Resumo: Muito tem se avaliado a respeito das propriedades físicas e químicas dos selantes de fóssulas e fissuras, mas pouco sobre seus efeitos no biofilme dentário. O objetivo deste estudo foi analisar as características bioquímicas e microbiológicas do biofilme dentário formado in situ sobre materiais que liberam flúor ou cálcio e fosfato. Dez voluntários utilizaram dispositivo intrabucal palatino contendo corpos-de-prova de materiais (Fuji IX GP, Auralay XF e Aegis) ou blocos de esmalte bovino. A fase experimental consistiu de 4 etapas de 8 dias cada e a utilização de sacarose para formação do biofilme. No 7º dia dos períodos experimentais foi determinado o pH do biofilme e no 8º dia, o biofilme dentário formado foi coletado para determinação de flúor (F), cálcio (Ca), fósforo (P) e polissacarídeos extracelulares insolúveis (PEI) além da microbiota. Verificou-se a liberação de F, Ca e P de cada material e dos blocos de esmalte após ciclagem de pH. Após a verificação da homogeneidade dos dados, testes paramétricos e não-paramétricos foram realizados para análise dos resultados (p<0,05). O biofilme dentário formado sobre os materiais que liberam flúor apresentou maior presença de F, Ca e P e menor número de estreptococos do grupo mutans quando comparado ao bloco de esmalte. Após o uso da sacarose (7º dia), o pH do biofilme foi maior na presença do material ionomérico. O biofilme sobre o material que contém fosfato de cálcio amorfo mostrou similar concentração de Ca e P, quando comparado aos materiais que contém flúor, e uma ação tamponante no meio, sem efeito na microbiota. Concluiu-se que os materiais que liberam flúor aumentaram as concentrações de F, Ca e P e diminuíram a de PEI e a microbiota cariogênica do biofilme dentário; e o que contém fosfato de cálcio amorfo aumentou as concentrações de Ca e P / Abstract: The chemical and physical properties of the pit and fissures sealants have been widely evaluated but rare researches focus on the effects on dental plaque. The aim of this study was to evaluate the biochemical and microbiological characteristics of the in situ dental plaque formed on materials that release fluoride or calcium and phosphate. Ten volunteers wore an intraoral palatal device containing specimens of materials (Fuji IX GP, Auralay XF and Aegis) or bovine enamel blocks. The experimental phase consisted of 4 stages with duration of 8 days each and use of sucrose to form the dental plaque. The dental plaque pH was determined at the 7th day of the experimental periods and the dental plaque was collected at the 8th day to determine the fluoride (F), calcium (Ca), phosphorus (P), insoluble extracellular polysaccharides (EPS) and microbiota. It was observed release of F, Ca and P from each material and from the enamel blocks after pH cycling. After verification of data homogeneity, parametric and non-parametric tests were performed (p<0.05). The dental plaque formed on the materials that release fluoride presented more F, Ca and P and reduced number of Streptococcus mutans in comparison to the enamel block. After use of sucrose (7th day), the dental plaque pH was higher with the presence of ionomeric material. The dental plaque on the material containing amorphous calcium phosphate exhibited similar Ca and P concentration compared to the ones on fluoride materials, and buffering action with no effect on the microbiota. It was concluded that the materials that release fluoride increased F, Ca and P concentrations, decreased EPS concentration and the cariogenic microbiota of the dental plaque; the amorphous calcium phosphate material increased concentrations of Ca and P / Orientador: Denise Pedrini / Coorientador: Alberto Carlos Botazzo Delbem / Banca: Cleide Cristina Rodrigues Martinhon / Banca: Stella Kossatz Pereira / Mestre

Abstract The purpose of this study was to analyse the effectiveness and cost of fissure sealant treatment in preventing dental caries in children in a practice-based research network using survival analysis. The survival times of first permanent molars in children were analysed in three countries: in Finland (age cohorts 1970–1972 and 1980–1982), in Sweden (1980–1982) and in Greece (1980–1982), and additionally at two municipal health centres in Finland (age cohorts 1988–1990 in Kemi and 1990 in Vantaa). The study population comprised altogether 8 551 children. The data were collected manually from paper dental records (Finland, Sweden and Greece), and an automatic data-mining system for collecting data from electronic dental records was used in the case of the two health centres in Finland (Kemi and Vantaa). Comparisons of the survival times of first molars caries-free were performed between sealed