Gypsum has been recognized as acceptable for human consumption as a dietary source of calcium. During contact with teeth, it releases Ca2+ ions needed for remineralization of tooth tissue, and therefore based on the concept of remineralization, gypsum may be a strategic additive for dental restorative materials. Hence, the objective of this study was to develop and characterize a novel dental material reinforced with different weight fraction of micro sized gypsum filler particle. A novel composite material was fabricated using conventional resin matrix consisting of Bisphenol‐A glycidyl methacrylate (Bis‐GMA), tri‐ethylene glycol dimethacrylate (TEGDMA), camphorquinone (CQ) and ethyl 4 dimethyl amino benzoate (EDMAB). Four different compositions were prepared by reinforcing different weight percentage (0–3 wt%) of silane functionalized micro sized gypsum particle. Fourier Transformed Infrared spectroscopy (FT‐IR), Transmission Electron Microscope (TEM) and Thermogravimetric Analysis (TGA) of silane treated filler were used to study the coupling phenomena between filler and resin. Polymerization shrinkage of composites was evaluated using specific gravity method. The Dynamic Mechanical Analysis (DMA) result revealed that the Glass transition temperature was found to be decreased by 15°C compared to unfilled composite. It was also found that the 2 wt% gypsum content recorded the highest value of storage modulus. Simultaneous Thermal Analysis (STA) result revealed that 2 wt% gypsum filled dental composite exhibited maximum thermal stability. The novel dental material exhibited better physical, optical, mechanical, thermal properties and lowest polymerization shrinkage with maximum conversion. POLYM. COMPOS., 38:404–415, 2017. © 2015 Society of Plastics Engineers

No abstract

The aim of this study was to analyze the effect of adding different weight percentages of nanoalumina particles on mechanical properties of resin-based dental composite materials. The composite specimens were prepared by dispersion of different percentage weight fractions (0 wt%, 1 wt%, 2 wt% and 3 wt%) of silane-modified nanoalumina filler in a monomer system containing 50% bisphenol-A glycidyl methacrylate, 49% tri-ethylene glycol dimethacrylate, 0.2% Camphorquinone and 0.8% Ethyl 4-dimethylaminobenzoate. The filler particle before and after silane treatment was characterized using Fourier-transform infrared spectroscopy and transmission electron microscopy. The presence of C ¼ O bond and Si-O-Si linkage between the monomer and filler was clearly indicated. Mechanical behavior of the lightcured samples was evaluated using compressive strength test, three-point flexural strength test, Vicker Micro hardness tests, dynamic mechanical analysis and simultaneous thermal analysis. The results indicated a more than 16% increase in the compressive strength in the samples containing nanoalumina filler particles. Vickers hardness of composite was increased by approximately 28% with respect to unfilled composite. The flexural modulus of composite mixed with alumina nanoparticles was increased from 1.7 to 5.1 GPa, while the values of composite were slightly decreased from 84.5 to 59.5 MPa. The dynamic mechanical analysis result revealed that the glass transition temperature was found to be increased by 30 C compared to unfilled composite. It was also found that the 1 wt% nanoalumina content recorded the highest value of storage modulus. The weight loss profile and thermal stability from thermogravimetric analysis results revealed that the composite filled with 2 wt% nanoalumina content exhibited maximum thermal stability.

In this study, dental composites were fabricated by adding different weight percentages of nanoalumina (5–20 wt%) and marble dust powder (5–20 wt%) in the base monomer system comprised of Bisphenol‐A glycidyl methacrylate, Tri‐ethylene glycol dimethacrylate, Camphorquinone, and Dimethyl Amino Ethyl Methacrylate. Physical and mechanical characterizations such as void content test, Micro‐hardness test, Compressive strength, Dynamic mechanical analysis (DMA), and thermo‐gravimetric analysis were performed to evaluate/compare the contribution of each of the nanoalumina and marble dust powder to the performance of dental composite. The result of experiment was indicated that by the addition of 5 wt% of nanoalumina increased the hardness and compressive strength by 88.46% and 23.25% whereas addition of 5 wt% of marble powder increased the hardness and compressive strength by 51.27% and 21.2%, respectively. DMA results revealed that addition of nanoalumina up to 20 wt% increased the storage modulus by 112.2%, whereas, the addition of marble powder up to 20 wt% increased the storage modulus by 191.2%. The thermal stability of dental composite was decreased with the addition of nanoalumina from 0 to 20 wt% and increased with the addition of marble dust powder from 0 to 20 wt%. Finally, it can be concluded that apart from economical aspect, marble dust powder filled dental composite also exhibited better thermo‐mechanical and thermal properties than that of nanoalumina filled dental composite. POLYM. COMPOS., 39:E321–E331, 2018. © 2016 Society of Plastics Engineers

No abstract