Pharmacological interventions in human aging.

Pharmacological interventions are emerging as potential avenues of alleviating age-related disease. However, the knowledge of ongoing clinical trials as they relate to aging and pharmacological interventions is dispersed across a variety of mediums. In this review we summarize 136 age-related clinical trials that have been completed or are ongoing. Furthermore, we establish a database that describe the trials (AgingDB, www.agingdb.com) keeping track of the previous and ongoing clinical trials, alongside their outcomes. The aim of this review and database is to give people the ability to easily query for their trial of interest and stay up to date on the latest results. In sum, herein we give an overview of the current pharmacological strategies that have been applied to target human aging.

Antibiofilm Activity and Biocompatibility of Temporin-SHa: A Promising Antimicrobial Peptide for Control of Fluconazole-Resistant Candida albicans.

The aim of the study was to investigate the effect of antimicrobial peptides (AMPs) Hylin-a1, KR-12-a5, and Temporin-SHa in Candida albicans as well as the biocompatibility of keratinocytes spontaneously immortalized (NOK-si) and human gingival fibroblasts (FGH) cells. Initially, the susceptible (CaS-ATCC 90028) and fluconazole-resistant (CaR-ATCC 96901) C. albicans strains were grown to evaluate the effect of each AMP in planktonic culture, biofilm, and biocompatibility on oral cells. Among the AMPs evaluated, temporin-SHa showed the most promising results. After 24 h of Temporin-SHa exposure, the survival curve results showed that CaS and CaR suspensions reduced 72% and 70% of cell viability compared to the control group. The minimum inhibitory/fungicide concentrations (MIC and MFC) showed that Temporin-SHa was able to reduce ≥50% at ≥256 µg/mL for both strains. The inhibition of biofilm formation, efficacy against biofilm formation, and total biomass assays were performed until 48 h of biofilm maturation, and Temporin-SHa was able to reduce ≥50% of CaS and CaR growth. Furthermore, Temporin-SHa (512 µg/mL) was classified as non-cytotoxic and slightly cytotoxic for NOK-si and FGH, respectively. Temporin-SHa demonstrated an anti-biofilm effect against CaS and CaR and was biocompatible with NOK-si and FGH oral cells in monolayer.

Engineered Salivary Peptides Reduce Enamel Demineralization Provoked by Cariogenic S. mutans Biofilm.

Engineering of the acquired enamel pellicle using salivary peptides has been shown to be a promising anticaries strategy. However, the mechanisms by which these peptides protect teeth against tooth decay are not fully understood. In this study, we evaluated the effect of the engineered salivary peptides DR9-DR9 and DR9-RR14 on enamel demineralization in two experimental conditions: (1) adsorbed onto the enamel surface forming the AEP, and (2) forming the AEP combined with their use to treat the biofilms 2×/day, using a validated cariogenic Streptococcus mutans in vitro biofilm model. Biofilms were grown for 144 h on enamel slabs and then collected to determine the bacterial viability (CFU/biofilm) and biofilm mass (mg protein/biofilm), and to extract cellular/extracellular proteins, which were characterized by mass spectrometry. The culture medium was changed 2×/day to fresh medium, and pH (indicator of biofilm acidogenicity) and calcium concentration (indicator of demineralization) was determined in used medium. DR9-RR14 peptide significantly reduced enamel demineralization (p < 0.0001) in both experimental conditions. However, this peptide did not have a significant effect on biofilm biomass (p > 0.05) nor did it modulate the expression of cellular and extracellular bacterial proteins involved in biofilm cariogenicity. These findings suggest that DR9-RR14 may control caries development mainly by a physicochemical mechanism.

Modulation of Streptococcus mutans Adherence to Hydroxyapatite by Engineered Salivary Peptides.

