Chiari Marina D S, Rodrigues Marcela C, Pinto Mirella F C, Vieira Douglas N, Vichi Flávio M, Vega Oscar, Chrzanowski Wojciech, Nagaoka Noriyuki, Braga Roberto R
University of São Paulo, Department of Biomaterials and Oral Biology, School of Dentistry, São Paulo, Brazil.
Cruzeiro do Sul University, São Paulo, São Paulo, Brazil.
Mater Sci Eng C Mater Biol Appl. 2020 Nov;116:111178. doi: 10.1016/j.msec.2020.111178. Epub 2020 Jun 17.
To synthesize and characterize brushite particles in the presence of acidic monomers (acrylic acid/AA, citric acid/CA, and methacryloyloxyethyl phosphate/MOEP) and evaluate the effect of these particles on degree of conversion (DC), flexural strength/modulus (FS/FM) and ion release of experimental composites.
Particles were synthesized by co-precipitation with monomers added to the phosphate precursor solution and characterized for monomer content, size and morphology. Composites containing 20 vol% brushite and 40 vol% reinforcing glass were tested for DC, FS and FM (after 24 h and 60 d in water), and 60-day ion release. Data were subjected to ANOVA/Tukey tests (DC) or Kruskal-Wallis/Dunn tests (FS and FM, alpha: 5%).
The presence of acidic monomers affected particle morphology. Monomer content on the particles was low (0.1-1.4% by mass). Composites presented similar DC. For FS/24 h, only the composite containing DCPD_AA was statistically similar to the composite containing 60 vol% of reinforcing glass (without brushite, "control"). After 60 days, all brushite-containing materials showed similar FS, statistically lower than the control composite (p<0.01). Composites containing DCPD_AA, DCPD_MOEP or DCPD_U ("unmodified") showed statistically similar FM/24 h, higher than the control composite. After prolonged immersion, all composites were similar to the control composite, except DCPD_AA. Cumulative ion release ranged from 21 ppm to 28 ppm (calcium) and 9 ppm to 17 ppm (phosphate). Statistically significant reductions in ion release between 15 and 60 days were detected only for the composite containing DCPD_MOEP.
Acidic monomers added to the synthesis affected brushite particle morphology. After 60-day storage in water, composite strength was similar among all brushite-containing composites. Ion release was sustained for 60 days and it was not affected by particle morphology.
在酸性单体（丙烯酸/AA、柠檬酸/CA和甲基丙烯酰氧乙基磷酸酯/MOEP）存在的情况下合成并表征透钙磷石颗粒，并评估这些颗粒对实验性复合材料的转化率（DC）、弯曲强度/模量（FS/FM）和离子释放的影响。
通过将单体添加到磷酸盐前驱体溶液中进行共沉淀来合成颗粒，并对单体含量、尺寸和形态进行表征。对含有20体积%透钙磷石和40体积%增强玻璃的复合材料进行DC、FS和FM测试（在水中24小时和60天后）以及60天离子释放测试。数据进行方差分析/图基检验（DC）或克鲁斯卡尔-沃利斯/邓恩检验（FS和FM，α：5%）。
酸性单体的存在影响颗粒形态。颗粒上的单体含量较低（质量分数为0.1 - 1.4%）。复合材料呈现出相似的DC。对于FS/24小时，仅含有DCPD_AA的复合材料在统计学上与含有60体积%增强玻璃的复合材料（无透钙磷石，“对照”）相似。60天后，所有含透钙磷石的材料显示出相似的FS，在统计学上低于对照复合材料（p<0.01）。含有DCPD_AA、DCPD_MOEP或DCPD_U（“未改性”）的复合材料在统计学上显示出相似的FM/24小时，高于对照复合材料。长时间浸泡后，除DCPD_AA外，所有复合材料均与对照复合材料相似。累积离子释放范围为21 ppm至28 ppm（钙）和9 ppm至17 ppm（磷）。仅对于含有DCPD_MOEP的复合材料，在15至60天之间检测到离子释放有统计学显著降低。
合成过程中添加的酸性单体影响透钙磷石颗粒形态。在水中储存60天后，所有含透钙磷石的复合材料的强度相似。离子释放持续60天，且不受颗粒形态影响。
