ABSTRACT
Abstract: Microscopic measurements are widely used in scientific research and the correct equipment to perform these evaluations could be critical to determine study results. Regarding microscopic measurements, three of the most used methods are: Optical Microscopy (OM), Scanning Electron Microscopy (SEM), and Micro-computed Tomography (MCT). It is important to select the best method for assessing diverse parameters, considering operational characteristics of the method, the equipment efficiency, and the machinery cost. Aim: Therefore, the main objective of this study was to define which is the most useful measurement method for assessing magnitudes below 0.4 mm. Methods: Ten dental implants, with known dimensions as defined by the manufacturer were randomly distributed. Two blinded observers assessed the distance between the second and the third screw vortex of the implants using three suggested methods. The true distance was defined to be 0.5 mm. Results: The assessed distances were: 0.597±0.007mm for OM, 0.578±0.017mm for SEM, and 0.613±0.006mm for MCT. The assessed distances were significantly different when the methods were compared (P>0.01). All measurements were into the CAD tolerances. Conclusion: It was possible to conclude that linear easurements between 595 and 605 µm could be performed by any of the described technologies (AU)
Subject(s)
Dental Implants , Microscopy, Electrochemical, Scanning/methods , Microscopy/methods , X-Ray Microtomography/methodsABSTRACT
Introduction: the recent enhancement of interest in green consumerism has given rise to a renewed scientiï¬c awareness towards essential oils. Essential oil from Baccharis trimera (Less.) DC. (B. trimera) (Asteraceae) is cited as one of the ten most consumed oils by the cosmetic and other industries in Brazil. Objective: to investigate the antimicrobial activity of the essential oil from the leaves of B. trimera against Staphylococcus epidermidis ATCC 12228, Proteus vulgaris ATCC 13315, Micrococcus luteus ATCC 7468 and Corynebacterium xerosis IAL105, which are the main bacteria responsible for bad perspiration odor. Methods: the gas chromatography (GC) analysis was performed and the antimicrobial activity was evaluated by means of the turbidimetric method, using a microdilution assay. Results: ywenty constituents were identified, being that ß-pinene (23.4 percent) was the major compound found. The minimum inhibitory concentration (MIC) values of the essential oil ranged from 500 µg/mL to 1,000 µg/mL. A detrimental effect of the essential oil was observed on the morphology of cell membranes of the bacteria studied by scanning electron microscopy (SEM). Conclusions: the results demonstrate the essential oil of B. trimera has potential in the application of antimicrobial agents in personal care products(AU)
Introducción: el reciente aumento del interés por el consumo verde ha dado lugar a una renovada conciencia científica hacia a los aceites esenciales. El aceite esencial de Baccharis trimera (Less.) DC. (B. trimera) (Asteraceae) es considerado uno de los diez aceites más consumidos por la industria cosmética del Brasil. Objetivos: valorar la actividad antimicrobiana del aceite esencial de hojas de B. trimera frente al Staphylococcus epidermidis ATCC 12228, Proteus vulgaris ATCC 13315, Micrococcus luteus ATCC 7468 y Corynebacterium xerosis IAL105, que son las principales bacterias responsables del mal olor que es consecuencia de la transpiración. Métodos: se realizó la cromatografía de gases (GG) y la actividad antimicrobiana fué valorada por el método turbidimétrico, usando el ensayo de microdilución. Resultados: se identificarón veinte constituyentes, siendo el ß-pineno (23,4 por ciento) el principal compuesto encontrado. Los valores de la concentración mínima inhibitoria (CMI) del aceite esencial variaron de 500 µg/mL a 1,000 µg/mL. Se observó un efecto perjudicial del aceite esencial en la morfología de las membranas celulares de las bacterias estudiadas por microscopía electrónica de barrido (SEM). Conclusión: los resultados demuestran que el aceite esencial de B. trimera tiene potencial en la aplicación de los agentes antimicrobianos en productos de higiene personal(AU)