Titanyum Dioksit Nanotüplerin Akışkan Kompozit Rezinin Antibakteriyel, Yüzey Pürüzlülüğü, Kesme Bağlanma Dayanıklılığı Özelliklerine Etkisi

Abstract

The aim of this in vitro study was to evaluate flowable composite resin?s antibacterial activity against Streptococcus mutans, surface roughness, shear bond strength to enamel and dentin by adding various percents of Titanium dioxide nanotubes. Titanium dioxide nanotubes were synthesized by dehydrothermal treatment from commercially available titanium dioxide nanoparticles and functionalized with methacrylic acid. The functionalized groups were characterized with Fourier transform infrared spectroscopy. Prepared nanotubes were added in the flowable composite Aelite Flo LV with various percentages (0.5, 1, 1.5, 2% by weight). TEM images of the prepared composite were taken. 5 groups were designed in this study and flowable composite resin without nanotube was used as control group. This study was consisted of three parts. In the first part, Biofilm test was done to assess the antibacterial effect of nanotubes. Disc shaped specimens (6x1 mm) were prepared for every group (n=12) and the half of the specimens (n=6) were exposed to ultraviolet light. All of the specimens were incubated with Streptococcus mutans and the biofilm formed on the specimens were assessed. In the second part, disc shaped specimens (10x1 mm) were prepared for every group (n=12) and polished. The surface roughness of the specimens were measured by optic profilometry. In the third part of the study, 150 extracted human premolar teeth were used. The teeth were randomly divided into two groups, flattened with sandpaper exposing enamel in first group and dentin in second group. Specimens in enamel and dentin groups (n=15) were etched with acid and then etch-and-rinse adhesive (One step) was applied. Various percentages of TiO2 nanotube added flowable composite (Aelite Flo LV), was placed to tooth surfaces adhesive applied, with the aid of a jig. Determining the shear bond strength, samples placed in a universal testing machine, the force applied to the adhesive interface between tooth and composite until fracture occurs. Stereomicroscope was used to analyze the samples? fracture mode. Data were analyzed by ANOVA and Kruskal Wallis in biofilm test, by Kruskal Wallis in surface roughness assessment, by Kruskal Wallis and Mann Whitney U in bond strength to enamel and dentin. Ultraviolet improved TiO2 nanotubes antibacterial effect (p<0.05). Increase in the percentage of TiO2, decreased the biofilm formation. Antibacterial activity was not observed on the specimens that were not exposed to ultraviolet. The highest surface roughness was measured in the 2% TiO2 resin group (p<0.05), there was no significant difference between the other groups (p>0.05). The addition of increasing percentages of TiO2 nanotube, reduced enamel bond strength (p<0.05). It was observed that adding nanotubes to composite resin did not effect the bond strength to dentin. Containing TiO2 nanotube composite resin exposed to ultraviolet light showed antibacterial activity, low amounts of nanotubes added to the resin did not affect the surface roughness and shear bond strength.