Effect of Simvastatin on kinetics of Osteoprotegrin/receptor activator nuclear kappa B Ligand mRNA expression in periapical lesions


Correspondence: Abbasali Khademi, Department of Endodontics and Torabinejad Research Center, Esfahan Dental College, Esfahan University of Medical Science, Esfahan, Iran (e-mail: a-khademi@dnt.mui.ac.ir).



To evaluate the therapeutic effect of Simvastatin on apical periodontitis in rats by assessing the osteoblast production of receptor activator of nuclear factor–Kappa B Ligand (RANKL) and Osteoprotegerin (OPG) cytokines that are essential for bone resorption.


Twenty-five healthy 8- to 10-week-old male rats were selected. Periapical lesions were induced by exposure of pulps through the occlusal surfaces of mandibular first molars. The pulps were extirpated and canals contaminated with saliva. The teeth were filled temporarily to make animal feeding feasible. The experimental group (n = 12) was placed on 20 mg−1 kg−1 day−1 of Simvastatin for 10 days (3 days before and 7 days after pulp exposure) and the control group (n = 12) received a placebo. After 1, 2 and 4 weeks, the animals were sacrificed and mRNA expression of OPG/RANKL was evaluated by real-time PCR. One rat was sacrificed without any interventions (negative control) to determine the baseline expression of the mediators involved. Data were analysed by one-way anova.


Simvastatin significantly (< 0.05) enhanced the expression of OPG and reduced the mRNA expression of RANKL in the experimental group compared with the control group.


Oral administration of Simvastatin attenuated RANKL expression and accelerated OPG expression in induced rat periapical lesions.