Development of Glass Fillers with Controlled Releasing Ability of Ions for Dental Application

以聚甲基丙烯酸甲酯为基体、玻璃粉为填充物的复合树脂用于蛀牙或损伤牙齿的修复已得到广泛研究，认为其与牙釉质的粘附性有效。然而，填料的化学耐久性、硬度、透明度有待提高。此外，非常需要具有其它功能如离子的受控释放的牙科材料。本研究旨在研制具有F^-和Sr^2+释放特性的玻璃填料，用于天然牙的氟化，以预防牙齿的龋坏。选择的玻璃体系为SiO_2-B_2O_3-BaO-SrO-AlF_3、SiO_2-B_2O_3-Al_2O_3-BaO-SrF_2、SiO_2-B_2O_3-Al_2O_3-BaF_2-SrF_2和SiO_2-B_2O_3-SrO-AlF_3-BaF_2。研究了各种性质的依赖关系，包括离子的提取率对它们的组成。结果总结如下 ...更多信息 OWS：1.玻璃中离子的萃取在初始阶段经过一个萃取反应过程后，是扩散控制的.玻璃中的铝元素起着降低离子总析出量的作用。这说明除了4配位的Al ^<3 +>离子改善了玻璃结构外，富Al^<3+>离子保护膜的形成阻止了离子的进一步萃取.硼元素的加入增加了离子的总提取量。除B-O-B结构单元在水中的耐久性差外，B_2O_3含量的增加使分相倾向增大，也是分相玻璃中富B_2O_3相的溶解性增加的另一个原因。从以上结果可以看出，利用Al ~（3+）离子的作用和选择玻璃组成，可以控制玻璃中离子的引出。并且还可以利用玻璃的分相特性制备具有离子控释能力的玻璃。少

Composite resins composed of PMMA as matrix and glass powders as fillers for restoration of decayd or injured teeth have been researched extensively, which are believed to be effective in cohesiveness with tooth enamel. However, the chemical durability, hardness, transparency of the fillers are to be improved. Furthermore, the dental materials having further functions such as controlled release of ions are greatly desired. This research is to develop glass fillers having F^- and Sr^<2+> releasing characteristic in order to fluorizate natural teeth for preventing tooth decaying. The optimization of required other physical and chemical properties of the glass fillers is also investigated.The selected glass systems were SiO_2-B_2O_3-BaO-SrO-AlF_3, SiO_2-B_2O_3-Al_2O_3-BaO-SrF_2, SiO_2-B_2O_3-Al_2O_3-BaF_2-SrF_2 and SiO_2-B_2O_3-SrO-AlF_3-BaF_2. The dependences of various properties including extraction rates of ions on their compositions were researched. The summarized results are as foll … More ows :1. The extraction of ions from glasses was diffusion controlled after a reaction process of extraction at the initial stage.2. Aluminum element in glass playd a role of reducing the total extraction of ions. It was explained that the formation of protective films being rich in Al^<3+> ions prevented further extraction of ions besides 4-coordinaded Al^<3+> ions improved the glass structure.3. Adding of boron element increased the total extraction of ions. Besides it was due to the poor durability of B-O-B structure unit in water, the dissolvability of B_2O_3 rich phases in phase separated glasses was another reason because increased tendency of phase separation was observed due to increasing of B_2O_3.From the above results, it is concluded that the extraction of ions from glass are controllable by using the effect of Al^<3+> ions and selecting glass composition, and glasses with controlled releasing ability of ions can also be prepared by useful application of phase separation characteristic of glass. Less