Chitosan microparticles loaded with essential oils inhibit duo-biofilms of Candida albicans and Streptococcus mutans

Abstract Oral candidiasis is a common fungal infection that affects the oral mucosa, and happens when Candida albicans interacts with bacteria in the oral microbiota, such as Streptococcus mutans, causing severe early childhood caries. C. albicans and S. mutans mixed biofilms are challenging to treat with conventional antimicrobial therapies, thus, new anti-infective drugs are required. Objective This study aimed to test a drug delivery system based on chitosan microparticles loaded with geranium and lemongrass essential oils to inhibit C. albicans and S. mutans mixed biofilms. Methodology Chitosan microparticles loaded with essential oils (CM-EOs) were obtained by spray-drying. Susceptibility of planktonic were performed according CLSI at 4 to 2,048 µg/mL. Mixed biofilms were incubated at 37ºC for 48 h and exposed to CM-EOs at 256 to 4,096 µg/mL. The antimicrobial effect was evaluated using the MTT assay, with biofilm architectural changes analyzed by scanning electron microscopy. RAW 264.7 cell was used to evaluate compound cytotoxicity. Results CM-EOs had better planktonic activity against C. albicans than S. mutans. All samples reduced the metabolic activity of mixed C. albicans and S. mutans biofilms, with encapsulated oils showing better activity than raw chitosan or oils. The microparticles reduced the biofilm on the slides. The essential oils showed cytotoxic effects against RAW 264.7 cells, but encapsulation into chitosan microparticles decreased their toxicity. Conclusion This study demonstrates that chitosan loaded with essential oils may provide an alternative method for treating diseases caused by C. albicans and S. mutans mixed biofilm, such as dental caries.

Erosive Effect of Analgesics on Primary Tooth Enamel - An in Vitro Study

Abstract Objective: To evaluate in vitro erosive effect of analgesics on primary tooth enamel. Material and Methods: The pH and the titratable acidity measurements of the medicines were performed in triplicate using a digital pH meter. Enamel slabs of primary teeth flat and polished were selected by initial surface microhardness analysis. Medications were selected and specimens were assigned into five groups (n=12): Dalsy; Magnopyrol; Paracetamol; Tylenol; and distilled water (negative control). Specimens were immersed in 5 ml of each group solution for 30 min, 4x/day for three days and stored in artificial saliva at 37 °C between immersions and at night. Final microhardness was determined. The data were submitted to Oneway ANOVA and Tukey's test. Scanning electron microscopy (SEM) analysis was performed in three specimens of each group. Results: Medicines showed acidic pH and mean values of titratable acidity ranged from 1.46 to 11.66 ml of 0.1N NaOH. The mineral loss of Magnopyrol was statistically significant in relation to the control group (p<0.01). Magnopyrol showed higher values when compared to Tylenol (p<0.05). SEM images displayed microstructure alterations in the Paracetamol group. Conclusion: Despite the low pH values, only Magnopyrol showed greater enamel softening. Paracetamol demonstrated morphological changes in primary tooth enamel (AU).

Prevalência de obesidade infantil: há motivo de preocupação? / Prevalence of childhood obesity: is there a cause for concern?

O objetivo deste estudo foi determinar a prevalência de sobrepeso/obesidade em pré-escolares e investigar a relação entre o índice de massa corporal (IMC) das crianças e o de seus pais. Para tanto, conduziu-se uma pesquisa transversal com 968 crianças, de 3-5 anos, regularmente matriculadas em pré-escolas públicas. O estado nutricional infantil foi definido pelo IMC após aferição do peso e estatura no próprio ambiente escolar, considerando-se o sexo e a idade em meses. De acordo com os critérios da Organização Mundial da Saúde (OMS), as crianças foram classificadas em eutróficas, baixo peso, risco de sobrepeso, sobrepeso ou obesas. O IMC dos pais foi calculado com os dados de peso e estatura obtidos por meio de questionário. Observou-se que 1% de crianças tinham baixo peso, 62% eram eutróficas, 17% apresentavam risco de sobrepeso, 12% sobrepeso e 8% obesidade. O IMC infantil mostrou-se positivamente correlacionado com o IMC materno e paterno (p < 0,05). Concluiu-se que a prevalência de obesidade e sobrepeso infantil na população estudada é alarmante e que o IMC da criança foi correlacionado ao dos pais. Tais achados devem ser motivo de preocupação das autoridades, reforçando a necessidade de estratégias de atenção à saúde abrangendo todo o núcleo familiar.

