Studies on radiopaque composites containing ZrO 2SiO 2 fillers prepared by the sol-gel process

Abstract

Radiopacity can facilitate diagnostic observations adjacent to dental composites. To produce radiopaque SiO 2-based fillers, ZrO 2SiO 2 powders containing up to 45wt% ZrO 2 were manufactured by the sol-gel process. The radiopacity of experimental composites containing Bis-GMA+TEGDMA+CQ +DMAEMA monomer mixture (25 wt%) and ZrO 2SiO 2 fillers (75 wt%) was evaluated and compared to that of human enamel and two commercial composites with different radiopacity. It became evident that the radiopacity of the experimental composites increased linearly with zirconium content and could match that of the control materials, while the composite containing 15wt% ZrO 2-85wt% SiO 2 filler possessed radiopacity analogous to that of human enamel. It was demonstrated here that the radiopacity of the composites could be precisely controlled by adjusting the ZrO 2 content in ZrO 2SiO 2 fillers. These radiopacity-adjustable composites have the potential to be very useful filling materials by enabling dentists to accurately distinguish secondary caries adjacent to the composite restorations.