A comparative study of bulk-fill composites: degree of conversion, post-gel shrinkage and cytotoxicity
A comparative study of bulk-fill composites: degree of conversion, post-gel shrinkage and cytotoxicity
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DOI：
10.1590/1807-3107bor-2018.vol32.0017
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发表时间：
2018-01-01
影响因子：
2.5
通讯作者：
Boaro, Letícia Cristina Cidreira
中科院分区：
文献类型：
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作者：
Gonçalves, Flávia;Campos, Luiza Mello de Paiva;Boaro, Letícia Cristina Cidreira
散装填充复合材料声称是修复材料中使用的深准备和有效的光活化层高达4毫米。本研究的目的是评估的转换程度，凝胶后体积收缩，和细胞毒性的6散装填充和两个传统的复合材料。通过FTIR光谱法测定转化程度;使用应变计法测定凝胶后体积收缩率;通过MTT试验间接评价人成纤维细胞中的细胞毒性。对数据进行单因素ANOVA/Tukey检验（α = 0.05）。所有材料，包括散装填充和传统的复合材料，被归类为无毒，细胞活力高于70%。体积填充复合材料的体积收缩率（1.4 - 0.4%）与常规复合材料（1.7-2.1%）相似或更低。然而，只有四个散装填充复合材料能够维持在4毫米的深度均匀转换。尽管其无毒和收缩类似于传统材料，但并非所有商业散装填充材料都能够在4 mm深度处保持高达80%的表层转化率，这表明一些商业品牌的散装填充设计存在一些缺陷。因此，在牙科实践中使用散装填充材料是有利的，但应特别注意材料的选择和正确使用。
Bulk-fill composites are claimed to be restorative materials used in deep preparations and effectively photoactivated in layers up to 4 mm. The aim of the present study was to evaluate the degree of conversion, post-gel volumetric shrinkage, and cytotoxicity of six bulk-fill and two conventional composites. Degree of conversion was determined by FTIR spectroscopy; post-gel volumetric shrinkage was determined using the strain gauge method; and cytotoxicity in human fibroblasts was evaluated indirectly by the MTT assay. Data were subjected to one-way ANOVA/Tukey's test (alpha = 0.05). All materials, including bulk-fill and conventional composites, were classified as non-toxic, with cell viability higher than 70%. Bulk-fill composites exhibited volumetric shrinkage similar to or lower (1.4 to 0.4%) than that of conventional composites (1.7-2.1%). However, only four of the bulk-fill composites were able to sustain a homogeneous conversion at the 4-mm depth. Despite their non-toxicity and shrinkage similar to that of conventional materials, not all commercial bulk-fill materials were able to maintain a conversion as high as 80% of the superficial layer, at the 4-mm depth, indicating some failure in the bulk-fill design of some commercial brands. Therefore, the use of bulk-fill materials in dental practice is advantageous, but special attention should be given to the selection and correct use of the materials.