Evaluation of sonic, ultrasonic, and laser irrigation activation systems to eliminate bacteria from the dentinal tubules of the root canal system

Abstract

Evaluation of sonic, ultrasonic, and laser irrigation activation systems to eliminate bacteria from the dentinal tubules of the root canal system Aiming to kill bacteria in dentin tubules of infected dental pulp cavities, we evaluated the effects of sodium hypochlorite (NaOCl) solution agitated by different irrigation protocols, i.e., conventional needle irrigation (CNI), passive ultrasonic irrigation (PUI), the EDDY tip, and the neodymium-doped yttrium aluminum perovskite (Nd:YAP) laser. The EDDY achieved good antibacterial effects as passive ultrasonic irrigation in the coronal and middle thirds. Nd:YAP laser irradiation and PUI were effective in the apical third of the root canal.Objectives: To evaluate the ability of NaOCl agitated by high-frequency sonic irrigation-EDDY, PUI, and Nd:YAP laser-to kill bacteria in infected root canal walls and if the associated temperature increases at the root surface during application. Methodology: Infected root canal models were established, and roots were randomly divided into six groups: negative control, positive control, CNI, PUI, sonic agitation with EDDY, and Nd:YAP laser groups. After irrigation, the teeth were split and stained using the LIVE/DEAD BacLight Bacterial Viability Kit. Dead bacteria depth was evaluated by a confocal laser scanning microscopy and the temperature at the root surface was assessed using a thermal imaging camera during the irrigation process. Results: In the coronal and middle thirds of the root canal, PUI and EDDY had stronger antibacterial effects than CNI (p<0.05); in the apical third, the antibacterial effects of PUI and Nd:YAP laser-activated irrigation were better than CNI (p<0.05). The maximum change in temperature was significantly greater during continuous Nd:YAP laser application compared with the other methods, but intermittent irrigation helped lessening this trend. Conclusions: NaOCl agitated by EDDY tip and PUI exhibited a similar bacteria elimination effect in the coronal and middle root canal. Nd:YAP laser was effective in the apical third and intermittent irrigation reduced its thermal impact.

Effect of different disinfection protocols in bacterial viability of an intraradicular biofilm formed in situ

“…The samples in those groups had a lower percentage of viable cells than the untreated samples. Previous investigations also found a positive effect of EC in the reduction of root canal infection using different methods 19 , 13 . Our results revealed that, even in a multispecies biofilm formed in situ , the biovolume of viable cells was significantly reduced in comparison with that found in untreated samples when this automated instrument for irrigant agitation was used.…”

“…The negative control samples confirmed the presence of biofilm in the root canals after volunteers had worn the appliances, as demonstrated by other investigations about in situ biofilms 20 , 22 ,. Monospecies biofilms, such as the one formed by Enterococcus faecalis , are commonly used to evaluate the antimicrobial effect of different protocols 19 , 23 , 27 . Multispecies biofilms can be produced in vitro by associating species such as Enterococcus faecalis , Eikenella corroden s, and Streptococcus anginosus 17 .…”

“…A considerable number of studies have evaluated different procedures for the disinfection of root canals 7 , 9 , 10 , 12 , 13 , 14 , 15 , 17 , 18 , 19 . However, there is no consensus in the literature about the effect of supplementary disinfection protocols on intraradicular multispecies biofilms under experimental conditions to simulate root canals with pulp necrosis.…”

Current Applications and Future Directions of Lasers in Endodontics: A Narrative Review

“…The results of a comparative study, which used transparent resin blocks in two standardized root canals as the test models, demonstrated that LAI using a 2940 nm Er:YAG laser resulted in greater biofilm-mimicking hydrogel removal than ultrasonically activated irrigation [ 41 ]. Another in vitro study performed by Liu et al [ 42 ] with thirty-eight mature single root canal premolars showed a different result. They found that the efficiency of passive ultrasonic irrigation for the purposes of bacteria removal presented more advantages in the coronal and middle thirds of the root canals when compared with LAI using a Nd:YAP laser, while both of them resulted in similar effects in the apical third.…”

Assessing the impact of obturation techniques, kinematics and irrigation protocols on apical debris extrusion and time required in endodontic retreatment

“…Moreover, the use of irrigant solutions associated or not with different activation techniques is necessary to achieve a better disinfection [17,18]. EDDY (VDW, Munich, Germany) is a sonic-powered device with a noncutting disposable polyamide tip (#25, taper 0.04) working at 5000 to 6000 Hz [19,20].…”