Synthesis of dental resins using diatomite and nano-sized SiO2 and TiO2

The mechanical properties of dental composites were improved by porous diatomite and nano-sized silica (OX-50) used as co-fillers. The resin composites, filled with silanized OX-50 and silanized diatomite (40:60 wt/wt), presented the best flexural strength (133.1 MPa), elastic modulus (9.5 GPa) and Vickers microhardness (104.0 HV). Besides these, TiO₂ nanoparticles were introduced to tune the dental resin composites colours which were valued by the CIE-Lab system. The colour parameters (L^?, a^?, b^?) showed that the colour changes of resin composites could be perceived obviously, when 300–400 nm TiO₂ particles were introduced as fillers. The resin composite, filled with 0.5 wt% TiO₂, exhibited both clear discolouration (ΔE^?=3.22) and high mechanical strength. Using scanning electron microscope (SEM) equipped with an energy dispersive X-ray (EDX), the titanium elemental mapping results indicated that the TiO₂ particles were distributed evenly in the prepared dental composites.