Since the modification of the proteinaceous components of the Acquired Enamel Pellicle (AEP) could influence the adhesion of Streptococcus mutans, the most cariogenic bacteria, to dental surfaces, we assessed if engineered salivary peptides would affect the adherence and modulate the bacterial proteome upon adherence. Single-component AEPs were formed onto hydroxyapatite (HAp) discs by incubating them with statherin, histatin-3, DR9, DR9-DR9, DR9-RR14, RR14, and parotid saliva. Then, the discs were inoculated with S. mutans UA159 and the bacteria were allowed to adhere for 2 h, 4 h, and 8 h (n = 12/treatment/time point). The number of bacteria adhered to the HAp discs was determined at each time point and analyzed by two-way ANOVA and Bonferroni tests. Cell-wall proteins were extracted from adhered, planktonic, and inoculum (baseline) bacteria and proteome profiles were obtained after a bottom-up proteomics approach. The number of adhered bacteria significantly increased over time, being the mean values obtained at 8 h, from highest to lowest, as follows: DR9-RR14 > statherin > RR14 = DR9-DR9 > DR9 = histatin3 > saliva (p < 0.05). Treatments modulated the bacterial proteome upon adherence. The findings suggested a potential use of our engineered peptide DR9-DR9 to control S. mutans biofilm development by reducing bacterial colonization.

Chemically soluble fluoride in toothpastes marketed in Colombia / Fluoruro químicamente soluble en cremas dentales distribuidas en Colombia / Fluoreto químico solúvel em cremos dentários distribuídos na Colômbia

Abstract Introduction and objective: Toothpastes should contain chemically soluble fluoride to have anti-caries efficacy. This study aimed at determining how much of the total fluoride (TF) concentration in the five top-selling children/family Colombian-toothpaste brands corresponds to total chemically soluble fluoride (TSF). Materials and methods: a convenience sample of three tubes of each of the following five toothpaste brands were obtained from three different chain stores, one-per-store, in five Colombian cities (n=3/brand/city): Colgate-Smiles-6+, Kolynos-Super-Blanco, Fortident-Cuatriacción, Colgate-Triple-Acción, Fluocardent. TF (sum of all toothpaste's fluoride) and TSF (toothpaste's chemically soluble fluoride) concentrations were determined in each fresh toothpaste sample (before expiry date) using a standardized ion-specific electrode direct-technique protocol. TF concentration was compared with the manufacturers' declared concentration. The difference between TF and TSF's concentrations purchased in different cities was compared with a one-way ANOVA (5%). Results: Most toothpastes' TF concentration complied with what was declared in the label. One toothpaste had a non-compatible fluoride/abrasive fluoride formulation and TSF < TF; however, it still complied with the minimum TSF requirement to exert a caries-preventive effect (>1000 ppm). Toothpastes' TF and TSF concentrations did not differ between cities (p>0.05). Conclusion: Fresh samples of highly distributed toothpaste brands sold in five Colombian-cities contain chemically available fluoride concentrations with the potential to control and prevent dental caries.

Resumen Introducción y objetivo: las cremas dentales requieren de la disponibilidad de fluoruro químicamente soluble para tener efecto anticaries. Este estudio tuvo como objetivo determinar qué parte de la concentración total de fluoruro (FT) en las cinco marcas de pastas dentales colombianas para niños/familias más vendidas corresponde al fluoruro total químicamente soluble (FTS). Materiales y métodos: se recolectaron tres tubos de cinco marcas diferentes en tres supermercados de cadena; una por tienda, en cinco ciudades colombianas (n=3/marca/ciudad): Colgate-Smiles-6+, Kolynos-Super-Blanco, Fortident-Cuatriacción, Colgate-Triple-Acción, Fluocardent. Las concentraciones de FT y FST se determinaron en cada una de las muestras frescas utilizando técnica directa con electrodo específico y un protocolo estandarizado. La concentración de FT se comparó con la concentración declarada por el fabricante. Se compararon las diferencias entre las concentraciones de FT y FST de la misma marca compradas en diferentes ciudades a con un análisis ANOVA (α=5%). Resultados: La mayoría de las cremas dentales cumplió con la concentración de FT declarada en la etiqueta. Una de las cremas dentale tenía una formulación de fluoruro/abrasivo no compatible y TSF <TF; sin embargo, aún cumplía con el requisito mínimo de TSF para ejercer un efecto preventivo de caries (> 1000 ppm). Las concentraciones de TF y TSF de las pastas de dientes no difirieron entre las ciudades (p> 0.05). Conclusión: Las muestras frescas de cremas dentales de las marcas más vendidas en cinco ciudades colombianas contienen concentraciones de fluoruro químicamente disponibles con el potencial de controlar y prevenir la caries dental.

