Protective effect of experimental mouthrinses containing NaF and TiF4 on dentin erosive loss in vitro

Objective This in vitro study assessed the anti-erosive effect of experimental mouthrinses containing TiF4 and NaF on dentin erosive loss.Material and Methods Bovine dentin specimens were randomly allocated into the groups (n=15): 1) SnCl2/NaF/AmF (Erosion Protection®/GABA, pH 4.5, positive control); 2) experimental solution with 0.0815% TiF4(pH 2.5); 3) 0.105% NaF (pH 4.5); 4) 0.042% NaF+0.049% TiF4 (pH 4.4); 5) 0.063% NaF+0.036% TiF4 (pH 4.5); 6) no treatment (negative control). Each specimen was cyclically demineralized (Sprite Zero, pH 2.6, 4x90 s/day) and exposed to artificial saliva between the erosive challenges for 7 days. The treatment with the fluoride solutions was done 2x60 s/day, immediately after the first and the last erosive challenges of the day. Dentin erosive loss was measured by profilometry (μm). The data were analyzed using Kruskal Wallis/Dunn tests (

Comparison between static and semidynamic models for microcosm biofilm formation on dentin

Microcosm biofilm has been applied to induce carious lesions in dentin. However, no study has been done to compare the impact of the type of model for providing nutrients to microcosm biofilm formation on dentin. Objective: This study compared the performance of two kinds of models (static and semi-dynamic) on the biofilm formation and the development of dentin carious lesions. Material and Methods: In both models, biofilm was produced using inoculum from pooled human saliva mixed with McBain saliva for the first 8 h (5% CO2 and 370C). Afterwards, for the static model, the samples were placed in 24-wells microplate containing McBain saliva with 0.2% sucrose, which was replaced at 24 h. In the semi-dynamic model, the samples were submitted to artificial mouth system with continuous flow of McBain saliva with 0.2% sucrose (0.15 ml/min, 370C) for 10 h a day (for the other 14 h, no flow was applied, similarly to the static model). After 5 days, biofilm viability was measured by fluorescence and dentin demineralization by transverse microradiography. Results: Biofilm viability was significantly lower for the static compared with semi-dynamic model, while dentin demineralization was significantly higher for the first one (p<0.05). The static model was able to produce a higher number of typical subsurface lesions compared with the semi-dynamic model (p<0.05). Conclusions: The type of model (static and semi-dynamic) applied in the microcosm biofilm may have influence on it's viability and the severity/profile of dentin carious lesions

In situ remineralisation response of different artificial caries-like enamel lesions to home-care and professional fluoride treatments

Abstract\ud \ud Background\ud Artificial lesions produced by different protocols might directly influence the response to different remineralising treatments. This study compared the response of different artificial caries-like enamel lesions to home-care and professional fluoride based-remineralising treatments in situ.\ud \ud \ud Methods\ud The tested demineralising protocols were methylcellulose- MC gel, polyacrylic acid - PA gel, tetraethyl methylene diphosphanate - TEMDP solution, and acetate- Buffer solution. The lesions were remineralised using an in situ model, following a crossover and double blind design. Twelve subjects wore intra-oral appliances during 3 phases (3 d each): control (C) (saliva); home-care F− treatment (FD) (1,100 ppm F− dentifrice, 2x1 min/day); and professional (FVD) (22,600 ppm F− varnish) plus FD. The de-remineralisation was measured by transverse microradiography-TMR and hardness (surface hardness/cross-sectional hardness, SH/CSH, respectively).\ud \ud \ud Results\ud For SH, lesions produced by PA gel were the only one showing significant differences among the remineralising treatments (C x FD x FVD); while the TEMDP lesion were not responsive to any fluoride treatment (for both SH/CSH). For TMR, there were no differences among the remineralising treatments, regardless of the type of lesion. Generally, the most responsive lesions to fluoride were the less demineralised lesions (considering hardness: PA gel and Buffer).\ud \ud \ud Conclusions\ud The type of lesion has influence on the surface remineralisation degree induced by home-care and professional fluoride treatments using this in situ model.We would like to thank the subjects who took part of the in situ research\ud and FAPESP by the financial support (scholarship for the first author, Process number: 2011/03907-1)

