Effect of cinnamate comonomers on the dental formulation properties

Abstract

This study reports the synthesis and characterization of two urethane dimethacrylates containing poly(ethylene oxide) or poly(propylene oxide) segment and cinnamate pendant moieties to be formulated in dental resin composites. 1 H NMR, 13 C NMR, and Fourier transform infrared spectroscopies, gel permeation chromatography, electrospray ionization-mass spectroscopy, and thermogravimetric measurements confirmed their structure, whereas the photopolymerization evolution of oligodimethacrylates relating to a low-molecular-weight dicinnamate methacrylate under ultraviolet irradiation was investigated by photo-differential scanning calorimeter, monitoring the degree of conversion (DC) and polymerization rate. The photopolymerization results reveal that the investigated derivatives display a good photoreactivity (DC: $ 70%) during the formation of crosslinked polymers, the DC depending especially on the sample viscosity. The polymerization shrinkage for several mixtures including the urethane oligocinnamates (20 wt %) and diglycidyl methacrylate of bisphenol A/triethyleneglycol dimethacrylate system in the absence of filler was determined, the obtained values being in the range of 6.1-8.2 vol %. For few cured specimens incorporating quartz filler (75 wt %), water sorption/ solubility, contact angle, and mechanical parameters were measured to establish if such monomers could be of interest in dentistry.

Composite resins based on novel and highly reactive bisglycidyl methacrylate monomers

“…Complete gel fraction conversion almost never occurs because the polymer immobilization, vitrification, gelation, or steric isolation inhibits the polymerization reaction. This behavior has been observed in some multifunctional glycidyl methacrylates …”

“…This is desirable, because the residual monomer trapped in the composite may reduce its biocompatibility and clinical serviceability. Oxidation and hydrolytic degradation of the monomer may occur and involve some discoloration or accelerated wear …”

“…This behavior has been observed in some multifunctional glycidyl methacrylates. [31][32][33] Figure 4 shows the FTIR spectra of MB-Cis-OH monomer and homopolymer. FTIR spectrum of the monomer (bottom) shows a band at 1638 cm 21 corresponding to the stretching vibration of the C@C (m) methylene terminal group, while in the FTIR spectrum of the polymer spectrum (top), this absorption band has been reduced drastically due to polymerization reaction.…”