This study aimed to determine the prevalence of overweight/obesity in preschoolers and to investigate the relationship between the body mass index (BMI) of the children and of their parents. Therefore, a cross-sectional study was conducted with 968 children aging 3-5 years old from public preschools. The children's nutritional status was defined by the BMI, after measuring their weight and height at the preschool, considering sex and age in months. According to the World Health Organization (WHO) criteria, the children were classified as eutrophic, thin, at risk of being overweight, overweight or obese. The parents' BMI was calculated using weight and height data obtained through a questionnaire. One percent of children were thin, 62% eutrophic, 17% at risk of overweight, 12% were overweight and 8% obese. Children's BMI was positively correlated with maternal and paternal BMI (p <0.05). It was concluded that the prevalence of obesity and overweight in the population studied is alarming, and the child's BMI was correlated to their parents' BMI. Such findings should be of concern for the authorities, reinforcing the need for health care strategies covering the entire family.

Extraction and purification of RNA from human carious dentine: an approach to enable bacterial gene expression studies / Extração e purificação de RNA proveniente de dentina humana cariada: uma abordagem para viabilizar estudos de expressão gênica

Background: RNA isolation from bacteria within dentine caries lesions could be difficult due to reduced amount of collectable biomass and high mRNA instability. Attempting to overcome this challenge we describe one protocol developed to extract and purify total RNA from dentine lesions. Objective: customize a bacterial RNA extraction and purification method from human carious dentine. Methods: quantity and purity of extracted RNA were measured with a microvolume UV-VIS spectrophotometer, RNA integrity was assessed by standard denaturing agarose gel electrophoresis and images were captured under ultraviolet light with camera and analyzed. DNase treatment removed genomic DNA and an additional step of purification was carried out in silica spin column. Results: final yield (ng/µl) was 67.01 ± 22.33, absorbance ratio A260/A280 = 2.0 ± 0.07 and RNA integrity were obtained. The purified samples were reversely transcribed and the expression of atpD and fabM gene from Streptococcus mutans analyzed by quantitative real-time PCR. Conclusion: the extraction methodology developed produced high-quality RNA from dentine microbiota for transcriptional analysis.

Introdução: o isolamento de RNA de bactérias dentro de lesões de dentina cariada pode ser difícil devido à quantidade reduzida de biomassa e alta instabilidade de mRNA. Na tentativa de superar esse desafio, descrevemos um protocolo desenvolvido para extrair e purificar o RNA total das lesões dentinárias. Objetivo: personalizar um método de extração e purificação de RNA bacteriano a partir da dentina cariada humana. Métodos: a quantidade e a pureza do RNA extraído foram medidas com um espectrofotômetro UV-VIS de microvolume, a integridade do RNA foi avaliada por eletroforese em gel de agarose desnaturante padrão e as imagens foram capturadas sob luz ultravioleta e analisadas. O tratamento com DNase removeu o DNA genômico e uma etapa adicional de purificação foi realizada em coluna de spin de sílica. Resultados: o rendimento final (ng / µl) foi de 67,01 ± 22,33, a razão de absorbância A260 / A280 = 2,0 ± 0,07 e a integridade do RNA foram obtidas. As amostras purificadas foram transcritas reversamente e a expressão do gene atpD e fabM de Streptococcus mutans analisadas por PCR quantitativo em tempo real (RT-qPCR). Conclusão: a metodologia de extração desenvolvida produziu RNA de alta qualidade da microbiota dentinária para análises transcricionais.

Fontes de estresse, bem-estar psicológico e saúde entre estudantes de Odontologia: uma comparação entre fases pré-clínica e clínica e entre os sexos / Sources of stress, psychological well-being and health among dental students: a comparison between preclinical and clinical phases and between sexes

