Calcium, inorganic phosphorus and fluoride in the fluid of dental biofilm formed under sucrose exposure

Orientador: Jaime Aparecido CuryTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de PiracicabaResumo: O biofilme dental formado na presença de sacarose apresenta matriz com alta concentração de polissacarídeos extracelulares (PEC) insolúveis e baixa concentração de cálcio (Ca), fósforo inorgânico (Pi) e fluoreto (F). O objetivo deste estudo foi avaliar a concentração desses íons no fluido do biofilme, onde ocorrem as trocas iônicas entre o biofilme e o mineral do dente, bem como sua cinética após a ingestão de açúcar ou após a interrupção dos desafios cariogênicos. Dezesseis voluntários utilizaram em 3 fases cruzadas de 15 dias, um dispositivo palatino contendo 8 blocos de esmalte humano, que foram expostos 8 vezes ao dia a água destilada deionizada (ADD), solução de glicose a 10% + frutose a 10% (GF) ou solução de sacarose a 20% (S). Após 14 dias os tratamentos com ADD ou os carboidratos foram invertidos. As variáveis analisadas foram acidogenicidade do biofilme (pH), Ca, Pi e F no fluido e no biofilme total (após 10 h de jejum, 5 min após desafio acidogênico por solução de glicose a 20% ou após a inversão dos tratamentos), e PEC insolúveis e polissacarídeos intracelulares (IP) no biofilme total. O pH do biofilme em repouso foi significativamente menor e a concentração de IP significativamente maior (p0,05). As concentrações de Ca, Pi e F no biofilme total foram menores para os grupos GF e S do que para o grupo ADD (p0,05). Ca, Pi e F no biofilme total aumentaram significativamente 24 h após a suspensão do tratamento com GF (p0,05). A concentração de PEC insolúveis foi significativamente maior para o grupo S em relação aos demais grupos (p<0,05). Os resultados sugerem que as mudanças induzidas pela sacarose ou seus monossacarídeos constituintes no biofilme total não se refletem no fluido do biofilmeAbstract: Dental biofilm formed in presence of sucrose presents in its matrix high concentration of insoluble extracellular polysaccharides (EPS) and low concentration of calcium (Ca), inorganic phosphorus (Pi) and fluoride (F). However, in the fluid of the biofilm formed in presence of sucrose, either the concentration of these ions or their mobilization soon after sugar ingestion or time after the interruption of sugar exposure are unknown. Sixteen volunteers wore, for 3 crossover phases of 15 days, a palatal appliance with 8 enamel blocks, which were exposed 8 times/day to deionized water (DW), 10% glucose + 10% fructose (GF) or 20% sucrose (S) solutions. After 14 days, treatments with DW or the carbohydrates were inverted. Variables analyzed were biofilm acidogenicity (pH), Ca, Pi and F, in the fluid and in whole biofilm (after 10-h fasting, 5 min after an acidogenic challenge by 20% glucose, or after inversion of treatments), and insoluble EPS and intracellular polysaccharides (IP) in whole biofilm. Resting biofilm pH was significantly lower and IP was significantly higher (p0.05). Ca, Pi and F in the whole biofilm were lower in the groups GF and S than in DW (p0.05). Ca, Pi and F in whole biofilm increased significantly 24 h after suspending the GF treatment, and Ca increased after suspending the S treatment (p<0.05), but this was not observed in the fluid (p>0.05). The insoluble EPS were significantly higher in the group S than in groups GF and DW (p<0.05). The findings suggest that the changes induced by sucrose or its component monosaccharides in the whole biofilm do not reflect in the biofilm fluidDoutoradoCariologiaDoutor em Odontologi

Riscos do uso do dentifrício fluoretado na prevenção e controle de cárie na primeira infância

