Solubility, salivary sorption and degree of conversion of dimethacrylate-based polymeric matrixes

This study investigated the relationship between the solubility, salivary sorption, and degree of conversion of dimethacrylate‐based polymeric matrixes. Six polymeric matrixes produced by mixing bis‐GMA, TEGDMA and UDMA dimethacrylate monomers were studied. Photoactivation was induced by camphoroquinone/ethyl N,N‐dimethyl‐4‐aminobenzoate. The specimens were light‐cured using an irradiance of 850 mW/cm2 for 20 s. The solubility and sorption (μg/mm3) were measured after immersion in artificial saliva (neutral pH) for 7 days. The degree of conversion (%) was obtained by using a FT‐IR spectrometer equipped with an attenuated total reflectance crystal (ATR). The degree of conversion varied from 39.15 ± 6.30 to 65.57± 4.80, and was influenced by the viscosity of the monomers present in the polymeric matrixes. The solubility of polymeric matrixes varied between 13.64 ± 0.39 and 25.08 ± 0.83, and was strongly influenced by the degree of conversion (Pearson, r = −0.9587, p < 0.01). No correlation was found between salivary sorption and the degree of conversion (p = 0.3918). Salivary sorption was only dependent on the chemical and physical structures of the monomers presented in the polymeric matrixes. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008