The effect of passive ultrasonic activation of 2% chlorhexidine or 3% sodium hypochlorite in canal wall cleaning

OBJECTIVES the purpose of this study was to compare debris removal and open tubules effectiveness of sodium hypochlorite (NaOCl) and chlorhexidine (CHX) applied as final irrigation in different protocols Study Design: sixty extracted premolars were divided into six groups according to the final irrigation technique: A and B 3 % NaOCl or 2 % CHX with the Miraject needle and no agitation; C and D, passive ultrasonic irrigation (PUI) with Irrisafe 20 tips and 3 % NaOCl or 2 % CHX; E and F, PUI with Irrisafe 25 tips and 3 % NaOCl or 2% CHX. The remaining dentine debris and opened tubules were evaluated by SEM at three root levels by two blinded investigators. The Kruskal Wallis and the Mann-Whitney U test was used to compare groups and levels, with a significance of p<0.05. RESULTS Debris elimination was significantly higher in PUI groups (p<0.05). PUI groups showed a higher capability to open tubules, compared to groups A and B. In the coronal third, groups D to F eliminated more debris and opened more tubules than conventional irrigation (p<0.05). In medium third, group E eliminated significantly more debris (1.60) than group A (2.60). No differences were obtained among groups in apical third. Both NaOCl and CHX applied with PUI showed no differences in debris elimination or opened tubules. CONCLUSIONS Final PUI with Irrisafe tips was the most effective procedure for eliminating the debris and opening up dentinal tubules, independent of the irrigant solution or Irrisafe type size. Key words:Ultrasonic irrigation, PUI, sodium hypochlorite, chlorhexidine.