Fluoride toothpaste has been considered responsible for the caries decline which occurred either in developed or in developing countries, such as Brazil. However, since children inadvertently ingest a certain amount of toothpaste while brushing their teeth, there is a concern on the subsequent fluorosis. Nevertheless, the potential risk of fluorosis from fluoride toothpaste has been overestimated based on the dose of fluoride ingested, considering as limit the dose of 0.07 mg F/kg body weight/day, and not on the actual fluorosis outcome. The dose of fluoride ingestion from toothpastes has been overestimated because It does not consider how much of fluoride is bioavailable to be absorbed and cause fluorosis. The lack of association between ingestion dose and fluorosis has been shown experimentally and observed epidemiologically by the mild degree of fluorosis found, which enables us to ratify the importance of the recommendation of fluoride toothpaste for caries control in young children, with few concerns on possible side effects.Dentifrício fluoretado tem sido considerado responsável pelo declínio de carie dentária ocorrida tanto em países desenvolvidos quanto nos em desenvolvimento, como o Brasil. Entretanto, como as crianças involuntariamente ingerem certa quantidade de dentifrício quando escovam os dentes, há preocupação com a fluorose decorrente. Entretanto, o risco em potencial do dentifrício provocar fluorose tem sido estimado com base na dose de ingestão de fluoreto, considerando como limite a dose de 0,07 mg F/dia/kg de peso e não na fluorose decorrente. A dose de ingestão de fluoreto por dentifrícios tem sido superestimada, porque não considera quanto do fluoreto ingerido está biodisponível para ser absorvido e provocar fluorose. A falta de associação entre dose de ingestão e fluorose tem sido mostrada experimentalmente e comprovada epidemiologicamente pelo grau não preocupante de fluorose encontrado, possibilitando ratificar a importância da recomendação do uso de dentifrício fluoretado para o controle de cárie, sem grandes preocupações com possíveis efeitos colaterais

Dispensing Device to Deliver Small and Standardized Amount of Fluoride Dentifrice on the Toothbrush

Objective: To evaluate the efficacy of a dispensing device specially developed to standardize the amount of fluoride dentifrice to be delivered on the toothbrush. The amount and variability of dentifrice applied using this device were compared with recommendations to apply dentifrice amounts equivalent to “rice size” or “pea-size”. Material and Methods: Two dentifrices, one used by children (NaF/Silica-based) and one used by the entire family (MFP/CaCO3-based), and five methods to apply them on the toothbrush (pea and rice sizes, and three different amounts using the developed device) were tested by 12 volunteers. The amount of dentifrice placed on the toothbrush was weighed, and the experiment was repeated three times. Data were analyzed by two-way ANOVA and Tukey test. Results: No differences were observed between the dentifrices used (p&gt;0.05), but the method of application significantly affected the amount&nbsp; of&nbsp; dentifrice applied (p&lt;0.05). Smaller amounts (p&lt;0.05) and less variability were observed when the volunteers used the dispenser device than when they were asked to apply a pea or rice size. Conclusion: The device can help parents and caregivers to safely use fluoride dentifrice on children

Qualidade da fluoretação da água de Capão Bonito, SP, Brasil, avaliada pelos controles operacional e heterocontrole

