Effect of Raloxifene on Periapical Lesions in Ovariectomized Rats

• Pathologic oral conditions are adversely affected by some aging diseases.
• Low estrogen concentration produces changes in oral tissues.
• Raloxifene was approved for osteoporosis in estrogen deficiency condition.
• Hypoestrogenism potentiates periapical lesions, but raloxifene can reverse it.

IntroductionThe aim of this study was to evaluate the effect of raloxifene (RLX) during progression of periapical lesions in ovariectomized (OVX) rats.MethodsFemale Wistar rats were OVX or subjected to sham surgery and received vehicle or RLX by gavage for 90 days. The treatment groups were as follows: sham surgery and treated with vehicle (SHAM-veh), OVX and treated with vehicle (OVX-veh), and OVX and treated with RLX (OVX-RLX). During treatment, the pulp of lower first molar was exposed to the oral environment for induction of periapical lesion that was analyzed 7 or 30 days after procedure. Blood samples were taken from jugular vein for measurement of estradiol, and the mandibles were removed and prepared for radiographic, histopathologic, histometric, and immunohistochemical analysis.ResultsEstradiol plasma concentration showed hypoestrogenism in OVX rats. The histopathologic analysis of the OVX/RLX group was similar to that of the SHAM-veh group, whereas OVX-veh group showed larger periapical lesions with more intense inflammatory response and more cells positive for tartrate-resistant acid phosphatase. Radiographically, the groups were similar, but lesions on day 7 were smaller than lesions on day 30.ConclusionsThe results suggest that hypoestrogenism potentiates the progression of periapical lesions, and such condition was reversed by treatment with RLX.