Titanium surface topography after brushing with fluoride and fluoride-free toothpaste simulating 10 years of use

ObjectivesTo conduct a controlled study contrasting titanium surface topography after procedures that simulated 10 years of brushing using toothpastes with or without fluoride.MethodsCommercially pure titanium (cp Ti) and Ti-6Al-4V disks (6 mm Ø × 4 mm) were mirror-polished and treated according to 6 groups (n = 6) as a function of immersion (I) or brushing (B) using deionised water (W), fluoride-free toothpaste (T) and fluoride toothpaste (FT). Surface topography was evaluated at baseline (pretreatment) and post-treatment, using atomic force microscope in order to obtain three-dimensional images and mean roughness. Specimens submitted to immersion were submerged in the vehicles without brushing. For brushed specimens, procedures were conducted using a linear brushing machine with a soft-bristled toothbrush. Immersion and brushing were performed for 244 h. IFT and BFT samples were analysed under scanning electron microscope with Energy-Dispersive X-ray Spectroscopy (EDS). Pre and post-treatment values were compared using the paired Student T-test (α = .05). Intergroup comparisons were conducted using one-way ANOVA with Tukey post-test (α = .05).Resultscp Ti mean roughness (in nanometers) comparing pre and post-treatment were: IW, 2.29 ± 0.55/2.33 ± 0.17; IT, 2.24 ± 0.46/2.02 ± 0.38; IFT, 2.22 ± 0.53/1.95 ± 0.36; BW, 2.22 ± 0.42/3.76 ± 0.45; BT, 2.27 ± 0.55/16.05 ± 3.25; BFT, 2.27 ± 0.51/22.39 ± 5.07. Mean roughness (in nanometers) measured in Ti-6Al-4V disks (pre/post-treatment) were: IW, 1.79 ± 0.25/2.01 ± 0.25; IT, 1.61 ± 0.13/1.74 ± 0.19; IFT, 1.92 ± 0.39/2.29 ± 0.51; BW, 2.00 ± 0.71/2.05 ± 0.43; BT, 2.37 ± 0.86/11.17 ± 2.29; BFT, 1.83 ± 0.50/15.73 ± 1.78. No significant differences were seen after immersions (p > .05). Brushing increased the roughness of cp Ti and of Ti-6Al-4V (p < .01); cp Ti had topographic changes after BW, BT and BFT treatments whilst Ti-6Al-4V was significantly different only after BT and BTF. EDS has not detected fluoride or sodium ions on metal surfaces.ConclusionsExposure to toothpastes (immersion) does not affect titanium per se; their use during brushing affects titanium topography and roughness. The associated effects of toothpaste abrasives and fluorides seem to increase roughness on titanium brushed surfaces.