The aim of this study was to characterize the ion release, pH changes and apatite formation ability of two potentially bioactive composites Cention N (CN) and Activa (ACT). Ion release and apatite formation was investigated in three different immersion media: Tris buffer pH 7.3 (TB), Artificial Saliva pH 4 (AS4) and Artificial Saliva pH 7 (AS7) in order to mimic the conditions present in the mouth. Fluoride release was followed using an ion selective electrode, whilst all other ions were determined by inductively coupled plasma optical emission spectroscopy. Apatite formation was followed by FTIR and XRD. SEM was used to follow glass degradation and apatite formation on both polished cross-sections and surfaces of the composites. ACT released very few ions including fluoride upon immersion in TB and AS7, but released more ions including significant quantities of Al in AS4. This would suggest the glasses in ACT are acid degradable fluoro-alumino-silicate glasses similar to the glasses used in glass ionomer cements. There was no evidence of any apatite formation with ACT. CN released more ions in TB and AS7 than ACT and formed an apatite like phase in AS7. The calcium fluoro-silicate glass in CN was observed to degrade significantly in AS4. CN has bioactive properties that may explain the low incidence of secondary caries found clinically with this composite.

中文翻译：

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两种商业复合材料的生物活性的表征。

这项研究的目的是表征两种潜在的生物活性复合材料Cention N（CN）和Activa（ACT）的离子释放，pH变化和磷灰石形成能力。在三种不同的浸入介质中研究了离子释放和磷灰石的形成：Tris缓冲液pH 7.3（TB），人工唾液pH 4（AS4）和人工唾液pH 7（AS7），以模拟口腔中的状况。使用离子选择电极跟踪氟化物的释放，同时所有其他离子通过电感耦合等离子体发射光谱法测定。通过FTIR和XRD追踪磷灰石的形成。SEM用于追踪复合材料的抛光横截面和表面上的玻璃降解和磷灰石的形成。ACT浸入TB和AS7后几乎没有释放出包括氟离子在内的离子，但在AS4中释放了更多的离子，包括大量的Al。这表明ACT中的玻璃是类似于玻璃离聚物水泥中使用的玻璃的酸可降解的氟铝硅酸盐玻璃。没有证据表明ACT会形成磷灰石。CN在TB和AS7中比ACT释放更多的离子，并在AS7中形成类似磷灰石的相。观察到CN中的氟硅酸钙玻璃在AS4中显着降解。CN具有生物活性，可以解释这种复合物在临床上发现的继发性龋齿发生率低。CN在TB和AS7中比ACT释放更多的离子，并在AS7中形成类似磷灰石的相。观察到CN中的氟硅酸钙玻璃在AS4中显着降解。CN具有生物活性，可以解释这种复合物在临床上发现的继发性龋齿发生率低。CN在TB和AS7中比ACT释放更多的离子，并在AS7中形成类似磷灰石的相。观察到CN中的氟硅酸钙玻璃在AS4中会明显降解。CN具有生物活性，可以解释这种复合物在临床上发现的继发性龋齿的发生率低。