The effect of diabetes mellitus on histopathological changes in the denture-supporting tissues under continuous mechanical pressure in rat

The histopathological changes in denture-supporting tissues of streptozotoc in-induced diabetes mellitus rat were studied in relation to continuous mec hanical pressure exerted through an experimental denture base. The experime ntal dentures were designed to load continuous mechanical pressures (3.4, 1 .5 or 0.5 kPa) to the hard palate of the molar region of a rat. From the re sults of this study, the following conclusions were drawn: the streptozotoc in-induced diabetic condition(1) tended to prolong the appearance period of a shortened epithelial ridge, and weakened the phenomenon, (2) reduced the appearance period and severity of the compression of epithelium, (3) delay ed the time of manifestation of the proliferative change in the recovery pr ocess of the shortened epithelial ridge, and weakened the phenomenon, (4) p rolonged the appearance period of the compressed lamina propria mucosae, an d enhanced the phenomenon, (5) reduced the number of osteoclasts, (6) lower ed the threshold for induction of the osteoclastic bone resorption to betwe en 1.5 and 0.5 kPa, (7) inhibited the appearance of osteoblast which follow s the disappearance of osteoclasts, (8) did not induce any inflammatory cha nge, and (9) tended to enhance the longitudinal change of the continuous me chanical pressure. The histopathological changes in the denture-supporting tissues of the streptozotocin-induced diabetes mellitus rat related highly to the longitudinal change of the continuous mechanical pressure exerted th rough the denture base. From the results of this study, it was suggested th at the streptozotocin-induced diabetic condition lowers the tolerance of th e denture-supporting tissues to continuous mechanical pressure.