Effect of raloxifene on periapical lesions in ovariectomized rats

Introduction: The aim of this study was to evaluate the effect of raloxifene (RLX) during progression of periapical lesions in ovariectomized (OVX) rats.

Methods: Female 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.

Results: Estradiol 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.

Conclusions: The results suggest that hypoestrogenism potentiates the progression of periapical lesions, and such condition was reversed by treatment with RLX.