Apical debris extrusion during instrumentation with continuous and reciprocating systems

Objective: to evaluate the amount of apical debris extrusion during root canal preparation using continuous and reciprocating systems. Material and Methods: Forty lower incisors were selected and randomly divided into four groups (n=10) for root canal preparation. Two multifile systems with continuous rotation (iRace® and Mtwo®) and two reciprocating single-file systems (Reciproc® and WaveOne®) were used. In the iRace® group, the R1 (15/.06), R2 (25/.04) and R3 (30/.04) instruments were used. In the Mtwo® group, the 10/.04, 15/.05, 20/.06, and 25/.06 instruments were used. In the Reciproc® and WaveOne® groups, the R25 and 25/.04 instruments were used, respectively. Apical debris extrusion was determined by calculating the difference between the pre- and post-instrumentation weight of the Eppendorf tubes. Statistical analysis was performed using the analysis of variance (ANOVA) test with the Bonferroni correction (p<0.05). Results: The iRace® group demonstrated significantly more apical extrusion than the Reciproc® group (p<0.05). There was no statistically significant difference between the Mtwo®, Reciproc®, and WaveOne® groups (p>0.05). Conclusion: All of the evaluated systems produced apical debris extrusion. The iRace® system produced more apical debris extrusion than the Reciproc® system, and there was no difference observed in this regard between the Mtwo®, Reciproc®, and WaveOne® systems.

Objetivo: avaliar a quantidade de debris extruidos apicalmente durante o preparo do canal radicular usando sistemas de rotação contínua e reciprocante. Materiais e Métodos: Quarenta incisivos inferiores foram selecionados e randomicamente divididos em quatro grupos (n=10) para o preparo do canal radicular. Dois sistemas de limas múltiplas de rotação contínua (iRace® e Mtwo®) e dois sistemas de limas únicas reciprocantes (Reciproc® e WaveOne®) foram usados. No grupo iRace®, foram utilizados os instrumentos R1 (15/.06), R2 (25/.04) e R3 (30/.04). No grupo Mtwo®, foram utilizados os instrumentos 10/.04, 15/.05, 20/.06, 25/.06. Nos grupos Reciproc® e WaveOne®, foram utilizados os instrumentos R25 e 25.04, respectivamente. A extrusão apical de debris foi calculada pela diferença entre os pesos dos tubos Eppendorf antes e após a instrumentação. A análise estatística foi feita usando o teste de análise de variância (ANOVA) seguida do teste de Bonferroni (p<0,05). Resultados: O grupo iRace® demonstrou significativamente mais extrusão quando comparado ao Reciproc (p<0,05). Não houve diferença estatisticamente significativa entre os grupos Mtwo®, Reciproc®, e WaveOne® (p>0,05). Conclusão: Todos os sistemas avaliados produziram extrusão apical de debris. O Sistema iRace® produziu mais extrusão apical de debris do que o Sistema Reciproc® e não foi observada diferença entre os sistemas Mtwo®, Reciproc® e WaveOne®.

Comparación de los niveles de contaminación por humo de tabaco ambiental en lugares de trabajo en 4 ciudades de Venezuela / Comparison of environmental tobacco smoke, indoor pollution levels in workplaces in 4 cities in Venezuela

Es bien sabido que el Humo de Tabaco Ambiental (HTA) es un contaminante del aire sumamente peligroso. Este humo contiene alrededor de 4.800 componentes químicos, de los cuales 69 son carcinógenos y muchos otros son irritantes, tóxicos y mutagénicos. Por esta razón Venezuela se ha unido a la lucha mundial contra este enemigo de la salud y para sustentarla se realizó en nuestro país en el año 2006 un estudio de los niveles de contaminación causada por HTA. Con esto se logró comparar la calidad de aire en ambientes cerrados sin prohibición para fumar, o con prohibición parcial (división de área para fumadores y no fumadores), como por ejemplo bares, restaurantes, casinos y transporte; con ambientes con prohibi-ción total para fumar, como universidades y hospitales. Este estudio se realizó midiendo en tiempo real la concentración (µg/m3) de partículas respirables con un diámetro menos a 2,5 µm (PM2.5), estas partículas son liberadas en grandes cantidades por cigarrillos encendidos y están relacionadas con los efectos adversos a la salud que produce el cigarrillo. Se determinó que en los ambientes con prohibición total los niveles de contaminación son 92% más bajos que los ambientes sin prohibición o con una prohibición parcial. Este resultado da a nuestro país el soporte científico para la implementación de políticas Ambientes Libres de Humo de Tabaco, que garanticen a la población un ambiente inocuo.

