RESIDUAL MONOMER CONTENT IN DIMETHACRYLATE DENTAL MONOMERS CONTAINING POLYSILSESQUIOXANES.

S. V. ASMUSSEN; C.I. VALLO

Los Cocos, Córdoba, Argentina

Simposio; Archipol 2009, V Argentine-Chilean Polymer Symposium. VIII Argentine Polymer Symposium. XI Chilean Symposium of Polymer Chemistry and Physical Chemistry; 2009

Dimethacrylate monomers are commonly used as the organic matrix of dental restorative composites materials. However, one of the problems of these resins is the release of unreacted residual monomers which have the potential to be toxic to tissues. In fact, one of the main efforts to improve the performance of composites for dental fillings centres on reducing the amount of monomer which leaches into the oral tissue. The purpose of the present study was to assess the residual monomer content in formulations of dental resins contaning silsesquioxanes (SSQO) with functional methacrylate groups. Oligomeric silsesquioxanes were prepared from hydrolysis and condensation of 3-methacryloxypropyl trimethoxysilane MPTMS using formic acid as catalyst. The formic acid serves as solvent, water source and catalyst for both hydrolysis and condensation. Water need not be present as an initial reactant as it is generated in situ during the reaction. The synthesis of SSQO was carried out using methacrylate monomers as reactive solvents. The reaction was followed by size exclusion chromatography (GPC), and final products were characterized by FTIR, 1H and 29Si NMR and viscosity. The residual monomer content in different formulations was assessed by GPC.