Uppsala University, Sweden.
Dent Mater. 2010 May;26(5):491-9. doi: 10.1016/j.dental.2010.01.008. Epub 2010 Feb 26.
The aim of the present work was to perform the first in vitro evaluation of a new interfacial bond-promoting material-and-method concept for on-demand long term bacteria inhibition in dental restoration procedures.
The bioactivity, mechanical bonding strength and photocatalytic bactericidal properties, induced by low dose ultraviolet-A (UV-A) irradiation of dental adhesives containing crystalline titania nanoparticles (NPs), were analyzed.
Dental adhesives with a NP content of 20wt% were shown to be bioactive in terms of spontaneous hydroxylapatite formation upon storage in simulated body fluid and the bioactivity was found to be promoted by chemical etching of the adhesives. The mechanical bonding strength between the adhesives and a HA tooth model was shown to be unaffected by the NPs up to a NP content of 30wt%. Elimination of Staphylococcus epidermidis in contact with the adhesives was found to depend both on UV photocatalytic irradiation intensity and time. Efficient elimination of the bacteria could be achieved using a UV-A dose of 4.5J/cm(2) which is about 6 times below the safe maximum UV dose according to industry guidelines, and 20 times below the average UV-A dose received during an ordinary sun bed session.
The combined features of bioactivity and on-demand bactericidal effect should open up the potential to create dental adhesives that reduce the incidence of secondary caries and promote closure of gaps forming at the interface towards the tooth via remineralization of adjacent tooth substance, as well as prevention of bacterial infections via on-demand UV-A irradiation.
本研究旨在首次对一种新的界面结合促进材料和方法概念进行体外评估，该概念旨在按需长期抑制牙科修复过程中的细菌。
分析了含有结晶二氧化钛纳米颗粒（NPs）的牙科胶粘剂在低剂量紫外线 A（UV-A）照射下的生物活性、机械结合强度和光催化杀菌性能。
研究表明，NP 含量为 20wt%的牙科胶粘剂具有生物活性，可在模拟体液中储存时自发形成羟基磷灰石，并且通过对胶粘剂进行化学蚀刻可促进其生物活性。胶粘剂与 HA 牙模型之间的机械结合强度在 NP 含量高达 30wt%时不受 NPs 的影响。与胶粘剂接触的表皮葡萄球菌的消除既取决于 UV 光催化照射强度又取决于其时间。使用 4.5J/cm²的 UV-A 剂量（约为行业指南规定的安全最大 UV 剂量的 6 倍，普通日光浴期间接受的平均 UV-A 剂量的 20 倍）可有效消除细菌。
生物活性和按需杀菌效果的结合特性有望创造出牙科胶粘剂，通过对相邻牙体物质的再矿化来减少继发龋的发生并促进界面处的间隙封闭，以及通过按需 UV-A 照射来预防细菌感染。