It is well known that secondhand smoke (SHS) is the main source of pollution in enclosed places to the people, such as: workplaces, public places, public transportation facilities, communities and home. This pollutant contains 4800 chemicals, 69 of which are carcinogens. In addition, many of these substances are toxic, poisonous and mutagenic to the human body. For this reason Venezuela has united to the worldwide fighting against this health hazard. In 2006 our country carried out a study evaluating the pollution levels caused by SHS. In this study was possible to compare air quality in partial or smoking places such as bars, restaurants and in public transport against nonsmoking places such as hospitals and universities. The study was done measuring concentrations (µg/m³) of breathable particles with a diameter less than 2.5 µm (PM2.5) in realtime, which are release by a lighted cigarette. Based on the measures taken, it was possible to determine that in free smoke places the pollution levels are 92% lower compare to smoking places. This result gives to our country the scientific support to establish policies for environments smokefree that warranty the public from the adverse health effects of passive smoking in public places.

Estudios de bioequivalencia: la necesidad de establecer la fiabilidad de los medicamentos genéricos / Bioequivalence studies: need for the reability of generic drugs

Un medicamento genérico es un medicamento que contiene un principio activo ya conocido y previamente desarrollado e inventado por otros. El coste de estos productos genéricos o multifuente debe ser menor que el de sus contrapartidasoriginales. Los efectos clínicos y el balance riesgo-beneficio de un medicamento no dependen exclusivamente de la actividadfarmacológica de la sustancia activa. La demostración de bioequivalencia de los medicamentos genéricos es de gran importancia. En Europa y en los Estados Unidos de Norteamérica la autorización de medicamentos genéricos descansa en la demostración de la bioequivalencia mediante estudios de biodisponibilidad comparada in vivo. Estos argumentos son imprescindibles para la autorización de la comercialización de los fármacos genéricos por parte de las autoridadessanitarias europeas y norteamericanas. Como medida de la cantidad de fármaco absorbido se utiliza el área bajo la curvaconcentración-tiempo (AUC), y como indicador de la velocidad de absorción se mide la concentración máxima (Cmax) alcanzada en la curva concentración-tiempo y el tiempo que tarda en alcanzarse (Tmax). Se entiende por bioequivalencia entre dos productos cuando presentan una biodisponibilidad comparable en condiciones experimentales apropiadas. El objetivo final de todo este proceso tiene como único sentido poner a disposición de la sociedad fármacos de calidad, que además puedan contribuir a una utilización más racional de los recursos económicos en el sistema sanitario.

A generic medicine is a pharmaceutical product containing an active ingredient already known and previously developed and invented by others. The cost of these generic or multisource products should be less than their counterparts original. Theclinical effects and the risk-benefit balance of a medicine do not depend exclusively on the activity of a pharmacologically active substance. Demonstration of bioequivalence of generic medicine is of great importance. In Europe and the UnitedStates generic medicine approval is based in the demonstration of bioequivalence through comparative bioavailability studies in vivo. These arguments are required for marketing approval of generic medicines by the European and North American health authorities. As a measure of the amount of drug absorbed it is used the area under the curve concentrationtime (AUC), and as an indicator of the rate of absorption it is measured the peak concentration (Cmax) reached in the concentration-time curve and the time for its occurrence (Tmax). It is known as bioequivalence between two products when they have a comparable bioavailability in the appropriate experimental conditions. The ultimate goal of this process is to make quality drugs available to society and contribute to a more rational use of economic resources in the health system.