Effect of air-blowing time and long-term storage on bond strength of universal adhesives to dentin

Abstract

Objectives

To evaluate the effects of air-blowing time and storage time on microtensile bond strength (μTBS) of universal adhesives to dentin.

Materials and methods

Ninety flat dentin surfaces from extracted human third molars were bonded with three universal adhesives (Clearfil Universal Bond-CU; G-Premio Bond-GP; Scotchbond Universal Adhesives-SB). Bonded dentin surfaces were air-dried for 5 s, 15 s, or 30 s followed by resin composite built-up. Resin-dentin beams were tested with μTBS test after different storage time in distilled water (24 h and 1 year). Data were analyzed by three-way ANOVA and Duncan test at (α = 0.05). Failure mode and resin-dentin interfaces were observed using a scanning electron microscope (SEM). Specific features of fractured beams after μTBS were further observed using SEM at high magnification.

Results

Extension of air-blowing time from 5 s to 30 s increased the 24 h μTBS of CU only. Bond strength of all adhesives significantly decreased after 1-year storage except for CU at 5 s and 30 s of air-blowing time. One-year μTBS were significantly higher when air-blowing times were extended to 15 s for SB and 30 s for CU. Air-blowing time had no influence on GP.

Conclusion

The effect of air-blowing time and storage time on resin-dentin bond was material-dependent.

Clinical relevance

Extended air-blowing time increased the bond strength and bond durability of CU. Extension of air-blowing time to 15 s and 30 s improve the long-term bond strength of SB and CU, respectively.

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