Resin-Dentin Bond Strengths and Nanoleakage at Nine Months Post-bonding

Objective: To evaluate dentin bond strengths and nanoleakage of two total-etch and two self-etching primer systems at 9 months. Methods: An experimental self-etching priming system (ABF, Kuraray), Clearfil SE Bond (Kuraray), Single Bond (3M ESPE), and One Step (Bisco) were used. Forty bovine incisors were ground with 600 grit SiC, bonded as recommended by the manufacturers, and restored with Clearfil AP-X (Kuraray), Z250 (3M Dental), or Renew (Bisco). After 24 h at 37°C, the teeth were sectioned into 0.7 mm thick slabs and trimmed for microtensile bond test. Half of the specimens were stored in water at 37°C and tested at 3, 6, and 9 months. The other half was tested at 24 hours. Alternate slices were immersed for 1 hour in Rhodamine B or water (control) and tested with a tabletop tester (EZ-test) at crosshead speed of 1mm/min. The data were analyzed by ANOVA and Fisher’s PLSD test (p<0.05) to determine differences within each material and subgroup. Rhodamine B and interfacial morphology were analyzed at each time interval. Results: MPa (SD) n=10

Same superscript letters indicate p<0.05. Conclusions: Bond strengths of ABF and One Step were stable from 24h to 9 months, and there was no time-related increase in Rhodamine B uptake at the interface. Supported by Kuraray Medical.