Resumo Introdução e objetivo: os cremes dentais requerem a disponibilidade de fluoreto quimicamente solúvel para ter um efeito anticárie. O presente estudo determinou a proporção de fluoreto total (FT) que corresponde ao fluoreto total quimicamente solúvel (FST) em cinco marcas de creme dental amplamente distribuídas na Colômbia. Materiais e métodos: três tubos de cinco marcas diferentes foram coletados em três supermercados da rede; uma por loja, em cinco cidades colombianas (n = 3 / marca / cidade): Colgate-Smiles-6 +, Kolynos-Super-Blanco, Fortident-Quad, Colgate-Triple-Action, Fluocardent. As concentrações de FT e FST foram determinadas em cada uma das amostras frescas, utilizando a técnica direta com eletrodo específico e um protocolo padronizado. A concentração de FT foi comparada com a concentração declarada pelo fabricante. As diferenças entre as concentrações de FT e FST da mesma marca comprada em diferentes cidades foram comparadas com a análise ANOVA (α = 5%). Resultados: a maioria das marcas possui concentrações de flúor que atendem à concentração declarada pelo fabricante. Uma marca contém uma formulação de sal abrasivo e fluoreto quimicamente não compatível e FST menor que FT; no entanto, as amostras frescas atenderam à concentração necessária para exercer um efeito anticárie (> 1000 ppm). As concentrações de FT e TSF não foram significativamente diferentes entre amostras da mesma marca compradas em diferentes cidades (p> 0,05). Conclusão: as amostras frescas (analisadas antes do prazo de validade) das cinco marcas de creme dental com maior distribuição na Colômbia contêm concentrações de fluoreto quimicamente solúvel, com potencial para controlar e prevenir a cárie dentária.

Patrón de distribución de severidad de fluorosis: ¿qué nos dice sobre exposición local a fluoruros? / Padrão de distribuição de severidade da fluorose: Que nos diz sobre exposição local ao fluoretos? / Distribution pattern of enamel fluorosis severity: What is it telling us about local fluoride exposure?

Resumen Introducción y objetivo: la severidad de la fluorosis dental refleja exposición a fluoruros durante el desarrollo del esmalte. Recientemente se han reportado asociaciones entre la exposición prenatal y postnatal a fluoruros y efectos negativos en el neurodesarrollo. El objetivo de este estudio fue describir y comparar la severidad y el patrón de distribución de la fluorosis en las denticiones primaria y permanente, como base para discutir la temporalidad de la exposición en niños viviendo en áreas endémicas en el departamento del Huila. Materiales y métodos: odontólogos entrenados diagnosticaron fluorosis en 840 niños (preescolares y escolares) de cuatro municipios usando el índice de Thylstrup & Fejerskov. Para estimar la prevalencia de las diferentes severidades, cada niño se clasifico de acuerdo con la severidad más alta en boca. La distribución de la prevalencia de severidades por grupo etario y tipo de dentición se reportan como tasas de prevalencia (%). Resultados: la prevalencia en preescolares y escolares fue de 97.2% y 99.9%, respectivamente y la fluorosis moderada la más prevalente (75.6% y 63.5%, respectivamente). En ambas denticiones, la fluorosis leve fue más prevalente en los dientes anteriores que en posteriores. Las severidades moderada y severa tuvieron mayor prevalencia en dientes posteriores que en anteriores. Conclusiones: el patrón de distribución de la severidad de la fluorosis sugiere exposición prenatal y postnatal a fluoruros, por encima de los niveles recomendados. Este estudio resalta la importancia de la alidación de la fluorosis del dental como un potencial biomarcador histórico de exposición a luoruros en momentos críticos para el neurodesarrollo.