and non-sealed individual teeth, and between the subjects in cases where a subject’s all first permanent molars were either sealed or non-sealed before the age of eight years. The cumulative costs of caries risk determination, use of xylitol, fissure sealant treatment, and restorations were calculated based on the data from the digital dental records of the health centres of Kemi and Vantaa. The results stressed the importance of caries-risk assessment on a tooth and subject level, when estimating the need for sealing treatment. Sealing of first molars of very high caries risk children (caries present in any of the permanent first molars before the age of eight years) seemed to be insufficient to prevent further dental decay later on. Instead, sealants were beneficial in caries prevention in medium-risk children (caries present in any of the permanent first molars between the ages of eight and ten years). Low-risk children (no caries in any of the permanent first molars before the age of ten years) did not benefit remarkably from sealant treatment. When sealant treatment were targeted only at high caries risk children based on risk-determination at the age of two years and all their permanent first molars were sealed (Kemi), their total treatment costs later were higher compared to the low-risk children, who were left unsealed. Significant differences in the survival curves of sealed and non-sealed first molars on a tooth and subject level confirmed that a translational approach is needed to study the effectiveness of preventive dental treatment in practice. The practice-based study model provides a good overview on the situation in real-life circumstances and helps to incorporate the evidence-based dentistry study results into everyday dental practice. / Tiivistelmä Tutkimuksen tarkoituksena oli analysoida fissuurapinnoituksen tehokkuutta ja kustannuksia lasten hammaskariesta ehkäisevänä toimenpiteenä käytäntöön perustuvan tutkimusmenetelmän ja elinkaarianalyysin avulla. Ensimmäisten pysyvien poskihampaiden elinkaarianalyysi tehtiin Suomen (ikäkohortit 1970–1972 ja 1980–1982), Ruotsin (1980–1982) ja Kreikan (1980–1982) aineistojen sekä lisäksi kahden suomalaisen terveyskeskusaineiston (Kemi 1988–1990 and Vantaa 1990) perusteella. Tutkimusaineisto koostui yhteensä 8 551 lapsesta. Tutkimukseen tarvittavat tiedot kerättiin manuaalisesti potilaspapereista Suomen, Ruotsin ja Kreikan aineistoista sekä elektronisesti suoraan kahden suomalaisen terveyskeskuksen (Kemi ja Vantaa) digitaalisista potilastietojärjestelmistä. Ensimmäisten pysyvien poskihampaiden elinkaarikäyriä verrattiin pinnoitettujen ja pinnoittamattomien hampaiden sekä pinnoitettujen ja pinnoittamattomien henkilöiden (kaikki neljä pysyvää ensimmäistä poskihammasta joko pinnoitettu tai pinnoittamatta kahdeksanteen ikävuoteen mennessä) välillä. Kumulatiiviset kustannukset karieksen riskimäärityksestä, ksylitolin käytöstä, pinnoituksista ja täytteistä laskettiin Kemin ja Vantaan terveyskeskusaineistojen perusteella. Tutkimuksen tulokset korostavat riskimäärityksen tärkeyttä pinnoituspäätöksen tekemisessä sekä hammaskohtaisesti että potilaskohtaisesti. Korkean kariesriskin lapsille (kariesta yhdessä tai useammassa ensimmäisessä pysyvässä poskihampaassa ennen kahdeksatta ikävuotta) pinnoitusten teho näytti olevan riittämätön estämään karieksen kehittymisen myöhemmällä iällä. Pinnoitukset olivat tehokkaita keskisuuren kariesriskin (kariesta yhdessä tai useammassa ensimmäisessä pysyvässä poskihampaassa kahdeksan ja kymmenen ikävuoden välillä) lapsilla. Matalan kariesriskin lapset (ei kariesta yhdessäkään ensimmäisessä pysyvässä poskihampaassa ennen kymmenettä ikävuotta) eivät hyötyneet merkittävästi pinnoitteiden kariesta ehkäisevästä vaikutuksesta. Kun pinnoitteet kohdennettiin valikoidusti lapsille joilla oli kahden vuoden iässä todettu korkea kariesriski ja heidän kaikki ensimmäiset pysyvät poskihampaat pinnoitettiin (Kemi), heidän osaltaan kokonaishoidosta seuranneet kustannukset myöhemmin olivat korkeampia verrattuna lapsiin joilla oli matala kariesriski ja joiden hampaita ei pinnoitettu. Pinnoitettujen ja pinnoittamattomien ensimmäisten pysyvien poskihampaiden hammas- ja henkilökohtaisten elinkaarikäyrien tilastolliset erot tutkituissa kohorteissa osoittavat, että käytäntöön perustuva tutkimusmenetelmä on suositeltava analysoitaessa hammashoidon tehokkuutta jokapäiväisessä toiminnassa. Käytäntöön perustuva tutkimusmalli antaa hyvän käsityksen todellisissa hoito-olosuhteissa tehtyjen toimenpiteiden tehokkuudesta ja avaa siihen uuden näkökulman sekä edesauttaa soveltamaan näyttöön perustuvan hammaslääketieteen tutkimustuloksia jokapäiväiseen hammaslääkärintyöhön vastaanotolla.

