Effect of professional fluoride application and fluoride dentifrice use on dental biofilm and root dentine

Orientador: Cinthia Pereira Machado TabchouryTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de PiracicabaResumo: A combinação de métodos de uso de flúor (F) tem sido indicada para indivíduos ou grupos considerados de alto risco de carie. O efeito aditivo da combinação da aplicação tópica profissional de flúor (ATF) e uso diário de dentifrício fluoretado (DF) resulta em uma modesta redução de carie em esmalte quando comparado ao uso isolado do DF. Entretanto, o efeito dessa combinação não tem sido estudado com relação a dentina radicular, a qual e mais susceptível a carie que o esmalte. Este trabalho de tese teve por objetivos avaliar o efeito da combinação da ATF e uso do DF na desmineralizacão da dentina radicular, na disponibilidade de F no biofilme dental formado in situ bem como nos produtos de reatividade formados sobre a dentina radicular. Doze voluntários adultos participaram desse estudo in situ cruzado e duplo-cego (em relação ao dentifrício) e utilizaram dispositivos palatinos contendo espécimes de dentina radicular bovina, com dureza de superfície pré-determinada. Os espécimes de dentina foram submetidos, em quatro fases experimentais de sete dias de duração cada uma, a um alto desafio criogênico (acumulo de biofilme e uso de solução de sacarose 8x/dia) e um dos seguintes tratamentos: dentifrício placebo (DP), dentifrício fluoretado contendo 1100 ppm de F (DF), ATF + DP e ATF + DF. Os espécimes dos grupos ATF foram pretratados com flúor fosfato acidulado em gel (1,23% F) por 4 minutos no inicio da respectiva fase experimental. Os dentifrícios foram usados 3x/dia. Para a análise estatística, um modelo fatorial 2 x 2 foi utilizado, onde os fatores em estudo foram ATF em dois níveis (aplicado ou não) e dentifrício fluoretado (sim ou nao) com limite de significância adotado de 5%. Menor desmineralização e maior concentração de F no fluido do biofilme foram observadas quando DF foi utilizado em comparação com DP (p <0,05) e quando ATF foi realizada em relação aos grupos onde não houve este tratamento (p <0,05). A combinacao da ATF e uso de DF mostrou efeito sinérgico na redução da desmineralização o da dentina radicular, na disponibilidade de F no fluido do biofilme e no aumento da retenção de produtos de reatividade em dentina, sugerindo que essa combinacao deve ser relevante no controle de carie radicular.Abstract: The combination of methods of fluoride (F) use has been suggested for high caries risk individuals or groups. The additive effect of the combination of professional application of fluoride and fluoride dentifrice (FD) use achieve a modest reduction in enamel caries compared to dentifrice used alone. Nevertheless the anti-caries effect of this combination has not been studied for root dentine, which is more susceptible to caries than enamel. This study aimed to evaluate the effect of the combination of application of acidulated phosphate fluoride (APF) and DF use on root dentine demineralization, F availability in dental biofilm formed in situ as well as on reactivity products formed on root dentine. Twelve adult volunteers took a part in this crossover, double-blinded (considering the dentifrices) in situ study and wore palatal appliances containing bovine root dentine slabs with pre-determined surface hardness. The dentine slabs were subjected during four experimental phases of seven days each to a high cariogenic challenge (biofilm accumulation and sucrose solution exposure 8x/day) and to one of the following treatments: placebo dentifrice (PD), 1,100 ppm F-dentifrice (FD), APF +PD and APF + FD. The slabs of APF groups were pre-treated with APF gel (1.23% F) for 4 min at the beginning of the respective experimental phase. The dentifrices were used 3x/day. For statistical analyses, a factorial 2 x 2 was used, with the APF (applied or not) and fluoride dentifrice (yes or not) considered as study factors. The significance limit was set at 5%. Lower demineralization and higher F concentration in biofilm fluid was observed when FD was used in comparison with PD (p<0.05) and when APF application was done in relation to those groups in which APF was not applied (p<0.05).The combination of APF and use of FD showed a synergic effect on reduction of root dentine demineralization, on F availability in biofilm fluid and on the enhanced retention of reactivity products formed on dentine, suggesting that the combination of APF gel application and the daily use of F dentifrice may be relevant to control root caries.DoutoradoCariologiaDoutor em Odontologi

Salivary Fluoride Levels after Use of High-Fluoride Dentifrice

The aim of the study was to evaluate salivary fluoride (F) availability after toothbrushing with a high-F dentifrice. Twelve adult volunteers took part in this crossover and blind study. F concentration in saliva was determined after brushing with a high-F dentifrice (5000 µg F/g) or with a conventional F concentration dentifrice (1100 µg F/g) followed by a 15 mL distilled water rinse. Samples of nonstimulated saliva were collected on the following times: before (baseline), and immediately after spit (time = 0) and after 1, 2, 3, 4, 5, 10, 15, 20, 30, 45, 60, 90, and 120 min. F analysis was performed with a fluoride-sensitive electrode and the area under curve of F salivary concentration × time (µg F/mL × min−1) was calculated. At baseline, no significant difference was found among dentifrices (P > 0.05). After brushing, both dentifrices caused an elevated fluoride level in saliva; however salivary F concentration was significantly higher at all times, when high-F dentifrice was used (P < 0.01). Even after 120 min, salivary F concentration was still higher than the baseline values for both dentifrices (P < 0.001). High-F dentifrice enhanced the bioavailability of salivary F, being an option for caries management in patients with high caries risk

