The cytotoxic effect of TiF4 and NaF on fibroblasts is influenced by the experimental model, fluoride concentration and exposure time

Abstract

ObjectiveTitanium tetrafluoride (TiF4) has shown promising effect in preventing tooth lesions. Therefore, we compared the cytotoxicity of TiF4 with sodium fluoride (NaF) (already applied in Dentistry) considering different fluoride concentrations, pH values and experimental models.Materials and methodsStep 1) NIH/3T3 fibroblasts were exposed to mediums containing NaF or TiF4 (from 0.15 to 2.45% F), both at native and adjusted pH, for 6 h. Step 2) NIH/3T3 were exposed to NaF or TiF4 varnishes with 0.95, 1.95 or 2.45% F (native pH), for 6, 12 or 24 h. We applied MTT (1st and 2nd steps) and Hoescht/PI stain (2nd step) assays. Step 3) NIH/3T3 were exposed to NaF or TiF4 varnish (2.45% F), at native pH, for 6 or 12 h. The cell stiffness was measured by atomic force microscopy (AFM).ResultsStep 1) All cells exposed to NaF or TiF4 mediums died, regardless of the F concentration and pH. Step 2) Both varnishes, at 1.90 and 2.45% F, reduced cell viability by similar extents (33–86% at 6 h, 35–93% at 12 h, and 87–98% at 24 h) compared with control, regardless of the type of fluoride. Varnishes with 0.95% F did not differ from control. Step 3) TiF4 and NaF reduced cell stiffness to a similar extent, but only TiF4 differed from control at 6 h.ConclusionsBased on the results of the 3 experimental steps, we conclude that TiF4 and NaF have similar cytotoxicity. The cytotoxicity was dependent on F concentration and exposure time. This result gives support for testing the effect of TiF4 varnish in vivo.

Assessing the protective effects of different surface coatings on NaYF4:Yb3+, Er3+ upconverting nanoparticles in buffer and DMEM

“…Verma et al showed that fluoride concentrations of 120 ppm decreased cell viability up to 60% 57 . Although fluoride is generally considered toxic at concentrations above 15 ppm 41 , 42 , long term exposure (up to 5 days) to non-lethal fluoride concentrations as low as 5 ppb of F - were shown to decrease cellular DNA synthesis and a F - concentration of 38 ppb almost completely inhibited it 41 .…”

“…4. This strongly enhanced UCNP stability is ascribed to the formation of a protective corona of adsorbed biomolecules on the UCNP surface, similar to the formation of a protein corona observed for many nanoparticle systems in plasma and in intracellular fluids which is known to significantly affect nanoparticle toxicity [38][39][40][41][42][43] .…”

Comparison between micro‐computed tomography and transverse microradiography of sound dentine treated with fluorides and demineralized by microcosm biofilm

“…Titanium tetrafluoride varnish also promoted higher deposition of calcium fluoride than NaF varnish as a result of its lower pH . Besides, TiF 4 varnish has cytotoxic potential on fibroblasts similarly to NaF varnish, which is widely applied in the mouth . However, there is a lack of knowledge about the protective effect of TiF 4 varnish on root dentine demineralization.…”

Effect of a Titanium Tetrafluoride Varnish in the Prevention and Treatment of Carious Lesions in the Permanent Teeth of Children Living in a Fluoridated Region: Protocol for a Randomized Controlled Trial

“…Due to its low pH, a TiF 4 varnish is able to enhance the enamel fluoride uptake compared to a NaF varnish [ 10 ]. The varnish may also reduce TiF 4 contact with soft tissues compared to a rinse solution, reducing the possibility of cytotoxicity due to its low pH [ 22 ]. A recent study has shown that a TiF 4 varnish presents similar levels of toxicity to murine fibroblast lineage (NIH/3T3) cells as a NaF varnish [ 22 ].…”

“…The varnish may also reduce TiF 4 contact with soft tissues compared to a rinse solution, reducing the possibility of cytotoxicity due to its low pH [ 22 ]. A recent study has shown that a TiF 4 varnish presents similar levels of toxicity to murine fibroblast lineage (NIH/3T3) cells as a NaF varnish [ 22 ]. To check for possible side effects of the TiF 4 varnish, patient satisfaction was evaluated using a simple, but effective tool for self-rated child pain [ 18 ].…”