Universitas Gadjah Mada, Faculty of Dentistry, Department of Dental Biomedical Science, Yogyakarta, Indonesia; University of Groningen and University Medical Center Groningen, Department of Biomedical Engineering, Groningen, The Netherlands.
Universitas Gadjah Mada, Faculty of Dentistry, Department of Dental Conservative, Yogyakarta, Indonesia.
Dent Mater. 2019 May;35(5):740-750. doi: 10.1016/j.dental.2019.02.024. Epub 2019 Mar 2.
The oral environment limits the longevity of composite-restorations due to degradation caused by chewing, salivary and biofilm-produced enzymes and acids. This study investigates degradation of two resin-composites in relation with biofilm composition in vitro and in vivo.
Surface-chemical-composition of two Bis-GMA/TEGDMA composites was compared using X-ray-Photoelectron-Spectroscopy from which the number ester-linkages was derived. Composite-degradation was assessed through water contact angles, yielding surface-exposure of filler-particles. Degradation in vitro was achieved by composite immersion in a lipase solution. In order to evaluate in vivo degradation, composite samples were worn in palatal devices by 15 volunteers for 30-days periods in absence and presence of manually-brushing with water. PCR-DGGE analysis was applied to determine biofilm composition on the samples, while in addition to water contact angles, degradation of worn composites was assessed through surface-roughness and micro-hardness measurements.
In vitro degradation by lipase exposure was highest for the high ester-linkage composite and virtually absent for the low ester-linkage composite. Filler-particle surface-exposure, surface-roughness and micro-hardness of both resin-composites increased during intra-oral wear, but filler-particle surface-exposure was affected most. However, based on increased filler-particle surface-exposure, the high ester-linkage composite degraded most in volunteers harvesting composite biofilms comprising Streptococcus mutans, a known esterase and lactic acid producer. This occurred especially in absence of brushing.
Degradation during intra-oral wear of a low ester-linkage composite was smaller than of a high ester-linkage composite, amongst possible other differences between both composites. S. mutans herewith is not only a cariogenic, but also a composite-degradative member of the oral microbiome.
由于咀嚼、唾液和生物膜产生的酶和酸的降解作用，口腔环境限制了复合修复体的寿命。本研究调查了两种树脂复合材料在体外和体内与生物膜组成的关系的降解情况。
使用 X 射线光电子能谱法比较了两种 Bis-GMA/TEGDMA 复合材料的表面化学成分，从中得出酯键的数量。通过水接触角评估复合材料的降解情况，得出填充颗粒表面暴露的情况。在体外通过将复合材料浸泡在脂肪酶溶液中来实现降解。为了评估体内降解，将复合材料样品在 15 名志愿者的腭部装置中佩戴 30 天，在没有和有手动用水刷牙的情况下。PCR-DGGE 分析用于确定样品上的生物膜组成，除了水接触角外，还通过表面粗糙度和显微硬度测量来评估磨损复合材料的降解情况。
在有脂肪酶暴露的情况下，高酯键复合材料的体外降解最高，而低酯键复合材料几乎不存在。在口腔内佩戴过程中，两种树脂复合材料的填充颗粒表面暴露、表面粗糙度和显微硬度都增加了，但填充颗粒表面暴露的影响最大。然而，基于增加的填充颗粒表面暴露，高酯键复合材料在收获含有变形链球菌的复合生物膜的志愿者中降解最多，变形链球菌是一种已知的酯酶和乳酸产生菌。这种情况尤其在没有刷牙的情况下发生。
在口腔内佩戴过程中，低酯键复合材料的降解比高酯键复合材料小，这可能是两种复合材料之间的其他差异之一。变形链球菌不仅是一种致龋菌，也是口腔微生物组中一种具有复合降解能力的成员。