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

OBJECTIVE: Titanium 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 METHODS: Step 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). RESULTS: Step 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. CONCLUSIONS: Based 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

Effect of type of artificial bovine enamel caries lesion on the remineralizing potential of Saliva, fluoride dentifrice and varnish: an in situ study

Este trabalho avaliou o efeito do tipo de lesão cariosa artificial em esmalte produzido por quatros protocolos in vitro em relação ao potencial remineralizante in situ, utilizando como variáveis de resposta a microdureza superficial (SH) e longitudinal (CSH) e a microradiografia transversal (TMR). Para tal, 288 espécimes de esmalte bovino polidos (4x4mm) foram divididos de acordo com os valores de SH inicial em 4 tipos de protocolos desmineralizantes: Gel MC (gel de metilcelulose a 8%, ácido lático 0,1 M, pH 4,6, 14 dias); Gel PA (ácido poliacrílico 20g/L, ácido lático 0,1 M com hidroxiapatita a 500 mg/L, pH 4,8, 16h); Solução MHDP (ácido lático 50 mM, cálcio, fosfato e tetraetil metilenodifosfanato, pH 5,0, 6 dias) e Solução Tampão (ácido acético 50 mM, cálcio, fosfato e fluoreto, pH 5,0, 16h). Os espécimes desmineralizados foram tratados com agentes remineralizantes em um modelo in situ cruzado e duplo cego, com a participação de 12 voluntários que utilizaram aparelhos palatinos contendo 2 amostras de cada tipo de lesão de esmalte em cada fase, durante 3 fases experimentais com duração de 3 dias cada. Na fase da saliva humana, os voluntários realizaram o tratamento dos espécimes com dentifrício placebo (sem fluoreto, solução 1:3) ex vivo, 2x1min/dia. Na fase dentifrício fluoretado, o mesmo procedimento foi repetido em relação ao tratamento dos espécimes, porém utilizando o Dentifrício Crest (1.100 ppm F). Na fase verniz fluoretado, os mesmos procedimentos da fase dentifrício fluoretado foram repetidos, porém os espécimes foram tratados com verniz Duraphat (22.600 ppm F, 6h in vitro) anteriormente à fase in situ. Os dados foram submetidos à análise estatística (ANOVA ou similar não paramétrico e ANOVA a 2 critérios, p Gel MC > solução Tampão = Gel PA) sendo nítida a diferença no grau de remineralização entre as diferentes lesões cariosas artificiais (resultados incoerentes entre SH, CSH e TMR). Na análise de SH, o Gel PA foi capaz de mostrar diferenças significativas entre os 3 protocolos remineralizantes, enquanto o Gel MC e Solução Tampão mostraram diferenças significativas entre as fases com fluoreto e controle. Para a solução MHDP não foi encontrada diferença significativa entre os tratamentos remineralizantes. Em relação à CSH, o padrão de remineralização foi inversamente relacionado ao grau de desmineralização inicial. Na análise da porcentagem de recuperação de CSH, apenas o gel PA foi capaz de mostrar diferenças significativas entre as fases com fluoreto e controle até os 30 &#x3BC;m de profundidade. Na análise pela TMR (parâmetro &#x394;&#x394;Z), houve diferença significativa entre as lesões cariosas artificiais em relação à remineralização (Solução Tampão MC Gel > Buffer solution = PA Gel). There was a clear difference in the degree of remineralization between the different artificial carious lesions (contradictories results among SH, CSH and TMR). In SH analysis, PA Gel was able to show significant differences among the 3 remineralizing protocols, while MC Gel and Buffer Solution showed significant differences between the fluoride phases and control. MHDP solution did not show any significant difference among the remineralizing treatments. In respect to the CSH, remineralization was inversely related to the degree of initial demineralization. In the analysis of the percentage of CSH recovery, only PA gel was able to show significant differences between the fluoride and control phases up to 30 &#x3BC;m depth. For TMR (&#x394;&#x394;Z parameter), there was significant difference between the artificial carious lesions in respect to the remineralization (buffer solution < MHDP Solution = PA gel < MC Gel), except during fluoride varnish phase. No significant differences were found among the remineralizing treatments by TMR, showing a modest remineralization, regardless of the treatment. It can be concluded that the type of artificial carious lesion has influence on the degree of enamel remineralization and this should be considered in experimental design

