In Vivo Antibacterial Efficacy of Ultrasound after Hand and Rotary Instrumentation in Human Mandibular Molars

Abstract

The purpose of this prospective, randomized, single-blind study was to compare the in vivo antibacterial efficacy of a hand/rotary technique versus a hand/rotary/ultrasound technique in mesial root canals of necrotic mandibular molars. The hand/rotary group consisted of 16 mesial roots prepared with a hand/rotary technique. The hand/rotary/ultrasound group consisted of 15 mesial roots prepared similarly, followed by 1 minute of ultrasonic irrigation per canal with an ultrasonic needle in a MiniEndo unit and 15 mL/canal of 6.0% sodium hypochlorite. Canals were sampled before and after instrumentation and after 1 minute of ultrasonic irrigation. Samples were incubated anaerobically on reduced blood agar for 7 days at 37 degrees C, and colony-forming units (CFUs) were counted. The addition of 1 minute of ultrasonic irrigation resulted in significant (p = .0006) reduction in CFU count and positive cultures (p = .0047). Logistic regression analysis indicated the addition of ultrasonic irrigation was 7 times more likely to yield a negative culture.

Irrigation effectiveness of continuous ultrasonic irrigation system: An <i>ex vivo</i> study

“…However, neither method addresses a potential confounder variable that is the influence of the apical anatomy on the potential extrusion of the irrigating solution. The apical third of the root has reportedly the highest incidence of accessory canals and apical deltas 32,23) . In addition, accessory apical foramina have also been shown to exist in mandibular molars 34) and could very well be present in other teeth.…”

“…Although the CUIS (CUI with saline) was able to completely remove the SL at the coronal level in 5 specimens that might be due to the ultrasonication, it was unable to remove the SL more apically. Previous studies revealed that ultrasonic irrigation cannot get through the apical area due to vapor lock 23,44) . However, with the aid of NaOCl, results showed the maximum SL removal in the apical third was attained equally with the EV and CUI (Table 3).…”

“…These mechanisms are responsible for a greater reduction of the intracanal biofilm 23,24) . The ultrasonic application mode might be intermittent or continuous.…”

Pressure Alteration Techniques in Endodontics- A Review of Literature

“…This may be due to the much higher velocity and volume of irrigant flow that are created in the canal during ultrasonic irrigation. Ultrasonics can effectively clean debris and bacteria from the root canal system, but cannot effectively get through the apical vapor lock [31][32][33].…”

Comparison of the Efficacies of Debris Removal With Four Different Irrigation Techniques

“…Recently, with its gradually increasing popularity, passive ultrasonic activation of endodontic instruments has been suggested as a means to improve canal debridement [13], canal disinfection [14] and canal sealing [15]. Passive ultrasonic irrigation (PUI) has also been recommended for removing Ca(OH) 2 from the root canal [16].…”