The purpose of this study was to evaluate the effect of a desensitizer on dentinal bond strength in cementation of composite resin inlay. Fifty four molar teeth were exposed the occlusal dentin. Class I inlay cavities were prepared and randomly divided into six groups. Control group ; no agent, Group 1 ; Isodan, Group 2 ; One-step, Group 3 ; All-Bond SE, Group 4 ; Isodan + One-step, Group 5 ; Isodan + All-Bond SE.

Desensitizing agent and dentin bonding agents were applied immediately after the completion of the preparations. Impressions were then made. The composite resin inlays (Tescera, Bisco) were fabricated according to the manufacturers' guidelines. Cementation procedures followed a standard protocol by using resin cement (Bis-Cem, Bisco). Specimens were stored in distilled water at 37℃ for 24 hours.

All specimens were sectioned to obtained sticks with 1.0 × 1.0 mm² cross sectional area. The microtensile bond strength (µTBS) was tested at crosshead speed of 1 mm/min. The data was analyzed using oneway ANOVA and Tukey's test. Scanning electron microscopy analysis was made to examine the details of the bonding interface.

1. Group 1 showed significantly lower µTBS than other groups (p<0.05).

2. There was no significant difference between the µTBS of Group 3 and Group 5.

3. The µTBS of Group 4 showed significantly lower than that of Group 2 (p<0.05).

In conclusion, a desensitizer (Isodan) might have an adverse effect on the bond strength of composite resin inlay to dentin.

This study investigated that the effect of rewetting agent on dentinal microtensile bond strength (µTBS). Human molars were sectioned to expose the superficial dentin surfaces.

Samples were divided into two groups according to type of adhesives-Single Bond (S) and One-Step (O)], and again subdivided into five groups by different dentin surface treatment-dry for 15s (D), blot dry (BD) or dry for 15s, and rewet with different rewetting agents [distilled water (DW), Gluma Desensitizer (GD) and Aqua-Prep (AP)] for 30s. After application of adhesive, composite resin was built up on the bonding surface. Each tooth was sectioned to obtain stick with 1 mm² cross sectional area and the µTBS was determined by EZ test.

In the S group, the mean µTBS of GD, AP and BD group was significantly higher than that of DW and D group (p < 0.05). In the O group, the mean µTBS of AP, GD, BD and DW group was significantly higher than that of D group (p < 0.05).

The data suggested that Gluma Desensitizer and Aqua-Prep could be successfully used as rewetting agents, and Distilled water could be acceptable in aceton based adhesive system only.

This study evaluated the influence of a desensitizer(MS coat) on microtensile bond strength of different adhesives: a three-step adhesive(All-Bond 2), a two-step adhesive(Single Bond), a one-step adhesive(One-up Bond F).

Non-caries extracted human molars were used. Dentin surface was obtained by horizontal section on midportion of crown using a water-cooled low speed diamond saw. Teeth were randomly divided into 6 group. AMO(MS coat + All Bond)-, SMO(MS coat + Single Bond)- and OMO(MS coat + One-up Bond F)-dentin surface were treated with 17% EDTA before bonded adhesive. AMX-, SMX- and OMX-dentin surface were bonded with All-Bond 2, Single Bond and One-up Bond F, respectively, with no previous treatment with MS coat and 17% EDTA. About 1cm high resin composite(Z-250™) were incrementally build-up on the treated surface. The specimens for the microtensile test were serially sectioned perpendicular to the adhesive layer to obtain 0.7×0.7 mm sticks. 30 sticks were prepared from each group.

After that, tensile bond strength for each stick was measured with Microtensile Tester at a 1mm/min crosshead speed. Fractured dentin surfaces were observed under the SEM. The results were statistically analysed by using a One-way ANOVA and Tukey's test(p<0.05).

Value in MPa were: AMO-44.35±13.21; SMO-39.35±13.32; OMO-31.07±10.25; AMX-49.22±16.38; SMX-56.02±13.35; OMX-72.93±16.19. Application of MS coat reduced microtensile bond strengths of both Single Bond and One-up Bond F, whereas microtensile bond strengths of All-Bond 2 were not affected significantly.