Physikochemische und bioaktive Eigenschaften von mit Methacryl-funktionalisierten Silica-Nanopartikeln modifizierten experimentellen Adhäsiven

Abstract

Aim: The aim of the study was to investigate the physico-chemical and bioactive properties of experimental dental adhesives containing methacryl-functionalized polyhedral oligomeric silsesquioxane (MA-POSS-8). Methods: Six different compositions of experimental adhesives based on BisGMA, TEGDMA and HEMA were prepared and infiltrated with MA-POSS-8 (5 wt%). Unfilled adhesives served as control. Camphorquinone and 2-(Dimethyl-amino)ethylmethacrylate were added as initiators to enable light-induced polymerization. The physico-chemical properties (degree of conversion, viscosity, Martens hardness, indentation modulus, water sorption and sol fraction) were analysed. Dispersion and hydrodynamic radius of MA-POSS-8 were investigated by dynamic light scattering. Precipitation of Ca/P was measured on the specimens after storage in artificial saliva for 28 days at 37°C. Statistical analysis was performed by two-way ANOVA and Tukeys post-hoc tests (p < 0.05). Results: For all experimental adhesives, degree of conversion and water sorption were not affected by the addition of MA-POSS-8. Sol fraction was below the detection limit. The addition of MA-POSS-8 led to a reduction in shear and complex viscosity in the adhesive with higher concentration of BisGMA (BisGMA: 60 wt%, TEGDMA: 15 wt%, HEMA: 25 wt%). The particles also led to a reduction in the Martens hardness and indentation modulus in one adhesive (BisGMA: 50 wt%; TEGDMA: 25 wt%, HEMA: 25 wt%). Formation of Ca/P precipitates could be shown on the specimens of all groups. Conclusion: MA-POSS-8 did not improve the bioactive potential and did not affect the material properties by except for slight differences in Martens hardness, indentation modulus, complex and shear viscosity.