Influence of concentration, time and method of application of citric acid and sodium citrate in root conditioning

objectives: the aim of this study was to establish the parameters of concentration, time and mode of application of citric acid and sodium citrate in relation to root conditioning. material and methods: a total of 495 samples were obtained and equally distributed among 11 groups (5 for testing different concentrations of citric acid, 5 for testing different concentrations of sodium citrate and 1 control group). after laboratorial processing, the samples were analyzed under scanning electron microscopy. a previously calibrated and blind examiner evaluated micrographs of the samples. non-parametric statistical analysis was performed to analyze the data obtained. results: brushing 25% citric acid for 3 min, promoted greater exposure of collagen fibers in comparison with the brushing of 1% citric acid for 1 minute and its topical application at 1% for 3 min. sodium citrate exposed collagen fibers in a few number of samples. conclusion: despite the lack of statistical significance, better results for collagen exposure were obtained with brushing application of 25% citric acid for 3 min than with other application parameter. sodium citrate produced a few number of samples with collagen exposure, so it is not indicated for root conditioning.