| Summary: | 碩士 === 國立臺北科技大學 === 材料科學與工程研究所 === 103 === It has been stated 8–35% of the population in the U.S. They suffers from dental hypersensitivity. In vivo studies provide strong evidence that the sensitivity cause from the exposure of open dentin tubules at the surface of the tooth and give rise to changes in the local environment, including temperature, pressure, osmolality, and chemical agents. These local environment changes cause fluids in the dentin tubules to move quickly, stimulating the nerves in pule and giving rise to pain as postulated in the hydrodynamic theory. Typical methods to cure the effects of dental hypersensitivity include occluding the open tubules with organic or inorganic chemicals and compounds, and applying chemical agents that suppress pain expression and interfere nerve transmission. The most effective and durable method for achieving relief would be to seal the dentin surface through tubule occlusion, thereby eliminating or minimizing movement of fluids in the tubules.
From DP-bioglass-containg toothpaste and Sensodyne brushing test, we can find that the more glass dissolve quickly, the more precipitates deposit. But there are only sporadic precipitation, not column. In this study, we add phosphoric acid into the toothpaste and control different pH value to observe the precipitation. The purpose of this study is the preparation of toothpaste containing the calcium and phosphate ions solution and hope that the closure exposed dentin tubule by brushing way to achieve the effect of curing tooth hypersensitivity.
The result shows that by brushing with DP9、DP7、DP5, the dentinal tubules could be occluded by precipitates as deep as 2~5 μm. We can find that DP5 group have deeper precipitates up to 10~20 μm under SEM observation, and it probably have longer effective time to cure dental hypersensitivity. In MTT、LDH test reveal that DP9、DP7、DP5 toothpaste have low toxicity and good biocompatibility.
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