O objetivo do estudo foi avaliar bem-estar psicológico, saúde geral e fontes de estresse de estudantes de Odontologia de quatro cursos, comparando as fases pré-clínica e clínica e os sexos. Três instrumentos foram aplicados: Dental Environment Stress (DES), Psychological General Well-Being Index (PGWB) e Health Survey (SF-36), respondidos por 203 estudantes, sendo 75 (37%) em fase pré-clínica e 128 (63%) em clínica. Desses, 59 (29%) eram homens e 144 (71%) mulheres. As comparações foram realizadas pelo teste de Mann-Whitney, adotando um nível de significância de 5%. Nos domínios analisados pelo DES (performance acadêmica; dificuldades e inseguranças sobre o futuro profissional; responsabilidade com pacientes; fatores pessoais e institucionais; relações interpessoais), estudantes em fase pré-clínica demonstraram escores significativamente menores quando comparados a estudantes em fase clínica. No escore total de PGWB e em dois domínios (ansiedade e saúde geral), observou-se também escores menores em estudantes em fase pré-clínica. Quatro domínios do SF-36 (dor corporal, funcionamento físico, funcionamento social e papel físico), apresentaram significativa melhor saúde geral dos estudantes em fase pré-clínica. Entre os sexos, dois domínios do DES (performance acadêmica, dificuldade e insegurança sobre o futuro profissional) mostraram menores fatores estressores para o sexo masculino. O PGWB demonstrou diferença significativa em quatro domínios (estado deprimido; autocontrole; saúde geral; vitalidade), com melhor bem-estar psicológico para homens. O sexo masculino apresentou melhor vitalidade no domínio do SF-36. Concluiu-se que estudantes em fase pré-clínica e do sexo masculino demonstraram menores fontes de estresse, melhor bem-estar psicológico e percepção de saúde geral (AU).

The aim of this study was to evaluate psychological well-being, overall health, and sources of stress among dental students from four Doctor of Dental Surgery (DDS) programs, comparing the preclinical and clinical phases and sexes. Three instruments were applied: Dental Environment Stress (DES), Psychological General Well-Being Index (PGWB) and Health Survey (SF-36), answered by 203 students, with 75 (37%) in the preclinical phase and 128 (63%) in the clinical one. Among them, 59 were male (29%) and 144 were female (71%). Comparisons were performed using the Mann-Whitney test, adopting a significance level of 5%. In the domains analyzed using DES (academic performance, difficulties and insecurities about their professional future, responsibilities with patients, personal and institutional factors, interpersonal relationships), preclinical students showed significantly lower scores than students enrolled in the clinical phases. For PGWB total score and in two domains (anxiety and general health), lower scores were also observed in preclinical students. Four domains of SF-36 (bodily pain, physical functioning, social functioning and role-physical) showed significantly better overall health for preclinical students. Among the sexes, two DES domains (academic performance and difficulties and insecurities about their professional future) showed lower stressors for males. PGWB showed a significant difference in four domains (depressed mood, self-control, general health and vitality), with better psychological well-being for males. Males showed better vitality in the SF-36 domain. Concluding, preclinical and male students showed lower sources of stress, better psychological well-being and better perception of their overall health (AU).

Active compounds and derivatives of camellia sinensis responding to erosive attacks on dentin

Abstract This research explored the potential of Camellia sinensis-derived teas and active compounds to be used as treatments to prevent dentin wear. Human root dentin slabs were randomly assigned to 5 groups (n = 10) as follows: distilled water (DW, control), epigallocatechin-3-gallate (EGCG), theaflavin gallate derivatives (TF), commercial green tea (GT), and commercial black tea (BT). The samples were submitted to a pellicle formation and an erosive cycling model (5x/day, demineralization using 0.01 M hydrochloric acid/60 s) followed by remineralization (human stimulated saliva/60 min) for three days. The samples were treated for 5 min using the test group solutions between the erosive cycles. Dentin changes were assessed with profilometry analysis and FT-Raman spectroscopy. The data regarding wear were analyzed by ANOVA followed by Tukey's test (p < 0.05). EGCG, TF derivatives, and both regular teas significantly suppressed erosive dentin loss (38-47%, p < 0.05). No obvious changes in the Raman spectra were detected in the specimens; however, the DW group had a minor relationship of 2880/2940 cm−1. The phenolic contents in both green and black tea and the important catechins appear to have protective effects on dentin loss.

Stressors, psychological well-being, and overall health amongst students from public and private dental schools

