Estrogen deficiency reduces the dentinogenic capacity of rat lower incisors

Abstract

Endogenous estrogen deficiency usually causes the systemic osteoporosis including the jaw bones. However, it remains unclear whether estrogen deficiency can affect the tooth mineralization. In this study, the classical osteoporotic rat model was established via the ovariectomy, which was subsequently confirmed by the detection of serum estradiol levels and body weights. The mineralization-related assays were performed to observe the potential changes in mineralized tissues of rat lower incisors. The clinical crown length, compressive strength, radiodensity, and calcium content in the ovariectomy group (OVX) were significantly downregulated (P < 0.01), as compared with the sham operation group (Sham). Histological results revealed that OVX incisors presented the thinner predentin structures than Sham incisors. Immunohistochemical staining and western blot assay further demonstrated that the odonto/osteoblast specific proteins (e.g., dentin sialoprotein, runt-related transcription factor 2, osterix, and osteocalcin) in the dentin–pulp complex of OVX incisors were significantly decreased in comparison with Sham counterparts. Together, estrogen deficiency reduces the dentinogenic capacity and calcium deposition in rat incisors, indicating that estrogen plays an important role in the dentinogenesis.

Influence of N‐methyl pyrrolidone on the activity of the pulp–dentine complex and bone integrity during osteoporosis

“…, Xu et al . ). Furthermore, in the NMP‐treated group (OVX NMP), DSP expression was clearly preserved and had a similar staining intensity to the Sham Veh group (Fig.…”

“…Earlier studies have demonstrated that pre-dentine can provide a supporting mechanical function for the pulp tissue (Xu et al 2014). Additionally, the pre-dentine layer thickness directly correlates with the dentinogenic activity function in human teeth (Couve 1987).…”

“…Xu et al . () linked their finding on the molecular level to a decrease in Runx2 and osterix expression. In the present study, NMP preserved the pre‐dentine structure, as in the OVX NMP group pre‐dentine was significantly thicker than in the OVX Veh group (Fig.…”

“…The results demonstrated that the pre-dentine layer was significantly thinner in the incisors of the OVX Veh group compared to the incisors of the Sham Veh group establishing that dentinogenic activity is inhibited after ovariectomy. Xu et al (2014) linked their finding on the molecular level to a decrease in Runx2 and osterix expression. In the present study, NMP preserved the pre-dentine structure, as in the Figure 3 Morphology of incisors and lower semimandible was observed after sacrifice.…”

“…Recently, it was reported that osteoporosis not only affects the skeleton but also reduces the dentinogenic capacity of rat mandibular incisors and the activity of the pulp-dentine complex (Xu et al 2014). Moreover, osteoporosis caused by oestrogen deficiency is associated with periodontal bone loss, reduced jawbone and tooth loss (Ames et al 2010, Mijares et al 2012.…”