Department of Biomaterials and Oral Biology, Univ. of São Paulo School of Dentistry, Av. Prof. Lineu Prestes, 2227, São Paulo, SP 05508-000, Brazil.
Department of Biomaterials and Oral Biology, Univ. of São Paulo School of Dentistry, Av. Prof. Lineu Prestes, 2227, São Paulo, SP 05508-000, Brazil.
Dent Mater. 2015 Jun;31(6):726-33. doi: 10.1016/j.dental.2015.03.015. Epub 2015 Apr 17.
To evaluate the effect of the replacement of barium glass by dicalcium phosphate dihydrate (DCPD) particles on the mechanical properties and degree of conversion (DC) of composites. Additionally, calcium and hydrogen phosphate (HPO4(2-)) release were followed for 28 days.
Nine composites containing equal parts (in mols) of BisGMA and TEGDMA and 40, 50 or 60 vol% of total filler were manipulated. Filler phase was constituted by silanated barium glass and 0%, 10% or 20% of DCPD particles. DC was determined by near-FTIR. Biaxial flexural strength (BFS) and modulus (E) were tested using the "piston on three balls" method, while fracture toughness (KIc) used the "single edge notched beam" method. Specimens were tested after 24h and 28 days in water. Ion release was determined using inductively coupled plasma optical emission spectrometry (ICP-OES). Data were analyzed by ANOVA/Tukey (DC and ion release) or Kruskal-Wallis/Mann-Whitney (mechanical properties; alpha: 5%).
DC was not affected by DCPD. The presence of DCPD reduced BFS for both storage times, while differences in E became evident after 28 days. After 24h, KIc increased with the addition of DCPD; after 28 days, however, KIc decreased only for DCPD-containing composites. Calcium release was similar for both DCPD contents and remained fairly constant during the 28-day period. Overall, HPO4(2-) release was higher at 7 days and did not decrease after 14 days.
The composite with the highest filler level and 10% DCPD represented the best compromise between mechanical properties after aging in water and ion release.
评估用二水磷酸二钙（DCPD）颗粒替代钡玻璃对复合材料的机械性能和转化率（DC）的影响。此外，还跟踪了 28 天内的钙和磷酸氢盐（HPO4(2-））释放情况。
制备了九种含有 BisGMA 和 TEGDMA 等摩尔份数和 40%、50%或 60%总填料的复合材料。填料相由硅烷化钡玻璃和 0%、10%或 20%的 DCPD 颗粒组成。使用近红外傅里叶变换（FTIR）测定 DC。采用“三球活塞”法测定双轴弯曲强度（BFS）和模量（E），采用“单边缺口梁”法测定断裂韧性（KIc）。在水储存 24h 和 28d 后对试件进行测试。采用电感耦合等离子体发射光谱法（ICP-OES）测定离子释放。数据通过方差分析/Tukey 检验（DC 和离子释放）或 Kruskal-Wallis/Mann-Whitney 检验（机械性能；alpha：5%）进行分析。
DCPD 的存在不影响 DC。在两种储存时间下，DCPD 的存在都会降低 BFS，而 E 的差异仅在 28d 后才明显。在 24h 时，添加 DCPD 会增加 KIc；然而，在 28d 后，只有含 DCPD 的复合材料的 KIc 才会降低。对于两种 DCPD 含量，钙释放相似，在 28 天期间保持相当稳定。总体而言，HPO4(2-) 释放在第 7 天较高，14 天后并未减少。
在老化水中的机械性能和离子释放之间具有最佳折衷的复合材料是具有最高填充水平和 10%DCPD 的复合材料。
