Influence of interchanging adhesive resins and self-etching primers on the mechanical properties of adhesive resins.

: This study determined the influence of interchanging adhesive resins and self-etching primers on the mechanical properties of adhesive resins. Four commercially available two-step self-etching primer systems were used. To measure microtensile strength, 0.5-mm thick dumbbell-shaped slabs of each combination of adhesive resin and self-etching primer were prepared. After 24 hours storage in 37 degrees C distilled water, these specimens were subjected to microtensile testing at a crosshead speed of 1.0 mm/minute. Fourier transformation infrared spectroscopy was used to determine the degree of conversion. The percentage of residual double bonds, including pendant and monomeric double bonds, was calculated by comparing the obtained ratio against uncured adhesive resin. The degree of conversion of the adhesive resins was obtained by subtracting the %C=C from 100%. Two-way ANOVAs, followed by Tukey tests, were done. The microtensile strengths and degree of conversion varied with different combinations of self-etching primer and adhesive resin. Numerically, the highest microtensile strengths were obtained when the primer/adhesive resin combinations from the same manufacturer were used. When the different combinations of self-etching primers and adhesive resins were mixed, the microtensile strength and degree of conversion of the adhesive resins tended to decrease for some combinations. Within the limitations of this study, which was far removed from clinical situations, the role of the self-etching primers on the mechanical properties of adhesive resins should be considered to create an authentic resin-dentin interface.