Objective: The aim of this study was to evaluate the effectiveness of technique variations regarding application method on primary dentin shear bond strength (SBS) of a self-etching adhesive (Futurabond M) before and after artificial aging in vitro. Methods: Sixty extracted primary molars were included. Dentin specimens were obtained under standardized conditions. The specimens were randomly assigned to one of the six groups of ten samples each. The adhesive application techniques in each group varied as follows: group 1-NA: one coat of bonding, no artificial aging, group 2-A: one coat of bonding, artificial aging (thermocycling, 5-55°C, 5000 cycles), 2-NA and 2-A: two coats of bonding, light curing after each coat application; 3-NA and 3-A: pre-etching for 10 s prior to bonding. In all groups Glasiosite served as compomer build up. SBS was measured using an universal testing machine. Results: Following SBS were evaluated (mean values and standard deviations in MPa):
| 1-NA | 1-A | 2-NA | 2-A | 3-NA | 3-A |
Mean | 12.9 | 11.2 | 12.6 | 9.3 | 12.2 | 11.5 |
+/- | 1.7 | 4.6 | 2.4 | 3.4 | 2.3 | 3.4 |
Statistical analysis showed a significant influence of application mode and artificial aging on SBS (p<0.001, ANOVA). The highest SBS were observed in the groups 1-NA and 1-A where the adhesive was used as recommended by the manufacturer (p<0.05, Tukey test). Artificial aging decreased SBS. Nevertheless, this decrease was not significant (p>0.05, Tukey test). Pairwise comparison between groups S/SC and between D/DC showed no significant differences in all groups. Conclusions: The results concerning the technique the SBS was not strongly influenced by the number of coats or pre-etching. However, a tendency to lower values was observed after artificial aging.