flap procedure, 1.2% SMV gel and covering the defect with OM (Group I), open flap procedure, 1.2% SMV gel and covering the defect with MPM (Group II), open flap procedure, 24% EDTA root surface etching,1.2% SMV gel and then coverage of the defect by OM (Goup III), or open flap procedure, 24% EDTA root surface etching, 1.2% SMV gel and then coverage of the defect by MPM (Group IV). Plaque index, gingival index,probing pocket depth, clinical attachment level, defect base level, crestal bone level, and radiodensitometric measurements were measured at baseline and reassessed at 6 and 9 months after therapy. Additionally, GCF was collected from group I, II, III and IV at 1,7,14, 21, and 30 days in order to evaluate SMV availability and the effect of EDTA root surface etching on its availability using High-performance liquid chromatography(HPLC).

Inclusion Criteria:

• Patients were all healthy and free from any systemic disease.

• No history of antibiotic therapy or periodontal treatment for at least six months preceding the study.

• Patients were willing and able to return for multiple follow up visits.

• Periodontal defects with

  1. Probing depth > 5 mm.
  2. Clinical attachment loss >4 mm.
  3. Standardized radiographic evidence of interproximal intrabony defect using periapical radiograph.

• Good level of oral hygiene (plaque and gingival indices score after initial phase therapy should be less than one).

Exclusion Criteria:

• Pregnancy, lactation for female patients.
• Smokers, alcoholics and those receiving any medication that could affect healing of soft tissue and bone as steroids and cyclosporines.
• History of allergic reaction to the medications used.
• Vulnerable groups and handicapped.