WEAR BEHAVIOR OF HYBRID COMPOSITE REINFORCED WITH TITANIUM DIOXIDE NANOPARTICLES

Abstract

The aim of the present study is to investigate the influence of polymerization times, normal loads and titanium dioxide nanoparticles content on the wear of hybrid composite resin reinforced with titanium dioxide (TiO2) nanoparticle. The materials used are hybrid composite resin and titanium dioxide nanoparticles (TiO2nanoparticles). Four groups of composite resin samples are prepared; one as received and three groups reinforced with   TiO2nanoparticles in contents of 0.1, 0.2 and 0.3 wt. %. Hybrid composites resin is manually mixed with TiO2 nanoparticles. The resulting blend is packed into plastic cylindrical bars. The samples are then cured from both sides for 10, 20, 40, 60 and 80 seconds using a visible light curing unit. To determine the wear, all samples are tested with two-body abrasion, reciprocating sliding apparatus at room temperature.  The test conditions are; sliding velocity= 60 strokes/min, load= 6, 8, 10, 12 and 14 N, time= 60 seconds. Results show that the wear decreases with the increase of polymerization time at all normal loads. Results showed also that wear depends on the normal load. The wear initially decreased and reached a minimum at a concentration of 0.1 wt. % TiO2 nanoparticles, above 0.1 wt. % TiO2 nanoparticles, the aggregation of TiO2 nanoparticles led to increase of the wear. The present study suggests that in order to minimize wear, it is important to use relatively higher polymerization time, lower TiO2content and lower force of chewing.