Osteoporosis is a skeletal disorder prevalent in post-menopausal women affecting bone including periodontal bone loss, tooth loss and resorption of jaw mass. It has been demonstrated that osteoporotic women are at higher risk of tooth loss and deterioration of mandibular bone. However, it remains unclear if osteoporosis affects simultaneously tooth mineralisation and bone mass. This study aimed to test the therapeutic efficacy of N-methylpyrrolidone (NMP) in preventing alveolar bone resorption and preservation of tooth integrity using the classical osteoporotic rat model established for the evaluation of enhanced osteoporosis through ovariectomy (OVX). Female Sprague-Dawley rats were randomly divided into sham-operated group (Sham) either treated or not with NMP. Bilateral ovariectomy or Sham operations were performed as previously designated and the weight of the animals was measured weekly. The rats were sacrificed after 15 weeks, the jaw bones were isolated and tooth pulp collected. Bone and tooth parameters were evaluated using X-ray radiography, immunohistochemistry, histology and scanning electron microscope. Histological results revealed that OVX incisors presented the thinner pre-dentin structures than Sham incisors and that NMP treatment normalized the pre-dentin thickness. Immunohistological staining and RT-PCR further demonstrated that odontoblasts specific protein dentin sialoprotein in the dentin pulp complex of rat incisors were significantly decreased in comparison with Sham and NMP treated group. Mandibular and teeth parameters were analysed using X-ray radiography and scanning electron microscopy confirming a significant difference between Sham, OVX NMP and OVX Veh group. It has been already established and we demonstrated here as well that estrogen deficiency causes loss of bone mass and reduces the dentinogenic capacity and tooth mineralisation. However, our results suggest that NMP has a remarkable antiosteoporotic activity preventing bone loss and minimising changes in tooth integrity making NMP a promising candidate for treatment of postmenopausal osteoporosis and other bone diseases.
Disclosure: The authors declared no competing interests. This research work was supported by grants from the Swiss National Science Foundation (31003A 140868) and (CR32I3_152809).