Effect of Simvastatin Combined with Photobiomodulation Therapy on Orthodontic Tooth Movement and the Expression of Metalloproteinases and Inhibitors - An Experimental Study.

Statins, such as simvastatin, are commonly used to treat hyperlipidemia and prevent cardiovascular diseases. However, simvastatin may suppress osteoclastogenesis, potentially reducing dental movement during orthodontic treatment. To mitigate this effect, low-level laser irradiation can be used for its photobiomodulatory properties. This study aims to assess the impact of combining simvastatin with photobiomodulation therapy on the regulation of bone metabolism. In this study, 56 male Wistar rats were divided into four groups: G1 - no orthodontic movement or simvastatin (n = 8); G2 - orthodontic movement with simvastatin 2.5 mg/kg (n = 16); G3 - orthodontic movement with saline solution and low-level laser 808 nm 1 J/point (n = 16); and G4 - orthodontic movement with simvastatin and low-level laser 808 nm 1 J/point (n = 16). Simvastatin was administered for 14 days, and dental movement was initiated with mini implants for the length of 7 or 14 days. Photobiomodulation occurred every 48 h during the experiment. The animals were euthanized after 14 and 21 days for clinical, histological, and micro-computed tomography analysis, as well as matrix metalloproteinase 2 (MMP2) and TIMP metallopeptidase inhibitor 1 (TIMP1) quantification. Statistical analysis was conducted using R software with a 5% significance level. Group G2 showed significantly less dental movement than G3 and G4 (p < 0.05). The BV/TV ratio was higher in G4 compared to G1 and G2. MMP2 levels were higher in G4 than G1 and G2 after 14 days, and in G3 compared to G2. After 21 days, MMP2 was higher in G2 and G3 than G1 and G4, and lower in G1 than G4 (p < 0.05). The results suggest that simvastatin reduces dental movement compared to laser-treated groups.