Effects of fluoride concentration and temperature of milk on caries lesion rehardening

Objectives The aim of the present in vitro study was to investigate the effects of fluoride concentration and temperature of milk on caries lesion rehardening under pH cycling conditions. Methods Incipient caries-like lesions were formed in human enamel specimens, characterized using Vickers surface microhardness (VHN) and assigned to seven treatment groups (n = 18 per group): fluoride was tested at five levels (0, 2.5, 5, 10, 20 mg/l, all 22 °C) and milk temperature at three levels (4, 22, 60 °C), but only for 10 mg/l F. Lesions were pH cycled for 15d (4×/daily 10 min milk treatments, 1×/daily 4 h acid challenge, remineralization in human/artificial saliva mixture). VHN of specimens were measured again and changes from lesion baseline were calculated. Subsequently, enamel fluoride uptake (EFU) was determined using the micro drill technique. Results Lesions responded to fluoride in a dose–response manner with higher fluoride concentrations resulting in more lesion rehardening (20 > 10 ≥ 5 ≥ 2.5 > 0 mg/l F). Furthermore, fluoridated milk at 60 °C was found to be more efficacious than at 4 °C (60 ≥ 22 > 4 °C). EFU results were similar (20 > 10 > 5 > 2.5 ≥ 0 mg/l F; 60 > 22 ≥ 4 °C). Conclusions Both fluoride concentration and milk temperature are likely to contribute to the anti-caries potential of fluoridated milk

Acceptance of Behavior Guidance Techniques Used in Pediatric Dentistry by Parents From Diverse Backgrounds

Objective. To investigate if parental background affects acceptance of behavior guidance techniques. Background. Behavior guidance techniques are used for the safe and effective treatment of pediatric patients. Acceptance of these techniques may vary by racial and ethnic background. Methods. A total of 142 parents were recruited and asked to rate videos showing: active restraint/protective stabilization (AR), general anesthesia (GA), nitrous oxide sedation (N2O), oral premedication/sedation (OP), passive restraint/protective stabilization (PR), tell-show-do (TSD), and voice control (VC) techniques. Results. Hispanic parents rated VC most acceptable, followed by TSD, PR, and pharmacologic techniques. Black and white parents rated TSD, followed by N2O, as most acceptable, and AR and PR as least favorable. Hispanics found GA significantly less acceptable than whites or blacks. Hispanics were less accepting of AR than blacks; but more accepting of PR than whites. TSD was highly rated among all 3 cohorts. Parental background affected acceptance of the techniques in this study

Relationship between enamel fluorosis severity and fluoride content

OBJECTIVES: Enamel fluorosis is a hypomineralization caused by chronic exposure to high levels of fluoride during tooth development. Previous research on the relationship between enamel fluoride content and fluorosis severity has been equivocal. The current study aimed at comparing visually and histologically assessed fluorosis severity with enamel fluoride content. METHODS: Extracted teeth (n=112) were visually examined using the Thylstrup and Fejerskov Index for fluorosis. Eruption status of each tooth was noted. Teeth were cut into 100 μm slices to assess histological changes with polarized light microscopy. Teeth were categorized as sound, mild, moderate, or severe fluorosis, visually and histologically. They were cut into squares (2 × 2 mm) for the determination of fluoride content (microbiopsy) at depths of 30, 60 and 90 μm from the external surface. RESULTS: Erupted teeth with severe fluorosis had significantly greater mean fluoride content at 30, 60 and 90 μm than sound teeth. Unerupted teeth with mild, moderate and severe fluorosis had significantly greater mean fluoride content than sound teeth at 30 μm; unerupted teeth with mild and severe fluorosis had significantly greater mean fluoride content than sound teeth at 60 μm, while only unerupted teeth severe fluorosis had significantly greater mean fluoride content than sound teeth at 90 μm. CONCLUSIONS: Both erupted and unerupted severely fluorosed teeth presented higher mean enamel fluoride content than sound teeth. CLINICAL SIGNIFICANCE: Data on fluoride content in enamel will further our understanding of its biological characteristics which play a role in the management of hard tissue diseases and conditions

An investigation into the potential anticaries benefits and contributions to mineral intake of bottled water