Resumo Introdução e objetivo: a severidade da fluorose dentária reflete a exposição a fluoretos durante o desenvolvimento do esmalte. Recentemente, associações entre a exposição pré-natal e pós-natal ao fluoretos e efeitos negativos no desenvolvimento neurológico foram relatadas. O objetivo deste estudo é descrever e comparar o padrão de severidade e distribuição da fluorose na dentição decídua e permanente, como intuito para a discussão sobre a temporalidade da exposição em crianças moradoras em áreas endêmicas de fluorose no departamento de Huila, Colômbia. Materiais e métodos: Cirurgiões-dentistas treinados diagnosticaram fluorose em 840 crianças (pré-escolares e escolares) de quatro municípios, utilizando o índice de Thylstrup & Fejerskov. Para estimar a prevalência dos diferentes estágios de severidade, cada criança foi classificada de acordo com o escore mais severo da boca. A distribuição da prevalência de fluorose nos diferentes estágios de severidade por faixa etária e tipo de dentição é apresentada como taxa de prevalência (%). Resultados: a prevalência de fluorose em pré-escolares foi de 97,2% e em escolares de 99,9%. Fluorose moderada foi a mais prevalente (75,6% e 63,5%, respectivamente). Em ambas as dentições, a fluorose leve foi mais prevalente nos dentes anteriores do que nos posteriores. Porém, tanto fluorose moderada como severa foram mais prevalentes nos dentes posteriores do que nos anteriores. Conclusões: o padrão de distribuição da severidade da fluorose sugere uma exposição pré- e pós-natal a fluoretos acima de níveis recomendados. Este estudo salienta a importância da validação da fluorose dentária como um potencial biomarcador histórico da exposição ao fluoretos durante momentos críticos para o neurodesenvolvimento.

Abstract Introduction and objective: dental fluorosis severity reflects fluoride exposure during dental enamel development. Recently, prenatal and postnatal exposure to fluoride has been associated with negative neurodevelopmental outcomes. The aim of this study was to describe and compare the severity and distribution pattern of dental fluorosis in the primary and permanent dentition, as a basis to discuss the timing and extent of fluoride exposure of children living in endemic areas of fluorosis in the department of Huila. Materials and methods: 840 children (preschoolers and schoolchildren) from four municipalities of the Huila Department were examined by trained dentists for dental fluorosis using the Thylstrup & Fejerskov Index. To estimate the prevalence of severities of fluorosis, each child was classified according to the most severe score. The distribution of the prevalence of enamel fluorosis severity by age-group and type of dentition were reported as prevalence rates (%). Results: Prevalence of dental fluorosis in preschoolers was of 97.2% and in schoolers of 99.9%. For both preschoolers and schoolers moderate fluorosis was the most prevalent (75.6% and 63.5%, respectively). For both primary and permanent teeth, mild fluorosis was more prevalent in anterior teeth than in posterior teeth. Moderate and severe fluorosis were more prevalent in posterior teeth than in anterior teeth. Conclusions: the distribution pattern of the severity of dental fluorosis suggests both prenatal and postnatal exposure to fluoride above recommended levels. This study raises the importance of the validation of dental fluorosis as a potential historical biomarker of fluoride exposure at moments that are critical for neurodevelopment.

Proteome difference among the salivary proteins adsorbed onto metallic orthodontic brackets and hydroxyapatite discs.

The aim of this study was to investigate the atomic composition and the proteome of the salivary proteins adsorbed on the surface of orthodontic metallic bracket. For this, the atomic composition of orthodontic metallic brackets was analyzed with X-ray Photoelectron Spectroscopy (XPS). The acquired bracket pellicle was characterized after brackets were immersed in human whole saliva supernatant for 2 hours at 37°C. Hydroxyapatite (HA) discs were used as a control. Acquired pellicle was harvested from the HA discs (n = 12) and from the metallic brackets (n = 12). Proteomics based on mass spectrometry technology was used for salivary protein identification and characterization. Results showed that most of the proteins adsorbed on the surface of orthodontic metallic brackets and on the HA discs were identified specifically to each group, indicating a small overlapping between the salivary proteins on each study group. A total of 311 proteins present on the HA discs were unique to this group while 253 proteins were unique to metallic brackets, and only 45 proteins were common to the two groups. Even though most proteins were unique to each study group, proteins related to antimicrobial activity, lubrication, and remineralization were present in both groups. These findings demonstrate that the salivary proteins adsorbed on the bracket surface are dependent on the material molecular composition.

One-Year Update on Salivary Diagnostic of COVID-19.

