Nascimento Armiliana Soares, Rodrigues José Filipe Bacalhau, Torres Rodolfo Henrique Nogueira, Santos Kleilton Oliveira, Fook Marcus Vinicius Lia, Albuquerque Monica Soares de, Lima Eliane Alves de, Filgueira Pedro Tardelly Diniz, Santos João Batista Morais Dos, Oliveira Leonardo Jose Rodrigues de, Braz Rodivan
Universidade de Pernamburco - UPE, Department of Dentistry, Tabatinga Camarajibe, PE, Brazil.
Universidade Federal de Campina Grande - UFCG , Department of Materials Science and Engineering, Campina Grande, PB, Brazil.
Braz Oral Res. 2019 Mar 18;33:e008. doi: 10.1590/1807-3107bor-2019.vol33.0008.
The aim of this study was to evaluate the degree of conversion (DC) and the thermal stability of bulk-fill and conventional composite resins. Eleven composite resin samples were prepared to evaluate the DC, Vickers microhardness (VMH), mass and residue/particle loss, glass transition temperature (Tg), enthalpy, and linear coefficient of thermal expansion (CTE) using infrared spectroscopy (FTIR), microdurometer analyses, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and dilatometry (DIL). The data were subjected to statistical analysis, with a significance level of 95%. DC and VMH were not influenced by the polymerized side of the sample, and statistical differences were recorded only among the materials. Decomposition temperature, melting, and mass and residue loss were dependent on the material and on the evaluation condition (polymerized and non-polymerized). Tg values were similar between the composites, without statistically significant difference, and CTE ranged from 10.5 to 37.1 (10-6/°C), with no statistical difference between the materials. There was a moderate negative correlation between CTE and the % of load particles, by weight. Most resins had a DC above that which is reported in the literature. TGA, Tg, and CTE analyses showed the thermal behavior of the evaluated composites, providing data for future research, assisting with the choice of material for direct or semidirect restorations, and helping choose the appropriate temperature for increasing the DC of such materials.
本研究的目的是评估大块充填复合树脂和传统复合树脂的转化率（DC）及热稳定性。制备了11个复合树脂样品，采用红外光谱（FTIR）、显微硬度计分析、热重分析（TGA）、差示扫描量热法（DSC）和热膨胀法（DIL）来评估DC、维氏显微硬度（VMH）、质量和残留/颗粒损失、玻璃化转变温度（Tg）、焓以及热膨胀线性系数（CTE）。对数据进行统计分析，显著性水平为95%。DC和VMH不受样品聚合面的影响，仅在材料之间记录到统计差异。分解温度、熔点以及质量和残留损失取决于材料和评估条件（聚合和未聚合）。复合材料之间的Tg值相似，无统计学显著差异，CTE范围为10.5至37.1（10⁻⁶/℃），材料之间无统计差异。CTE与负载颗粒重量百分比之间存在中等程度的负相关。大多数树脂的DC高于文献报道的值。TGA、Tg和CTE分析显示了所评估复合材料的热行为，为未来研究提供数据，有助于选择直接或半直接修复材料，并有助于选择提高此类材料DC的合适温度。