Indiana University-Purdue University Indianapolis (IUPUI) / Occlusal pits and fissures are ideal places for caries development. Placement of dental sealants has been reported to be effective in preventing this process. However, the effectiveness of dental sealants has been reported to be influenced by clinical factors, such as preparation and placement techniques. A report recently published by the American Dental Association on the clinical recommendations for use of pit-and-fissure sealants included critical evaluation and a summary of relevant scientific evidence on the use of sealants aimed at assisting clinicians. The report addressed concerns such as: Does placing sealants over early (noncavitated) lesions prevent progression of the lesions? Are there any techniques that could improve sealants’ retention and ffectiveness in caries prevention? The investigators concluded that there is limited and conflicting evidence to support that mechanical preparation with a bur results in higher retention rates in children and recommend that pit-and-fissure sealants should be placed on early (noncavitated) carious lesions. The purpose of this in vitro study was to evaluate two methods of fissure treatment before sealant placement on different caries levels. In this study, 135 extracted human molars (ICDAS codes 0 to 2) were collected and ranked by a calibrated examiner into three groups. These were further divided into three subgroups (nine total). Occlusal surfaces were prepared with: 1) a ¼-mm round bur, 2) air abrasion, and 3) no treatment as a control. All groups were etched with 3.0- percent phosphoric acid for 15 seconds, rinsed thoroughly, and dried with an air water syringe. Opaque dental sealants were placed on the etched occlusal surfaces according to the accepted clinical standards and light-cured for 30 seconds. All groups were thermocycled for 5000 cycles. The roots of the teeth were painted with nail varnish, root apices were sealed with wax, and the occlusal surfaces were immersed in 1.0-percent methylene blue for a full 24 hours. The next day the teeth were cleaned, and the roots were sectioned to expose the crowns. Crowns were cut along the occlusal surfaces in the buccolingual direction. The sectioned surfaces were examined under the Nikon SMZ 1500 microscope for sealant penetration in the fissure and microleakage along the sealant enamel interface. The analyses were performed on a transformation of the sealant penetration percentage commonly used for calculated percentages: sin-1(p1/2). The effects of the type of group, the ICDAS code, and the fissure type on sealant penetration percentage were compared using ANOVA. The effects on microleakage and bubbles were compared using GEE methods applied to logistic regression. The effects on dye penetration were compared using GEE methods applied to cumulative logistic regression to account for the ordered categories of the dye penetration scale. In the findings of sealant penetration, the group type did not have a significant effect on sealant penetration (p = 0.195). ICDAS codes had a significant effect on sealant penetration (p = 0.0113) where ICDAS Code 0 had greater penetration than ICDAS codes 1 and 2. Fissure type had a significant effect on sealant penetration (p = 0.0001) where fissure types V and U had greater sealant penetration than Fissure types Y and W. In the findings of microleakage, the type of group had a significant effect on microleakage (p = 0.0004) where the abrasion group had increased microleakage as compared with the 1/4 round bur and control groups. ICDAS code had a significant effect on microleakage (p = 0.0022) where ICDAS code 0 had less microleakage as compared with ICDAS code 1 and 2. Fissure types V, U, Y, and W did not have a significant effect on microleakage (p = 0.721).

Este estudo in situ avaliou em esmalte bovino desmineralizado, submetido ou não a um desafio cariogênico, os efeitos de um cimento de ionômero de vidro de alta viscosidade (CIVav) e de um selante resinoso, comparativamente a um controle (sem selamento). Doze voluntários usaram dispositivos intrabucais palatinos (DIP) contendo 12 blocos de esmalte bovino desmineralizado, fixados dois a dois para simular uma fissura em V, a qual foi selada com um dos materiais: CIVav (Ketac, Molar Easymix), selante resinoso (Delton) ou controle (sem selamento). Metade dos espécimes foi submetida ao acúmulo de biofilme, recebendo oito aplicações diárias de sacarose a 20% para provocar um desafio cariogênico, além de outras três, de solução de dentifrício fluoretado (1 g : 3 mL), enquanto a outra metade não sofreu acúmulo de biofilme, mas também recebeu o dentifrício. Após 14 dias, foram avaliadas as concentrações de flúor no biofilme e no esmalte, bem como o conteúdo mineral (microdureza em secção longitudinal). Os dados obtidos foram analisados estatisticamente ('alfa'= 5%). O teste Friedman ANOVA revelou que a concentração de flúor no biofilme foi estatisticamente maior com o uso do CIVav, em comparação ao selante resinoso e ao controle. A ANOVA e o teste de Tukey constataram que houve maior concentração de flúor no esmalte associado ao CIVav, sobretudo na ausência de desafio cariogênico, enquanto o selante resinoso e controle foram semelhantes. Em relação ao conteúdo mineral, a ANOVA e o teste de Tukey detectaram diferenças entre os grupos na camada mais superficial do esmalte. Com desafio cariogênico, o conteúdo mineral foi sempre maior no esmalte associado ao CIVav do que naquele