Background: Coronavirus disease 2019 (COVID-19) is a global health problem, which is challenging healthcare worldwide. In this critical review, we discussed the advantages and limitations in the implementation of salivary diagnostic platforms of COVID-19. The diagnostic test of COVID-19 by invasive nasopharyngeal collection is uncomfortable for patients and requires specialized training of healthcare professionals in order to obtain an appropriate collection of samples. Additionally, these professionals are in close contact with infected patients or suspected cases of COVID-19, leading to an increased contamination risk for frontline healthcare workers. Although there is a colossal demand for novel diagnostic platforms with non-invasive and self-collection samples of COVID-19, the implementation of the salivary platforms has not been implemented for extensive scale testing. Up to date, several cross-section and clinical trial studies published in the last 12 months support the potential of detecting SARS-CoV-2 RNA in saliva as a biomarker for COVID-19, providing a self-collection, non-invasive, safe, and comfortable procedure. Therefore, the salivary diagnosis is suitable to protect healthcare professionals and other frontline workers and may encourage patients to get tested due to its advantages over the current invasive methods. The detection of SARS-CoV-2 in saliva was substantial also in patients with a negative nasopharyngeal swab, indicating the presence of false negative results. Furthermore, we expect that salivary diagnostic devices for COVID-19 will continue to be used with austerity without excluding traditional gold standard specimens to detect SARS-CoV-2.

Statherin-derived peptides as antifungal strategy against Candida albicans.

OBJECTIVE: The aim of this in vitro study was to evaluate the effect of statherin and its naturally occurring peptides (DR9-2, DR9, GE-12, IT-32, GQ-19, IP-18) on Candida albicans metabolism and biofilm development. DESIGN: After the killing assay, a peptide pellicle was formed on the bottom of a polystyrene plate at the IC50 of each peptide. Over the peptide pellicle, Candida albicans biofilm (48 h) was grown. The peptides antimicrobial activity after the peptides treatment was evaluated by alamarBlue, total biofilm biomass and colony forming units (CFU) counting. RESULTS: The pellicle with statherin and the peptides (DR9-2, DR9, GE-12, IP-18, GQ-19) was able to reduce he viability of Candida albicans compared to the negative control. They also decreased cell proliferation by 20 % and total biomass. IT-32 showed the highest reduction in cell proliferation and biomass, which was similar to the positive control, histatin 5. CONCLUSIONS: These results suggest that the naturally occuring peptides from statherin are able to decrease Candida albicans colonization and biofilm proliferation.

Fluoride Dentifrice Overcomes the Lower Resistance of Fluorotic Enamel to Demineralization.

We evaluated if the low resistance of fluorotic enamel to demineralization could be overcome by fluoride dentifrice (FD) treatment. Paired enamel slabs of sound and fluorotic enamel (n = 20/group) from human teeth presenting Thylstrup and Fejerskov index (TF) scores from 0 to 4 were obtained. Half of the anatomic surface of the enamel slabs was isolated and used as a control (baseline) regarding enamel mineralization and fluoride concentration. The slabs were submitted to a pH-cycling model simulating a high cariogenic challenge, and 2×/day they were treated with placebo dentifrice (PD) or FD (1,100 µg F/g, as NaF). After 10 days, the slabs were cut into two halves. Enamel demineralization was evaluated by cross-sectional microhardness in one half, and the fluoride formed (FF) concentration was determined in the other half. For statistical analysis, the data on net demineralization area (ΔΔS) and FF (µg F/g) were grouped into TF0, TF1-2, and TF3-4, and analyzed by two-way ANOVA followed by Tukey's test (α = 5%). The factors studied were TF (0, 1-2, and 3-4) and dentifrice treatment (PD or FD). The effect of the factors was statistically significant for ΔΔS and FF (p < 0.05). In the PD group, the following pattern for ΔΔS was observed: TF3-4 > TF1-2 > TF0 (p < 0.05); however, the groups did not differ (p > 0.05) when FD was used. Regarding FF, the groups treated with PD did not differ (p > 0.05), but the greatest (p < 0.05) FF concentration was found in group TF3-4 treated with FD. These findings suggest that the higher susceptibility of fluorotic enamel to demineralization lesions is decreased by the use of FD.

Higher Fluorosis Severity Makes Enamel Less Resistant to Demineralization.

