Changes in denture-supporting tissues under continuous pressure in osteoporosis

2001 Fiscal Year Final Research Report Summary

• Project/Area Number: 12671884
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: 補綴理工系歯学
• Research Institution: OKAYAMA UNIVERSITY
• Principal Investigator: MORI Shingo Okayama University, Graduate School of Medicine and Dentistry, Research Associate, 大学院・医歯学総合研究科, 助手 (30252993)
• Co-Investigator(Kenkyū-buntansha): SHIRAI Hajime Okayama University, Graduate School of Medicine and Dentistry, Research Associate, 大学院・医歯学総合研究科, 助手 (00263591) ; HARA Tetsuya Okayama University Hospital of Dentistry, Removable Prothodontics, Assistant Professor, 歯学部・附属病院, 講師 (60238160) ; SATO Takashi Okayama University, Graduate School of Medicine and Dentistry, Professor, 大学院・医歯学総合研究科, 教授 (80034172)
• Project Period (FY): 2000 – 2001
• Keywords: Osteoporosis / Denture-supporting tissues / Continuous pressure / AgNOR / Histopathology / Rat

Research Abstract

In this study, the experimental denture base on the hard palate of the molar region of osteoporotic rats was designed to cover without any mechanical pressure or to load continuous pressure (0.5, 1.5 or 3.4 kPa). Experimental osteoporosis was induced by ovariectomy and feeding on a low calcium diet. The histopathological changes and the changes in the argyrophilic nucleolar organizer region (AgNOR) counts in mucosal epithelium that was revealed to the cellular activity, induced by non-pressure covering or continuous pressure in the tissues uncler the experimental denture bases were examined. Regarding the histological changes induced by continuous pressure, this was evaluated in relation to the time course of the intensity of the continuous pressure. In the tissues under the denture base in osteoporotic condition with non-pressure covering, no histopathological changes caused by nonpressure covering were observed except for a transient slight proliferative reaction in the epithelial ridge. The following histopathological changes were observed in the tissues under the denture base in the osteoporotic condition bearing continuous pressure ; (1) bone resorption was induced on the periosteal surface in the osteoporotic-3.4kPa group, and on the pressure side of the endocortical surface in the osteoporotic-1.5 and -3.4kPa group. (2) histopathological changes in the tissues under the denture base in experimental osteoporosis bearing continuous pressure had an intimate relationship with the initial intensity and the time course of continuous pressure, and with the AgNOR counts in mucosal epithelium.