Aim: This study aimed to correlate stressors with psychological well-being and health factors in dental students from public and private schools. Methods: From February to May 2015, three different instruments (Dental Environment Stress ­ DES ­ Psychological General Well-Being ­ PGWB ­ and SF-36 Health Survey) were applied to students from two public and two private dental schools from the State of Ceará, Brazil. Mann-Whitney test or t test for independent samples were used in order to compare the stressors between private and public dental schools students. Correlations to each DES domain were performed using Kendall's Tau C test. Results: A total of 92 (45.32%) and 111 (56.68%) students from public and private schools, respectively, answered the questionnaire. Students from public schools demonstrated significantly higher scores in DES/academic performance and DES/personal and institutional factors (p<0.05). Significant negative correlations were detected between PGWB/anxiety and PGWB/general with all DES domains for both public and private schools (p<0.05). Additionally, DES/academic performance was significantly correlated with several SF-36 domains, such as physical function, vitality, and social functioning, to both public and private schools (p<0.05). However, DES/academic performance and SF-36/role physical was only significantly correlated in private school students (r=-0.171, p=0.039), while SF-36/bodily pain (r=-0.274, p<0.001), general health (r=-0.245, p=0.001), and mental health (r=-0.286, p<0.001) were significantly correlated with DES/academic performance only in public school students. Conclusion: Students from public and private dental schools presented different stressor patterns. Additionally, most of DES domains were significantly associated with PGWB and SF-36 to both public and private schools

Sucrose induced dentin demineralization in a microcosm biofilm model / Desmineralización de la dentina inducida por sacarosa en un modelo de biofilm microcosmo

The aim of this in vitro study was to assess the root dentin demineralization caused by a microcosm biofilm model that has been exposed to sucrose in different ways. Materials and Methods: Saliva of two volunteers was inoculated into an artificial medium for biofilm growth and dentin blocks were immersed into these media. Dentin specimens were randomly exposed to one of the five experimental conditions: C (control group - no saliva inoculum or sucrose), 0S (saliva inoculum without sucrose, negative control), 3S (three daily one-minute immersions in 20 % sucrose), 6S (six daily one-minute immersions in 20 % sucrose), and CS (continuously immersed in 5 % sucrose). After five days, biofilm was collected to determine the concentration of intracellular and extracellular polysaccharides and the dentin surface hardness loss (SHL) was measured. The experiment was carried out in triplicate. Results: The dentin SHL was higher in groups that were exposed to sucrose (3S, 6S and CS) and there was a statistically significant difference between all groups (p<0.001). CS had higher concentrations of polysaccharides (p>0.001) and there was no statistically significant difference between the other groups (0S, 3S and 6S) (p>0.005). Conclusion: The microcosm biofilm model developed has the potential to produce root dentin demineralization at different exposures to sucrose.

El objetivo de esta investigación in vitro fue evaluar la desmineralización de la dentina radicular causada por un modelo de biofilm microcosmo que fue expuesto de diferentes maneras a la sacarosa. La saliva de dos voluntarios fue colocada en un medio artificial para crecimiento del biofilm y los bloques de dentina fueron sumergidos en estos medios. Al aza rlos bloques fueron expuestos a una de las cinco condiciones experimentales: C (grupo control ­ sin inoculación de saliva o sacarosa), 0S (inoculación de saliva sin sacarosa, control negativo), 3S (tres inmersiones diarias de un minuto en sacarosa a 20 %), 6S (seis inmersiones diarias de un minuto en sacarosa a 20 %), y CS (sumergidos continuamente en 5 % de sacarosa). Después de cinco días, el biofilm fue recogido para determinar la concentración de polisacáridos intracelulares y extracelulares y fue medida la pérdida de dureza superficial de la dentina (SHL). El experimento se repitió en tres ocasiones. La dentina SHL era mayor en los grupos que fueron expuestos a la sacarosa (3S, 6S E CS) y hubo diferencia estadísticamente significativa entre todos los grupos (P<0,001). CS presentó mayor concentración de polisacáridos (p<0,001) y no hubo diferencia estadísticamente significativa entre los demás grupos (0S, 3S E 6S) (p>0,005). El modelo del biofilm desarrollado tiene potencial para producir desmineralización de la dentina radicular en diferentes exposiciones a la sacarosa.

Effectiveness of different removal methods of artificially demineralized dentin / Efetividade de diferentes métodos de remoção de dentina desmineralizada artificialmente

