Tensile Bond Strength of Single-Step Self-Etch Adhesives to Er:YAG Laser-Irradiated Dentin

Abstract

Objective: The purpose of this study was to evaluate the influence of Er:YAG laser irradiation on the bond strength to dentine of three single-step adhesives (AQ Bond Plus, G-Bond, and Clearfil Tri-S Bond), and one two-step self-etch adhesive (Clearfil Megabond) as a control. Background Data: The vast majority of the numerous reports on resin bonding to Er:YAG-lased dentine have concluded that Er:YAG laser irradiation is less effective in terms of bond strength, because of the sub-surface damage it produces. However, its effect in combination with single-step adhesives on bonding to dentine remains to be clarified. Methods: Eighty bovine incisors were ground with silicon carbide paper to obtain a flat dentine surface, which 40 were irradiated with an Er:YAG laser. Both lased and unlased dentine was bonded to a resin composite with each adhesive. Tensile bond strength was determined after 24 h of storage in water at 37°C. Failure patterns after tensile bond testing was analyzed by scanning electron microscopy. Results: The two-step self-etch adhesive (Clearfil Megabond) showed the highest bond strength to unlased dentine, but was significantly less effective on lased dentine than the three single-step adhesives. On the other hand, AQ Bond Plus produced an effective bond strength to both lased and unlased dentine, perhaps due to its low viscosity. Conclusion: The single-step adhesives tested in this study were as effective in combination with Er:YAG-lased dentine as the two-step self-etch adhesive.3

The impact of Er,Cr:YSGG laser on the shear strength of the bond between dentin and ceramic is dependent on the adhesive material

“…However, we cannot say for certain whether the fracture occurred in the topmost layer of the laser-treated dentin, but the mainly adhesive fracture behavior can possibly be seen to be in line with the higher values of the shear bond tests. Several studies have shown that laser irradiation causes subsurface damage, and this could explain cohesive fractures occurring within the dentin [22,25]. This weakened dentin may be a reason for the lower shear bond values in other studies.…”

Influence of Hydrophilic Pre-treatment on Resin Bonding to Zirconia Ceramics

“…On the other hand, as an all-in-one adhesive, SBP needs to possess a self-etching function, and therefore contains water and ethanol. Due to this difference in composition, all-in-one adhesives have lower viscosity than 2-step-etch adhesives 14,16) . Consequently, they blend on the TZP surface better than 2-step-etch adhesives 2) , which may increase bond strength.…”

Comparison of the micro-tensile bond strengths of four different universal adhesives to caries-affected dentin after ER:YAG laser irradiation

“…Cavities prepared with Er:YAG laser show irregular margins and rugged cavity walls and a rough floor, that differs from the essential principles of cavity preparation found by Black 6) . The surface asymmetry of laser-irradiated dentin appears well suited to adhesive restorations, although some reports have cast doubts on the bonding capacity of irradiated dentin 7,8) . Since the approval by the U.S. Federal Drug Administration in 1997 of the use of the Er:YAG laser for caries removal, in addition to cavity preparation and conditioning of tooth texture, there have been many reports on its use, in combination with composite materials [9][10][11][12] .…”