• Vichuda Sereepanpanich, D.D.S., Grad. Dip. in Clin. Sc. (Operative Dentistry)
• Sirivimol Srisawasdi, D.D.S., M.S., Ph.D.

Objective This study evaluated microtensile bond strength (MTBS) of two newly developed
self-etch adhesives compared to a two-step self-etch adhesive and a three-step total-etch adhesive,
and determined the effect of surface moisture on MTBS of the new single-step self-etch adhesive.

Materials and methods Twenty-five extracted human third molars were ground flat to expose
mid-coronal dentin, and teeth were randomly divided into five experimental groups, which were Adper
Scotchbond Multipurpose, Clearfil SE Bond, Adper SE Plus Self-Etch Adhesive, Adper Easy Bond
Self-Etch Adhesive, and Adper Easy Bond Self-Etch Adhesive in moist condition groups. Each of the
adhesives was used to bond resin-based composite to the dentin surface. After 24 hours of water
storage, each specimen was sectioned into 8 beams. All beams were tested for MTBS at a cross-head
speed of 1 mm/min. Data were statistically analyzed using one-way ANOVA and Tamhaneûs multiple
comparison tests (α = 0.05).

Results One-way ANOVA revealed significant difference in mean MTBS values among the groups
(p < 0.05). Tamhaneûs multiple comparison tests showed that Adper Scotchbond Multipurpose
exhibited the highest mean MTBS value, however, it was not significantly different from the mean
MTBS value obtained from Clearfil SE Bond and Adper Easy Bond Self-Etch Adhesive in moist
condition. Adper Easy Bond Self-Etch Adhesive showed significant differences in mean MTBS
between moist and dry condition, in which moist condition improved the mean MTBS. Adper SE Plus
Self-Etch Adhesive exhibited the lowest MTBS, which was significantly different from MTBS
obtained from all groups except that from Adper Easy Bond Self-Etch Adhesive.

Conclusion The dentin bond strengths produced by Adper Scotchbond Multipurpose three-step
total-etch adhesives and Clearfil SE Bond two-step self-etch adhesive were higher than that of the
newly developed simplified adhesives (Adper SE Plus and Adper Easy Bond). MTBS of Adper Easy
Bond single-step self-etch adhesive significantly increased when bonded to moist dentin.

(CU Dent J. 2009;32:191-202)