Bioseguridad en el laboratorio dental / Biosafety in the dental laboratory

Una enfermedad infecciosa es aquella producida por un agente infeccioso (bacterias, hongos, virus, etc.) que ingresa y se desarrolla en el organismo de un hospedero. Posteriormente, puede trasmitirse de un individuo a otro directamente por contacto entre ambos, o bien, indirectamente, por medio de un vec-tor biológico (de naturaleza animal o vegetal), o de un fómite (objeto inanimado). Las vías por las que un agente infeccioso puede ingresar a un hospedero son: inhalación (respiración de aerosoles), ingestión (salpicaduras de gotas), penetración de mucosas (na-sal, ocular y bucal) o lesiones en la piel o mucosas. Las fuentes de infección pueden ser los pacientes, el personal del consultorio o laboratorio, las superficies e instrumental contaminados y las prótesis o com-ponentes de éstas. Para evitar la propagación de los agentes microbianos se debe interrumpir el proceso de transmisión de los mismos. Todo profesional debe fortalecer y readecuar normas y protocolos de biose-guridad en la tarea diaria, para minimizar el riesgo de transmisión directa y cruzada entre el profesional, su equipo auxiliar, el laboratorista y los pacientes (AU)

An infectious disease is one caused by an infectious agent (bacteria, fungi, virus, etc.) that enters and develops in a host. Then it can be transmitted from one individual to another directly by contact between the two or, indirectly through a biological vector (an animal or plant nature), or a fomite (an inanimate object). The routes by which an infectious agent can enter a host are: inhalation (breathing of aerosols), ingestion (splash of droplets), penetration of mucous membranes (nasal, ocular and oral) and skin or mucous lesions. Sources of infection can be patients, office or laboratory personnel, contaminated surfaces and instruments and the prosthesis or component thereof. To prevent the spread of microbial agents, the process of their transmission must be interrupted. Every professional must strengthen and readjust biosafety standards and protocols in daily work to minimize the risk of direct and cross-transmission between the professional, his auxiliary team, the laboratory technician and the patients (AU)

Endodontic microorganism susceptibility by direct contact test.

The aim of this study was to evaluate in vitro the duration of the antimicrobial effect of endodontic sealers by means of the Direct Contact Test. The sealers tested were: Endomethasone - Septodont, Endomethasone C-Septodont, Endion-Voco, Diaket-ESPE, Pulp Canal Sealer-SybronEndo, and AH26-Dentsply DeTrey. The endodontopathic microorganisms (MO) confronted were: Staphylococcus aureus (Sa), Candida albicans (Ca), Enterococcus faecalis (Ef), Prevotella intermedia (Pi), Porphyromonas gingivalis (Pg) and Fusobacterium nucleatum (Fn). Test specimens of each sealer were prepared and placed on the surface of agar plates that had been inoculated with each MO, and after predetermined periods, transfers were made from the contact area between the test specimen and the cultured agar and from the area that had not been in contact with the test specimens (control). The results were read as presence/absence of microbial growth and analyzed statistically using the Kruskal-Wallis test. It was concluded that the structural features and virulence of endodontopathic microorganisms determine their response to the sealers, independently of the time during which sealers act and the mechanism by which the antiseptic reaches the microorganism, which in this case was by direct contact.

