Histological and immunohistochemical evaluation to the effects of orally ingested atorvastatin on the alveolar bone of white albino rats

Introduction Statins have been used as prospective agents in the management of some bone diseases as osteoporosis. Reviews of medical studies have shown increased bone mass in patients on long‑term treatment with statins. Objective The objective of this study was to evaluate histologically and immunohistochemically effects of ingestion of atorvastatin on the cortical plates of alveolar bone of white albino rats in normal intact periodontium. Materials and methods Fifteen males of adult albino rats at the age 6–8 weeks, weighting 150–200 g were used in the study. They were divided into two main groups, control group and two experimental groups. Rats in experimental group I received 20 mg/kg body weight atorvastatin by gastric tube for 6 weeks. Experimental group II rats, received 40 mg/kg body weight atorvastatin for the same period. Specimens were fixed using formal saline solution, demineralized using EDTA solution then processed to be stained using hematoxylin and eosin stain for general histological examination and osteopontin for immunohistochemical study. Results Histological results revealed increased alveolar bone turnover in both experimental groups. In experimental group I, osteoclasts appeared in their Howships’ lacunae resorbing old bone and reversal lines were found to separate between the newly formed bone and the old bone. In experimental group II, filling cones of the newly formed bone were clearly detected. Immunohistochemical results showed positive immunoreactive cement lines to osteopontin in both experimental groups. Experimental group II appeared with weak positive immunoreactions in the matrix of the newly formed bone. Conclusion It has been concluded that atorvastatin increased alveolar bone remodeling in dose dependent manner. The effect was clearly detected in the cortical plates of the alveolar bone in the form of cutting cones lined by osteoclasts and filling cones with central capillaries.