Efeito do verniz de tetrafluoreto de titânio sobre fibroblastos (NIH/3T3): ensaios de viabilidade, morfologia e sinalização celular para apoptose

Current knowledge supports the application of TiF4 varnish to protect against tooth caries and erosion; however, it is indispensable to know its cytotoxic potential and the mechanism involved on it before applying in patients. Therefore, this study aimed to evaluate 1) The cytotoxic effect of titanium tetrafluoride (TiF4) varnish compared with sodium fluoride (NaF) varnish on murine fibroblast (NIH/3T3), varying the fluoride concentration and time of treatment and 2) The percentage of apoptosis and its mechanism (both mitochondrial mediated by the Bcl-2 family- and death receptorpathways) in human gingival fibroblasts (HGF) and murine fibroblasts (NIH/3T3) treated with TiF4 varnish compared to NaF varnish for 6 h. Step 1) NIH/3T3 were exposed to NaF or TiF4 varnishes containing 0.95, 1.95 or 2.45% F, for 6, 12 or 24 h. MTT viability (n=6) and Hoescht/PI stain assays (n=3) as well as the cells morphology (HE, only for 24 h, n=3) and stiffness (AFM, only for 2.45% F, 6 or 12 h) were analyzed. Both varnishes, at 1.90 and 2.45% F, reduced cells viability by similar extent (33-86% at 6 h, 35-93% at 12 h, and 87-98% at 24 h) compared to control, regardless of the type of fluoride. TiF4 and NaF (2.45% F) reduced cell stiffness to a similar extent, but only TiF4 differed from control. Step 2) HGF and NIH/3T3 were exposed to NaF or TiF4 (2.45% F) varnishes for 6 h. Cells were examined by the TUNEL method using fluorescence microscope. The caspases-3, -8 and -9 activities were assessed. The cDNA for cytocrome c, Bax, Bad, Bcl-2, VDAC-1 and Fas-L was amplified by quantitative PCR (qPCR). Bax, Bcl-2 and Fas-L were further detected by western blot. Both fluorides similarly increased the percentage of apoptosis, while they failed in activating caspases-3, -8 and -9 for both types of cells. Bax/Bcl-2 ratio, cytochrome C and VDAC-1 gene expressions were not altered by both fluoride treatments. However, NaF varnish increased the amplification of Fas-L gene for NIH/3T3 and HGF, while TiF4 varnish induced lower Bad/Bcl-2 ratio expression compared to control for NIH/3T3, but not for HGF. No effect of the fluorides was detected in the proteins analysis. TiF4 and NaF have similar cytotoxicity on NIH/3T3, which is dependent on the F concentration and the exposure time. Both fluorides, at the studied conditions, similarly induce a low percentage of apoptosis, with consequent modest activation of Bcl-2 and Fas-L-dependent signaling pathways.Conhecimento atual suporta a aplicação de verniz de TiF4 para proteção contra cárie e erosão dentárias; entretanto, é indispensável conhecer o seu potencial citotóxico e o mecanismo envolvido antes de aplicá-lo em pacientes. Portanto, o objetivo deste estudo foi avaliar 1) o efeito citotóxico do verniz de tetrafluoreto de Titânio (TiF4) comparado ao fluoreto de sódio (NaF), em fibroblastos NIH/3T3, variando a concentração de fluoreto e o tempo de tratamento 2) a porcentagem de apoptose e seus mecanismos (ambos mitocondrial mediado pela família Bcl-2 e pelo receptor de morte celular) em fibroblastos gengivais humanos (FGH) e fibroblastos murinos (NIH/3T3) tratados com verniz de TiF4 comparado com verniz de NaF por 6 h. Etapa 1) NIH/3T3 foram expostos a vernizes de NaF e TiF4 contendo 0,95, 1,95 ou 2,45% F, por 6, 12 ou 24 h. Ensaios de viabilidade por MTT (n=6) e Hoechst 33342/iodeto de propídeo (n=3) bem como a morfologia (HE, apenas para 24 h, n = 3) e a rigidez celular (MFA, apenas para 2,45% F, 6 ou 12 h) foram realizados. Ambos os vernizes com 1,90 e 2,45% F reduziram a viabilidade das células de forma semelhante (33-86% em 6 h, 35-93% em 12 h e 87-98% em 24 h) em comparação com o controle, independentemente do tipo de fluoreto. TiF4 e NaF (2,45%) reduziram de forma similar a rigidez celular, mas somente TiF4 diferiu do controle no período de 6 h. Etapa 2) FGH e NIH/3T3 foram tratadas com verniz de NaF ou TiF4 por 6h. As células foram examinadas pelo método de TUNEL, usando microscopia de fluorescência. A atividade das caspases -3, -8 e -9 foram avaliadas. O cDNA para citocromo C, Bax, Bad, Bcl-2, VDAC-1 e Fas-L foi amplificado e quantificado por PCR em tempo real (qPCR). A expressão das proteínas Bax, Bcl-2 e Fas-L foi quantificada por western blot. Ambos os fluoretos aumentaram de forma semelhante a porcentagem de apoptose, enquanto falharam na ativação de caspases-3, -8 e -9 para ambos tipos celulares. A expressão gênica da relação Bax/Bcl-2, do citocromo C e do VDAC-1 não foram alteradas por ambos fluoretos. No entanto, o verniz NaF aumentou a amplificação do gene Fas-L para ambas as células, enquanto que o verniz TiF4 induziu menor expressão da razão Bad/Bcl-2 em comparação com o controle para NIH/3T3, mas não para FGH. Nenhum efeito foi detectado na análise de proteínas. TiF4 e NaF apresentam citotoxicidade similar em NIH/3T3, a qual é dependente da concentração de F e do tempo de exposição. Ambos os fluoretos, nas condições estudadas, induzem uma baixa porcentagem de apoptose, com consequente modesta ativação das vias de sinalização dependentes de Bcl-2 e Fas-L