Endodontic microorganism susceptibility by direct contact test

El objetivo de este trabajo fue evaluar in vitro la duración del efecto antimicrobiano de los selladores endodónticos mediante la Prueba de Contacto Directo. Los selladores probados fueron: Endomethasone - Septodont®, Endomethasone C – Septodont®, Endion – Voco®, Diaket – ESPE®, Pulp Canal Sealer – SybronEndo® y AH26 – Dentsply DeTrey®. Los microorganismos endodontopáticos (MO) enfrentados fueron: Staphylococcus aureus (Sa), Candida albicans (Ca), Enterococcus faecalis (Ef), Prevotella intermedia (Pi), Porphyromonas gingivalis (Pg) yFusobacterium nucleatum (Fn). Se prepararon las probetas con cada uno de los selladores, se colocaron sobre la superficie de placas de agar sembradas con cada MO y luego de períodos predeterminados se realizaron repiques de las zonas de contacto probeta-agar sembrado y de la zona que no estuvo en contacto con las probetas (testigo). Se realizó la lectura de los resultados: presencia/ausencia de desarrollo microbiano y se analizaronestadísticamente mediante la Prueba de Kruskal- Wallis. Pudo concluirse que las características estructurales y la virulencia de los microorganismos endodontopáticos son determinantes de la respuesta de los mismos frente a los selladores independientemente del tiempo durante el cual estos actúen y del mecanismo por el cual el antiséptico alcance al microorganismo, en este caso por contacto directo.

Antimicrobial effect in vitro of chlorhexidine and calcium hydroxide impregnated gutta-percha points.

UNLABELLED: The aim of this study was to evaluate the antimicrobial activity of points containing antiseptics used for temporary obturation in endodontics. Points containing calcium hydroxide (Roeko and Hygienic), and chlorhexidine (Roeko) were tested and gutta-percha points served as control (Meta Dental Corp.). The following microorganisms were studied: Streptococcus mutans (Sm), Enterococcus faecalis (Ef), Staphylococcus aureus (Sta), Candida albicans (Ca), Fusobacterium nucleatum (Fn) ATCC 25586, Porphyromonas gingivalis (Pg) ATCC 33277, and Prevotella intermedia (Pi) ATCC 25611. The experiments were organized in three stages: 1st stage: one point of each kind was placed on agar plates previously seeded with microorganisms. 2nd stage: Another group of points was immersed in broth for 24 hours and placed on the seeded agar. Samples were then incubated at 37 degrees in the conditions of oxygen and for the time required by each microorganism. The zones of bacterial inhibition around each point were measured. The pH values of the broths were recorded. 3rd stage: the immersion broths were inoculated with suspensions of microorganisms, incubated, seeded on plates by dissemination and incubated. CFU counts were performed. RESULTS: points containing chlorhexidine showed inhibition zones with every microorganism in the 1st stage and, in the 2nd stage, with most of the microorganisms studied, except for Fn and Pi. Calcium hydroxide containing points did not inhibit any of the microorganisms assessed. Broth pH values did not exhibit any changes. CFU counts of the broths in which chlorhexidine points had been immersed showed total inhibition for all the microorganisms. The differences between materials were statistically significant (p<0.05) (ANOVA). In the conditions of this study, chlorhexidine-containing points proved to be effective against most of the tested strains.

Antimicrobial effect in vitro of chlorhexidine and calcium hydroxide impregnated gutta-percha points

El objetivo de este trabajo fue evaluar "in vitro" la actividad antimicrobiana de conos antisépticos para obturación temporaria frente a microorganismos endodontopáticos. Fueron empleados conos con hidróxido de calcio (Roeko(R) e Hygienic (H)) con clorhexidina (Roeko) y conos de gutapercha como testigos. Los microorganismos estudiados fueron Streptococcus mutans (Sm), Enterococcus faecalis (Ef), Staphylococcus aureus Sta), Candida albicans (Ca) (ATCC 3153), Fusobacterium nucleatum (Fn)(ATCC 25586), Porphyromonas gingivalis (Pg)(ATCC 33277) y Prevotella intermedia (Pi)(ATCC 25611). La experiencia se dividió en tres etapas: 1º etapa: un cono de cada tipo se colocó sobre la superficie de placas de agar previamente sembradas con una suspensión homologada de cada microorganismo. 2º etapa: un cono de cada tipo fue sumergido prevo a su utilización en 2 ml de caldo durante 24 horas. Luego, se retiraron los conos y se los depositó sobre placas de agar previamente sembradas igual que en la 1º etapa. Todas las placas fueron incubadas de acuerdo a los requerimientos de oxígeno y tiempo de cada microorganismo. Los resultados se registraron a través de la extensión de los halos de inhibición microbiana observada. Se midió el pH de los caldos con tiras indicadoras de pH (Merck) rango 0-14, previo a la inmersión de los conos y después de retirarlos. 3º etapa: los caldos que contuvieron los conos se inocularon en suspensiones de los microorganismos en estudio, transcurrido el tiempo de incubación, 20 ul de los caldos se sembraron en cajas de Petri, se incubaron y se realizó el recuento de unidades formadoras de colonias (UFC). Resultados: los conos con clorhexidina presentaron halos de inhibición en la 1º etapa con todos los microorganismos probados y en la 2º etapa con Sm, Ef, Ca, Sta y Pg. Los conos con hidróxido de calcio, tanto Hygienic como Roeko, no produjeron halos de inhibición con ninguna de las cepas probadas. El pH de los caldos no se modificó. En el recuento de UFC los conos con clorhexidina produjeron inhibición total para todas las cepas. Se encontró efecto significativo para material (p<0.05)(ANOVA). Puede concluirse que bajo las condiciones del presente estudio, los conos que contienen clorhexidina son los más efectivos sobre los microorganismos probados

