Analysis of the fluoride uptake in dental enamel “in vivo” after the use of low fluoride concentrations dentifrices and its relation to bioavailability of fluoride in these dentifrices compared to others available commercially / Análise da incorporação de flúor no esmalte dentário in vivo após o uso de dentifrícios com concentrações reduzidas de flúor e sua relação com a biodisponibilidade de flúor nestes dentifrícios em comparação com outros comercialmente disponíveis

AUTOR(ES)
DATA DE PUBLICAÇÃO

2005

RESUMO

The aims of this study were: to assess the fluoride uptake in dental enamel clinically sound from low fluoride dentifrices; to analyze the kinetics of F in saliva of these F dentifrices and to assess the F bioavailability from these dentifrices in relation to pH and abrasive system. In the 1st study, doubleblind and crossover, it were tested the follow dentifrices: experimental formulations containing 1,100; 550; 275 ppm F, NaF (pH 5.5), Crest™ (positive control), Colgate Baby™ (500 ppm F, NaF, pH 6.9) and a placebo dentifrice, pH 5.5 (negative control). Sixteen 18-35-year-old volunteers tooth brushed 3 times a day with the tested dentifrices during 2 weeks with each concentration. The phases differed according to dentifrice used and they were separated by an interval of 1 week. Biopsies were obtained applying 5 µL 0.5 M HCl on the delimitated area (5 s), followed by neutralization of the area applying 5 µL 0.25 M NaOH, 2 times. The 2nd study was a double – blind study, carried out in 5 phases, which 10 18-35-year-old recruits brushed with one of the F dentifrices described early. Intervals of one week separated the five phases, period during which was utilized placebo dentifrice. The collections of unestimulated total saliva (3 min) were done in the times baseline, 0, 3, 6, 9, 15, 30, 45 and 60 min, after the brushing with 1.5 g of the proposed dentifrice. In the 3rd experiment, the F bioavailability of the fluoridated formulations was analyzed in relation to the abrasive system and pH, in a double-blind protocol. Nine 18-35-year-old volunteers fasted for 12 h and ingested 2 mg F in solution of dentifrice. In phases I – IV, the dentifrices used were: Sorriso Dentes Brancos™ – 1,500 ppm F (MFP), CaCO3, pH 9.5; 1,100 ppm F (NaF), silica, pH 5.5; 1,100 ppm F (NaF), silica, pH 7.0 and Crest™ - 1,100 ppm F (NaF), silica, pH 6.5, respectively. Intervals of one week separated the four phases. They fasted by additional 8 h and received a standard breakfast with low fluoride content (0.07 mg). Samples of total saliva were collected before the intake of dentifrices and, after this, every 20 min up to 2h, every 40 min up to 4 h and then every hour up to 8 h. Urine was collected during 24 h before and during the experimental day. In the three experiments, F was analyzed by direct method or with the ion specific electrode, after HMDS facilitated diffusion and P was analyzed by the colorimetric method. Data were tested using the ductal saliva AUC estimate, ANOVA and Tukey’s post hoc test (p<0.05). There were not statistically significant differences among the tested dentifrices in relation to F uptake in dental enamel. Considering the total saliva, the 550 ppm F dentifrice was similar to gold standard. The AUC estimate demonstrated that there was not statistically significant difference of the bioavailability among them. Urine data showed that there was not statistically significant difference among the intaked dentifrices. The results suggest that acidulated and low F concentration dentifrices are effective to increase the F levels in total saliva appropriately in relation to prevent dental caries, being that the F bioavailability of these dentifrices is not affected by pH or abrasive system.

ASSUNTO(S)

esmalte dentário flúor dentifrício fluoretado

ACESSO AO ARTIGO

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