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중합직후의 가열이 복합레진의 기계적 성질에 미치는 영향에 관한 실험적 연구
윤숭철,이종갑 大韓小兒齒科學會 1987 大韓小兒齒科學會誌 Vol.14 No.1
Although resin has recently become a popular restorative material in more extended areas than ever, it still remains for further studies to overcome such problems as wear resistance. biological compatibility, and marginal leakage of Dental Composite Resins. This study is to evaluate the effect of heating immediately after polymerization on mechanical properties of composite resin materials. The author has performed a study of Rockwell's superficial hardness and diametral tensile strength of anterior (??) and posterior (??) composite resin with 100 specimens, disc types of 6 mm in diameter, 3 mm in height, which was heat treated at room temperature, 40℃, 60℃, 80℃, 100℃ for 10 minutes for each group, composed of 10 specimens. The results and the conclusion are as follows: 1. The hardness and the diametral tensile strength of posterior composite resin were significantly higher than those of anterior composite resin regardless of heating temperature. 2. As the temperature of post-cure heating was elevated, the hardness of both anterior and posterior composite resin was significantly increased. 3. As the temparature of post-cure heating was elevated, the diametral tensile strength of anterior composite reisn was not significantly increased, and there was no correlation between the strength and the temperature. 4. There was a significant correlation between the diametral tensile strength and the temperature of posterior composite resin. 5. This study has revealed that post-cure heating enhances the mechanical properties of composite resin materials.
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윤숭철,손흥규 大韓小兒齒科學會 1995 大韓小兒齒科學會誌 Vol.22 No.2
An use of fluoride is one of the most effective method for caries prevention, however, the definite mechanism of caries prevention by fluoride has not yet been clarified. Recently the effect of fluoride in physicochemical process of dilution of hydroxyapatite has been argued whether it is caused by firmly bound fluoride lie fluoroapatite or by fluoride ion adsorbed onto the surface or by the fluoride ion solution. So the purpose of this study is to evaluate the effect of fluoride in soluble state on the degree of enamel remineralization and the effect of fluoride contained in enamel like fluoridated hydroxyapatite and free fluoride ion diluted in solution on prevention for enamel demineralization. Enamel powder from the bovine teeth with constant particle size (diameter 106∼150㎛) was used. The degree of remineralization was observed from recording the ?? concentration changes in solution with ?? electrode for 90 minutes during the inducing process of crystalinization by mechanically stirring under remineralization buffer solutions gaving four group of different NaF concentration(0,??,??,??) with pH 7.2 and containing 1.0mM CaCl₂ and 7.5mM KH₂PO₄. And also, the amount of fluoride incorporated to the crystal during the remineralization process with ?? electrodes was measured. The amount of dilution of enamel by recording the output of ?? into the solution with ?? electrodes for 70 miniutes during the demineralization process in the 0.1 M lactic acid buffered solution with four groups of different NaF concentration(0,??,??,??) with pH 4.5 was observed. And previous remineralized enamel powder from four groups of different NaF concentration was demineralized without the addition of fluoride in 0.1M latic acid buffered solution with pH 4.5 and the output of ?? with ?? eletrode was continuously recorded for 70 minutes. And results were 1) as the concentration of fluoride in the solution increased, the degree of remineralization of enamel powder increased, 2) as the concentration of fluoride in solution increased, the amount of demineralization of enamel powder decreased, 3) the small amount of fluoride bound to crystals as fluroapatite during enamel remineralization did not affect the process of demineralization, 4) the fluoride diluted in solution slowly reacted in the process of remineralization of enamel powder, and immediately in the process of demineralization. From the above results, fluoride is more effective on enamel demineralization as the state of diluted in solution than as the state of fluoroapatite. So for the effective use of fluoride, to maintain low concentration of free fluoride ion in oral fluid by slow flouride releasing device is advisable.
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