In vitro assessment of interaction between lidocaine hydrochloride and irrigating solutions on root canal dentin: a scanning electron microscope study / Evaluación in vitro de la interacción entre el clorhidrato de lidocaína y las soluciones de irrigación en la dentina del conducto radicular: un estudio con microscopio electrónico de barrid

Aim: To investigate the precipitate formed from the interaction between 2% lidocaine hydrochloride with adrenaline (LA) with 2.5% sodium hypochlorite (NaOCl) and 0.2% chitosan nanoparticles on root canal dentin, using scanning electron microscopy (SEM). Material and Methods: Sixty mandibular premolars were decoronated, and the root length standardised. The specimens were randomly distributed into the following groups: Group 1 (control): 2% LA mixed with sterile water without root canal instrumentation, Group 2: 2% LA with 2.5% NaOCl in water without root canal instrumentation, and Group 3: 2% LA with 0.2% chitosan nanoparticles in water without root canal instrumentation. Teeth specimens were split and subjected to SEM analysis at cervical, middle, and apical root thirds. On observing precipitate formation in Group 2, 10 premolars were decoronated and treated with 2% LA and 2.5% NaOCl and subjected to root canal instrumentation. Results: Group 1 and Group 3 showed patent dentinal tubules and no precipitate formation. Group 2 showed precipitate blocking dentinal tubules in all the three sections, and the precipitate could not be removed completely after cleaning and shaping. Conclusion: NaOCl forms an insoluble precipitate on interaction with local anaesthetic solution that cannot be removed after chemo-mechanical preparation. Chitosan nanoparticles do not form any such precipitate and show patent dentinal tubules. Hence, chitosan can be used as a flushing irrigant.

Objetivo: Investigar el precipitado formado a partir de la interacción entre el clorhidrato de lidocaína al 2% con adrenalina (LA), el hipoclorito de sodio al 2,5% (NaOCl) y nanopartículas de quitosano al 0,2% en la dentina del conducto radicular, mediante microscopía electrónica de barrido (SEM). Material y Métodos: Se decoraron 60 premolares mandibulares y se estandarizó la longitud de la raíz. Los especímenes se distribuyeron aleatoriamente en los siguientes grupos: Grupo 1 (control): 2% la que fue mezclado con agua estéril sin instrumentación del conducto radicular, Grupo 2: 2% LA con 2,5% de NaOCl sin instrumentación del conducto radicular y Grupo 3: 2 % LA con 0,2% de nanopartículas de quitosano sin instrumentación del conducto radicular. Las muestras de dientes se dividieron y se sometieron a análisis SEM en los tercios radiculares cervical, medio y apical. Al observar la formación de precipitado en el Grupo 2, 10 premolares fueron decorados y tratados con LA al 2% y NaOCl al 2,5% y sometidos a instrumentación de conductos radiculares. Resultado: El Grupo 1 y el Grupo 3 mostraron túbulos dentinarios permeables y sin formación de precipitados. El grupo 2 mostró precipitado que bloqueaba los túbulos dentinarios en las tres secciones, y el precipitado no se pudo eliminar por completo después de limpieza y conformación. Conclusión: el NaOCl forma un precipitado insoluble al interactuar con la solución anestésica local que no se puede eliminar después de la preparación quimiomecánica. Las nanopartículas de quitosano no forman ningún precipitado de este tipo y muestran túbulos dentinarios permeables. Por lo tanto, el quitosano se puede utilizar como irrigante para el lavado.

Bactericidal efficacy of electrochemically activated solutions and of commercially available hypochlorite.

Electrochemical activation (ECA) has been developed as a quick and efficient method of hypochlorite production, and many claim increased efficacy when compared to conventional disinfectant solutions. Numerous potential applications, including hospital disinfection, waste-water treatment, routine drinking water disinfection and biological decontamination have been suggested. In this study, three solutions were produced by electrochemical activation of 0.5% NaCl and compared to commercially available NaOCl. The NaOCl concentration and pH of each solution was measured, and the minimum bactericidal concentration of each was determined using seven common microbial pathogens. All solutions were effective, the most significant of which was the ECA anolyte solution. This is notable due to its neutral pH and antimicrobial efficacy that is four times that of commercially available NaOCl. This process may lead to production of a highly effective yet non-caustic disinfectant that would have countless scientific, medical, military and public health applications.

Sodium hypochlorite: history, properties, electrochemical production.