BACKGROUND: Bottled water has become the most consumed beverage in the United States. The authors aimed to inform the dental profession about the potential anticaries benefits of some bottled waters and to provide information about their possible contributions to fluoride, calcium, magnesium, sodium, and potassium intakes. METHODS: The authors chose a convenience sample by purchasing all different bottled waters from the main supermarkets operating in Indianapolis, Indiana. The authors analyzed the fluoride content using a fluoride ion-specific electrode and metal concentrations using atomic absorption spectroscopy. They used dietary reference intakes to calculate hypothetical intakes of all minerals. RESULTS: The authors identified 92 different bottled waters. Fluoride concentrations were generally low (mean, 0.11 parts per million [ppm]; median, 0.04 ppm). Only 2 waters contained more than 0.7 ppm fluoride (0.95 ppm and 1.22 ppm). Metal concentrations varied considerably among waters. Calcium concentrations ranged from less than 0.1 through 360 ppm (mean, 26.9 ppm; median, 5.2 ppm), which were greater than those of magnesium (range, < 0.01-106 ppm; mean, 7.5 ppm; median, 1.9 ppm), sodium (range, < 0.01-109 ppm; mean, 11.1 ppm; median, 2.9 ppm), and potassium (range, < 0.01-43 ppm; mean, 3.6 ppm; median, 1.2 ppm). Overall, most bottled waters do not contribute to adequate intakes of fluoride, potassium, or sodium or to recommended dietary allowances for calcium and magnesium. Nonetheless, some waters can provide meaningful contributions to fluoride, calcium, and magnesium intake. CONCLUSIONS: The fluoride concentration in 90 of the 92 studied bottled waters is insufficient to contribute to caries prevention. Only a few bottled waters can be considered health-promoting. PRACTICAL IMPLICATIONS: Dental professionals should consider the mineral content of water consumed by their patients during caries risk assessment

Fluoride in the diet of 2-years-old children

Objectives This study aimed to calculate the fluoride concentrations of commonly consumed foods and beverages for 2-years-old children utilizing market basket information for the US Midwest region. Methods Total Diet Study food lists were cross-referenced with National Health and Nutrition Examination Survey—What We Eat in America data to determine the foods and beverages to be included. Fluoride concentrations were determined using a modification of the hexamethyldisiloxane microdiffusion technique. Fluoride concentrations were summarized for each of the food categories. Daily dietary fluoride intake was estimated using a simulation analysis. Results Food and beverage fluoride concentrations varied widely, ranging from nondetectable for some oils and dairy products to more than 3.0 μgF/g food for some processed meats, fish and fruits. The estimated mean (±SD) daily dietary fluoride intake, excluding dentifrice and supplements, was 412±114 μgF/d. The estimated average ingestion for a 2-years-old weighing 12.24 kg was 0.034±0.009 mg/kg/d. A diet based on foods and beverages in the fifth percentile of fluoride intake distribution for an average child would result in 247 μgF/d or 0.020 mg/kg/d, while a diet with foods and beverages in the 95th percentile would result in a total intake of 622 μgF/d or 0.051 mg/kg/d. Conclusions The fluoride concentrations of foods and beverages vary widely, and, if items in the 95th percentile of fluoride intake distribution are ingested, children could consume more fluoride than the recommended 0.05 mg/kg/d. Fluoride intake calculated in this study was higher than historically reported dietary levels

Midwestern Latino caregivers’ knowledge, attitudes and sense making of the oral health etiology, prevention and barriers that inhibit their children’s oral health: a CBPR approach

Using community-based participatory research, the Health Protection Model was used to understand the cultural experiences, attitudes, knowledge and behaviors surrounding caries etiology, its prevention and barriers to accessing oral health care for children of Latino parents residing in Central Indiana

Long-term thermal sensitivity of Earth’s tropical forests

The sensitivity of tropical forest carbon to climate is a key uncertainty in predicting global climate change. Although short-term drying and warming are known to affect forests, it is unknown if such effects translate into long-term responses. Here, we analyze 590 permanent plots measured across the tropics to derive the equilibrium climate controls on forest carbon. Maximum temperature is the most important predictor of aboveground biomass (−9.1 megagrams of carbon per hectare per degree Celsius), primarily by reducing woody productivity, and has a greater impact per °C in the hottest forests (>32.2°C). Our results nevertheless reveal greater thermal resilience than observations of short-term variation imply. To realize the long-term climate adaptation potential of tropical forests requires both protecting them and stabilizing Earth’s climate