associado ao selante resinoso, sendo que o controle apresentou resultados intermediários. Sem o desafio cariogênico, houve uma tendência de um maior conteúdo mineral no grupo controle. Os resultados sugerem que o CIVav, aplicado sobre uma superfície desmineralizada e sob desafio cariogênico, demonstrou um potencial cariostático pela sua capacidade de doar flúor à estrutura e ao biofilme dentários, minimizando os efeitos da desmineralização, mas não melhorou a remineralização. / This in situ study evaluated on demineralized bovine enamel, submitted or not to a cariogenic challenge (dental biofilm), the effects of a high viscosity glass ionomer cement (HV-GIC) and a resin sealant in comparison with a control group (without sealing). Twelve volunteers wore a palatal appliance containing 12 blocks of demineralized bovine enamel mounted (2 by 2) to simulate a fissure in a V shape and sealed with: HV-GIC (Ketac? Molar Easymix), resin sealant (Delton) or maintained with no sealing material (control). Half of specimens was submitted to a cariogenic challenge by dripping a 20% sucrose solution 8 times/day besides a fluoride dentifrice solution (1 g : 3 mL) 3 times/day. The others specimens only received a dentifrice solution. After 14 days, the concentration of fluoride in dental biofilm and enamel was evaluated as well as the mineral content (cross-sectional microhardness) of the enamel. The concentration of fluoride in dental biofilm was higher with HV-GIC (Friedman ANOVA, p<0.05) in comparison with resin sealant and control group. The concentration of loosely-bound fluoride on enamel was significant (ANOVA and Tukey test, p< 0.05) specially without a cariogenic challenge for HVGIC, while it was similar for the resin sealant and control group. Concerning the mineral content, ANOVA and Tukey test (p<0.05) detected differences among the groups on the superficial layers of the enamel. Under the dental biofilm influence the mineral content was always higher on the enamel associated with HV-GIC than with resin sealant and the control group presented intermediary results. Without dental biofilm the control group presented a tendency of a higher mineral content. The results suggest that HV-GIC applied on a demineralized surface and under the dental biofilm influence has shown a cariostatic potential by its ability to give fluoride to the dental structure and biofilm reducing the demineralization effects.

Made available in DSpace on 2014-12-17T15:43:54Z (GMT). No. of bitstreams: 1 CeliaAAS_DISSERT.pdf: 2988608 bytes, checksum: 5a7fdda483527741ad6df9d2c47ad611 (MD5) Previous issue date: 2013-08-23 / Among the non-invasive techniques employed in the prevention of caries highlights the sealing pits and fissures which is a conservative maneuver, in order to obliterate them to protect them from attack acid bacteria. Influenced by the studies of pre-heating composite resin, which has experienced great improvement in some of their physical properties, this study aimed to evaluate in vitro the superficial and internal marginal adaptation of different materials and sealants in pre-heating or not. A total of 40 extracted human third molars (n=10) that had their occlusal surfaces prepared to receive sealant. We tested two types of sealing materials: resin sealant (Fluoroshield) and low-viscosity resin (Permaflo), where 50% of previously received heated material and the other half received sealant material at room temperature. All samples were subjected to thermal cycling and pH, simulating a cariogenic oral environment, and later were analyzed appliance OCT (optical coherence tomography). The images obtained alterations were recorded and analyzed statistically. Change was considered as the emergence of bubbles, gaps and cracks in the sealant. Comparisons of the same material, assessing the fact that it is not sealed or preheated material, as well as comparisons between different materials subjected to the same temperature were carried out. The nonparametric Tukey test was used (p < 0,05). The results showed that there was statistically significant difference between both the materials analyzed, as between the situations in which the sealant material was submitted (preheated or not). On the issue of marginal adaptation and internal surface, seen through Optical coherence tomography, may suggest that there is a difference between the use of one type or another of the sealing material analyzed, with superiority attributed to resin Permaflo compared to sealant Fluroshield, telling is the same for the different techniques used / O selamento de f?ssulas e fissuras destaca-se entre as t?cnicas n?o invasivas empregadas na preven??o de c?ries. Consiste em uma manobra conservadora que as oblitera e protege da destrui??o dos ?cidos bacterianos. Influenciado pelos estudos de pr?