Protective Effect Of Experimental Mouthrinses Containing Naf And Tif4 On Dentin Erosive Loss In Vitro.

This in vitro study assessed the anti-erosive effect of experimental mouthrinses containing TiF4 and NaF on dentin erosive loss. Bovine dentin specimens were randomly allocated into the groups (n=15): (1) SnCl2/NaF/AmF (Erosion Protection/GABA, pH 4.5, positive control); (2) experimental solution with 0.0815% TiF4(pH 2.5); (3) 0.105% NaF (pH 4.5); 4) 0.042% NaF+0.049% TiF4 (pH 4.4); (5) 0.063% NaF+0.036% TiF4 (pH 4.5); (6) no treatment (negative control). Each specimen was cyclically demineralized (Sprite Zero, pH 2.6, 4x90 s/day) and exposed to artificial saliva between the erosive challenges for 7 days. The treatment with the fluoride solutions was done 2x60 s/day, immediately after the first and the last erosive challenges of the day. Dentin erosive loss was measured by profilometry (μm). The data were analyzed using Kruskal Wallis/Dunn tests (p<0.05). Mouthrinses containing TiF4or Sn/F were able to show some protective effect against dentin erosive loss compared to negative control. The best anti-erosive effect was found for experimental solution containing 0.0815% TiF4 (100% reduction in dentin loss), followed by 0.042% NaF+0.049% TiF4 (58.3%), SnCl2/NaF/AmF (52%) and 0.063% NaF+0.036% TiF4 (40%). NaF solution (13.3%) did not significantly differ from control. The daily application of experimental mouthrinse containing TiF4 and NaF has the ability to reduce dentin erosion, as well as Erosion Protection and TiF4 alone.23486-49