Dentifricio de baixa concentração de fluoreto : efeito anticarie e mecanismos envolvidos / Low-F concentration dentifrice : anticaries effect and mechanisms involved

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

The anticaries efficiency of fluoride (F) dentifrices containing 1000-1500 µg F/g is well established, but they are considered a risk factor to dental fluorosis. In order to reduce this risk, low-F concentration dentifrices (500-550 µg F/g) have been recommended, but their anticaries efficiency has not been demonstrated. Thus, this study aimed to: 1. compare salivary F availability after brushing with low- F concentration (LC, 500 µg F/g, NaF) or conventional F concentration (CC, 1100 µg F/g, NaF) dentifrices, followed or not by a water rinse and 2: evaluate in situ the anticaries potential of these dentifrices, studying the anticaries effect of F available on the dental biofilm after brushing, associated or not to F products formed on enamel by F dentifrice application was evaluated. In both studies, a crossover, double blind design was used. In study 1, samples of non-stimulated saliva from 5 volunteers were collected before and immediately after brushing with LC or CC, followed or not by a rinse, and after 1, 2, 3, 4, 5, 10, 15, 20, 30, 45 and 60 min. The area under the curve of salivary F concentration versus time was calculated to determine F bioavailability in saliva. F salivary bioavailability was reduced 2.5 X by the post-brushing rinse (p<0.05) and it was similar when LC was used without rinsing and CC was used followed by a rinse (p>0.05). In study 2, twelve volunteers brushed with dentifrices containing distinct F concentrations (placebo (P) – negative control, LC or CC) and used a palatal appliance containing bovine enamel blocks previously treated or not with a slurry of assigned dentifrice. The blocks were covered with a test plaque from S. mutans IB 1600 and after 30 min in situ, F concentration in the fluid of plaque was assessed. A sucrose rinse was performed as a cariogenic challenge and after 45 min the remaining blocks and plaque test were removed to evaluate, respectively, mineral loss (as a function of plaque thickness) and F concentration in plaque fluid. The isolated effect of the pretreatment of enamel blocks with F dentifrices did not reduced mineral loss when compared to the control (p>0.05), but resulted in higher F concentration in the plaque fluid (p<0.05). Brushing with F dentifrices increased F concentration in the plaque fluid, which was significantly different between LC and CC (p<0.05), and resulted in lower mineral loss when compared to the control (p<0.05). Additionally, although LC and CC did not differ when mineral loss was evaluated on a plaque thickness simulation of up to 0.5 mm, CC was more efficient than LC at thicker plaque (1 to 1.5 mm) (p<0.05). The results suggest that conventional F concentration dentifrice is more efficient than the low-F one in the inhibition of mineral loss. Additionally, post-brushing rinse should be recommended after the use of conventional F concentration dentifrices by young children.

ASSUNTO(S)

bioquimica biofilm biochemistry biofilme

ACESSO AO ARTIGO

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