Polarization of dental caries among individuals aged 15 to 18 years

OBJECTIVE: To evaluate the role of socioeconomic variables and self-perceived oral health in the polarization of caries among adolescents in Santa Bárbara D'Oeste, Brazil. MATERIAL AND METHODS: Cross-sectional study. Sampling was randomized and sample size was defined according to WHO criteria. Two hundred and seventy seven adolescents (15 to 18 year-old) were examined by five trained examiners that assessed DMFT index according to WHO criteria. Self-perceived oral health, access to dental services and socio-demographic variables were self-reported. Student's t tests, chi-square tests, and multivariate logistic regression (with significant caries index (SiC) as the outcome), were performed. RESULTS: Mean DMFT was 5.48 (&plusmn;4.22) and the proportion of "caries free" subjects was 15.5%. Mean DMFT (9.71&plusmn;2.85) and mean D (1.67&plusmn;2.18) of SiC positive subjects were significantly higher than mean DMFT (2.88&plusmn;2.17) and mean D (0.45&plusmn;0.87) of SiC negative subjects (

Praeceptor, 1928

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Recolonization of mutans streptococci after application of chlorhexidine gel

Streptococcus mutans is specifically suppressed by intensive treatment with chlorhexidine gel, but the time for recolonization and the effect on other oral bacteria are not totally clear. In this study, recolonization of mutans streptococci was evaluated in nine healthy adult volunteers, who were highly colonized with this microorganism. Stimulated saliva was collected before (baseline) and at 1, 7, 14, 21 and 28 days after application of 1% chlorhexidine gel on volunteers’ teeth for two consecutive days. On each day, the gel was applied using disposable trays for 3 x 5 min with intervals of 5 min between each application. Saliva was plated on blood agar to determine total microorganisms (TM); on mitis salivarius agar to determine total streptococci (TS) and on mitis salivarius agar plus bacitracin to determine mutans streptococci (MS). Chlorhexidine was capable of reducing the counts of MS and the proportion of MS with regard to total microorganisms (%MS/ TM) (p0.05) after 14 days for MS and 21 days for %MS/TM. The counts of TM and TS and the proportion of MS to total streptococci did not differ statistically from baseline (p>0.05) after chlorhexidine treatment. The results suggest that the effect of chlorhexidine gel treatment on suppression of mutans streptococci is limited to less than a month in highly colonized individuals.Streptococcus mutans é especificamente suprimido pelo tratamento intensivo com clorexidina em gel, mas o tempo de recolonização e o efeito em outras bactérias orais não está totalmente claro. Nesse estudo, a recolonização de estreptococos do grupo mutans foi avaliado em nove voluntários adultos saudáveis, os quais eram altamente colonizados por esse microrganismo. Saliva estimulada foi coletada antes (baseline) e 1, 7, 14, 21 e 28 dias após a aplicação de clorexidina em gel a 1% nos dentes dos voluntários por dois dias consecutivos. Em cada dia, o gel foi aplicado utilizando moldeiras descartáveis por 3 x 5 min com intervalos de 5 min entre cada aplicação. A saliva foi inoculada em ágar sangue para determinação dos microrganismos totais (MT); em mitis salivarius ágar para determinação dos estreptococos totais (ET) e em meio mitis salivarius com bacitracina para determinar a contagem de estreptococos do grupo mutans (EGM). O tratamento com clorexidina foi capaz de reduzir as contagens de EGM e a proporção de EGM em relação aos microrganismos totais (%EGM/MT) (p0,05) após 14 dias para EGM e 21 dias para %EGM/MT. As contagens de MT e ET e a proporção de EGM em relação a estreptococos totais não difereriram estatisticamente do baseline (p>0,05) após o tratamento com clorexidina. Os resultados sugerem que o efeito do tratamento com clorexidina em gel na supressão de estreptococos do grupo mutans é limitado a menos de um mês em indivíduos altamente colonizados

Effect of high-fluoride dentifrice on root dentine and bacterial composition in a multispecies biofilm model

The present study evaluated the effect of high-fluoride dentifrice on dentine demineralization and bacterial composition in a multispecies biofilm model in vitro. A seven-organism bacterial consortium was grown on bovine dentine discs in a high-throughput active attachment model. The biofilms were submitted twice per day to the following dentifrices treatments: 5,000 ppm F, 1,100 ppm F, with placebo as a negative control. After 5 days of biofilm growth, dentine samples were assessed by transversal microradiography, the biofilm was collected for bacterial counts and the pH of the media was determined. Lower integrated mineral loss values were observed when 5,000 ppm F-treatment was used compared to the other treatments. Overall microbiological counts decreased with increasing F-concentration as well the pH of the media throughout the experiment. The 5,000 ppm F-treatment caused a shift in microbial composition and reduced dentine demineralization in the in-vitro experimental model

Análise da variação dos níveis de fluoreto salivar após escovação com dentifrício fluoretado de alta concentração nos períodos diurno versus noturno

Assim, pode-se concluir que o dentifrício de alta concentração de flúor aumentou a biodisponibilidade do F salivar durante os períodos diurno e noturno em comparação com o dentifrício convencional, sendo assim uma opção para o manejo da cárie em pacientes de alto risco