792 Enamel/Dentin Bonding Effectiveness of Self-etching Borate-initiated Self-cure 1-step Adhesive

Friday, March 23, 2012: 2 p.m. - 3:15 p.m.
Presentation Type: Poster Session
S. ARMSTRONG, College of Dentistry, University of Iowa, Iowa City, IA, K. HIRATA, University of Iowa, Tsukuba-City, Japan, and F. QIAN, Preventive and Community Dentistry, University of Iowa, Iowa City, IA

Objectives: Determine micro-tensile bond strength (mTBS) of an experimental self-etching, borate-initiated self-curing one-step adhesive system containing self-reinforcing (SR) multi-functional monomer (DBC510) bonded to enamel and dentin.

Methods: Five adhesive groups: DBC510 (DBC, experimental, self-etch 1 step self-cure, Tokuyama Dental), DBC510 with phosphoric acid etching (DBC/E, experimental, etch-and-rinse 2 step self-cure, Tokuyama Dental), Optibond Solo Plus (OSP, etch-and-rinse 2 step light-cure, Kerr), Clearfil SE (CSE, self-etch 2 step light-cure, Kuraray) and Optibond All-in-One (OBA, self-etch 1 step light-cure, Kerr) were applied to occlusal dentin and buccal/lingual enamel of 200 carbide bur-cut human molars followed by resin-based composite (Z100, 3M-ESPE). Twenty-four hours later restored teeth were sectioned with diamond blades into 2x2mm square sticks then dumbbell shaped specimens (0.5mm2 round cross-sectional area, 1mm gage length, 0.6mm radius of curvature) were formed using a CNC Specimen Former (University of Iowa). One-half of the specimens were then tensile-tested at a crosshead speed of 1mm/min in a calibrated materials testing machine (Z2.5, Zwick). Both ANOVA and Weibull regression models were performed, both ignoring and considering the random effect of the tooth (multiple specimens per tooth) to detect a difference in enamel and dentin bond strengths between adhesives.



Microtensile bond strength (MPa (SD))





54.9 (9.9) A,a

31.1 (7.5) B,b


55.2 (8.2) A,a

49.9 (15.8) A,a


47.2 (10.2) A,a

45.0 (10.4) A,a


52.0 (10.2) A,a

32.2 (13.0) B,b


48.4 (13.9) A,a

23.7 (7.8) B,c

**means with the same uppercase letter are not significantly different using a simple random effect in Mixed Model ANOVA with post-hoc Tukey's test and with the same lower case letter are not significantly different using Weibull regression models (P > 0.05). n = 20 per group.

Conclusions: No difference in mTBS to dentin was detected between adhesives. mTBS to enamel was significantly stronger when phosphoric acid etching was performed (DBC/E and OSP).

Acknowledgements: Sponsored by Tokuyama Dental Corp. K. Hirata is an employee of Tokuyama.

This abstract is based on research that was funded entirely or partially by an outside source: Industrial Contract: Tokuyama Dental Corp

Keywords: Adhesion, Dental materials, Dentin, Dentin bonding agents and Enamel
Presenting author's disclosure statement: Study sponsored by Tokuyama Dental Corp.