Effect of denture removal during night time on histopathological changes in denture supporting tissues was investigated. Experimental denture base was applied to molar region of the hard palate of Wistar rat, and continuous pressure was exerted to the denture supporting tissues through the denture base. The experimental denture was removed during night time from the palate of the denture removal group, whereas the denture was worn continuously day and night in the denture wearing group. The palatal tissue was examined histopathologically up to 7 days after the insertion of the denture.
In the denture wearing group, bone resorption and decrease of the thickness of epithelial tissue and connective tissue were observed. These tissue changes came out early and severe with increasing the continuous pressure. Whereas no remarkable tissue change was observed in the denture removal group throughout the experimental period. From these results, it was revealed that the half a day loading of mechanical continuous pressure to the denture supporting tissues would not cause bone resorption, and was suggested that denture removal during night time was effective for the preservation of denture supporting tissues.