Objective: This study aimed to evaluate the effectiveness of different mechanical methods for the removal of demineralized dentin. Methods: Healthy human third molars were prepared in such a way that the flat occlusal surfaces of the dentin were exposed and longitudinally sectioned in a vestibular-lingual direction. One section of each tooth was submitted to the pH-cycling model, while the other section was kept intact. The tooth sections were joined, and a single operator performed dentin removal using a steel bur, a hand instrument,or a polymer bur. The tooth’s sections were then separated, and digital images were obtained. The depth of the prepared cavities and the microhardness measurements were checked and analyzed statistically using the Kruskal-Wallis One-Way ANOVA in Ranks, the Tukey test, while desmineralized dentin were comparedusing the One-Way ANOVA, and the Holm-Sidak method (p < 0.05). Results: The steel bur produced the deepest cavities in mineralized and demineralized dentin. The polymer bur generated the shallowest cavitiesin demineralized dentin. The measurements of microhardness of the deepest surfaces of the cavities prepared in demineralized dentin indicated that the steel bur and hand instrument presented similar values, while those values produced by polymer burs proved to be lower. Conclusion: The effectiveness of the removalof demineralized dentin varied among the three methods used in this study. The polymer bur proved to bethe most conservative of the methods used. By contrast, the steel bur and hand instrument showed a similareffectiveness in the removal of dentin, according to the microhardness of the remaining dentin, even thoughthey produced different cavity depths.

Effect of chlorhexidine on the bond strength of a self-etch adhesive system to sound and demineralized dentin

This study evaluated the effect of a 2% chlorhexidine-based disinfectant (CHX) on the short-term resin-dentin bond strength of a self-etch adhesive system to human dentin with different mineral contents. Dentinal mineralization was tested at 4 levels (sound, and after 2, 4, or 8 days of demineralization-remineralization cycles) and disinfectant at 2 levels [deionized water (DW, negative control) and CHX]. Dentin demineralization induced by pH-cycling was characterized by cross-sectional hardness (CSH). Each dentin surface was divided into halves, one treated with DW and the other with CHX (5 minutes). Each surface was bonded with a self-etch adhesive system and restored. The specimens were sectioned and subjected to microtensile bond testing. CSH and microtensile bond strength (µTBS) data were analyzed by regression analysis and ANOVA-Tukey tests (α = 5%), respectively. The groups treated with CHX resulted in mean µTBS similar to those found for the groups in which the dentin was exposed to DW (p = 0.821). However, mean µTBS were strongly influenced by dentin mineralization (p < 0.05): the bond strength found for sound dentin was lower than that found for dentin cycled for 8 days, which was even lower than the bond strengths for dentin cycled for 2 or 4 days. The results suggest that the degree of dentin demineralization affects the bond strength of self-etching adhesives, but the use of CHX does not modify this effect.

Avaliação da infiltração marginal em restaurações com compósitos à base de metacrilato e à base de silorano / Evaluation of marginal leakage on restorations of methacrilate and silorane-based composites

Objetivo: O objetivo deste estudo in vitro foi avaliar o nível de infiltração marginal em restaurações realizadas com sistemas restauradores à base de metacrilato e à base de silorano. Materiais e método: Cavidades classe V em forma de caixa (4 x 4 x 2mm) foram preparadas na junção cemento-esmalte nas faces vestibular, lingual, mesial e distal com margens em esmalte e dentina de vinte molares humanos hígidos. Os dentes foram divididos aleatoriamente em dois grupos e restaurados da seguinte forma: Grupo 1 (G1) - Clearfil SE, aplicado se-gundo as instruções do fabricante e restaurado com re-sina composta Filtek Z250, e Grupo 2 (G2) - P90 Bond, aplicado segundo as instruções do fabricante e restau-rado com resina composta Filtek P90. Resina composta foi aplicada em incremento único e fotopolimerizada por 40s. Os espécimes foram imersos em solução de azul de metileno a 2% por 4h e seccionados longitu-dinalmente no centro da restauração. A penetração de corante na interface adesiva foi avaliada usando-se lupa esterioscópica e escores de 0 a 3 foram atribuídos às margens de esmalte e dentina. A significância dos dados foi analisada utilizando-se os testes estatísticos Kruskall Wallis e Student-Newman-Keuls. Resultados: Não houve diferença estatística entre os dois sistemas restauradores testados tanto nas margens de dentina (P = 0,19) quanto nas margens de esmalte (P = 0,97). Conclusão: Não houve diferença na capacidade sela-dora dos materiais restauradores testados.

Dentin hypersensitivity after treatment with desensitizing agents: a randomized, double-blind, split-mouth clinical trial

The aim of this study was to evaluate the efficacy of two desensitizing agents in the reduction of dentin hypersensitivity in a randomized, double-blind, split-mouth clinical trial. Seventy-seven teeth from 13 patients that presented some degree of sensitivity to probing and/or air stimulation were treated with one of the following desensitizing agents: Oxa-Gel (G1), Sensi Kill (G2) and placebo gel (G3 - control). According to paired t-test, all treatments, even the placebo gel, were capable of reducing sensitivity scores for both stimuli. Analysis of data by ANOVA and Tukey's test (?=0.05) showed that the sensitivity scores were significantly lower only for Sensi Kill in comparison to the other products (Oxa-Gel and placebo), when air stimulus was applied. It may be concluded that treatment with Sensi Kill presented a slightly better performance in reducing dentin hypersensitivity when compared to the other desensitizing agent.