Taking the pulse of Earth's tropical forests using networks of highly distributed plots

Tropical forests are the most diverse and productive ecosystems on Earth. While better understanding of these forests is critical for our collective future, until quite recently efforts to measure and monitor them have been largely disconnected. Networking is essential to discover the answers to questions that transcend borders and the horizons of funding agencies. Here we show how a global community is responding to the challenges of tropical ecosystem research with diverse teams measuring forests tree-by-tree in thousands of long-term plots. We review the major scientific discoveries of this work and show how this process is changing tropical forest science. Our core approach involves linking long-term grassroots initiatives with standardized protocols and data management to generate robust scaled-up results. By connecting tropical researchers and elevating their status, our Social Research Network model recognises the key role of the data originator in scientific discovery. Conceived in 1999 with RAINFOR (South America), our permanent plot networks have been adapted to Africa (AfriTRON) and Southeast Asia (T-FORCES) and widely emulated worldwide. Now these multiple initiatives are integrated via ForestPlots.net cyber-infrastructure, linking colleagues from 54 countries across 24 plot networks. Collectively these are transforming understanding of tropical forests and their biospheric role. Together we have discovered how, where and why forest carbon and biodiversity are responding to climate change, and how they feedback on it. This long-term pan-tropical collaboration has revealed a large long-term carbon sink and its trends, as well as making clear which drivers are most important, which forest processes are affected, where they are changing, what the lags are, and the likely future responses of tropical forests as the climate continues to change. By leveraging a remarkably old technology, plot networks are sparking a very modern revolution in tropical forest science. In the future, humanity can benefit greatly by nurturing the grassroots communities now collectively capable of generating unique, long-term understanding of Earth's most precious forests. Resumen Los bosques tropicales son los ecosistemas más diversos y productivos del mundo y entender su funcionamiento es crítico para nuestro futuro colectivo. Sin embargo, hasta hace muy poco, los esfuerzos para medirlos y monitorearlos han estado muy desconectados. El trabajo en redes es esencial para descubrir las respuestas a preguntas que trascienden las fronteras y los plazos de las agencias de financiamiento. Aquí mostramos cómo una comunidad global está respondiendo a los desafíos de la investigación en ecosistemas tropicales a través de diversos equipos realizando mediciones árbol por árbol en miles de parcelas permanentes de largo plazo. Revisamos los descubrimientos más importantes de este trabajo y discutimos cómo este proceso está cambiando la ciencia relacionada a los bosques tropicales. El enfoque central de nuestro esfuerzo implica la conexión de iniciativas locales de largo plazo con protocolos estandarizados y manejo de datos para producir resultados que se puedan trasladar a múltiples escalas. Conectando investigadores tropicales, elevando su posición y estatus, nuestro modelo de Red Social de Investigación reconoce el rol fundamental que tienen, para el descubrimiento científico, quienes generan o producen los datos. Concebida en 1999 con RAINFOR (Suramérica), nuestras redes de parcelas permanentes han sido adaptadas en África (AfriTRON) y el sureste asiático (T-FORCES) y ampliamente replicadas en el mundo. Actualmente todas estas iniciativas están integradas a través de la ciber-infraestructura de ForestPlots.net, conectando colegas de 54 países en 24 redes diferentes de parcelas. Colectivamente, estas redes están transformando nuestro conocimiento sobre los bosques tropicales y el rol de éstos en la biósfera. Juntos hemos descubierto cómo, dónde y porqué el carbono y la biodiversidad de los bosques tropicales está respondiendo al cambio climático y cómo se retroalimentan. Esta colaboración