PURPOSE: To evaluate the quality of drinking water fluoridation of Capão Bonito, SP, Brazil, whose optimal fluoride concentration should be between 0.6 to 0.8 ppm F, considering the balance benefits/risks. METHODS: Historical records (n=1,964) from 2005 to 2009 of the water treatment plant (operational control) were evaluated. Also, from July 2009 to June 2010, 120 samples of the network water were collected for analysis and the fluoride concentrations found (external control) were compared with records of operational control of the same period. RESULTS: According to the historical records, 76.3% of the samples had acceptable fluoride concentration and this value was confirmed by the external control done during one year, which found that 80.8% of samples were within the optimal range. However, considering the samples out the optimal range, while the records of the operational control showed values below the minimum, the results of the external control found higher percentage of samples above the maximum. CONCLUSION: The data show the relevance to have a quality control of drinking water fluoridation because at same time the operational control analysis suggests that certain percentage of the population would not be receiving anticaries benefits, the external control indicates that it would be in increased risk of fluorosis.To evaluate the quality of drinking water fluoridation of Capão Bonito, SP, Brazil, whose optimal fluoride concentration should be between 0.6 to 0.8 ppm F, considering the balance benefits/risks. Historical records (n=1,964) from 2005 to 2009 of the water treatment plant (operational control) were evaluated. Also, from July 2009 to June 2010, 120 samples of the network water were collected for analysis and the fluoride concentrations found (external control) were compared with records of operational control of the same period. According to the historical records, 76.3% of the samples had acceptable fluoride concentration and this value was confirmed by the external control done during one year, which found that 80.8% of samples were within the optimal range. However, considering the samples out the optimal range, while the records of the operational control showed values below the minimum, the results of the external control found higher percentage of samples above the maximum. The data show the relevance to have a quality control of drinking water fluoridation because at same time the operational control analysis suggests that certain percentage of the population would not be receiving anticaries benefits, the external control indicates that it would be in increased risk of fluorosis264285290Avaliar a qualidade da fluoretação da água de Capão Bonito, SP, Brasil, cuja concentração de fluoreto deveria estar entre os limites de 0,6 e 0,8 ppm F, considerando o equilíbrio benefícios/riscos. Foram consultados 1964 registros feitos de 2005 a 2009 pela empresa responsável pelo tratamento da água (controle operacional). De 07/2009 a 06/2010, 120 amostras de água foram coletadas e as concentrações de fluoreto encontradas (heterocontrole) foram comparadas com as registradas pelo controle operacional do mesmo período. De acordo com os registros históricos, 76% das amostras tinham concentrações aceitáveis de fluoreto e este valor médio foi confirmado pelo heterocontrole feito, o qual encontrou um valor de 81%. Entretanto, considerando as amostras abaixo e acima dos limites aceitáveis, enquanto os registros do controle operacional mostraram maior porcentagem de valores abaixo do mínimo, os resultados do heterocontrole detectaram maior porcentagem acima do limite máximo. O relatado mostra a importância de haver um controle de qualidade da fluoretação da água de abastecimento publico, porque enquanto as análises feitas pelo controle operacional sugerem que uma porcentagem da população não estaria recebendo os benefícios da fluoretação, o heterocontrole aponta que ela estaria sob risco aumentado de fluorose dentári

The importance of fluoride dentifrices to the current dental caries prevalence in Brazil

Similar to that which occurred in most developed countries, dental caries have shown a significant decline in Brazil over the last two decades. Water fluoridation, expansion of preventive programs at schools, and especially, the widespread use of fluoride dentifrice are discussed as factors related to this reduction in caries. Data from epidemiological surveys and historical facts are presented to support the importance of fluoride dentifrices to the current caries prevalence in Brazil.Assim como observado na maioria dos países desenvolvidos, a prevalência de cárie dental no Brasil apresentou um declínio significativo nas últimas duas décadas. A fluoretação das águas de abastecimento público, a expansão de programas preventivos nas escolas e principalmente o uso abrangente de dentifrícios fluoretados no país são apresentados como fatores relacionados a essa redução de cárie. Dados de levantamentos epidemiológicos e fatos históricos são apresentados para corroborar a importância dos dentifrícios fluoretados na atual prevalência de cárie no Brasil16717

Effect of plaque accumulation and salivary factors on enamel demineralization and plaque composition in situ

