Effect of Novel Nanotechnology to Conventional Glass Ionomer Cement on its Physical-Chemical-Biological Properties

Abstract

Titanium dioxide (TiO2) has been suggested as a promising material in numerous applications including dental restorative materials. However, the influence of nanotechnology on physic-chemical and biological properties of glass ionomer cement (GIC) is not well established. Thus, this in vitro study investigates the influence of the addition of different concentrations of TiO2 nanotubes in physical-chemical and biological properties of conventional GIC. The powder component of GIC was incorporated with TiO2 nanotubes [3%, 5% and 7% (w/w)], and unblended powder was used as control. Physical-chemical analysis included: 1. Spectroscopy energy dispersive (EDS) and Fourier-transform Raman (FT-Raman) (n=4) - detector X-ray system attached to Scanning Electron Microscopy (SEM) set at 15 kV, working distance of 20 mm and 100X and RFS 100/S, respectively; 2. Superface roughness (SR) (n=8) -surface roughness tester - 1,25 mm in length/cut-off of 0,25 mm; 3. Knoop Hardness (SH) - Knoop microhardness (50 g/10 s); 4. Sorption (Wsp) and solubility (Wsl) - calculation of sorption and water solubility (¼g/mm3); 5. Fluoride releasing analysis - specimens will be immersed in different storage media: RE - remineralization solution; pH=7.0; DE - demineralization solution; pH=4.3) at 37oC for 15 days, and specific electrodes will be used to determine fluoride concentration at 1st, 2nd, 3rd, 5th, 7th, 9th, 12th, 15th days). For biological evaluations, the tests will consist: 1. Cell metabolism by MTT assay in four evaluation times (6, 24, 48 and 72 h); 2. Cell morphology by SEM; 3. Quantification of collagen and non-collagen human fibroblast fibers by Sirius Red staining. The biological experiments will be performed in triplicate for each experimental group. The experiments will be performed in triplicate for each experimental group. Data will be analyzed by appropriate statistical tests, considering a significance level of 5%. (AU)