The purpose of the present study was to make a histometrical evaluation of bone resorption under the denture base caused by lack of self-cleaning as a result of coverage by the denture base.
The experimental denture base was designed to make contact with the molar region of the palate of the rat and to transmit no occlusal force to the tissues under the denture base. The denture base was not removed throughout the experimental period. This procedure caused lack of self-cleaning, and it also caused continuous pressure to palatal tissues under the denture base by the accumulation of exfoliative horny cells, which induced bone resorption under the denture base.
Five rats of each denture wearing group and control group were sacrificed every week during the observation period of 10 weeks after the insertion of the experimental denture base. Palatal tissues were prestained with Villanueva bone stain, and then processed for undecalcified resin section for quantitative bone histomorphometry. These specimens were analyzed using a two-dimensional graphic analyzing system.
From the results of this study, it was revealed histometrically that bone resorption of palatal surface of hard palate bone tissue initiated under the denture base caused by the lack of self-claning as a result of coverage by the denture base one week after, became most active two weeks after and ceased five weeks after the insertion of the experimental denture base. But on the nasal surface of hard palate bone tissue, bone resorption was not observed.