Systematic Variation of Interfacial Phase Reactivity in Dental Nanocomposites
K S. Wilson, K Zhang, Joseph M. Antonucci
The goal of this study was to determine the effect of varying the chemistry of the interfacial phase on critical composite properties in dental nanocomposite materials. Silica nanoparticles were silanized with varying ratios of 3-methacryloxypropyltrimethoxysilane (MPTMS) and octyltrimethoxysilane (OTMS) while keeping the amount of total silane constant at 10 % by mass. The nanoparticles (60 % by mass) were mixed into a dimethacrylate resin. The composites were photo-cured and tested by biaxial flexure and three point bend flexure testing. Fracture surfaces were analyzed by field-emission scanning electron microscopy (FE-SEM). In formulating the composite pastes, the maximum mass fraction of silanized silica that could be successfully mixed into the resin increased as the fraction of OTMS on the silica increased relative to MPTMS, suggesting improved processability compared to those silanized with only MPTMS.The flexure strengths and moduli of the dual silanized composites were similar up to 5 % OTMS but decreased as OTMS fractions in the silane mixture increased to 7.5 % and 10 %. FE-SEM images revealed evidence for phase separation in the composites containing silica silanized with high fractions of OTMS. Generally, nanocomposites filled with dual silanized (MPTMS and OTMS) silica nanoparticles had mechanical properties comparable to nanocomposites filled with MPTMS-silanized nanoparticles. Among the practical benefits of dual silanized nanoparticles were the improved processability of composite pastes and higher filler loadings tha should lead to lower cure shrinkage.
, Zhang, K.
and Antonucci, J.
Systematic Variation of Interfacial Phase Reactivity in Dental Nanocomposites, Biomaterials, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=852400
(Accessed December 3, 2023)