J Korean Acad Conserv Dent.  2005 Sep;30(5):402-408.

The effect of estrogen deficiency on rat pulpodentinal complex

• Kim M
• Yang WK
• Baek J
• Kim JJ
• Kim WK
• Lee YK

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.

Keyword

Ovariectomy; Estrogen deficiency; Osteonectin; Predentin; Pulp

MeSH Terms

Animals
Estrogens*
Female
Formaldehyde
Humans
Molar
Osteonectin
Ovariectomy
Rats*
Rats, Sprague-Dawley
Tooth
Estrogens
Formaldehyde
Osteonectin

Figure

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  Figure 1. Radiographic view of mandibular sections of SHAM Rat.

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  Figure 2. Radiographic view of mandibular sections of OVX Rat.

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  Figure 3. Immunohistochemical staining of SHAM Rat (original magnification × 400). Osteonectin (Arrow-brown) in the cytoplasm of active, matrix-producing odontoblasts in predentin areas.

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  Figure 4. Immunohistochemical staining of SHAM Rat (original magnification × 400). Adjoining immunoreactive polarized odontoblasts (Arrow) were stained heavily with osteonectin antibodies.

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  Figure 5. Immunohistochemical staining of OVX Rat (original magnification × 400). Absence of staining of quiescent odotoblasts in the predentin areas.

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  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.

Reference

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