The Effect of Estrogen Deficiency on Rat Pulpodentinal Complex

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Restor Dent Endod. 2005;30(5):402-408

Publication date (electronic) : 2005 January 14

doi : https://doi.org/10.5395/JKACD.2005.30.5.402

Miri Kim ¹, Won-Kyung Yang ¹, Jin Baek ², Jong-Jin Kim ², Won-Kyung Kim ³, Young-Kyoo Lee ³^,

¹Department of Conservative Dentistry, Asan Medical Center, Seoul

²Department of Prothodontics, Asan Medical Center, Seoul

³Department of Periodontology, Asan Medical Center, Seoul

^*Corresponding author: Young-Kyoo Lee, Department of Dentistry, Asan Medical Center, 388-1 Poongnap-Dong, Songpa-Gu, Seoul, Korea 138-736, Tel: 82-2-3010-3824 Fax: 82-2-3010-6967, E-mail: kmr333@unitel.co.kr

Received 2005 March 23; Revised 2005 June 22; Accepted 2005 August 24.

Abstract

The purpose of this study was to investigate the effects of estrogen deficiency on pulpodentinal complex of tooth in ovariectomized rats. Thirty female Sprague-Dawley rats, 10 weeks old, were used. Rats were grouped into two groups. One group (n = 15) was subjected to sham surgery (SHAM) and the other group (n = 15) was ovariectomized bilaterally (OVX). Animals were sacrificed 12 weeks later, and their mandibular molars and associated periodontal supporting tissues were dissected out, and fixed in 10% buffered formalin. For comparison of groups, immunostained for osteonectin. Histomorphometrical measurement of change of teeth was performed using an image analysis system and paired t-test was used and the level of significance for overall differences was set at p < 0.05.

In immunostaining of osteonectin, they were significantly different from each other. The predentin thickness in OVX rats was wider than in SHAM rats. And in SHAM rats, osteonectin was more specifically stained in predentin areas than in OVX rats. These results indicate that estrogen deficiency increased the unmineralized predentin areas and decreased osteonectin content in pulpal tissues in rats. If our result is applicable to human studies, odotoblast is affected by estrogen deficiency.

Keywords: Ovariectomy; Estrogen deficiency; Osteonectin; Predentin; Pulp

Figure 1.

Radiographic view of mandibular sections of SHAM Rat.

Figure 2.

Radiographic view of mandibular sections of OVX Rat.

Figure 3.

Immunohistochemical staining of SHAM Rat (original magnification × 400). Osteonectin (Arrow-brown) in the cytoplasm of active, matrix-producing odontoblasts in predentin areas.

Figure 4.

Immunohistochemical staining of SHAM Rat (original magnification × 400). Adjoining immunoreactive polarized odontoblasts (Arrow) were stained heavily with osteonectin antibodies.

Figure 5.

Immunohistochemical staining of OVX Rat (original magnification × 400). Absence of staining of quiescent odotoblasts in the predentin areas.

Figure 6.

Immunohistochemical staining of OVX Rat (original magnification × 400). Weakly osteonectin labeling (Arrow) is present in polarized odontoblasts, but absent from the cells of the central pulp and dentin.

Table 1.

The mean and standard deviation for predentin thickness of the OVX rats and SHAM rats are shown (p < 0.05)

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