This paper analyses the evolution of hypochlorite as strong disinfectant. The electrochemical production of hypochloric acid or sodium hypochlorite represents the best method to obtain a pure product. To have a good production (as quality and quantity), it is necessary to optimize the electrochemical process with the optimal of electrocatalytic electrodes (cathode and anode) the gap between electrodes, the temperature of electrochemical cell. It is very important for the product stability during a long period, avoid the presence of heavy metal ions and particulate as impurity-like carbon micro-powders in suspension. It is necessary a rigorous control of the pH of final product to have the optimal disinfection power of hypochlorite solution. The most stable sodium hypochlorite solutions are those that show the following characteristics: (1) low concentration of hypochlorite; (2) pH -> 11.5 and <13; (3) absence of graphite particulate and metallic ions; (4) storage at controlled temperature <30 degrees C. Packing in containers impermeable to light.

Compatibility of electrolytically produced sodium hypochlorite solutions on long- term implanted dialysis catheters.

More than 20% of the world's population use a catheter for dialysis, despite guidelines limiting their use. Although the structure and design of the catheters differ by manufacturer, the material used in central venous catheters and peritoneal dialysis catheters are the same across manufacturers. Given the long-term use of these catheters in the dialysis population, the good compatibility of the antiseptics and disinfectants used on the catheters is imperative to prevent failure and cracking of the catheter material. Tensile strengths of commercially available catheters were measured after exposure to commonly used disinfectants. The tensile strength was then compared between the catheters by analyzing the displacement vs. force (N) curves produced during the evaluation. A total of 44 catheter lumens were evaluated. The electrolytically produced sodium hypochlorite solution, Alcavis 50/ExSept Plus, was the only solution shown to be compatible with all three catheter materials resulting in a deviation of less than 10% for each of the different catheter types. Electrolytically produced sodium hypochlorite solutions were the only solutions in this study that did not alter the physical properties of any of the catheters after long-term exposure.

Preparation of cellouronic acids and partially acetylated cellouronic acids by TEMPO/NaClO oxidation of water-soluble cellulose acetate.

Water-soluble cellulose acetates with a degree of substitution (DS) of 0.5, prepared by partial deacetylation of cellulose acetate of DS=2.5, were oxidized with catalytic amount of 2,2,6,6,-tetramethyl-1-piperidinyloxy radical (TEMPO), sodium hypochlorite, and sodium bromide to provide useful cellouronic acids. The oxidation was conducted at a constant pH of 10 and at 2 degrees C to avoid the occurrence of side products. Whereas only the primary hydroxyl groups of cellulose acetate were oxidized, a variable degree of oxidation (DO) resulted in a range of 0.33 to 1.0, depending on the concentration in sodium hypochlorite. Thus, polyglucuronic acid as well as partially acetylated cellouronic acid, having a range of DO were obtained.

Sodium hypochlorite and its use as an endodontic irrigant.

Sodium hypochlorite has been used as an endodontic irrigant for more than 70 years, and is now one of the most common solutions for this purpose. The chemical properties and production of commercial sodium hypochlorite are reviewed. Domestic bleaches and an infant sanitizer are compared from the point of view of cost and ease of use--Milton being recommended where a 1% solution is required. The cost of syringes and needles for endodontic irrigation is many times greater than the hypochlorite they contain, and total annual practice costs for hypochlorite are low. Brief guidelines for clinical use, storage, handling and disposal are included.

[Use of the electrochemical set ELMA-1 for preparation of sodium hypochlorite solutions in therapeutic and preventive institutions]. / Ispol'zovanie v lechebno-profilakticheskikh uchrezhdeniiakh élektrokhimicheskoi ustanovki ELMA-1 dlia polucheniia rastvorov gipokhlorita natriia.

A study was made of the small electrochemical set up MA-1 together with a possibility of its use in treatment-and-prophylactic institutions to prepare a disinfectant solution of sodium hypochlorite. As a result of the laboratory and practical tests it is recommended that the set up may be used for preparing disinfectant solutions of sodium hypochlorite in different treatment-and-prophylactic institutions. It is desirable that in practice of those institutions, 0.125-0.25-0.3-0.5% sodium hypochlorite solutions may be used depending on the type of the causative agent of an infectious disease.

Estudio in vitro del hipoclorito de sodio como irrigador / Study in vitro of the sodium hipochlorite as irrigant

Se realizó un estudio in vitro del Hipoclorito de Sodio al uno por ciento como irrigador de conductos radiculares. Los resultados indicaron que el Hipoclorito de Sodio no alcanzó el tercio apical de los conductos con diámetros inferiores al número 80, cuando fue llevado con el método de jeringa y aguja hipodérmica calibre 22. La solución irrigadora penetró más profundamente en los conductos cuando fue llevada con el método de inyectadora metálica y aguja hipodérmica calibre veintisiete