The acrylic resin denture base is used more than the usual metal denture base because of the low cost, simple process to make and easy rebasing. But, as the strength of the resin is weaker, the upper resin denture base is three to four times as thick as the metal denture base. So, a study was made to make the upper complete resin denture base thinner while maintaining the strength of the resin denture bases currently in use now. To make the palatal area of the denture base thinner was made possible by the application of carbon fiber (CF)-cloth reinforcement. The resin denture base reinforced by the CF-cloth was of a thickness of 0.7 mm and was evaluated for the mechanical properties of bending. As a result, it was found that both the stiffness and strength were improved by 10% or more as compared with those of the ordinary resin denture bases.
The effect of fluoroacetate (FA) on the physiological distal drift of the rat molar was investigated in this study. FA produced a dose-dependent inhibition of the bone formation ratio on the modeling side. The total number of osteoclast population on the remodeling side decreased with the increase of the dose of FA, but not dose-dependently. Therefore, the physiological distal drift seemed to be inhibited by the FA injections and the rate of the distal drift seemed to be not proportional to the total number of osteoclasts on the remodeling side. Among the oseteoclast population, the number of multinucleated cells in contact with the bone surface (on-bone multinucleated 'osteoclasts) decreased considerably when the physiological distal drift was inhibited by the FA injections. The availability of the change in the number of the on-bone multinucleated osteoclasts as a marker of the degree of bone resorption was also discussed.