This study was carried out to evaluate the curing characteristics of a flowable resin composite, Estelite Flow Quick (EFQ, Tokuyama Dental).
EFQ paste of shade A2, A4or Inc was filled into a split cylindrical mold and irradiated for 5 or 20 seconds with a halogen lamp. After the longitudinal split surface was polished, micro-hardness was measured on the surface by the nano-indentation method at the depth of50, 100 or500μm and1, 2or3mm from the top surface. As a control, Medium Flow A3irradiated for20seconds was used.
For Inc, 5-seconds irradiation gave a constant hardness regardless of the depth (Tukey HSD,
p>0.05). Fiveseconds irradiation resulted in lower hardness than20-seconds irradiation for any shade of EFQ (
P<0.05), but generated comparable hardness with the control (
p>0.05) except for A4at the depth of2and3mm.
The results indicated that the curing property of EFQ was enhanced by the radical amplified photo-polymerization initiator contained. However, the shorter irradiation may cause insufficient polymerization at the deeper part for the darker shade.
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