EFFECT OF IRRADIATION TIME ON DEPTH OF CURE, WATER SORPTION AND SOLUBILITY OF TWO BULK FILL RESIN COMPOSITES

Objectives: To evaluate the effect of irradiation time on depth of cure, water sorption and solubility of two bulk fill resin composites.
 
Methods: A total of 40 resin composite cylinders were prepared (6mm x 4mm) and divided into 4 groups according the resin composite used; X-tra fil (VOCO) and Quixfil (DENTSPLY) and irradiation time; 10s or 20s. Top and bottom hardness were measured using Vickers microhardness tester. Depth of cure was measured using bottom / top hardness ratio. For water sorption and solubility assessment, 40 disc shaped specimens (15mm x 1mm) were prepared and tested according to the ISO 4049. Data were tabulated and statistically analyzed.
 
Results: No significant differences were recorded between X-tra fil and Quixfil regarding depth of cure and water sorption at both irradiation times. Water sorption significantly decreased at 20s curing for both resin composites. At 10s irradiation time, X-tra fil recorded a significantly higher solubility (10.99±2.58) than 20s (6.57±1.78) and higher solubility than Quixfil (5.79±2.62).
 
Conclusion: X-tra fil and Quixfil showed depth of cure within the acceptable threshold value. Both materials showed acceptable water sorption and solubility according to the ISO 4049 except X-tra fil showed unacceptable solubility at 10s curing. Longer irradiation time greatly improved water sorption and solubility. Both bulk fill resin composites behave similarly at longer irradiation time.