Fluorotic teeth could either be more resistant or more susceptible to the caries process than sound ones due to their higher enamel fluoride concentration and higher porosity (subsurface hypomineralization), respectively; however, there is no consensus on this subject. In this study, a total of 49 human unerupted third molars presenting Thylstrup and Fejerskov (TF) fluorosis scores 0-4 were used. Two enamel slabs were obtained from each tooth. The rest of the tooth crown was powdered, and the enamel was separated from the dentine. In purified powdered enamel, the calcium (Ca), inorganic phosphate (Pi), and fluoride (F) concentrations were determined. The F concentration gradient throughout the enamel and in the enamel volume was determined in one slab. The other enamel slab was isolated with acid-resistant varnish, subjecting the exposed enamel surface half to a pH-cycling model to evaluate its demineralization resistance and to calculate the demineralization area. The nonexposed surface was used to determine the natural hypomineralization area found in fluorotic enamel and normalize the demineralization data. The hypomineralization and demineralization areas were assessed by cross-sectional microhardness. For statistical analyses, the data for TF1 and 2, and for TF3 and 4 were pooled. Concentrations of powered enamel Ca and Pi were not significantly different (p > 0.05) among groups TF0, TF1-2 and TF3-4, but a higher F concentration was found in fluorotic enamel (p < 0.05). Highly fluorotic teeth (TF3-4) presented a greater hypomineralization subsurface area and demonstrated lower demineralization resistance than sound enamel (p < 0.05). The findings suggest that a higher severity of fluorosis makes enamel less resistant to the caries process due to its greater subsurface mineral area exposed to demineralization and deeper acid diffusion through the enamel.

Diente cónico: presentación de dos casos / Conic teeth: report of two cases

Las anomalías dentales son un grupo de alteraciones morfológicas, que se pueden expresar en la corona o en la raíz dental; aparecen durante el desarrollo de los órganos dentales, se ha establecido que tienen un componente genético y molecular importante. También se han planteado influencias medioambientales, traumáticas y microbiológicas. Las anomalías morfológicas dentarias son comunes, y se presentan con una incidencia de 74,7% según Freer (1998). Los dientes cónicos, en clavija o reducidos tienen una incidencia menor y muestran mayor incidencia en dentición permanente, así como en los incisivos laterales superiores. El mencionado defecto va a ser origen de alteraciones en la oclusión, la longitud de arco, compromisos estéticos que van a afectar la autoestima del paciente. El propósito de este trabajo es presentar dos casos de dientes cónicos, uno en dentición permanente, otro en dentición temporal relacionándolos con el marco teórico encontrado en la literatura sobre las influencias genéticas que juegan un papel importante en la aparición de la mencionada anomalía, aunque no se pudo realizar el estudio genético que se quisiera a causa limitaciones económicas.

Dental anomalies are a group of morphological alterations of the teeth, which can be expressed in the tooth crown or root and appear during tooth development. It has been established to have a strong molecular and genetic component. There also have been proposed environmental, traumatic and microbiological influence. Dental morphological anomalies are common with an incidence of 74.7% according to Freer (1998). The alteration known as conical teeth, peg-shaped teeth or reduced teeth show a more reduced incidence and are most commonly found in the permanent dentition and upper lateral incisors. This defect is associated with impaired occlusion alteration, arc length anomalies, aesthetic and self-esteem. The purpose of this paper is to present two cases of conical teeth, one in permanent dentition and another in temporary dentition and its relationship to the theory found in the literature regarding genetic influences that plays an important role in the presentation of this anomaly. Not genetic studies were performed because of the economic factor.

Estandarizacion de la tecnica de biopsia para determinacion de fluoruro en esmalte dental / Biopsy technique standardization to determine fluoride content in dental enamel

