Division of Orthodontics and Dentofacial Orthopedics, Department of Oral Growth and Development, Health Sciences University of Hokkaido, Hokkaido, Japan.
Angle Orthod. 2012 Mar;82(2):187-95. doi: 10.2319/020411-78.1. Epub 2011 Aug 9.
To determine if the enamel around orthodontic brackets is significantly altered after demineralization followed by application of adhesives with and without fluoride-releasing ability.
One hundred eight noncarious human premolars were divided into six groups of 18 each and exposed to a demineralization solution. Stainless steel brackets were bonded using two conventional composite resin etch-and-rinse systems, three self-etching primer (SEP) composite resin systems, and one resin-modified glass ionomer cement (RMGIC) system. One conventional and one SEP composite resin adhesive did not have fluoride-releasing ability, which was claimed for the other four adhesives. The elastic modulus and hardness of the enamel were determined with a nanoindenter at 10 equidistant depths ranging from 1-46 µm and at four regions: control (not exposed) enamel surface, under the adhesive, and at 50 µm and 100 µm from the bracket edges. Using the Kruskal-Wallis and Mann-Whitney U-tests (P < .0125 for statistical significance), these properties were compared at different regions.
The same behavior was observed for values of elastic modulus and hardness. Significant differences were found within approximately 21 µm of the enamel surface for etching with 35% phosphoric acid or priming with SEP, but only minimal changes occurred for the SEP adhesive. Increases in near-surface elastic modulus and hardness of enamel were found with the SEP adhesive and RMGIC with fluoride-releasing ability.
Clinical use of the fluoride-releasing adhesives investigated may prevent demineralization of enamel around brackets during orthodontic treatment.
确定在脱矿后应用具有和不具有氟释放能力的黏结剂是否会显著改变正畸托槽周围的牙釉质。
将 108 颗无龋的人前磨牙分为 6 组，每组 18 颗，每组暴露于脱矿溶液中。使用两种传统的复合树脂酸蚀-冲洗系统、三种自酸蚀底漆（SEP）复合树脂系统和一种树脂改性玻璃离子水门汀（RMGIC）系统粘结不锈钢托槽。一种传统的和一种 SEP 复合树脂黏结剂没有氟释放能力，而其他四种黏结剂声称具有这种能力。使用纳米压痕仪在从 1 到 46 µm 的 10 个等距深度处以及在四个区域（未暴露的釉质表面、黏结剂下、距托槽边缘 50 µm 和 100 µm）处测定釉质的弹性模量和硬度。使用 Kruskal-Wallis 和 Mann-Whitney U 检验（统计学显著性为 P <.0125），在不同区域比较这些性质。
弹性模量和硬度值的行为相同。在用 35%磷酸酸蚀或 SEP 底漆处理时，在距釉质表面约 21 µm 内观察到显著差异，但 SEP 黏结剂仅发生最小变化。在具有氟释放能力的 SEP 黏结剂和 RMGIC 中，发现近表面弹性模量和硬度增加。
在正畸治疗中临床使用所研究的具有氟释放能力的黏结剂可能会防止托槽周围釉质脱矿。