-aquecimento das resinas compostas, em que se observou grande melhora em algumas de suas propriedades f?sicas, este trabalho objetivou analisar, in vitro, a adapta??o marginal superficial e interna de diferentes materiais seladores e em situa??es de pr? aquecimento ou n?o. Foram utilizados 40 terceiros molares humanos extra?dos (n=10), os quais tiveram suas superf?cies oclusais preparadas para receber o material selador. Foram testados dois tipos de materiais seladores: selante resinoso (Fluoroshield) e resina de baixa viscosidade (Permaflo). Dentre estes, 50% recebeu material aquecido previamente e a outra metade recebeu material selador em temperatura ambiente. Todas as amostras foram submetidas ? Ciclagem T?rmica e de pH, simulando um ambiente oral cariog?nico. Em seguida foram analisadas em aparelho de OCT (Tomografia de coer?ncia ?tica). As imagens obtidas tiveram suas altera??es registradas e analisadas estatisticamente. Como altera??o foi considerado o surgimento de bolhas e fendas. Compara??es para o mesmo material, avaliando o fato do mesmo ser ou n?o selado com material pr? aquecido, bem como compara??es entre os diferentes materiais submetidos ? mesma temperatura, foram realizadas. O teste n?o param?trico de Tukey foi empregado (p<0,05). Os resultados mostraram ter havido diferen?a estatisticamente significativa tanto entre os materiais analisados, como entre as situa??es em que o material selador foi submetido (pr? aquecido ou n?o). No quesito adapta??o marginal superficial e interna, visto atrav?s de Tomografia de Coer?ncia ?tica, pode-se sugerir que h? diferen?a entre o uso de um tipo ou outro dos materiais seladores analisados, com superioridade atribu?da ? resina Permaflo em rela??o ao selante Fluroshield, dizendo-se o mesmo em rela??o ?s diferentes t?cnicas utilizadas

Este estudo in situ, desenvolvido em uma fase de 14 dias, teve como objetivo avaliar o efeito de dois cimentos de ionômero de vidro (CIV) comparados a um selante resinoso, utilizados para selamento de fossas e fissuras aplicados em esmalte bovino hígido, com acúmulo de biofilme dentário, por meio da análise do conteúdo de flúor do biofilme dentário e da microdureza em secção longitudinal. Foram utilizados 88 blocos de esmalte (4mm x 4mm) de incisivos bovinos, selecionados por seu valor de microdureza inicial. Os blocos formaram uma fissura artificial em forma de \"V\" a qual foi selada, para compor os seguintes grupos: GI-CIVav (Ketac? Molar Easymix); GII-CIV modificado por resina (Vitremer?); GIII-selante resinoso sem flúor (Helioseal® Clear) ou GIV-controle, sem selamento. As fissuras artificiais foram fixadas em um dispositivo intrabucal palatino (DIP), em duas fileiras distintas que foram cobertas por uma tela plástica para favorecer o acúmulo de biofilme dentário. Onze voluntários utilizaram o DIP 24 h/dia; gotejaram 8x/dia, uma solução de sacarose a 20% e, uma solução de dentifrício fluoretado (3ml de água deionizada : 1g de dentifrício fluoretado) sobre todas as fissuras 3x/dia. Após o período experimental, coletou-se o biofilme acumulado para a avaliação do conteúdo de flúor. As fissuras foram seccionadas ao meio para a avaliação da microdureza em secção longitudinal a partir da superfície do esmalte, em 4 profundidades (10, 30, 50, 70 µm). O limite esmalte/material da região oclusal era a posição zero (borda do material) e, a partir deste, realizadas seqüências de impressões a 50, 150 e 500 µm interna e externamente à borda do material. Os dados obtidos foram analisados estatisticamente (a= 5%). O teste de Friedman revelou que a concentração de flúor no biofilme não foi estatisticamente significante entre os grupos, (p<0,07), com uma tendência de melhores resultados para o CIVav. Quanto ao conteúdo mineral, a ANOVA e o teste de Tukey detectaram significância (p<0,05) para todos os grupos individualmente, na camada mais superficial do esmalte (10 µm). Nesta profundidade, não houve diferença entre os grupos. Essas comparações foram válidas para a maioria das distâncias analisadas. / This in situ study, developed in a 14-day period, aimed to evaluate the effect of two glass ionomer cements (GIC) compared to a resin sealant, employed for pit and fissure sealing on intact bovine enamel, with accumulation of dental biofilm, by analysis of the fluoride content on the dental biofilm and longitudinal microhardness. Eighty-eight enamel blocks (4mm x 4mm) of bovine incisors were employed, selected according to their initial microhardness value. The blocks formed a V-shaped artificial fissure that was sealed, constituting the following groups: GI - high-viscosity conventional GIC (Ketac? Molar Easymix); GII - resin-modified GIC (Vitremer?); GIII - resin sealant without fluoride (Helioseal? Clear); and GIV - control, without sealing. The artificial fissures were fixated on a palatal plate (PP), in two distinct rows, which were covered with a plastic screen to favor the accumulation of dental biofilm. Eleven volunteers employed the PP for 24h/day, dripped a 20% sucrose solution 8 times a day, and used a fluoridated dentifrice solution (3ml of deionized water : 1g of fluoridated dentifrice) on all fissures 3 times a day. After the study period, the accumulated biofilm was collected for evaluation of the fluoride content. The fissures were sectioned through the middle for evaluation of longitudinal microhardness from the enamel surface, at 4 depths (10, 30, 50, 70 µm). The enamel/material limit at the occlusal region was the zero position (material margin); from this point, indents were sequentially performed at 50, 150 and 500 µm internally and externally to the material margin. Data were statistically analyzed (a = 5%). The Friedman test revealed that the fluoride concentration in the biofilm was not statistically significantly different among groups (p<0.07), yet there was a tendency of better outcomes for the high-viscosity conventional GIC. With regard to the mineral content, the ANOVA and Tukey test revealed significance (p<0.05) for all groups individually, at the most superficial enamel layer (10 µm). At this depth, there was no difference among groups. These comparisons were valid for most distances analyzed..

