RESUMO
PURPOSE: To test the effect of different water samples, used for rinsing the dentin, following acid conditioning, on the bond strength of a resin-based composite (RBC) restorative material (Z100), to dentin using a one-bottle dentin adhesive (Single Bond). MATERIALS AND METHODS: In preliminary experiments two experimental shear bond strength methods were compared, and one was selected which was deemed to permit more uniform application of the adhesive and better light curing. In the definitive experiments there were five experimental groups, according to rinsing water used (1) distilled water as control, (2) water with 3.5 ppm iodine, (3) water 3.0 ppm sodium hypochlorite, (4) water with 2% ethanol, (5) water contaminated with 6 x 10(4) cfu/mL of E. coli BH5V. For each experimental group the shear bond strength to moist dentin from 10 human intact impacted third molars was measured. The dentin samples were etched, washed and gently blotted to leave the dentin moist. Following application of the adhesive and resin, specimens were stored at 37 degrees C for 24 hours prior to testing in an Instron testing machine at a rate of 0.5 mm/minute. RESULTS: Data (in MPa +/- standard deviation) were: Group 1: 21.2 +/- 4.1; Group 2: 20.8 +/- 5.6; Group 3: 21.8 +/- 6.2; Group 4: 22.9 +/- 5.9; Group 5: 19.6 +/- 5.5. These data support the null hypothesis that the water types used in this work had no significant effect on the bonding of a resin composite to dentin (P= 0.74, ANOVA).
