Avaliação da limpeza das limas endodônticas, antes de sua reutilização na instrumentação de canais radiculares

Abstract

The purpose of this study was to evaluate the cleanness condition of graduation students endodontic files as well as the knowledge about necessary cares for their reutilization. It was also evaluated three files cleaning forms related to endodontic treatments, with and without vitality and retreatments. In the first part of the study (questionnaire evaluation) 72.29% of the students registered on fifth to eighth semester answered four questions regarding the frequency that the files were used and sterilized, which cleaning form was used and which bio-safety cares were taken. With the evaluation of the answers gotten it can be observed the necessity to guide the students about the biosafety cares and the significance of carrying through the use control of each file, as well as its periodic substitution necessity. In the second research stage was evaluated 27 Kerr files series of 25 mm (15-40), of the students registered on fifth to eighth semester, with optic microscope Toolmaker`s (Mitutoyo Corporation) in a 40x increase, attributing values for the presence or absence of adhered debris in the surface of each millimeter of the file active section (0 absence; 1 debris presence on file points of sprinkled aspect of; 2 debris presence up to 50% and 3 presence in more than 50% of the surface). Only 20.14% of the evaluated sites were free of debris and when score 2 and 3 values were added (which represent visible presence debris with the naked eye) the value of 40, 20% was gotten, showing that the students are not carrying through the visual inspection after the instruments cleaning. In the last research stage eighteen files Kerr type series (15-40) of 25 mm (Dentsply/Malleifer) sterilized and ready for use, were divided in 3 groups corresponding to six endodontic treatments in teeth with pulp vitality, six teeth without pulp vitality and six with endodontic treatment necessity. During the vitality and non-vitality cases treatment the professional used sodium hypochlorite 2.5% as irrigating solution and saline solution for final irrigation, in retreatment cases beyond these solutions it was used eucalypt oil for guttapercha removal. When instrumentation was finished, the files were conditioned in a 100% humidity bottle and evaluated, following the described methodology, and after that they were submitted to one of the cleaning processes: file torsion against gauze damped in 70% alcohol, brush and detergent cleaning, and ultrasonic Cuba and detergent cleaning and evaluated again. All the tested cleaning processes promoted significant reduction in the debris values, however there was no method 100% effective in all analyzed situations.