O objetivo desse estudo foi avaliar a eficiência de dois agentes dessensibilizantes na redução da hipersensibilidade dentinária, em um estudo clínico aleatório do tipo boca-dividida e duplo-cego. Setenta e sete dentes de 13 pacientes que apresentavam algum grau de sensibilidade à sondagem e/ou estímulo ao ar foram tratados com um dos seguintes agentes dessensibilizantes: Oxa-Gel (G1), Sensi Kill (G2) e gel placebo (G3-controle). De acordo com o teste t pareado, todos os tratamentos, inclusive o placebo, foram capazes de reduzir os escores para ambos os estímulos. A análise dos dados pelos testes de ANOVA e de Tukey (?=0,05) demonstrou que os escores de sensibilidade foram significantemente menores somente para o Sensi-Kill em comparação aos outros produtos (Oxa-Gel e placebo) quando o estímulo ar foi aplicado. Pode-se concluir que o tratamento com Sensi-Kill apresentou um desempenho ligeiramente melhor na redução da hipersensibilidade dentinária quando comparados aos outros agentes dessensibilizantes.

Efficacy of smear layer removal by cavity cleaning solutions: an atomic force microscopy study / Eficácia da remoção da lama dentinária por soluções de limpeza cavitária: estudo de microscopia de força atômica

PURPOSE: To evaluate the efficacy of smear layer removal by cavity cleaning agents by the use of atomic force microscopy (AFM). METHODS: Five intact human third molars were sectioned in the coronal portion to obtain dentin disks, which were ground with 600-grit abrasive paper for 10 s. Serial longitudinal sections were made perpendicular to each other to create four specimens, from each tooth. The specimens were divided into four treatment groups: GI, 2 percent chlorhexidine; GII, calcium hydroxide solution; GIII, 1.23 percent fluoride solution; and GIV, 37 percent phosphoric acid. The solutions were applied with a brush for 60 s, with the exception of the 37 percent phosphoric acid, which was applied for 15 s and rinsed with distilled water for 60 s. The specimens were examined by AFM. RESULTS: All of the specimens in GI and GII showed 100 percent of the dentin tubules obliterated by the smear layer. However, all of the specimens in GIII and GIV showed 0 percent of the dentin tubules obliterated by the smear layer. CONCLUSION: The 1.23 percent fluoride solution was effective in removing the smear layer and can be used as a cavity cleanser.

OBJETIVO: Avaliar a eficácia da remoção de lama dentinária por agentes de limpeza cavitária através da análise de microscopia de força atômica (MFA). METODOLOGIA: Cinco terceiros molares humanos hígidos foram seccionados transversalmente na porção coronária, obtendo discos de dentina de 2 mm, que foram desgastados com lixas de granulação 600, por 10 s.Foram feitos cortes seriados longitudinais e perpendiculares entre si, obtendo-se quarto espécimes de cada dente. Os espécimes foram divididos em 4 grupos: GI- clorexidina a 2 por cento; GII- água de hidróxido de cálcio; GIII- solução fluoretada a 1,23 por cento; GIV - ácido fosfórico 37 por cento. As soluções foram aplicadas com pincel por 60 s, com exceção do ácido fosfórico que foi aplicado por 15 s e lavado com água destilada pelo mesmo tempo. Os espécimes foram analisados por MFA. RESULTADOS: Todos os espécimes de GI e GII apresentaram 100 por cento dos túbulos dentinários obliterados por lama dentinária. Os espécimes de GIII e GIV apresentaram 0 por cento dos túbulos obliterados por lama dentinária. CONCLUSÃO: A solução de fluoretada a 1,23 por cento foi eficiente na remoção de lama dentinária, podendo ser empregada na limpeza de cavidades.