pan-tropical de largo plazo ha expuesto un gran sumidero de carbono y sus tendencias, mostrando claramente cuáles son los factores más importantes, qué procesos se ven afectados, dónde ocurren los cambios, los tiempos de reacción y las probables respuestas futuras mientras el clima continúa cambiando. Apalancando lo que realmente es una tecnología antigua, las redes de parcelas están generando una verdadera y moderna revolución en la ciencia tropical. En el futuro, la humanidad puede beneficiarse enormemente si se nutren y cultivan comunidades de investigadores de base, actualmente con la capacidad de generar información única y de largo plazo para entender los que probablemente son los bosques más preciados de la tierra. Resumo Florestas tropicais são os ecossistemas mais diversos e produtivos da Terra. Embora uma boa compreensão destas florestas seja crucial para o nosso futuro coletivo, até muito recentemente os esforços de medições e monitoramento foram amplamente desconexos. É essencial formarmos redes para obtermos respostas que transcendem fronteiras e horizontes de agências financiadoras. Neste estudo nós mostramos como uma comunidade global está respondendo aos desafios da pesquisa de ecossistemas tropicais, com equipes diversas medindo florestas, árvore por árvore, em milhares de parcelas monitoradas à longo prazo. Nós revisamos as maiores descobertas científicas deste trabalho, e mostramos também como este processo está mudando a ciência de florestas tropicais. Nossa abordagem principal envolve unir iniciativas de base a protocolos padronizados e gerenciamento de dados a fim de gerar resultados robustos em escalas ampliadas. Ao conectar pesquisadores tropicais e elevar seus status, nosso modelo de Rede de Pesquisa Social reconhece o papel-chave do produtor dos dados na descoberta científica. Concebida em 1999 com o RAINFOR (América do Sul), nossa rede de parcelas permanentes foi adaptada para África (AfriTRON) e Sudeste asiático (T-FORCES), e tem sido extensamente reproduzida em todo o mundo. Agora estas múltiplas iniciativas estão integradas através de uma infraestrutura cibernética do ForestPlots.net, conectando colegas de 54 países de 24 redes de parcelas. Estas iniciativas estão transformando coletivamente o entendimento das florestas tropicais e seus papéis na biosfera. Juntos nós descobrimos como, onde e por que o carbono e a biodiversidade da floresta estão respondendo às mudanças climáticas, e seus efeitos de retroalimentação. Esta duradoura colaboração pantropical revelou um grande sumidouro de carbono persistente e suas tendências, assim como tem evidenciado quais direcionadores são mais importantes, quais processos florestais são mais afetados, onde eles estão mudando, seus atrasos no tempo de resposta, e as prováveis respostas das florestas tropicais conforme o clima continua a mudar. Dessa forma, aproveitando uma notável tecnologia antiga, redes de parcelas acendem faíscas de uma moderna revolução na ciência das florestas tropicais. No futuro a humanidade pode se beneficiar incentivando estas comunidades basais que agora são coletivamente capazes de gerar conhecimentos únicos e duradouros sobre as florestas mais preciosas da Terra. Résume Les forêts tropicales sont les écosystèmes les plus diversifiés et les plus productifs de la planète. Si une meilleure compréhension de ces forêts est essentielle pour notre avenir collectif, jusqu'à tout récemment, les efforts déployés pour les mesurer et les surveiller ont été largement déconnectés. La mise en réseau est essentielle pour découvrir les réponses à des questions qui dépassent les frontières et les horizons des organismes de financement. Nous montrons ici comment une communauté mondiale relève les défis de la recherche sur les écosystèmes tropicaux avec diverses équipes qui mesurent les forêts arbre après arbre dans de milliers de parcelles permanentes. Nous passons en revue les principales découvertes scientifiques de ces travaux et montrons comment ce processus modifie la science des forêts tropicales. Notre approche principale consiste à relier les initiatives de base à long terme à des protocoles standardisés et une gestion de données afin de générer des résultats solides