Introduccion. El fluoruro incorporado en el esmalte dental durante el periodo preeruptivo refleja su exposicion sistemica durante la amelogenesis, proponiendose el esmalte como marcador biologico de exposicion a fluoruros. En Colombia, no existen estudios en que se emplee la tecnica de biopsia de esmalte, la cual permite determinar el gradiente de concentracion de fluoruro por medio de la estructura del esmalte dental. Objetivo. Estandarizar la tecnica de biopsia de esmalte y determinar la concentracion de fluoruro en el esmalte de dientes sanos no erupcionados. Metodos. Previa firma del consentimiento informado, se recolectaron cinco terceros molares no erupcionados sanos y de cada uno se obtuvieron dos bloques de esmalte a partir del tercio medio de la corona, en sentido transversal. Todas las superficies de cada bloque fueron cubiertas con cera, excepto la superficie externa del esmalte. Cada bloque fue tratado con HCl 0,5 M por 15, 30, 60 y 120 segundos bajo agitacion constante. Se determino la concentracion de fluoruro en cada extracto, usando un electrodo de ion especifico para el fluoruro y, la masa de esmalte removido (gramos) se calculo tras el analisis espectrofotometrico de fosforo inorganico en la muestra. Se determino la concentracion de fluoruro en cada capa de esmalte removido (mg F/g de esmalte) y en todo el esmalte removido (¦Ìg F/cm3). Resultados. Se encontro un gradiente de concentracion de fluoruro desde la superficie hacia el interior del esmalte, siendo mayor la concentracion en la superficie (1.663,49¡À266,61 ¦Ìg F/g de esmalte). La concentracion total de fluoruro en el volumen de esmalte removido fue de 1,02¡À0,25 ¦Ìg F/cm3. Conclusiones. La tecnica de biopsia de esmalte fue estandarizada. Similar a lo reportado en la literatura cientifica, existe un gradiente de concentracion de fluoruro desde la superficie hacia el interior del esmalte sano.

Introduction. Pre-eruptive incorporation of fluoride into dental enamel reflects its systemic exposition during amelogenesis, leading to the use of dental enamel as a biomarker of fluoride exposure. There are not reported studies in Colombia using the enamel biopsy technique, which allows the determination of the fluoride distribution pattern throughout dental enamel. Aim. To standardize the enamel biopsy technique and determine the fluoride content in the enamel of sound unerupted teeth. Methods. With ethical approval and informed consent forms, there were collected 5 third unerupted molar-teeth and of each tooth it were obtained two enamel blocks from the middle third of the crown, in a cross-sectional way. All surfaces were covered with acid-resistant wax leaving the external enamel surface exposed, which were treated with 0.5M HCl for 15, 30, 60, and 120 seconds under constant agitation. Fluoride concentration was determined in each acid extract by means of a fluoride ion-specific electrode and the mass of removed enamel was established (grams) after Pi analyses. The fluoride content in each layer of removed enamel was determined (¦Ìg F/g enamel) and in the total of removed enamel (¦Ìg F/cm3). Results: There was a fluoride distribution pattern from the surface to the inner enamel, being higher the fluoride concentration in the outer enamel surface (1663.49 ¡À 266.61 ¦Ìg F/g enamel). Total fluoride concentration in the total of removed enamel was 1.02 ¡À 0.25 ¦Ìg F/cm3. Conclusions: Enamel biopsy technique was standardized. There was found a fluoride distribution pattern from the surface to the inner enamel, similar to the data reported in the literature.

Estandarizacion de la tecnica de biopsia para determinacion de fluoruro en esmalte dental / Biopsy technique standardization to determine fluoride content in dental enamel

Introduccion. El fluoruro incorporado en el esmalte dental durante el periodo preeruptivo refleja su exposicion sistemica durante la amelogenesis, proponiendose el esmalte como marcador biologico de exposicion a fluoruros. En Colombia, no existen estudios en que se emplee la tecnica de biopsia de esmalte, la cual permite determinar el gradiente de concentracion de fluoruro por medio de la estructura del esmalte dental. Objetivo. Estandarizar la tecnica de biopsia de esmalte y determinar la concentracion de fluoruro en el esmalte de dientes sanos no erupcionados. Metodos. Previa firma del consentimiento informado, se recolectaron cinco terceros molares no erupcionados sanos y de cada uno se obtuvieron dos bloques de esmalte a partir del tercio medio de la corona, en sentido transversal. Todas las superficies de cada bloque fueron cubiertas con cera, excepto la superficie externa del esmalte. Cada bloque fue tratado con HCl 0,5 M por 15, 30, 60 y 120 segundos bajo agitacion constante. Se determino la concentracion de fluoruro en cada extracto, usando un electrodo de ion especifico para el fluoruro y, la masa de esmalte removido (gramos) se calculo tras el analisis espectrofotometrico de fosforo inorganico en la muestra. Se determino la concentracion de fluoruro en cada capa de esmalte removido (mg F/g de esmalte) y en todo el esmalte removido (¦Ìg F/cm3). Resultados. Se encontro un gradiente de concentracion de fluoruro desde la superficie hacia el interior del esmalte, siendo mayor la concentracion en la superficie (1.663,49¡À266,61 ¦Ìg F/g de esmalte). La concentracion total de fluoruro en el volumen de esmalte removido fue de 1,02¡À0,25 ¦Ìg F/cm3. Conclusiones. La tecnica de biopsia de esmalte fue estandarizada. Similar a lo reportado en la literatura cientifica, existe un gradiente de concentracion de fluoruro desde la superficie hacia el interior del esmalte sano.(AU)