Made available in DSpace on 2014-06-11T19:27:47Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-02-24Bitstream added on 2014-06-13T18:56:30Z : No. of bitstreams: 1 ferreira_l_me_araca.pdf: 1328677 bytes, checksum: e8654f5c6e3eb77d8eb2d430f398667d (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Muito tem se avaliado a respeito das propriedades físicas e químicas dos selantes de fóssulas e fissuras, mas pouco sobre seus efeitos no biofilme dentário. O objetivo deste estudo foi analisar as características bioquímicas e microbiológicas do biofilme dentário formado in situ sobre materiais que liberam flúor ou cálcio e fosfato. Dez voluntários utilizaram dispositivo intrabucal palatino contendo corpos-de-prova de materiais (Fuji IX GP, Auralay XF e Aegis) ou blocos de esmalte bovino. A fase experimental consistiu de 4 etapas de 8 dias cada e a utilização de sacarose para formação do biofilme. No 7º dia dos períodos experimentais foi determinado o pH do biofilme e no 8º dia, o biofilme dentário formado foi coletado para determinação de flúor (F), cálcio (Ca), fósforo (P) e polissacarídeos extracelulares insolúveis (PEI) além da microbiota. Verificou-se a liberação de F, Ca e P de cada material e dos blocos de esmalte após ciclagem de pH. Após a verificação da homogeneidade dos dados, testes paramétricos e não-paramétricos foram realizados para análise dos resultados (p<0,05). O biofilme dentário formado sobre os materiais que liberam flúor apresentou maior presença de F, Ca e P e menor número de estreptococos do grupo mutans quando comparado ao bloco de esmalte. Após o uso da sacarose (7º dia), o pH do biofilme foi maior na presença do material ionomérico. O biofilme sobre o material que contém fosfato de cálcio amorfo mostrou similar concentração de Ca e P, quando comparado aos materiais que contém flúor, e uma ação tamponante no meio, sem efeito na microbiota. Concluiu-se que os materiais que liberam flúor aumentaram as concentrações de F, Ca e P e diminuíram a de PEI e a microbiota cariogênica do biofilme dentário; e o que contém fosfato de cálcio amorfo aumentou as concentrações de Ca e P / The chemical and physical properties of the pit and fissures sealants have been widely evaluated but rare researches focus on the effects on dental plaque. The aim of this study was to evaluate the biochemical and microbiological characteristics of the in situ dental plaque formed on materials that release fluoride or calcium and phosphate. Ten volunteers wore an intraoral palatal device containing specimens of materials (Fuji IX GP, Auralay XF and Aegis) or bovine enamel blocks. The experimental phase consisted of 4 stages with duration of 8 days each and use of sucrose to form the dental plaque. The dental plaque pH was determined at the 7th day of the experimental periods and the dental plaque was collected at the 8th day to determine the fluoride (F), calcium (Ca), phosphorus (P), insoluble extracellular polysaccharides (EPS) and microbiota. It was observed release of F, Ca and P from each material and from the enamel blocks after pH cycling. After verification of data homogeneity, parametric and non-parametric tests were performed (p<0.05). The dental plaque formed on the materials that release fluoride presented more F, Ca and P and reduced number of Streptococcus mutans in comparison to the enamel block. After use of sucrose (7th day), the dental plaque pH was higher with the presence of ionomeric material. The dental plaque on the material containing amorphous calcium phosphate exhibited similar Ca and P concentration compared to the ones on fluoride materials, and buffering action with no effect on the microbiota. It was concluded that the materials that release fluoride increased F, Ca and P concentrations, decreased EPS concentration and the cariogenic microbiota of the dental plaque; the amorphous calcium phosphate material increased concentrations of Ca and P

Este estudo in situ avaliou em esmalte bovino desmineralizado, submetido ou não a um desafio cariogênico, os efeitos de um cimento de ionômero de vidro de alta viscosidade (CIVav) e de um selante resinoso, comparativamente a um controle (sem selamento). Doze voluntários usaram dispositivos intrabucais palatinos (DIP) contendo 12 blocos de esmalte bovino desmineralizado, fixados dois a dois para simular uma fissura em V, a qual foi selada com um dos materiais: CIVav (Ketac, Molar Easymix), selante resinoso (Delton) ou controle (sem selamento). Metade dos espécimes foi submetida ao acúmulo de biofilme, recebendo oito aplicações diárias de sacarose a 20% para provocar um desafio cariogênico, além de outras três, de solução de dentifrício fluoretado (1 g : 3 mL), enquanto a outra metade não sofreu acúmulo de biofilme, mas também recebeu o dentifrício. Após 14 dias, foram avaliadas as concentrações de flúor no biofilme e no esmalte, bem como o conteúdo mineral (microdureza em secção longitudinal). Os dados obtidos foram analisados estatisticamente ('alfa'= 5%). O teste Friedman ANOVA revelou que a concentração de flúor no biofilme foi estatisticamente maior com o uso do CIVav, em comparação ao selante resinoso e ao controle. A ANOVA e o teste de Tukey constataram que houve maior concentração