Post-cure depth of cure of bulk fill dental resin-composites.

OBJECTIVES: To determine the post-cure depth of cure of bulk fill resin composites through using Vickers hardness profiles (VHN). METHODS: Five bulk fill composite materials were examined: Tetric EvoCeram((R)) Bulk Fill, X-tra base, Venus((R)) Bulk Fill, Filtek Bulk Fill, SonicFill. Three specimens of each material type were prepared in stainless steel molds which contained a slot of dimensions (15 mm x 4 mm x 2 mm), and a top plate. The molds were irradiated from one end. All specimens were stored at 37 degrees C for 24h, before measurement. The Vickers hardness was measured as a function of depth of material, at 0.3mm intervals. Data were analysed by one-way ANOVA using Tukey post hoc tests (alpha=0.05). RESULTS: The maximum VHN ranged from 37.8 to 77.4, whilst the VHN at 80% of max.VHN ranged from 30.4 to 61.9. The depth corresponding to 80% of max.VHN, ranged from 4.14 to 5.03 mm. One-way ANOVA showed statistically significant differences between materials for all parameters tested. SonicFill exhibited the highest VHN (p<0.001) while Venus Bulk Fill the lowest (p</=0.001). SonicFill and Tetric EvoCeram Bulk Fill had the greatest depth of cure (5.03 and 4.47 mm, respectively) and was significant's different from X-tra base, Venus Bulk Fill and Filtek Bulk Fill (p</=0.016). Linear regression confirmed a positive regression between max.VHN and filler loading (r(2)=0.94). SIGNIFICANCE: Bulk fill resin composites can be cured to an acceptable post-cure depth, according to the manufacturers' claims. SonicFill and Tetric EvoCeram Bulk Fill had the greatest depth of cure among the composites examined.