Este estudo foi realizado para avaliar o efeito de alguns fatores salivares e da composição da placa dental na progressão da cárie in situ. O fluxo salivar, a capacidade tampão e os níveis de estreptococos mutans na saliva de 13 voluntários foram determinados inicialmente. Durante 3 períodos distintos de 4, 7 e 10 dias, eles utilizaram um dispositivo palatino contendo 4 blocos de esmalte bovino. Dez vezes ao dia, uma solução de sacarose a 20% foi gotejada sobre os blocos de esmalte. Durante o experimento, os voluntários utilizaram um dentifrício não fluoretado. Estreptococos mutans (EM), cálcio (Ca) e polissacarídeos insolúveis (PI) foram quantificados na placa formada sobre os blocos após cada período. A desmineralização do esmalte foi avaliada através de microdureza de superfície, e a porcentagem de perda de dureza de superfície (%PDS) foi calculada em relação aos valores de dureza iniciais. Houve desmineralização do esmalte após cada período de acúmulo de placa (p < 0,05) e a %PDS aumentou com o tempo (de 13,8 para 48,3%). As concentrações de Ca e PI na placa dental não foram diferentes entre os tempos experimentais, mas correlações significantes foram encontradas entre elas e a %PDS. Os fatores salivares avaliados inicialmente e os níveis de estreptococos mutans na placa não apresentaram correlação estatisticamente significante com a %PDS. Os resultados mostraram que a desmineralização do esmalte depende do tempo e está mais relacionada à composição do biofilme formado do que aos fatores salivares estudados.This study evaluated the effect of some plaque and salivary factors on caries progression in situ. The salivary secretion rate, buffering capacity and mutans streptococci counts from 13 volunteers were determined. For three distinct periods of time, 4, 7 and 10 days, each of them wore a palatal appliance containing 4 bovine enamel blocks. They used a non-fluoridated dentifrice during the experiment and a 20% sucrose solution was dripped onto the blocks 10 times a day. Mutans streptococci (MS), calcium (Ca), and insoluble polysaccharide (IP) were quantified in the dental plaque formed on the enamel blocks, after each period. Enamel demineralization was assessed by surface microhardness, and the percentage of surface microhardness change (%SMC) in relation to the baseline values was calculated. Enamel demineralization occurred after each period of plaque accumulation (p < 0.05), and the %SMC increased with time (from 13.8 to 48.3%). The concentrations of Ca and IP in plaque were not statistically different among the experimental times, but significant correlations were found between these concentrations and %SMC. Neither the salivary factors assessed initially nor mutans streptococci in plaque presented statistically significant correlations to %SMC. The results suggest that enamel demineralization is time-dependent and is more related to the composition of the biofilm formed than to the salivary factors studied

Fluoride rinse effect on retention of Caf2 formed on enamel/dentine by fluoride application

Calcium fluoride-like materials ("CaF2") formed on dental surfaces after professional fluoride application are unstable in the oral environment but can be retained longer with a daily NaF mouthrinse. We tested the effect of twice daily 0.05% NaF rinses on the retention of "CaF2" formed on enamel and dentine after applying acidulated phosphate fluoride (APF). "CaF2" formed on enamel/dentine by APF application significantly decreased after exposure to artificial saliva and the 0.05% NaF rinse was ineffective to avoid this reduction. These findings suggest that the combination of APF and 0.05% NaF is not clinically relevant, either for caries or dental hypersensitivity.Calcium fluoride-like materials ("CaF2") formed on dental surfaces after professional fluoride application are unstable in the oral environment but can be retained longer with a daily NaF mouthrinse. We tested the effect of twice daily 0.05% NaF rinses on the retention of "CaF2" formed on enamel and dentine after applying acidulated phosphate fluoride (APF). "CaF2" formed on enamel/dentine by APF application significantly decreased after exposure to artificial saliva and the 0.05% NaF rinse was ineffective to avoid this reduction. These findings suggest that the combination of APF and 0.05% NaF is not clinically relevant, either for caries or dental hypersensitivity3011

Proteolytic activity, degradation, and dissolution of primary and permanent teeth

BackgroundPrimary and permanent teeth composition may influence dissolution and degradation rates.AimTo compare the dissolution and degradation of primary and permanent teeth.DesignEnamel and dentin powders were obtained from primary molars and premolars and incubated within different pH buffers. Calcium and inorganic phosphate release was quantified in the buffers by atomic absorption and light spectrophotometry. A colorimetric assay was used to assess the MMP activity of primary dentin (PrD) and permanent dentin (PeD). Collagen degradation was assessed by dry mass loss, change in elastic modulus (E), and ICTP and CTX release. Data were submitted to ANOVA and Tukey’s tests (α = 0.05).ResultsSimilar dissolution was found between PrD and PeD after 256 hours. At pH 4.5, enamel released more minerals than dentin whereas at pH 5.5 the inverse result was observed. MMP activity was similar for both substrates. PrD showed higher dry mass loss after 1 week. In general, greater reduction in E was recorded for PrD. Higher quantities of ICTP and CTX were released from PrD after 1 week.ConclusionsPrimary and permanent teeth presented similar demineralization rates. Collagen degradation, however, was faster and more substantial for PrD.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/156418/2/ipd12632_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156418/1/ipd12632.pd