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.
References
1. Hargreaves KM, Goodis HE. Seltzer and Bender's Dental Pulp. Quintessence publishing Co.;Chicago: p. p95–99. 2002.
2. Geurs NC, Lewis CE, Jeffcoat MK. Osteoporosis and periodontal disease progression. Periodontology 2000. 32:105–110. 2003.
3. Jiang G, Matsumoto H, Fujii A. Mandible bone loss in osteoporosis rats. J Bone Miner Metab. 21:388–395. 2003.
4. Gilles JA, Carnes DL, Dallas MR, Holt SC, Bonewald LF. Oral bone loss is increased in ovariectomized rats. J Endodon. 23:419–422. 1997.
5. Kribbs PJ, Chestnut CH 3rd, Ott SM, Kilcoyne RF. Relationships between mandibular and skeletal bone in a population of normal woman. J Prosthet Dent. 63:86–89. 1990.
6. Yokose S, Zhungfeng C, Tajima Y, Fujieda K, Katayama I, Katayama T. The effects of estrogen deficiency on glycosylation of odontoblasts in rats. J Endodon. 24:645–647. 1998.
7. Termine JD, Kleinman HK, Whitson SW, Conn KM, McGarvey ML, Martin GR. Osteonectin, a bone-specific protein linking mineral to collagen. Cell. 26:99–105. 1981.
8. Jundt G, Berghauser KH, Termine JD, Schulz A. Osteonectin -a differentiation marker of bone cells. Cell Tissue Res. 248:409–415. 1987.
9. Kim M, Kim B, Yoon S. Effect on the healing of periapical perforations in dogs of the addition of growth factors to calcium hydroxide. J Endodon. 27:734–737. 2001.
10. Bolander ME, Robey PG, Fisher LW, Conn KM, Prabhakar BS, Termine JD. Monoclonal antibodies against osteonectin show conservation of epitopes across species. Calcif Tissue Int. 45:74–80. 1989.
11. Sage H, Mecham R, Johnson C, Bornstein P. Fetal calf ligament fibroblasts in culture secrete a low molecular weight collagen with a unique resistance to proteolytic degradation. J Cell Biol. 97:1933–1938. 1983.
12. Tracy RP, Shull S, Riggs BL, Mann KG. The osteonectin family of proteins. Int J Biochem. 20:653–660. 1988.
13. Papagerakis P, Berdal A, Mesbah M Peuchmaur, Malaval L, Nydegger J, Simmer J, Macdougall M. Investigation of osteocalcin, osteonectin, and dentin sialophosphoprotein in developing human teeth. Bone. 30:377–385. 2002.
14. Ninomiya M, Ohishi M, Kido J, Ohsaki Y, Nagata T. Immunohistochemical localization of osteopontin in human pulp stones. J Endodon. 27:269–272. 2001.
15. Garcia JM, Martins MD, Jaeger RG, Marques MM. Immunolocalization of bone extracellular matrix proteins (type I collagen, osteonectin and bone sialopro-tein) in human dental pulp and cultured pulp cells. Int Endod J. 36:404–410. 2003.
16. Chong BS. . Radiological assessment of the effects of potential root-end filling materials on healing after endodontic surgery. Endod Dent Trauma. 13:176–179. 1997.
17. Wysocki GP, Daley TD, Ulan RA. Predentin changes in patients with chronic renal failure. Oral Surg Oral Med Oral Pathol. 56:167–173. 1983.