Evaluation of Bis-GMA/TEGDMA Leaching From a Hybrid Resin Composite

Methods: 36 Composite disc specimens (Hybrid Filtek Z250 3M ESPE)(5mm diameter and 2mm depth) were made and they were divided in 4 groups. The samples were polymerized with LED or Halogen light curing units.The samples were immersed in either water or saliva and incubated at 37oC for 24 hours.The amounts of each monomer(Bis-GMA and TEGDMA) released in different mediums were detected by high-Performance liquid chromatography(HPLC).Data were analyzed with two-way ANOVA and one-way ANOVA tests(p<0.05).

Results: The samples that were cured with halogen light and immersed in water released significantly more Bis-GMA(10.422+/-3.935) than TEGDMA(4.2+/-1.794;P=0.004). The samples that were cured with LED light and immersed in water released significantly more Bis-GMA(6.6+/-2.603) than TEGDMA (1.448+/-0.626;P=0.001). TEGDMA(18.577+/-12.183) leached significantly more than Bis-GMA (5.266+/-2.019;P=0.018) from samples were cured with halogen light and immersed in saliva; nevertheless, there was no significant difference in leaching TEGDMA(5.595+/- 2.901) compared with Bis–GMA(6.413+/-1.674;NS) from samples that were cured with LED and immersed in saliva. Halogen curing unit induced significantly more monomer elution than LED(p=0.001); in addition , saliva caused elution of more monomer than water(p=0.007).

Conclusion: It was concluded that the quantity of monomers leached from composite-resins is affected by curing light unit and the type of immersion media. Saliva medium and halogen curing unit can cause greater monomer leaching from composite-resins.