Bioaktivität und physikochemische Eigenschaften von mit funktionalisierten Silica-Nanopartikeln versetzten Universaladhäsiven

Abstract

Objectives: This study aims to analyze the effect of methacrylate polyhedral oligomeric silsesquioxane (POSS-8, Hybrid Plastics, Inc., Hattiesburg,USA) particles on the polymerization process, shear bond strength and bioactivity of several commercial universal dental adhesives. Methods: Five universal dental adhesives (Adhese Universal – Ivoclar Vivadent,Schaan, Lichtenstein; Clearfil Universal Bond – Kuraray, Tokyo, Japan; Futurabond U – VOCO GmbH, Cuxhaven, Germany; iBond Universal – Heraus Kulzer, Hanau, Germany; Scotchbond Universal – 3M ESPE, Maplewood, USA) were filled with POSS-8 particles (10wt%, by Scotchbond Universal 2wt% and 5wt% were additionally studied). The size and dispersion of the particles in ethanol and acetone were examined by dynamic light scattering. The degree of conversion of the filled and control (pure adhesives) groups were measured. Shear bond strength test was performed on the bovine specimen treated with different adhesive groups and using (Venus Diamond, Heraeus Kulzer GmbH, Hanau, Germany) composite and the failure modes were estimated. Specimen were stored in an artificial saliva at 37°C for 14; 21 and 28 days and the growth of calcium phosphate precipitates on the surface was analyzed by energy-dispersive X-ray spectroscopy and scanning electron microscopy. Results: The hydrodynamic radius of POSS-8 was similar in both solvents revealing a good dispersion. No change of degree of conversion and shear bond strength was found upon addition of the particles in all adhesives. Ca/P precipitates appeared on the iBond filled with POSS-8 after 4 weeks of immersion that was not detected on the unfilled adhesive. The bioactive potential in all other groups was not improved through the POSS-8 particles. Significance: The POSS-8 particles were successfully incorporated into the universal adhesives without negatively changing their degree of conversion and bonding performance. The Ca/P precipitation was stimulated by POSS-8 only in iBOND Universal.