Antimicrobial photodynamic therapy (aPDT) is characterized by the association of photosensitizing agents, promoting the generation of reactive oxygen species like free radicals and singlet oxygen, which are cytotoxic to certain bacteria. Simvastatin (SMV) enhances alkaline phosphatase activity and increases the expression of bone sialoprotein, osteocalcin, and type I collagen and is shown to have an anti-inflammatory effect by decreasing the production of C-reactive protein (CRP), IL-6, and IL-8. SMV is also reported to stimulate VEGF release in a dose-dependent manner which promotes osteoblast differentiation and bone nodule formation. The aim of this study is to evaluate the adjunctive effects of SMV with and without aPDT in chronic periodontitis patients.

Inclusion Criteria:

• Patients were all healthy and free from any systemic disease;
• no history of antibiotic therapy or periodontal treatment for at least 6 months preceding the study;
• patients were willing and able to return for multiple follow-up visits;
• good levels of oral hygiene

Exclusion Criteria:

• Pregnant and lactating female patients,
• smokers,
• alcoholics,
• those receiving any medication that could affect healing of soft or hard tissue