Brazilian Navy, Navy Central Clinic, Rio de Janeiro, RJ, Brazil.
Dent Mater. 2011 Mar;27(3):244-52. doi: 10.1016/j.dental.2010.10.009. Epub 2010 Nov 13.
The aim of this study was to evaluate the degradation of different resin filling materials after a caries challenge, by high performance liquid chromatography (HPLC) and contact angle (θ) measurement.
Four different polymeric restorative materials (a resin composite, a polyacid-modified resin composite, an ormocer and a resin-modified glass ionomer cement) were tested. Five samples (30 mm × 6 mm × 2 mm) of each material were formed in a Teflon mold, following the manufacturer's instructions. After pH cycles, the solutions were injected in an HPLC. The θ was obtained, before and after pH cycle, by a goniometer at 60% air humidity and 25°C. A distilled water drop (0.006 ml) was put on the material surface, and after 6 min, 10 measures were obtained at 20s intervals. Each sample received 4 drops, one at a time, on different areas.
HPLC results showed elution of byproducts in all materials. This was greater in the acid medium. Bis-GMA and TEGDMA were detected in TPH Spectrum and Definite residues. Analyses of the contact angle by ANOVA and Student-Neuman-Keuls's test showed that the surfaces of TPH Spectrum, Dyract AP and Definite were altered, except Vitremer (p<0.05).
All materials tested degraded on a caries simulated medium, suggesting that a great effort should be made to disseminate oral health information, since a high caries challenge environment (low pH) can lead to dental composite degradation, with potential toxic risks to patients.
本研究旨在通过高效液相色谱（HPLC）和接触角（θ）测量来评估龋齿挑战后不同树脂填充材料的降解情况。
测试了四种不同的聚合修复材料（树脂复合材料、酸改性树脂复合材料、有机硅改性树脂和树脂改性玻璃离子水门汀）。按照制造商的说明，在聚四氟乙烯模具中形成每个材料的五个样本（30mm×6mm×2mm）。在 pH 循环后，将溶液注入 HPLC。在 60%空气湿度和 25°C 的条件下，通过测角仪获得 pH 循环前后的 θ。将一滴水（0.006ml）滴在材料表面上，6 分钟后，每隔 20 秒获得 10 次测量。每个样品在不同区域一次接收 4 滴水。
HPLC 结果显示所有材料都有副产物洗脱。在酸性介质中更为明显。在 TPH 光谱和 Definite 残留物中检测到 Bis-GMA 和 TEGDMA。通过方差分析和 Student-Neuman-Keuls 检验对接触角进行分析表明，TPH 光谱、Dyract AP 和 Definite 的表面发生了变化，除了 Vitremer（p<0.05）。
所有测试的材料在龋齿模拟介质中降解，这表明应该大力传播口腔健康信息，因为高龋齿挑战环境（低 pH）会导致牙科复合材料降解，对患者有潜在的毒性风险。
