Dye Penetration Into Dentinal Tubules After Ultrasonic Passive Activation

Objectives: To compare the depth of dye penetration into the root canal dentinal tubules using passive ultrasonic irrigation (PUI) and traditional needle irrigation. Methods: Forty-three mandibular premolars with single straight root canal were instrumented using ProTaper rotary files to the apical size of F5, and final irrigated with 17% EDTA and 2.5% NaOCl. The teeth were randomly assigned to 2 experimental groups of 20 each. Group 1 received PUI. A stainless steel file (size 15) was inserted 1 mm short from working length, activated for 3 minutes and the 0.2 ml Safanin-O was replenished after every minute. Group 2 received traditional needle irrigation with Safanin-O for 3 minutes and the 0.2 ml Safanin-O was replenished after every minute. The roots were splited longitudinally and photographed with a digital camera. The apical portion of the root was magnified to 50X. The depth of dye penetration into the dentinal tubule was calculated at 2 mm, 6 mm and 10 mm from apical foramen as determined by Image Processing System. Results: Passive ultrasonic irrigation resulted in significantly (p< 0.001) better penetration of dye into the dentinal tubule at 2 mm, 6 mm and 10 mm from apical foramen compared to traditional needle irrigation. The 10 mm group revealed deeper dye penetration than the 6 mm and 2 mm groups and the 6 mm group showed better result than the 2 mm group. Conclusions: Passive ultrasonic irrigation resulted in better penetration of dye into the dentinal tubule.