Antimicrobial effect in vitro of chlorhexidine and calcium hydroxide impregnated gutta-percha points

El objetivo de este trabajo fue evaluar "in vitro" la actividad antimicrobiana de conos antisépticos para obturación temporaria frente a microorganismos endodontopáticos. Fueron empleados conos con hidróxido de calcio (Roeko(R) e Hygienic (H)) con clorhexidina (Roeko) y conos de gutapercha como testigos. Los microorganismos estudiados fueron Streptococcus mutans (Sm), Enterococcus faecalis (Ef), Staphylococcus aureus Sta), Candida albicans (Ca) (ATCC 3153), Fusobacterium nucleatum (Fn)(ATCC 25586), Porphyromonas gingivalis (Pg)(ATCC 33277) y Prevotella intermedia (Pi)(ATCC 25611). La experiencia se dividió en tres etapas: 1º etapa: un cono de cada tipo se colocó sobre la superficie de placas de agar previamente sembradas con una suspensión homologada de cada microorganismo. 2º etapa: un cono de cada tipo fue sumergido prevo a su utilización en 2 ml de caldo durante 24 horas.

Antimicrobial effect in vitro of chlorhexidine and calcium hydroxide impregnated gutta-percha points.

The aim of this study was to evaluate the antimicrobial activity of points containing antiseptics used for temporary obturation in endodontics. Points containing calcium hydroxide (Roeko and Hygienic), and chlorhexidine (Roeko) were tested and gutta-percha points served as control (Meta Dental Corp.). The following microorganisms were studied: Streptococcus mutans (Sm), Enterococcus faecalis (Ef), Staphylococcus aureus (Sta), Candida albicans (Ca), Fusobacterium nucleatum (Fn) ATCC 25586, Porphyromonas gingivalis (Pg) ATCC 33277, and Prevotella intermedia (Pi) ATCC 25611. The experiments were organized in three stages: 1st stage: one point of each kind was placed on agar plates previously seeded with microorganisms. 2nd stage: Another group of points was immersed in broth for 24 hours and placed on the seeded agar. Samples were then incubated at 37 degrees in the conditions of oxygen and for the time required by each microorganism. The zones of bacterial inhibition around each point were measured. The pH values of the broths were recorded. 3rd stage: the immersion broths were inoculated with suspensions of microorganisms, incubated, seeded on plates by dissemination and incubated. CFU counts were performed. RESULTS: points containing chlorhexidine showed inhibition zones with every microorganism in the 1st stage and, in the 2nd stage, with most of the microorganisms studied, except for Fn and Pi. Calcium hydroxide containing points did not inhibit any of the microorganisms assessed. Broth pH values did not exhibit any changes. CFU counts of the broths in which chlorhexidine points had been immersed showed total inhibition for all the microorganisms. The differences between materials were statistically significant (p<0.05) (ANOVA). In the conditions of this study, chlorhexidine-containing points proved to be effective against most of the tested strains.