'Aryldiazonium-based surface functionalization enhances the bond strength between PMMA and cobalt-chromium or carbon fiber prosthetic frameworks'.

OBJECTIVES

This laboratory study investigated the effect of aryldiazonium-based surface functionalization on the tensile bond strength (TBS) between polymethyl methacrylate (PMMA) and cobalt-chromium (Co-Cr) or carbon fiber (CF) prosthetic framework materials.

METHODS

Forty specimens were fabricated and allocated into four groups (n = 10): Co-Cr treated with metal primer (AC), diazonium-grafted Co-Cr (DC), CF treated with bonding resin (FA), and diazonium-modified CF (FD). Specimens were thermocycled (5000 cycles; 5-55 °C; dwell time: 30 s) and subjected to tensile bond strength testing using a universal testing machine. Failure modes were analysed by stereomicroscopy and scanning electron microscopy (SEM-EDS). Statistical analysis was performed using one-way ANOVA followed by Bonferroni post hoc tests (α = 0.05).

RESULTS

The AC group exhibited the significantly lowest TBS values in the study (p < 0.001). No significant differences were observed among DC, FA, and FD groups (p > 0.05). Diazonium-treated specimens predominantly showed cohesive or mixed failure patterns, whereas adhesive failures were prevalent in the metal-primer group

CONCLUSIONS

The use of diazonium salts as surface primers may increase the bond strength of prosthetic framework materials such as Co-Cr or carbon fiber to acrylic resin.

CLINICAL SIGNIFICANCE: Aryldiazonium surface functionalization may improve the bonding performance of PMMA to both metallic and carbon fiber frameworks, representing a promising strategy for enhancing the durability of prosthetic framework-resin interfaces.