Influence of environmental conditions on properties of ionomeric and resin sealant materials

OBJECTIVES: The aim of this study was to determine the effect of environmental conditions on the degradation of ionomeric and resin sealant materials. MATERIAL AND METHODS: FluroShield, Vitremer, and Ketac Molar disc-shaped specimens (n=18/material) were prepared, polished, subjected to initial hardness and roughness readings. Six discs of each material were randomly assigned to one of three different storage solutions: 0.3 percent citric acid (CA), demineralization solution (DE), and remineralization solution (RE). The specimens were individually immersed in 3 mL of the test solutions, which were daily changed. After 15 days of storage, new surface roughness and hardness readings were done. Fluoride release in the solutions was measured within 15 days. Data were analyzed by ANOVA and Tukey's and Contrast tests (á=0.05). RESULTS: The storage in CA increased the roughness of Vitremer and Ketac Molar. A significant reduction in hardness was observed for all materials after storage in all solutions. For all materials, the greatest amounts of fluoride release occurred during the 1st day. FluroShield presented the same patterns of fluoride release in all solutions. Ketac Molar and Vitremer released the highest amounts of fluoride in the CA solution. CONCLUSIONS: Ionomeric materials are more susceptible to degradation than resin-based materials under acidic conditions. Acidic conditions lead to a higher fluoride release from ionomeric materials.

Efeito in situ do laser de CO2 na cárie do esmalte dentário adjacente às restaurações de resina composta / In situ effect of the CO2 laser on enamel caries adjacent to composite restorations

Esta pesquisa investigou in situ o efeito do laser de CO2 pulsado (λ= 10,6 11m) na redução da desmineralização do esmalte humano ao redor de restaurações de resina composta. O estudo duplo-cego, boca dividida, foi realizado em uma fase de 14 dias, na qual 14 voluntários utilizaram aparelhos palatinos com quatro blocos de esmalte dentário restaurados com resina composta, aleatoriamente divididos em dois grupos: controle (sem irradiação) e irradiação com laser de CO2 no ângulo cavo-superficial da cavidade. Os voluntários usaram dentifrício fluoretado e gotejaram solução de sacarose a 20%, oito vezes ao dia, sobre os blocos dentários para aumentar o desafio cariogênico. A perda mineral foi quantificada pela análise de microdureza transversal nas distâncias de 25 e 50 11µm da margem da restauração e profundidades de 10, 20, 40, 60, 80, 100, 140 e 220 µm a partir da superfície do esmalte. Os resultados foram analisados estatisticamente pelo teste t e teste Tukey (p < 0,05). Na distância de 25 µm, houve diferença significativa na redução da desmineralização para as profundidades de 10, 20 e 40 µm e os valores de porcentagem de volume mineral foram 90,35:1:5,64; 89,24:1:3,66 e 90,87:1:4,31, respectivamente, para o grupo irradiado e 84,24±7,95; 85,75±7,60 e 88,69±5,44 para o grupo controle. Para a distância de 50 µm da margem da restauração, foi evidenciada diferença significativa entre o grupo irradiado com laser de CO2 na profundidade de 10 µm, com valor de porcentagem de volume mineral de 89,88±4,94 e de 87,54±5,53 para o grupo controle. Concluiu-se que a irradiação com laser de CO2 pulsado foi capaz de reduzir a desmineralização do esmalte ao redor de restaurações de resina composta.

This in situ study investigated the effect of a pulsed CO2 laser (1O.6µm) on the reduction of enamel demineralization around composite-resin restorations. During 14-day experimental period, 14 volunteers wore palatal appliances containing 4 human dental enamel slabs restored with a resin-based composite, which were assigned into 2 treatrnent groups: control (no irradiation) and CO2 laser irradiation on the cavosurface angle of cavity. A 20% sucrose solution was dripped onto the slabs 8x/day to increase the cariogenic challenge. Enamel mineral loss was assessed by cross-sectional microhardness analysis, at distances of 25 and 50 µm from the restoration margins and depths of 10, 20, 40, 60, 80, 100, 140 e 220 µm from the enamel surface, The results were statistically analyzed by ANOVA and Tukey's test (p < 0.05). At 25 µm from the restoration, a significant difference on demineralization reduction was observed on depths of 10, 20 and 40 µm and the volume percentage mineral values were of 90.35±5.64, 89.24±3.66; 90.87±4.31, respectively, for the CO2 laser irradiation group and 84.24±7.95; 85.75±7.60; 88.69±5.44 for the control group. At 50 µm from the restoration, a significant difference on the reduction of caries was observed between the CO2 laser irradiation group and the control group on depth of 10 µm, and the volume percentage mineral values were of 89.88±4.94 for the CO2 laser irradiation group, and 87.54±5.53 for the control group. In condusion, the irradiation of a pulsed CO2 laser was able to reduce the enamel demineralization on cavity margins around composite restorations.

