Dental restorative composites containing methacrylic spiroorthocarbonate monomers as antishrinking matrixes

Abstract

ABSTRACTIn this work, the synthesis of two new antishrinking methacrylic monomers of spiroorthocarbonate type, SOC‐IP‐UDMA and SOC‐UDMA, is discussed, along with studies of their performance as polymeric matrix in dental composites. The monomers were photoactive with components of a conventional resin composite. In order to study the photocuring kinetics of these SOC monomers, a real‐time test was performed using FTIR spectroscopy. It was found that SOCs promoted higher double bond conversions (DC) than conventional methacrylic monomer bis‐GMA (48%), reaching a DC value of 68% for SOC‐UDMA and 75% for SOC‐IP‐UDMA. The shrinkage stress that accompanies curing of dental composites was measured by a universal testing machine. These new monomer SOCs are capable of reducing the shrinkage up to 51.1% and 27.7% for both methacrylic monomers when they were compared with bis‐GMA as control. Also, a dynamical mechanical analysis was conducted on the dental composites, obtaining a higher modulus and a range of T g values from 80 to 100 °C. Others parameters like flexural properties, solubility, and sorption water were determined, obtaining values better than or equal to the parameters established by the standard ISO 4049. These monomers can be considered as alternative matrixes to replace bis‐GMA in dental composites. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47114.