de flúor no esmalte associado ao CIVav, sobretudo na ausência de desafio cariogênico, enquanto o selante resinoso e controle foram semelhantes. Em relação ao conteúdo mineral, a ANOVA e o teste de Tukey detectaram diferenças entre os grupos na camada mais superficial do esmalte. Com desafio cariogênico, o conteúdo mineral foi sempre maior no esmalte associado ao CIVav do que naquele associado ao selante resinoso, sendo que o controle apresentou resultados intermediários. Sem o desafio cariogênico, houve uma tendência de um maior conteúdo mineral no grupo controle. Os resultados sugerem que o CIVav, aplicado sobre uma superfície desmineralizada e sob desafio cariogênico, demonstrou um potencial cariostático pela sua capacidade de doar flúor à estrutura e ao biofilme dentários, minimizando os efeitos da desmineralização, mas não melhorou a remineralização. / This in situ study evaluated on demineralized bovine enamel, submitted or not to a cariogenic challenge (dental biofilm), the effects of a high viscosity glass ionomer cement (HV-GIC) and a resin sealant in comparison with a control group (without sealing). Twelve volunteers wore a palatal appliance containing 12 blocks of demineralized bovine enamel mounted (2 by 2) to simulate a fissure in a V shape and sealed with: HV-GIC (Ketac? Molar Easymix), resin sealant (Delton) or maintained with no sealing material (control). Half of specimens was submitted to a cariogenic challenge by dripping a 20% sucrose solution 8 times/day besides a fluoride dentifrice solution (1 g : 3 mL) 3 times/day. The others specimens only received a dentifrice solution. After 14 days, the concentration of fluoride in dental biofilm and enamel was evaluated as well as the mineral content (cross-sectional microhardness) of the enamel. The concentration of fluoride in dental biofilm was higher with HV-GIC (Friedman ANOVA, p<0.05) in comparison with resin sealant and control group. The concentration of loosely-bound fluoride on enamel was significant (ANOVA and Tukey test, p< 0.05) specially without a cariogenic challenge for HVGIC, while it was similar for the resin sealant and control group. Concerning the mineral content, ANOVA and Tukey test (p<0.05) detected differences among the groups on the superficial layers of the enamel. Under the dental biofilm influence the mineral content was always higher on the enamel associated with HV-GIC than with resin sealant and the control group presented intermediary results. Without dental biofilm the control group presented a tendency of a higher mineral content. The results suggest that HV-GIC applied on a demineralized surface and under the dental biofilm influence has shown a cariostatic potential by its ability to give fluoride to the dental structure and biofilm reducing the demineralization effects.

Este estudo in situ, desenvolvido em uma fase de 14 dias, teve como objetivo avaliar o efeito de dois cimentos de ionômero de vidro (CIV) comparados a um selante resinoso, utilizados para selamento de fossas e fissuras aplicados em esmalte bovino hígido, com acúmulo de biofilme dentário, por meio da análise do conteúdo de flúor do biofilme dentário e da microdureza em secção longitudinal. Foram utilizados 88 blocos de esmalte (4mm x 4mm) de incisivos bovinos, selecionados por seu valor de microdureza inicial. Os blocos formaram uma fissura artificial em forma de \"V\" a qual foi selada, para compor os seguintes grupos: GI-CIVav (Ketac? Molar Easymix); GII-CIV modificado por resina (Vitremer?); GIII-selante resinoso sem flúor (Helioseal® Clear) ou GIV-controle, sem selamento. As fissuras artificiais foram fixadas em um dispositivo intrabucal palatino (DIP), em duas fileiras distintas que foram cobertas por uma tela plástica para favorecer o acúmulo de biofilme dentário. Onze voluntários utilizaram o DIP 24 h/dia; gotejaram 8x/dia, uma solução de sacarose a 20% e, uma solução de dentifrício fluoretado (3ml de água deionizada : 1g de dentifrício fluoretado) sobre todas as fissuras 3x/dia. Após o período experimental, coletou-se o biofilme acumulado para a avaliação do conteúdo de flúor. As fissuras foram seccionadas ao meio para a avaliação da microdureza em secção longitudinal a partir da superfície do esmalte, em 4 profundidades (10, 30, 50, 70 µm). O limite esmalte/material da região oclusal era a posição zero (borda do material) e, a partir deste, realizadas seqüências de impressões a 50, 150 e 500 µm interna e externamente à borda do material. Os dados obtidos foram analisados estatisticamente (a= 5%). O teste de Friedman revelou que a concentração de flúor no biofilme não foi estatisticamente significante entre os grupos, (p<0,07), com uma tendência de melhores resultados para o CIVav. Quanto ao conteúdo mineral, a ANOVA e o teste de Tukey detectaram significância (p<0,05) para todos os grupos individualmente, na camada mais superficial do esmalte (10 µm). Nesta profundidade, não houve diferença entre os grupos. Essas comparações foram válidas para a maioria das distâncias analisadas. / This in situ study, developed in a 14-day period, aimed to evaluate the effect of two glass ionomer cements (GIC) compared to a resin sealant, employed for pit and fissure sealing on intact bovine