Background: The use of endodontic ultrasound (EUS) improves the irrigating properties of 5% NaOCl and its use on 2% CHX accelerates its degradation and production of parachloroanilina (PCA). The objective of this study was to quantify the PCA formed by the use EUS in an endodontic treatment using 5% NaClO and 2% CHX as irrigators.
Methods and Findings: In ex-vivo study, 30 premolars divided into control and two experimental groups underwent a protocolized endodontic treatment and divided into 13 phases, using 5% NaOCl and 2% chlorhexidine. EUS was used in phases 4,12 and 13. In phases 5,6,7,9,10 and 11 NaOCl was quantified by UV spectrophotometry. In phase 12 and 13 its quantified PCA by visible spectrophotometry.
The highest NaOCl values were found in experimental group No 1, these values of hypochlorite in all stages are greater than 40% to those found in the control group. These differences were statistically significant, p<0.05. Values found in control group and experimental group No 2 are much smaller and similar to each other. There were no differences between groups, with p>0.05.
PCA is found in the three groups, being higher in the experimental group No 1 worth 1.09 × 10-2 mg/ml. The measured values of PCA in experimental group No 2 are inferior to group 1 but much higher than the control group. Between the experimental groups Nos. 1 and 2 and the control group the differences were statistically significant (p<0.05), but between the experimental groups there was no statistical difference with p> 0.05.
Conclusions: Parachloroaniline was found and quantified in the three groups under study. The highest amount of PCA found is located in the experimental group No 1, where it was activated with endodontic ultrasound on 5% NaOCl. The maximum amounts of PCA formed could produce immunotoxic type effects.
Yevenes I, Neira M, Parada J, Correa V, Araya P