O emprego do laser de CO2 no controle da cárie dentária / The use of CO2 laser on dental caries control

O laser de dióxido de carbono atua na inibição da desmineralização do esmalte, reduzindo sua solubilidade aos ácidos e, este efeito pode ser potencializado quando associado a agentes fluoretados. Assim, o objetivo deste trabalho foi descrever as características do laser de CO2, discutir os mecanismos de ação do laser na inibição da desmineralização do esmalte e ainda, revisar a literatura a respeito de seus efeitos quando combinado ao íon flúor.

Carbon dioxide laser acts on the enamel demineralization inhibition by reducing its acid solubility and this effect can be enhanced when associated with fluoridated agents. Therefore, the aim of this paper was to describe CO2 laser characteristics, discuss its action mechanisms on the inhibition of enamel demineralization and also to review the literature concerning the laser effects when combined with fluoride ion.

Influence of storage solution on enamel demineralization submitted to pH cycling / Influência da solução de armazenagem na desmineralização do esmalte submetido à ciclagem de pH

Dentes humanos extraídos são freqüentemente utilizados para propósitos educacionais ou de pesquisa. Desta forma, é necessário o armazenamento dos mesmos em soluções desinfetantes que não alterem a estrutura dental. Para tanto, sessenta espécimes foram divididos nos seguintes grupos: esmalte armazenado em formol (F1), armazenado em timol (T1), armazenado em formol e submetido à ciclagem de pH (F2) e armazenado em timol e submetido à ciclagem de pH (T2), sendo avaliados por meio de análise de microdureza longitudinal e tiveram a porcentagem de volume mineral pro micrômetro determinada. Diferenças entre os grupos foram encontradas até a profundidade de 30µm da superfície do esmalte (p<0,05), onde o grupo mais desmineralizado era T2. Foi concluído que a solução de armazenagem influenciou na reação do substrato dental a um desafio cariogênico, sugerindo que o formaldeído pode aumentar a resistência do esmalte à desmineralização promovida pelo modelo de ciclagem de pH, quando comparado à desmineralização ocorrida no esmalte armazenado em timol.

Autopercepção da fluorose pela exposição a flúor pela água e dentifrício / Self-perception of fluorosis due to fluoride exposure to drinking water and dentifrice

A percepção da fluorose dental e seu impacto em escolares de Piracicaba, SP, Brasil, expostos ao uso de flúor pela água e dentifrício, foram avaliados. O problema foi encontrado em 72 por cento das crianças, mas o grau de alteração decorrente não provocou nenhum impacto na satisfação das crianças com seus dentes. Embora a fluorose dental, devido à ingestão de flúor pela água e ao uso de dentifrício fluoretado, não tenha comprometido a estética da amostra populacional avaliada, estudo mais abrangente deve ser realizado

Análise de flúor em enxaguatórios bucais encontrados no comércio brasileiro e o uso de eletrodo íon-específico / Analysis of fluorine in mouthrinses found in the Brazilian marketplace and the utilization of an ion-specific electrode

A condiçäo mínima para que produtos comerciais tenham potencial anticárie é a presença de uma concentraçäo significativa de flúor solúvel nos mesmos. Considerando-se que essa condiçäo é inclusive regulamentada por lei, o presente trabalho teve por objetivo primário analisar as concentraçöes de íon flúor de sete marcas comerciais de enxaguatórios bucais. Para isso utilizou-se um eletrodo específico para flúor Orion 96-09 acoplado a um analisador de íons Orion EA 940, ambos previamente calibrados, sendo o objetivo secundário deste trabalho descrever operacionalmente a realizaçäo dessa análise. Os resultados encontrados (média ñ dp; n = 3) de íon flúor (ppm) foram: Kolynos Flúor© - 213,3 ñ 9,0; Fluordent© - 223,7 ñ 1,7; Plax Kids© - 229,1 ñ 3,8; Cepacol Júnior© - 218,6 ñ 1,1; Sorriso Herbal© - 220,6 ñ 6,5; Fresh Breath Menta© - 88,7 ñ 1,1; Fresh Breath Menta Azul© - 88,0 ñ 3,7. Os resultados mostraram que apenas os enxaguatórios da marca Fresh Breath estavam em desacordo com a Portaria nº 29 de 28 de agosto de 2000 da Agência Nacional de Vigilância Sanitária (Anvisa) do Ministério da Saúde do Brasil e que a técnica de análise com eletrodo íon-específico é precisa e exata