ABSTRACT
OBJECTIVES: Aiming to contribute to the study of mechanisms involved in the anticariogenic properties of dental materials, this study assessed the suitability of a short-term in situ model to evaluate the anticariogenic potential of ionomeric materials. METHODS: The study used a 3-phase crossover, double blind design, and in each phase eight volunteers wore palatal appliances containing four enamel blocks restored with one of the following materials: composite resin (CR-Z250) (negative control), a conventional glass ionomer cement (GIC-Ketac-Fil) or a resin-modified GIC (RM-GIC-Vitremer). The restored blocks were covered with a "test plaque" of S. mutans, placed in palatal appliances and a cariogenic challenge was made during 1 min with 20% sucrose solution. After 45 min, test plaque was collected for fluoride (F) analysis. Enamel surface microhardness was previously determined at one side of the restoration and the percentage of surface microhardness change (%SMC) in relation to baseline (other side) was calculated. F concentration in enamel was also evaluated. RESULTS: Split-plot ANOVA showed a statistically lower %SMC on enamel around the ionomeric materials than around the CR (p<0.05). This result was supported by a statistically higher F concentration in test plaque (P<0.001) and in enamel (P<0.001) restored with the ionomeric materials when compared to the CR. CONCLUSIONS: The results suggest that the short-term in situ model tested is useful for studying the anticariogenic potential of dental materials that release fluoride.
Subject(s)
Cariostatic Agents/therapeutic use , Fluorides/therapeutic use , Glass Ionomer Cements/therapeutic use , Tooth Demineralization/prevention & control , Animals , Cattle , Dental Plaque/chemistry , Epidemiologic Methods , Female , Humans , MaleABSTRACT
Considerando que a eficácia dos produtos para aplicação tópica profissional de flúor (géis, espumas e vernizes) está relacionada com a reatividade do flúor (F) com o esmalte e sendo esta dependente da disponibilidade do F em cada produto, este estudo foi conduzido. A concentração de F nos seguintes produtos foi estudada: I - Flúor Fosfato Acidulado (FFA) gel (1,23% F), II - FFA espuma (1,23% F) e III- Verniz fluoretado (2,26% F). Foram confeccionados 40 blocos de esmalte bovino, tratados de acordo com os grupos descritos, sendo um deles utilizado como controle. O F fracamente ligado (''CaF2'') ao esmalte foi determinado após a extração com 1.0 M KOH e analisado em eletrodo específico. A concentração de F encontrada no gel foi de 12.642, na espuma 12.755 e no verniz 23.183 mg F/g. Todos os produtos formaram uma quantidade significantemente maior de ''CaF2'' na superfície do esmalte, comparado ao grupo controle (p < 0,05), mas entre eles, esta diferença não foi significante (p > 0,05). Assim, a formação de ''CaF2'' na superfície do esmalte não foi proporcional ao conteúdo de F nos produtos, sugerindo que o pH e o veículo utilizado são mais importantes.
Subject(s)
Dental Enamel , Fluorine/analysis , In Vitro Techniques , Fluorides, Topical/analysis , Fluorides, Topical/classificationABSTRACT
Since the efficacy of topical fluoride products is related to the fluoride (F) availability and its reactivity with enamel, this study was conducted. The F concentration of the following materials was verified: I- acidulated phosphate fluoride (APF) gel (1.23% F), II- APF foam (1.23% F) and III- Varnish (2.26% F). Forty blocks of bovine enamel were divided into 4 groups and treated according to the materials described, being one of them used as control. Loosely bound fluoride (''CaF2'') was determined on enamel after extraction with 1.0M KOH and analyzed by ion-selective electrode. Total F concentration found in gel was 12,642, in foam 12,755 and in varnish 23,183 mg F/g. All products formed statistically higher amounts of ''CaF2'' on enamel compared to the control group (p < 0.05), but the difference between them was not significant (p > 0.05). Thus, ''CaF2'' formation was not proportional to the total F content in the products, suggesting that the pH and the vehicle used are more important.
ABSTRACT
O objetivo do estudo foi avaliar o efeito de soluções de fluoreto de sódio a 0,05% contendo 2,5% ou 12,5% de xilitol no número de estreptococos do grupo mutans presentes na saliva. Participaram do estudo duplo cego, do tipo cruzado, 50 meninos entre 8 e 16 anos, distribuídos aleatoriamente em quatro grupos. Destes, 33 finalizaram o estudo. As soluções utilizadas foram: solução placebo; solução de fluoreto de sódio a 0,05%; solução de fluoreto de sódio a 0,05% + 2,5% xilitol + 2% sorbitol; solução de fluoreto de sódio a 0,05% + 12,5% xilitol + 2% sorbitol. Os indivíduos utilizaram 20 mL de uma das soluções, duas vezes ao dia. Cada solução foi utilizada por um período experimental de 28 dias. Os períodos experimentais foram intercalados por períodos de descanso de 10 dias. As soluções contendo xilitol a 2,5% e 12,5% não apresentaram diferença significativa (P = 0,32) em termos do logaritmo do número de estreptococos do grupo mutans. No entanto, a diferença foi significativa quando essas soluções foram comparadas às soluções de fluoreto de sódio e placebo (P < 0,001). Os resultados sugerem que a solução de fluoreto de sódio a 0,05% com adição de xilitol a 2,5% ou 12,5% reduziu significativamente o número de estreptococos do grupo mutans.
The objective of this study was to assess the effect of 0.05% sodium fluoride solutions containing 2.5% or 12.5% xylitol on the number of Streptococcus mutans in the human mouth. Fifty boys between 8 and 16 years of age participated in this double-blind crossover study. Of the original 50 boys, 33 finished the study. Participants were randomly divided into four groups. The following solutions were employed: placebo solution; 0.05% sodium fluoride solution; 0.05% sodium fluoride + 2.5% xylitol + 2% sorbitol; 0.05% sodium fluoride + 12.5% xylitol + 2% sorbitol. Each solution was used for a 28-day period (20 mL/day, twice a day), with a 10-day washout period between solutions. There were no significant differences (P = 0.32) between the two xylitolcontaining solutions (2.5% vs. 12.5%) concerning the number of Streptococcus mutans. However, there was a significant difference between these two xylitol-containing solutions and the sodium fluoride and placebo solutions (P < 0.001). Our results suggest that the 0.05% sodium fluoride solutions containing either 2.5% or 12.5% xylitol caused a significant reduction in the number of Streptococcus mutans