Effect of oxygen inhibition of self-etching adhesives on enamel-dentin polymer bond.
OBJECTIVE
To determine effects of light curing of self-etching adhesives under ambient air or nitrogen on inhibition depths, enamel and dentin bond strengths, and marginal adaptation in dentin cavities.


METHODS
The adhesives investigated were: AQ Bond (AQB, Sun Medical; Kyoto, Japan), iBond (IBO, Heraeus Kulzer; Hanau, Germany), One-Up Bond F II (OUB, Tokuyama; Tokyo, Japan), and Prompt L-Pop (PLP, 3M/ESPE; Seefeld, Germany). Inhibition layer thickness (ILT) was microscopically measured on 3 disk-shaped specimens each. Shear bond strengths (SBS) on enamel and dentin (n = 8) were determined after 10 min and 24 h water storage of bonded composite specimens (Venus, Heraeus Kulzer). The marginal adaptation of bonded Venus restorations in cylindrical dentin cavities was microscopically evaluated after 10 min of specimen storage (n = 8) in water. The data were statistically analyzed using parametric and nonparametric ANOVA and post-hoc tests at p < 0.05.


RESULTS
Adhesive curing under air revealed significant ILT (microm) differences: IBO (4) < AQB (8) < PLP (12) < OUB (23). Upon curing in nitrogen atmosphere, no inhibition occurred with AQB, IBO, and PLP, and < 3 microm for OUB. SBSs on enamel after 10 min or 24 h did not differ according to curing atmospheres (p > 0.05). On dentin, SBSs were higher after curing under N2 (p < 0.05). Irrespective of the curing atmosphere, marginal adaptation was good for AQB and IBO and poor for PLP; OUB revealed significantly smaller gaps under N2 than under air curing.


CONCLUSIONS
Oxygen inhibition of the four self-etching adhesives investigated had no or only moderate effects on bonding efficacy to enamel and dentin.
Endo
Tatsuo
T
Graduate School of Dentistry, Department of Restorative Dentistry, Division of Operative Dentistry, Tohoku University, Sendai, Japan.
Osada
Takayuki
T
Finger
Werner J
WJ
Hoffmann
Marcus
M
Kanehira
Masafumi
M
Komatsu
Masashi
M
D000388:Air; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003743:Dental Enamel / Q000648:ultrastructure*; D018772:Dental Marginal Adaptation; D003804:Dentin / Q000648:ultrastructure*; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D009584:Nitrogen / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D033081:Shear Strength; D013314:Stress, Mechanical; D013499:Surface Properties; D013997:Time Factors; D014867:Water / Q000737:chemistry
C453842:AQ bond; D003188:Composite Resins; D017220:Dentin-Bonding Agents; D008689:Methacrylates; C446260:One-Up-Bond F; D011108:Polymers; C408584:Prompt L-Pop; D019279:Resin Cements; C488393:Venus (composite resin); C477386:iBond; D014867:Water; D009584:Nitrogen; D010100:Oxygen