à grande échelle. En reliant les chercheurs tropicaux et en élevant leur statut, notre modèle de réseau de recherche sociale reconnaît le rôle clé de l'auteur des données dans la découverte scientifique. Conçus en 1999 avec RAINFOR (Amérique du Sud), nos réseaux de parcelles permanentes ont été adaptés à l'Afrique (AfriTRON) et à l'Asie du Sud-Est (T-FORCES) et largement imités dans le monde entier. Ces multiples initiatives sont désormais intégrées via l'infrastructure ForestPlots.net, qui relie des collègues de 54 pays à travers 24 réseaux de parcelles. Ensemble, elles transforment la compréhension des forêts tropicales et de leur rôle biosphérique. Ensemble, nous avons découvert comment, où et pourquoi le carbone forestier et la biodiversité réagissent au changement climatique, et comment ils y réagissent. Cette collaboration pan-tropicale à long terme a révélé un important puits de carbone à long terme et ses tendances, tout en mettant en évidence les facteurs les plus importants, les processus forestiers qui sont affectés, les endroits où ils changent, les décalages et les réactions futures probables des forêts tropicales à mesure que le climat continue de changer. En tirant parti d'une technologie remarquablement ancienne, les réseaux de parcelles déclenchent une révolution très moderne dans la science des forêts tropicales. À l'avenir, l'humanité pourra grandement bénéficier du soutien des communautés de base qui sont maintenant collectivement capables de générer une compréhension unique et à long terme des forêts les plus précieuses de la Terre. Abstrak Hutan tropika adalah di antara ekosistem yang paling produktif dan mempunyai kepelbagaian biodiversiti yang tinggi di seluruh dunia. Walaupun pemahaman mengenai hutan tropika amat penting untuk masa depan kita, usaha-usaha untuk mengkaji dan mengawas hutah-hutan tersebut baru sekarang menjadi lebih diperhubungkan. Perangkaian adalah sangat penting untuk mencari jawapan kepada soalan-soalan yang menjangkaui sempadan dan batasan agensi pendanaan. Di sini kami menunjukkan bagaimana sebuah komuniti global bertindak balas terhadap cabaran penyelidikan ekosistem tropika melalui penglibatan pelbagai kumpulan yang mengukur hutan secara pokok demi pokok dalam beribu-ribu plot jangka panjang. Kami meninjau semula penemuan saintifik utama daripada kerja ini dan menunjukkan bagaimana proses ini sedang mengubah bidang sains hutan tropika. Teras pendekatan kami memberi tumpuan terhadap penghubungan inisiatif akar umbi jangka panjang dengan protokol standar serta pengurusan data untuk mendapatkan hasil skala besar yang kukuh. Dengan menghubungkan penyelidik-penyelidik tropika dan meningkatkan status mereka, model Rangkaian Penyelidikan Sosial kami mengiktiraf kepentingan peranan pengasas data dalam penemuan saintifik. Bermula dengan pengasasan RAINFOR (Amerika Selatan) pada tahun 1999, rangkaian-rangkaian plot kekal kami kemudian disesuaikan untuk Afrika (AfriTRON) dan Asia Tenggara (T-FORCES) dan selanjutnya telah banyak dicontohi di seluruh dunia. Kini, inisiatif-inisiatif tersebut disepadukan melalui infrastruktur siber ForestPlots.net yang menghubungkan rakan sekerja dari 54 negara di 24 buah rangkaian plot. Secara kolektif, rangkaian ini sedang mengubah pemahaman tentang hutan tropika dan peranannya dalam biosfera. Kami telah bekerjasama untuk menemukan bagaimana, di mana dan mengapa karbon serta biodiversiti hutan bertindak balas terhadap perubahan iklim dan juga bagaimana mereka saling bermaklum balas. Kolaborasi pan-tropika jangka panjang ini telah mendedahkan sebuah sinki karbon jangka panjang serta arah alirannya dan juga menjelaskan pemandu-pemandu perubahan yang terpenting, di mana dan bagaimana proses hutan terjejas, masa susul yang ada dan kemungkinan tindakbalas hutan tropika pada perubahan iklim secara berterusan di masa depan. Dengan memanfaatkan pendekatan lama, rangkaian plot sedang menyalakan revolusi yang amat moden dalam sains hutan tropika. Pada masa akan datang, manusia sejagat akan banyak mendapat manfaat jika memupuk komuniti-komuniti akar umbi yang kini berkemampuan secara kolektif menghasilkan pemahaman unik dan jangka panjang mengenai hutan-hutan yang paling berharga di dunia

