Effect of titanium dioxide nanoparticles on mechanical strength and bacterial inhibition of glass ionomer cements / 中国组织工程研究

ABSTRACT

BACKGROUND:Glass ionomer cements have been gradual y employed in many aspects of dental clinical field. However, low mechanical strength and antibacterial effect restrict its further applications. OBJECTIVE:To proportional y explore the effects of titanium dioxide nanoparticles on the mechanical strength and antibacterial effect of traditional glass ionomer cements. METHODS:Base on different mass fractions of titanium dioxide nanoparticles in glass ionomer cements, al the glass ionomer cement samples were divided into control group (no titanium dioxide nanoparticles), low titanium dioxide group (containing 3%titanium dioxide nanoparticles), medium titanium dioxide group (containing 6%titanium dioxide nanoparticles), and high titanium dioxide group (containing 9%titanium dioxide nanoparticles). A universal material testing machine and a hardness tester were used to examine flexural strength, compressive strength, and surface hardness of glass ionomer cement samples, respectively. Glass ionomer cement samples were immerged into the artificial saliva, and fluoride release was measured by using a fluoride ion selective electrode. The direct contact test was used to investigate antibacterial effect of glass ionomer cement samples towards Streptococcus mutans. RESULTS AND CONCLUSION:Compared with the control group, few titanium dioxide nanoparticles (low and medium titanium dioxide group) could significantly improve flexural strength, compressive strength and surface hardness of glass ionomer cement samples (P<0.05), and high titanium dioxide nanoparticles (high titanium dioxide group) significantly decreased flexural strength, compressive strength and surface hardness (P<0.05). The introduction of titanium dioxide nanoparticles had little effect on fluorine release behavior of glass ionomer cement samples, and greatly improved antibacterial effect of glass ionomer cement samples towards Streptococcus mutans.