Introduction. Pre-eruptive incorporation of fluoride into dental enamel reflects its systemic exposition during amelogenesis, leading to the use of dental enamel as a biomarker of fluoride exposure. There are not reported studies in Colombia using the enamel biopsy technique, which allows the determination of the fluoride distribution pattern throughout dental enamel. Aim. To standardize the enamel biopsy technique and determine the fluoride content in the enamel of sound unerupted teeth. Methods. With ethical approval and informed consent forms, there were collected 5 third unerupted molar-teeth and of each tooth it were obtained two enamel blocks from the middle third of the crown, in a cross-sectional way. All surfaces were covered with acid-resistant wax leaving the external enamel surface exposed, which were treated with 0.5M HCl for 15, 30, 60, and 120 seconds under constant agitation. Fluoride concentration was determined in each acid extract by means of a fluoride ion-specific electrode and the mass of removed enamel was established (grams) after Pi analyses. The fluoride content in each layer of removed enamel was determined (¦Ìg F/g enamel) and in the total of removed enamel (¦Ìg F/cm3). Results: There was a fluoride distribution pattern from the surface to the inner enamel, being higher the fluoride concentration in the outer enamel surface (1663.49 ¡À 266.61 ¦Ìg F/g enamel). Total fluoride concentration in the total of removed enamel was 1.02 ¡À 0.25 ¦Ìg F/cm3. Conclusions: Enamel biopsy technique was standardized. There was found a fluoride distribution pattern from the surface to the inner enamel, similar to the data reported in the literature.(AU)

Factores causales de la deserción estudiantil en el pregrado de la Facultad de odontología de la Universidad de Antioquia de 1997 a 2004 / Causal factors of student desertion from school of dentistry of the University of Antioquia from 1997 to 2004

Introducción: la deserción estudiantil es el abandono definitivo de las aulas de clase por diferentes razones y la no continuidad en el programa académico. Existen diferentes factores que la determinan, tanto intrínsecos propios del estudiante como extrínsecos cuando estos no dependen del estudiante. Métodos: investigación educacional descriptiva retrospectiva, con análisis cualicuantitativo para determinar los factores causales de la deserción estudiantil en la Facultad de Odontología de la Universidad de Antioquia. De los 71 estudiantes desertores en el período comprendido entre 1997-1 y 2004-1, sólo 50 respondieron a la encuesta, 16 de reingreso y 34 desertores, los cuales se consideraron los dos grupos de estudio. Se realizó una encuesta diferente para cada grupo, para conocer los factores intrínsecos y extrínsecos, variables socioculturales y demográficas que pudieron influir en la deserción. Los resultados de estas encuestas se profundizaron para su análisis con grupos focales. Resultados: la deserción estudiantil en la Facultad es un fenómeno que paulatinamente ha aumentado en los últimos diez años, con el pico más alto en 2001 (18,1 por ciento para los desertores y 35,7 por ciento para reingreso). La mayor deserción se presentó en el cuarto semestre (29,4 por ciento para desertores y 31,3 por ciento para reingreso), puede atribuirse según el análisis llevado a cabo en el grupo focal, al inicio de la Clínica, donde confrontan sus temores y sienten mayores problemas de manejo y de responsabilidad frente al paciente. Conclusiones: entre de los factores extrínsecos de la deserción, en orden según su relevancia aparece el factor económico, por motivos laborales, carga académica, mala metodología y por acoso sexual. Entre los intrínsecos se destaca el cambio de programa por falta de motivación al no llenar sus expectativas y por falta de tiempo. Se sugiere que las instituciones de educación superior ofrezcan mayor flexibilidad curricular especialmente en su...