Viability and antibacterial efficacy of four root canal disinfection techniques evaluated using confocal laser scanning microscopy

Abstract

Background:Several disinfection techniques have been recently introduced with the main objective of improving root canal disinfection in the inaccessible areas of the root canal system. This in vitro study was done to evaluate the antimicrobial effect and viability of Enterococcus faecalis biofilms using conventional irrigation, EndoActivator (Dentsply, Tulsa Dental, USA), diode laser irradiation and photon-initiated photoacoustic streaming (PIPS).Materials and Methods:Root canals of 130 single rooted mandibular premolars, standardized to a uniform length of 20 mm were instrumented until finishing file, F1 (Universal Protaper Rotary System, Dentsply, Tulsa Dental Specialties, USA). After smear layer removal and sterilization, five teeth were randomly selected to assure sterility before bacterial inoculation. The remaining 125 samples were contaminated with E. faecalis suspension, incubated for 21 days and divided into five groups (n = 25). In Group 1; untreated group (positive control), the root canals were not subjected to any disinfection procedure. Sampling was performed within the canals and the colony-forming unit count was evaluated for 20 samples. Five samples were selected to visualize the pattern of colonization at Level 1 (4 mm from the apex) and Level 2 (1 mm from the apex) by confocal laser scanning microscopy. Samples in Groups 2-5 namely conventional needle irrigation, EndoActivator, diode laser and PIPS were subjected to their respective disinfection procedures. Postdisinfection sample evaluation criteria was followed for all groups as same as that for Group 1.Results:Diode laser displayed the highest antibacterial efficacy and least viable bacteria than the other three disinfection techniques.Conclusion:Diode laser group showed better antibacterial efficacy and least viable bacteria when compared to conventional needle irrigation, PIPS and EndoActivator groups in minimally instrumented, experimentally infected root canals.

Comparison of efficacy of various root canal irrigation systems in removal of smear layer generated at apical third: An SEM study

“…The results are in accordance with the study done by Mathew et al , to evaluate antimicrobial efficacy where EndoActivator showed better results (1.79 ± 0.21 × 10 6 CFU/ml) than conventional needle irrigation (2.45 ± 0.22 × 10 6 CFU/ml). [ 9 ] This was also confirmed in the study where significantly greater efficiency of the EndoActivator against intracanal Enterococcus faecalis biofilm compared to the NaOCl irrigation alone was found. [ 10 ] Similar bacterial load reduction was reported by Pasqualini et al , (2010).…”

Effect of a passive sonic irrigation system on elimination of Enterococcus faecalis from root canal systems of primary teeth, using different concentrations of sodium hypochlorite: An in vitro evaluation

“…Clinical and in vitro studies show controversial results regarding the priority of sonic irrigation systems rather than routine syringe irrigation. 26 , 27 , 28 , 29 To the best of our knowledge, this is the first study evaluating the use of a sonic activation system in root canal irrigation of primary teeth and it was shown that activation with sonic devices would not significantly improve removal of the bacteria from the root canal systems of primary teeth. However, it should be considered that the current study was performed on single-rooted teeth.…”

Antibacterial effect of urushiol onE. faecalisas a root canal irrigant

“…However, it is unlikely to remove microorganisms completely because of the complex anatomy of the canal system such as fins, isthmuses, lateral canals, apical deltas, etc. 8 Therefore, persistence of intracanal bacteria is believed to be one of the most common causes of endodontic treatment failure. 9 …”