| Purpose: Limited surface treatments have been proposed to improve the bond strength
between autopolymerizing resin and polyamide denture base materials. Still, the bond
strength of autopolymerizing resins to nylon polymer is not strong enough to repair the
fractured denture effectively. This study aimed to introduce a novel method to improve
the adhesion of autopolymerizing resin to polyamide polymer by a double layer deposition of sol-gel silica and N-2-(aminoethyl)-3-aminopropyltrimethoxysilane (AEAPTMS).
Materials and Methods: The silica sol was synthesized by acid-catalyzed hydrolysis of tetraethylorthosilicate (TEOS) as silica precursors. Polyamide specimens
were dipped in TEOS-derived sol (TS group, n = 28), and exposed to ultraviolet
(UV) light under O2 flow for 30 minutes. UV-treated specimens were immersed in
AE-APTMS solution and left for 24 hours at room temperature. The other specimens were either immersed in AE-APTMS solution (AP group, n = 28) or left
untreated (NT group, n = 28). Surface characterization was investigated by fourier
transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM). Two
autopolymerizing resins (subgroups G and T, n = 14) were bonded to the specimens, thermocycled, and then tested for shear bond strength with a universal testing machine. Data were analyzed with one-way ANOVA followed by Tukey’s HSD
(α = 0.05).
Results: FTIR spectra of treated surfaces confirmed the chemical modification and
appearance of functional groups on the polymer. One-way ANOVA revealed significant differences in shear bond strength among the study groups. Tukey’s HSD showed
that TST and TSG groups had significantly higher shear bond strength than control
groups (p = 0.001 and p < 0.001, respectively). Moreover, bond strength values of
APT were statistically significant compared to controls (p = 0.017).
Conclusion: Amino functionalized TEOS-derived silica coating is a simple and
cost-effective method for improving the bond strength between the autopolymerizing
resin and polyamide denture base. Clinical implications: Amino-functionalized silica
coating could represent a more applicable and convenient option for improving the
repair strength of autopolymerizing resin to polyamide polymer. |