Effect of four chemical reagents on the shear bond strength of four different metal alloys bonded with self-adhesive resin cement.

BACKGROUND: To evaluate the effectiveness of four chemical reagents in modifying the surfaces of four different metal alloys, specifically focusing on determining their shear bond strength (SBS) when bonded to self-adhesive resin cement.

METHODS: Two hundred and eight metal alloy specimens (base metal alloys, noble metal alloys, high-noble metal alloys and titanium alloys) were divided into twenty groups based on the primers applied (Alloy primer, V-primer, Superbond C&B monomer and Monobond etch & prime). The modified surfaces were bonded to composite rods with RelyX U200. They were immersed in distilled water and subjected to 5000-cycle thermocycling. Subsequently, SBS was evaluated using a universal testing machine. Failure modes were examined with stereomicroscopy. Data were collected and statistically analyzed using Two-way ANOVA followed by Tukey's post-hoc tests at 0.05 level of significance.

RESULTS: Using an Alloy primer for high-noble metal and titanium alloys led to higher SBS than with base metal alloys and noble metal alloys (p < 0.05). Conversely, the groups that utilized V-primer or Superbond C&B monomer demonstrated the highest SBS when applied to high-noble metal alloys or base metal alloys, respectively. Additionally, in the group that used Monobond etch & prime followed by rinsing with water, titanium alloys displayed a notably higher SBS than the other metal alloy groups (p < 0.05).

CONCLUSIONS: The surface modification of four different metal alloys with various chemical reagents affects the SBS between the surfaces of these alloys and self-adhesive resin cement.