Effects of suplementation and calving season on preweaning growth of female crossbred calves

En un sistema de producción semi intensivo bajo condiciones de bosque sub-húmedo tropical y localizado en Venezuela, se utilizaron 30 becerras con predominio racial Holstein (H), Pardo Suizo (PS) y Mosaico (M) a objeto de evaluar el efecto de dos fuentes se suplementación alimenticia (1: Harina de maíz y 2: Alimento concentrado) y la época de nacimiento (húmeda y seca) sobre el crecimiento predestete. La cantidad de suplemento aportada a cada animal correspondió al 2% de su peso vivo. El análisis de varianza-covarianza por cuadrados mínimos incluyó los efectos del predominio racial, suplementación y época de nacimiento del animal. Variables como la ganancia diaria de peso vivo (GDP), incremento diario en perímetro torácico (IDPT), altura a la cruz (IDAC) altura a la cadera (IDAK) y longitud corporal (IDLC) fueron afectados por el tipo de suplementación (P <.05), siendo favorecidas las becerras suplementadas con alimento concentrado. Toda las variables a excepción del IDLC fueron afectadas por la época de nacimiento de la becerra, siendo la estación húmeda la que arrojó los mejores resultados. Las becerras H y M superaron a las PS en cuanto a la GDP (H = 418.16 PS = 392.39 y M = 424.88 g/día). En cuanto a IDPT e IDAC las becerras H y (2.04 y 1.21 mm/día) superaron a las PS (1.93 y 1.17 mm/día) y a las M (1.93 y 1.16 mm/día). En el IDAK se observaron diferencias significativas (P<05) entre los tres grupos raciales evaluados (H= 1.27 PS= 1.36 y M= 1.20 mm/día). El evaluar el IDLC, las becerras H (2.2 mm/día) y PS (2.2 mm/día) aventajaron a las M (2.0 mm/día). El estudio de las interacciones reveló efectos favorables de las becerras M suplementadas con alimento concentrado y nacidas en la época húmeda (P<05).75 - [email protected] a faro with semi-intensive production system under a tropical sub-humid forest, located in Venezuela, thirty female crossbred calves, Holstein (H), Brown Swiss (BS) and Mosaicos (M) were studied to evaluate the supplementation effects (1: corn meal and 2: commercial concentrate) on preweaning growth. Least-square analysis of variance-covariance included effects of breed, supplementation and calving season (humid and dry). The average daily gain (ADG), thorax perimeter (IDTP), hip height (IDWH), croup height (IDCH) and body length (IDBL) were affected by calving season and the humid season had got the best response. The ADG was greater in H (418.16) and M (424.88) than BS (392.39 g/day) female calves. IDTP and IDWH were greater in H (2.04 and 1.21) than BS (1.93 and 1.17) and M (1.93 and 1.16 mm/day). Between H (1.27), BS (1.36) and M (1.20 mm/day) there were significant differences (P<01) for IDCH. IDBL was greater in H (2.2) and PS (2.2) than M (2.0 mm/day). The interactions revealed advantageos for the M female calves supplemented with basal diet and born in the humid season

Prevalence of molar-incisor hypomineralization and other enamel defects and associated sociodemographic determinants in Indiana

Background The aim of this study was to determine the prevalence and severity of molar-incisor hypomineralization (MIH) in a cohort of school-aged children in Indiana. Methods A calibrated examiner screened eligible school-aged children for MIH and other enamel defects. The authors used the integrated Modified Developmental Defects of Enamel Index and the European Academy of Pediatric Dentistry criteria to examine the permanent first molars, permanent incisors, and primary second molars. The authors used descriptive statistics, exact 95% confidence intervals, and χ2 tests for analysis (α = 5%). Results A total of 337 participants (mean [standard deviation] age, 9.1 (1.7) years; 52% 6 through 8 years; 66% non-Hispanic white) were examined. The prevalence estimate for MIH was 13% as opposed to a 52% prevalence estimate for any enamel defect (AED) of any of the index teeth. Living in an area with water fluoridation levels greater than 0.7 parts per million or being non-Hispanic black was significantly associated with higher prevalence of AED (P < .05) but not with the prevalence of MIH. Demarcated opacities were the most prevalent defects (43%), followed by atypical restorations (32%). Higher age and higher number of MIH-affected surfaces were associated with larger MIH defect extension (P < .05). Conclusions Nearly 1 in 6 children in Indiana had at least 1 permanent first molar with MIH. Water fluoridation levels and race or ethnicity were associated with the prevalence of AED but not with MIH prevalence