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.

Cell density and solvent are critical parameters affecting formazan evaluation in MTT assay

The aim of this study was to establish the more accurate protocol for fibroblast cell viability using MTT assay. NIH/3T3 fibroblasts were seeded at the following cell densities: 3.125x10³; 1.156x10(4); 3.125x10(4); 1.156x10(5) and 3.125x10(5) cells/cm². Following 24h of seeding, MTT was added to the wells. After 4h of the MTT addition, different solvents were added to solubilize the formazan crystals: 1) HCl/SDS group- 20% SDS and 0.01 M HCl; 2) EtOH/ HAc group-50% ethanol and 1% acetic acid; 3) DMSO group- 99.5% dimethyl sulfoxide; and 4) PropOH group- 99.5% isopropanol. The absorbance values were measured using a spectrophotometer at 570 nm. The data were analyzed by 2-way ANOVA (p<0.05) and showed that the absorbance average varied according to the number of cells and solvents: HCl/SDS (0 to 0.13), EtOH/HAc (0 to 0.22), DMSO (0.76 to 1.31) and PropOH (0.66 to 1.04). The DMSO and PropOH groups presented the most appropriate protocols for NIH/3T3 fibroblasts cell viability, especially at the density of 1.156x10(4) cells/cm².

Impacto da obesidade na saúde bucal: revisão de literatura / Impact of obesity on oral health: a literature review

As taxas de prevalência e de incidência referentes à obesidade têm se tornado alarmantes, tanto em adultos como em crianças. O acúmulo excessivo de gordura no organismo pode acarretar prejuízos à saúde dos indivíduos. Objetivo: o presente estudo tem como objetivo apresentar uma revisão de literatura sobre a interação da obesidade com a saúde bucal por meio de um estudo ordenado em periódicos de circulação nacional e internacional. Materiais e método: foram encontrados 514 estudos, dentre os quais, foram selecionados 18 artigos, com base nos seguintes critérios: época de publicação, tema adequado ao proposto neste trabalho, ideias claras, objetivas e condizentes com o título do estudo. Resultados: os estudos selecionados mostraram associações entre doença periodontal e obesidade. Já em relação aos trabalhos que associavam cárie dental e obesidade, houve algumas divergências, estando estas em minoria. Conclusão: conclui-se que os pacientes obesos necessitam de atenção em saúde bucal, especialmente em relação à prevenção da doença periodontal e cárie dentária.

Prevalence and incidence rates regarding obesity have become alarming in both adults and children. The excessive fat buildup in the body may lead to health problems of individuals. Objective: this study aims to present a literature review on the interaction between obesity and oral health from a study ordered in journals of national and international circulation. Materials and method: five hundred and fourteen (514) studies were found, among which 18 were selected based on the following criteria: time of publication, proper subject to the proposal of this work, clear, objective and consistent ideas for the title of the study. Results: the selected studies have shown associations between periodontal disease and obesity. There were differences regarding the work that linked obesity to dental caries, but those were the minority. Conclusion: it is concluded that obese patients require oral health care, especially concerning prevention of periodontal disease and dental caries.