Silicon ( IF 3.4 ) Pub Date : 2020-05-29 , DOI: 10.1007/s12633-020-00521-2 Sukriti Yadav , Swati Gangwar
Fracture toughness of dental restoratives is of greater relevance, especially in stress relevance applications, i.e., resistance to crack propagation. This work aims to determine the mode I fracture toughness (KIC), void contents, and Vickers micro-hardness of the MPTS (3-methacryloxypropyl) trimethoxy silane) and APTES (3-aminopropyl) triethoxysilane) treated nanohydroxyapatite (n-HAPs) filled Dental Restorative Composites (DRCs). The void contents of the dental restoratives were determined by calculating theoretical and experimental densities of the material whereas, microhardness and mode I fracture toughness was determined by using the indentation and single edge notched bend (SENB) method after storing all the samples for 24 h in distilled water respectively. The result shows that void contents and microhardness of fabricated dental restoratives continue to increase with an increase in the weight fraction of fillers. And the fracture toughness (KIC) of both the series increased with the weight fraction of fillers up to a maximum value of 2.883 ± 0.19 MPa√m for (DRC-8 M) and 2.536 ± 0.18 MPa√m for DRC-8A after that KIC shows a marginal decrease in its value for 12 wt.% of fillers. The fractography of the DRCs reveals the various energy dissipating mechanism developed during crack propagation and contribute to the improved value of fracture toughness as compared to unfilled dental restoratives, i.e., crack deflection and crack pinning effect of hydroxyapatite nanoparticles.
中文翻译:
n-HAPs填充牙科修复复合材料的I型断裂韧性分析
牙齿修复剂的断裂韧性具有更大的相关性,尤其是在应力相关的应用中,即对裂纹扩展的抵抗力。这项工作旨在确定I型断裂韧性(K ICMPTS(3-甲基丙烯酰氧基丙基)三甲氧基硅烷)和APTES(3-氨基丙基)三乙氧基硅烷)处理的纳米羟基磷灰石(n-HAP)填充的牙科修复复合材料(DRC)的空隙含量和维氏显微硬度。通过计算材料的理论和实验密度来确定牙科修复剂的空隙率,而将所有样品在室温下保存24小时后,使用压痕和单边切口弯曲(SENB)方法来确定显微硬度和I型断裂韧性。分别用蒸馏水。结果表明,随着填料重量分数的增加,制成的牙科修复剂的空隙率和显微硬度继续增加。和断裂韧性(K IC这两个系列的)随填充物的重量分数增加而增加(对于(DRC-8 M)为2.883±0.19MPa√m,对于DRC-8A为2.536±0.18MPa√m,此后K IC显示出一定程度的下降占填充料重量的12%。DRC的分形图显示了裂纹扩展过程中产生的各种能量耗散机制,并且与未填充的牙科修复剂相比,有助于提高断裂韧性,即羟基磷灰石纳米粒子的裂纹偏转和裂纹钉扎效果。