Titanium dioxide nanotubes added to glass ionomer cements affect S. mutans viability and mechanisms of virulence

Abstract

Titanium dioxide nanotubes added to glass ionomer cements affect S. mutans viability and mechanisms of virulenceAbstract: This in vitro study evaluated the impact of TiO 2 nanotubes (n-TiO 2 ) incorporated into glass ionomer cement (GIC) on Streptococcus mutans (S. mutans) characteristics at cellular and molecular levels. n-TiO 2 , synthesized by the alkaline method (20 nm in size), was added to Ketac Molar EasyMix ® at 0%, 3%, 5%, and 7% by weight. S. mutans strains were cultured on GIC disks with addition or not of n-TiO 2 for 1, 3, and 7 days and the following parameters were assessed: inhibition halo (mm) (n=3/group); cell viability (live/dead) (n=5/group); cell morphology (SEM) (n=3/group); and gene expression by real-time PCR (vicR, covR, gtfB, gtfC, and gtfD) (n=6/group). The data were analyzed by the Kruskal-Wallis test, repeated-measures ANOVA or two-way ANOVA, and Tukey's and Dunn's post-hoc tests (α=0.05). The agar diffusion test showed a higher antibacterial property for 5% n-TiO 2 compared with 3% and 7% (p<0.05) with no effect of time (1, 3, and 7 days). The cell number was significantly affected by all n-TiO 2 groups, while viability was mostly affected by 3% and 5% n-TiO 2 , which also affected cell morphology and organization. Real-time PCR demonstrated that n-TiO 2 reduced the expression of covR when compared with GIC with no n-TiO 2 (p<0.05), with no effect of time, except for 3% n-TiO 2 on vicR expression. Within-group and between-group analyses revealed n-TiO 2 did not affect mRNA levels of gtfB, gtfC, and gtfD (p>0.05). Incorporation of n-TiO 2 at 3% and 5% potentially affected S. mutans viability and the expression of key genes for bacterial survival and growth, improving the anticariogenic properties of GIC.

Titanium dioxide nanotubes applied to conventional glass ionomer cement influence the expression of immunoinflammatory markers: An in vitro study

“…1 ). Subsequently, nanotubes were manually incorporated into the KM powder and thoroughly mixed with the assistance of a vortex device (Biomixer, Tafl, CA, USA) for 2 min, following a method described previously [ 11 , [13] , [14] , [15] , 17 ].…”

“…TiO 2 nanoparticles—an inorganic particle in the anatase form—have been proposed as a key adjunct to ensure favorable physicomechanical properties of dental materials [ [8] , [9] , [10] , [11] , [12] , [13] , [14] , [15] ]. Their addition to GIC has also been shown to affect bacterial growth [ 8 , 16 , 17 ]. For instance, in vitro studies have reported that TiO 2 -nt significantly improved the compressive strength, surface microhardness, and solubility resistance of GIC, as well as its fluoride release levels, color opacity, and radiopacity [ 11 , 13 , 15 , 18 ], and reduced weight loss after wear [ 13 ].…”

“…On the other hand, TiO 2 -nt did not affect the adhesion properties of GICs to dentin, the aluminum release levels, or the morphology of fibroblasts [ 11 , [13] , [14] , [15] ]. Overall, greater knowledge has been gained ongoingly in this area to improve GIC performance [ 4 , [8] , [9] , [10] , [11] , [12] , [13] , [14] , [15] , [16] , [17] , [18] ].…”

New Technological Approaches for Dental Caries Treatment: From Liquid Crystalline Systems to Nanocarriers

“…Araújo and coworkers demonstrated that 5% TiO 2 nanotubes incorporated into GIC presented higher antibacterial properties against S. mutans compared to 3% and 7% TiO 2 nanotubes, regardless of the in vitro treatment time. GIC with 5% nanoparticles affected the morphology and organization of S. mutans , probably due to reduced expression of covR when compared with GIC with nanoparticles, enhancing the anti-cariogenic properties of GIC [ 128 ]. Another study also reported superior results for antimicrobial activities on S. mutans and mechanical strength of GIC containing 3% (w/w) titanium nanoparticles [ 35 ].…”

The Impact of Nano- and Micro-Silica on the Setting Time and Microhardness of Conventional Glass–Ionomer Cements

“…During the past decade, a range of inorganic nanoparticles (INPs) (i.e., Ag, AgVO 3 , Al 2 O 3 , BaSO 4 , Ca 5 (PO 4 ) 3 OH, Cu, CuO, MgO, Mg 2 SiO 4 , SiO 2 , TiO 2 , YbF 3 , ZnO ZrO 2 , bioactive glasses, amorphous calcium phosphate, graphene oxide, carbon nanotubes, and aluminosilicate nanoclays) has been incorporated into glass–ionomer cements with the objective of improving their mechanical, chemical, and/or biological properties [ 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ]. In brief, enhanced antimicrobial properties are reported for Ag-, AgVO 3 -, Cu-, CuO-, MgO-, TiO 2 -, and ZnO-blended GICs [ 3 , 4 , 6 , 7 , 10 , 11 , 12 , 13 , 14 , 16 ]. The incorporation of silica (SiO 2 ), hydroxyapatites (Ca 5 (PO 4 ) 3 OH), and bioactive glasses is observed to give rise to superior cytocompatibility and bioactivity [ 18 , 20 , 21 , 22 , 23 ], and improved mechanical properties are noted for GICs blended with a wide range of metal and metal oxide nanostructures [ 3 , 4 , 5 , 6 ...…”