Dentin Bond Strength of Composites with Self-etching Adhesives Using LED Curing Lights

Abstract

The purpose of this study was to investigate the effect of light-emitting diode (LED) light curing units (LCUs) compared with halogen LCUs on the shear bond strength (SBS) of one nanofill composite (Filtek Supreme) and one microhibrid composite (Artemis) with self-etch adhesives. The buccal surfaces of 60 non-carious extracted human molars were flattened to expose dentin and, subsequently, polished for 60 seconds with 600-grit wet silicon carbide abrasive paper. Specimens were assigned into six groups (n=10) according to composite material, self-etch adhesive, and curing light used as follows: Group 1: Adper Prompt L-Pop (AP) and Filtek Supreme (FS) using an Elipar Free Light (EFL); Group 2: AP and FS using an Elipar Free Light 2 (EFL2); Group 3: AP and FS using a Hilux Expert (HE) light, Group 4: AdheSE (AS)+Artemis (AR) using an EFL; Group 5: AS+AR using an EFL2; and Group 6: AS+AR using a HE light. The specimens were thermocycled for 500 cycles (5 masculineC-55 masculineC) and then loaded to failure in a Zwick universal testing machine at a crosshead speed of 5 mm/minute. SBS values were calculated as megapascals (MPa) and statistically analyzed using the one-way analysis of variance (ANOVA) test at a significance level of 0.05. Mean SBS (+/- standard deviations) values were as follows: Group1: 15.99+/-5.18; Group 2: 18.76+/-6.71; Group 3: 17.70+/-5.04; Group 4: 16.93+/-3.99; Group 5: 18.01+/-5.19, and Group 6: 17.46+/-5.40. There were no statistically significant differences for SBS to dentin among the groups tested. The LED curing lights used in the study seem to be comparable with the halogen curing light for nanofill and microhybrid composites used in conjunction with self-etching systems in dentin. The EFL2 reduces curing time, which can be considered as an advantage.