Mechanical properties of experimental dental composites containing a combination of mesoporous and nonporous spherical silica as fillers

Objectives. Mesoporous fillers have been investigated for use in dental composites because of their potential for creating micromechanical filler/resin matrix interphase bonding. Such a micromechanical bonding could eliminate the need for the silane treatment of fillers for interfacial chemical bonding that is prone to hydrolysis in the oral environment. in the case of micromechanical bonding, dental polymer chains are threaded mechanically (like a necklace) through nanosized channels in the fillers. Methods. A combination of mesoporous silica, which was synthesized using the nonsurfactant templating method, and nonporous spherical silica (500 nm) was used to prepare experimental dental composites. The porous silica used in this study contained interconnected pores and channels as opposed to porous fillers containing surface pores. The compressive strength, compressive modulus, flexural modulus, and flexural strength of these composites were evaluated. Results. The results showed that composites containing a combination of mesoporous and nonporous fillers have better mechanical properties than the composites having either of these fillers alone. Significance. The results showed that a combination of mesoporous and nonporous materials can be used to prepare stronger dental materials that may resist hydrolysis and wear. (C) 2008 Published by Elsevier Ltd on behalf of Academy of Dental Materials. All rights reserved.