National Institute of Occupational Health, Oslo, Norway.
Institute of Health and Society, University of Oslo, Oslo, Norway; Oral Health Centres of Expertise in Eastern Norway, Oslo, Norway.
Dent Mater. 2021 Jul;37(7):1121-1133. doi: 10.1016/j.dental.2021.03.011. Epub 2021 Apr 10.
The project aims to evaluate whether inhalation of particles released upon grinding of dental composites may pose a health hazard to dentists. The main objective of the study was to characterize the dust from polymer-based dental composites ground with different grain sized burs and investigate particle uptake and the potential cytotoxic effects in human bronchial cells.
Polymerized blocks of two dental composites, Filtek™ Z250 and Filtek™ Z500 from 3M™ ESPE, were ground with super coarse (black) and fine (red) burs inside a glass chamber. Ultrafine airborne dust concentration and particle size distribution was measured real-time during grinding with a scanning mobility particle sizer (SMPS). Filter-collected airborne particles were characterized with dynamic light scattering (DLS) and scanning electron microscopy (SEM). Human bronchial epithelial cells (HBEC-3KT) were exposed to the dusts in dose-effect experiments. Toxicity was measured with lactate dehydrogenase (LDH) assay and cell counting kit-8 (CCK8). Cellular uptake was observed with transmission electron microscopy (TEM).
Airborne ultrafine particles showed that most particles were in the size range 15-35 nm (SMPS). SEM analysis proved that more than 80% of the particles have a minimum Feret diameter less than 1 μm. In solution (DLS), the particles have larger diameters and tend to agglomerate. Cell toxicity (LDH, CCK8) is shown after 48 h and 72 h exposure times and at the highest doses. TEM showed presence of the particles within the cell cytoplasm.
Prolonged and frequent exposure through inhalation may have negative health implications for dentists.
本项目旨在评估牙科复合材料研磨时释放的颗粒吸入是否会对牙医造成健康危害。研究的主要目的是对不同粒度金钢砂车针研磨的聚合物基牙科复合材料粉尘进行特性描述，并研究人支气管细胞对颗粒的摄取和潜在的细胞毒性作用。
3M ESPE 公司的 Filtek™ Z250 和 Filtek™ Z500 两种牙科复合材料的聚合块在玻璃室内用超粗（黑色）和细（红色）金钢砂车针研磨。在研磨过程中，使用扫描迁移率颗粒谱仪（SMPS）实时测量超细空气粉尘浓度和粒径分布。使用动态光散射（DLS）和扫描电子显微镜（SEM）对收集到的空气中的颗粒进行特性描述。人支气管上皮细胞（HBEC-3KT）进行剂量效应实验暴露于粉尘中。使用乳酸脱氢酶（LDH）测定法和细胞计数试剂盒-8（CCK8）测量毒性。用透射电子显微镜（TEM）观察细胞摄取情况。
空气中的超细颗粒表明，大多数颗粒的粒径范围为 15-35nm（SMPS）。SEM 分析证明，超过 80%的颗粒最小 Feret 直径小于 1μm。在溶液中（DLS），颗粒的直径较大，且易于团聚。细胞毒性（LDH、CCK8）在 48h 和 72h 暴露时间和最高剂量时表现出来。TEM 显示颗粒存在于细胞质内。
长时间和频繁的吸入暴露可能对牙医的健康产生负面影响。
