Conversion, shrinkage, water sorption, flexural strength and modulus of re-mineralizing dental composites
Conversion, shrinkage, water sorption, flexural strength and modulus of re-mineralizing dental composites
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DOI：
10.1016/j.dental.2015.08.149
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发表时间：
2015-11-01
期刊：
影响因子：
5
通讯作者：
Young, A. M.
中科院分区：
文献类型：
--
作者：
Aljabo, A.;Xia, W.;Young, A. M.
目标。为减少龋病复发，对含有洗必泰(CHX)和活性磷酸钙(CAP)的新型牙科复合材料的固化、体积变化和力学性能进行了评估。将质量分数为20%的光固化二甲基丙烯酸甲酯液体与质量分数为80%的含10%CHX的玻璃填料和0~40%的CaP混合。用傅里叶变换红外光谱分析了S光照射20或40次时的转换随深度的变化。用ISO4049和17304分别测定了固化深度和聚合收缩。在4周内测定随后的体积膨胀和水浸泡后的双向弯曲强度和弹性模量的变化。1周后观察模拟体液中羟基磷灰石的沉淀情况。转化率随深度和盖层含量的增加而线性下降。平均凝固深度分别为4.5、3.9、3.3、2.9和5.0，盖板含量分别为0、10、20和40%，商用复合材料Z250的平均凝固深度为5.0。在这些深度，实验材料的转化率为53+/-2%，而Z250的转化率仅为32%。使用Z250，转化率超过50%，仅在1.1 mm以下。实验材料和Z250的收缩分别为3%和2.5%。早期的吸水率呈线性增加，而强度和模数在绘制时呈指数下降到最终值，而时间的平方根。最大体积膨胀率在10-20wt%的盖板上随着盖子的升高和平衡收缩而线性增加。Z250的强度和定伸应力分别从191降到158 Mpa和3.2降到2.5 Gpa。随着上限的增加，复合材料的初始强度和初始定伸应力分别从169 Mpa和5.8 Gpa线性下降到139 Mpa和3.8 Gpa。外推终值分别从156~84 Mpa和4.1~1.7 GPa.所有含有CaP的材料都促进了羟基磷灰石的析出。复合修复体的下表面应该是实心的，并且有50%以上的转换率。因此，结果表明，实验复合材料可能被放置在比Z250厚得多的层中，并且减少了无结合的细胞毒性单体。此外，重量百分比为10-20wt.%的实验材料还具有体积膨胀，以补偿收缩、抗菌和再矿化成分以及具有竞争力的机械性能。(C)2015年提交人。爱思唯尔有限公司出版。
Objectives. Cure, volumetric changes and mechanical properties were assessed for new dental composites containing chlorhexidine (CHX) and reactive calcium phosphate-containing (CaP) to reduce recurrent caries.Methods. 20 wt.% of light curable urethane dimethacrylate based liquid was mixed with 80 wt.% glass filler containing 10 wt.% CHX and 0-40 wt.% CaP. Conversion versus depth with 20 or 40 s light exposure was assessed by FTIR. Solidification depth and polymerization shrinkage were determined using ISO 4049 and 17304, respectively. Subsequent volume expansion and biaxial flexural strength and modulus change upon water immersion were determined over 4 weeks. Hydroxyapatite precipitation in simulated body fluid was assessed at 1 week.Results. Conversion decreased linearly with both depth and CaP content. Average solidification depths were 4.5, 3.9, 3.3, 2.9 and 5.0 with 0, 10, 20, and 40% CaP and a commercial composite, Z250, respectively. Conversions at these depths were 53 +/- 2% for experimental materials but with Z250 only 32%. With Z250 more than 50% conversion was achieved only below 1.1 mm. Shrinkage was 3% and 2.5% for experimental materials and Z250, respectively. Early water sorption increased linearly, whilst strength and modulus decreased exponentially to final values when plotted versus square root of time. Maximum volumetric expansion increased linearly with CaP rise and balanced shrinkage at 10-20 wt.% CaP. Strength and modulus for Z250 decreased from 191 to 158 MPa and 3.2 to 2.5 GPa. Experimental composites initial strength and modulus decreased linearly from 169 to 139 MPa and 5.8 to 3.8 GPa with increasing CaP. Extrapolated final values decreased from 156 to 84 MPa and 4.1 to 1.7 GPa. All materials containing CaP promoted hydroxyapatite precipitation.Significance. The lower surface of composite restorations should both be solid and have greater than 50% conversion. The results, therefore, suggest the experimental composite may be placed in much thicker layers than Z250 and have reduced unbounded cytotoxic monomer. Experimental materials with 10-20 wt.% additionally have volumetric expansion to compensate shrinkage, antibacterial and re-mineralizing components and competitive mechanical properties. (C) 2015 The Authors. Published by Elsevier Ltd.