enamel, with accumulation of dental biofilm, by analysis of the fluoride content on the dental biofilm and longitudinal microhardness. Eighty-eight enamel blocks (4mm x 4mm) of bovine incisors were employed, selected according to their initial microhardness value. The blocks formed a V-shaped artificial fissure that was sealed, constituting the following groups: GI - high-viscosity conventional GIC (Ketac? Molar Easymix); GII - resin-modified GIC (Vitremer?); GIII - resin sealant without fluoride (Helioseal? Clear); and GIV - control, without sealing. The artificial fissures were fixated on a palatal plate (PP), in two distinct rows, which were covered with a plastic screen to favor the accumulation of dental biofilm. Eleven volunteers employed the PP for 24h/day, dripped a 20% sucrose solution 8 times a day, and used a fluoridated dentifrice solution (3ml of deionized water : 1g of fluoridated dentifrice) on all fissures 3 times a day. After the study period, the accumulated biofilm was collected for evaluation of the fluoride content. The fissures were sectioned through the middle for evaluation of longitudinal microhardness from the enamel surface, at 4 depths (10, 30, 50, 70 µm). The enamel/material limit at the occlusal region was the zero position (material margin); from this point, indents were sequentially performed at 50, 150 and 500 µm internally and externally to the material margin. Data were statistically analyzed (a = 5%). The Friedman test revealed that the fluoride concentration in the biofilm was not statistically significantly different among groups (p<0.07), yet there was a tendency of better outcomes for the high-viscosity conventional GIC. With regard to the mineral content, the ANOVA and Tukey test revealed significance (p<0.05) for all groups individually, at the most superficial enamel layer (10 µm). At this depth, there was no difference among groups. These comparisons were valid for most distances analyzed..

Background: The light-cured resin-based pit and fissure sealants success and longevity are enhanced by sufficient curing. Multiple emission peak Light Emitting Diode Light Curing Units offer a wider range of wavelengths and different levels of irradiances to ensure sufficient curing.The irradiance is considered a main curing factor that can affect the material properties. Purpose: The aim of this study was to assess the effect of different settings of a multiwave LED LCU on the degree of conversion and microhardness of a pit and fissure sealant comparing the irradiance of 1000 mW/cm2 to 1400 mW/cm2 and 3200 mW/cm2 irradiances of the LCU using manufacturer’s guidelines for curing times at 2, 4 and, 6 mm distances. Methods: A multiwave LED light curing unit was evaluated on three different irradiance levels 1000 mW/cm2 (S), 1400 mW/cm2 (H), and 3200 mW/cm2 (X). A total of 90 samples made from the fissure sealant were fabricated and divided into eighteen groups (n=5/group). Samples were cured following manufacturer’s guidelines of curing times for each curing mode at 2, 4, or 6 mm distance between the light tip and top of samples. The DC was measured using (ATR-FTIR) spectroscopy. The KHN test was performed on five different locations of each specimen using a hardness tester (Leco LM247AT, MI, USA, software; Confident V 2.5.2). Results: The top DC for H-8 was significantly higher than S-10 at 2 and 4mm, H-20 DC was significantly lower than S-30 at only 2mm. The bottom DC for H-8 was significantly higher than S-10 at 2mm only, H-20 DC was significantly lower than S-30 at 4 and 6mm only. H-8 KHN at top surface was significantly lower than S-10 at 2mm only, H-20 was significantly lower than S-30 at 2 and 6mm only. H-8 KHN at bottom surface was significantly lower than S-10 at 4 and 6mm but significantly higher at 2mm. H-20 was significantly lower than S-30 at 2mm but significantly higher at 4 and 6mm. The top DC for X-3 was significantly lower than S-10 at all curing distances with no significant difference at all curing distances between X-9 and S-30. The bottom DC for X-3 was significantly higher than S-10 at all curing distances with no significant difference between X-9 and S-30. X-3 KHN at top surface was significantly lower than S-10s at all curing distances. X-9 was significantly lower than S-30 at 6mm only. X-3 KHN at bottom surface was significantly lower than S-10 at 2 and 4mm only with no significant difference at all curing distances between X-9 and S-30. Conclusions: Using a multiwave LED LCU to polymerize Delton Opaque resin-based fissure sealants will result in an optimal DC and KHN values for any irradiance level if the curing distance is kept at 4 mm or less and with at least two cycles of the shortest curing time recommended by the manufacturer. Using a multiwave LED LCU with 1000, 1400 or 3200 mW/cm2 irradiance levels with shortest curing times recommended resulted in unsatisfactory DC and KHN levels. LED LCU with high and extra high irradiance levels (1400 and 3200 mW/cm2) can result in high DC and KHN levels when used adequately. Xtra Power mode (3200 mW/cm2) used on shortest curing time (3 seconds) resulted in significantly lower mechanical properties and for that reason it is not recommended to be used.