Torres Carlos Rocha Gomes, Prado Taiana Paola, Ávila Daniele Mara da Silva, Pucci Cesar Rogério, Borges Alessandra Bühler
Department of Restorative Dentistry, Institute of Science and Technology, Sao Paulo State University-UNESP, São José dos Campos, Brazil.
Int J Dent. 2024 Oct 21;2024:2123406. doi: 10.1155/2024/2123406. eCollection 2024.
The objective of this study was to evaluate the influence of light-curing time and increment thickness on the microhardness and degree of conversion (DC) of bulk fill composite resins with different application systems. Translucency parameter (TP) was also measured. Specimens of resin composites were prepared in a circular matrix using a single increment with different thicknesses (2, 4, and 6 mm) and light-cured with distinct times (10, 20, and 40 s). The materials tested ( = 5 pergroup) were Filtek One (FO) bulk fill, Tetric N-Ceram (TC) bulk fill, SonicFill 3 (SF), VisCalor (VC) bulk. After 24 h, Knoop microhardness (KN) was measured, and the bottom/top ratio (B/T) was calculated. The DC was measured using Fourier transformed infrared (FTIR) spectroscopy. The TP was assessed in additional specimens with 1 mm thick ( = 5). The data were statistically analyzed with analysis of variance (ANOVA) and Tukey's tests (5%). Significant differences were observed for all factors, for both B/T and DC ( < 0.05). The higher increment thickness and the lower curing times resulted in lower B/T and DC means. The VC and TC resins exhibited the overall higher B/T, and the highest TP. SF presented the lowest values of B/T and DC, with compromised polymerization at 6 mm depth. TP (means ± SD) were FO (12.85 ± 1.0), SF (15.62 ± 0.73), TC (20.32 ± 0.49), and VC (20.53 ± 0.73). We concluded that the greater the thickness of the increment, the lower the DC. Higher light curing times resulted on increased DC of the tested composites. The higher translucent materials VC and TC showed the greater B/T and FO resin exhibited the higher DC values.
本研究的目的是评估光固化时间和增量厚度对不同应用系统的大块充填复合树脂的显微硬度和转化率（DC）的影响。还测量了透明度参数（TP）。使用不同厚度（2、4和6毫米）的单一增量在圆形模具中制备树脂复合材料试样，并采用不同的时间（10、20和40秒）进行光固化。测试的材料（每组n = 5）为Filtek One（FO）大块充填材料、Tetric N-Ceram（TC）大块充填材料、SonicFill 3（SF）、VisCalor（VC）大块充填材料。24小时后，测量努氏显微硬度（KN），并计算底部/顶部比率（B/T）。使用傅里叶变换红外（FTIR）光谱法测量DC。在另外1毫米厚的试样（n = 5）中评估TP。采用方差分析（ANOVA）和Tukey检验（5%）对数据进行统计学分析。对于B/T和DC，所有因素均观察到显著差异（P < 0.05）。增量厚度越大且固化时间越短，B/T和DC的平均值越低。VC和TC树脂总体上表现出较高的B/T，以及最高的TP。SF的B/T和DC值最低，在6毫米深度处聚合受到影响。TP（平均值±标准差）分别为FO（12.85±1.0）、SF（15.62±0.73）、TC（20.32±0.49）和VC（20.53±0.73）。我们得出结论，增量厚度越大，DC越低。较高的光固化时间导致测试复合材料的DC增加。较高透明度的材料VC和TC显示出更大的B/T，而FO树脂表现出更高的DC值。
