Yamaguchi Kanako, Miyazaki Masashi, Takamizawa Toshiki, Inage Hirohiko, Moore B Keith
Department of Operative Dentistry, Nihon University Graduate School of Dentistry, 1-8-13, Kanda-Surugadai, Tokyo 101-8310, Japan.
J Dent. 2006 Mar;34(3):230-6. doi: 10.1016/j.jdent.2005.06.005. Epub 2005 Aug 19.
The purpose of this study was to determine the effect of Casein Phosphopeptide-Amorphous Calcium Phosphate (CPP-ACP) paste on demineralization of bovine enamel by measuring changes in the ultrasound transmission velocity.
The enamel specimens were prepared by cutting bovine teeth into blocks. The specimens were stored in 0.1 M lactic acid buffer solution (pH 4.75, Ca 0.75 mM, P 0.45 mM) for 10 min twice a day, and then stored in the artificial saliva (pH 7.0). Other specimens were stored in a 10-times diluted solution of CPP-ACP paste and a placebo paste without CPP-ACP for 10 min, followed by 10 min immersion into a demineralization solution twice a day before storage in the artificial saliva. The propagation time of longitudinal ultrasonic waves was measured by a Pulser-Receiver (Model 5900, Panametrics) with a transducer (V112, Panametrics). Six specimens were used for each condition, and one-way ANOVAs followed by the Tukey HSD tests (alpha = 0.05) were done.
The sonic velocity was found to decrease with time for specimens stored in the demineralization solution. On the other hand, a significant increase in sonic velocity was found for specimens stored in the CPP-ACP solution.
From the result of this study, it was suggested that the conditions of de- and remineralization of the enamel structure could be measured non-destructively by using an ultrasonic pulse method. It could be concluded that the inorganic components contained in high concentrations in CPP-ACP acted to enhance remineralization of the enamel structure.
本研究的目的是通过测量超声传播速度的变化来确定酪蛋白磷酸肽 - 无定形磷酸钙（CPP - ACP）糊剂对牛牙釉质脱矿的影响。
将牛牙切成块制备牙釉质标本。标本每天两次在0.1 M乳酸缓冲溶液（pH 4.75，钙0.75 mM，磷0.45 mM）中保存10分钟，然后保存在人工唾液（pH 7.0）中。其他标本在10倍稀释的CPP - ACP糊剂溶液和不含CPP - ACP的安慰剂糊剂中保存10分钟，然后每天两次在脱矿溶液中浸泡10分钟，再保存在人工唾液中。用带换能器（V112，Panametrics）的脉冲接收器（型号5900，Panametrics）测量纵向超声波的传播时间。每种情况使用6个标本，并进行单因素方差分析，随后进行Tukey HSD检验（α = 0.05）。
发现保存在脱矿溶液中的标本声速随时间降低。另一方面，保存在CPP - ACP溶液中的标本声速显著增加。
从本研究结果表明，牙釉质结构脱矿和再矿化的情况可以通过超声脉冲法无损测量。可以得出结论，CPP - ACP中高浓度含有的无机成分起到增强牙釉质结构再矿化的作用。
