Comparative Evaluation of the Antibacterial Efficacy of Four Different Disinfection Techniques in Minimally Instrumented Experimentally Infected Root Canals: An in vitro Study

Abstract

Aim: This study was set out to evaluate the antibacterial efficacy of four disinfection techniques namely needle irrigation, diode laser, Photon-induced Photoacoustic Streaming (PIPS) with Er,Cr:YSGG and EndoActivator in minimally instrumented, experimentally infected root canals. Materials and methods: Eighty single-rooted teeth were selected, prepared to an apical size # 20, taper 0.7; the specimens were sterilized and were inoculated with Enterococcus faecalis for 2 weeks. Disinfection was performed with needle irrigation, 940 nm diode laser, PIPS with 2,740 nm Er,Cr:YSGG laser. After disinfection, aerobic sampling was performed and bacterial counts (colony-forming units) and the incidence of positive samples after 24 hours and 7 days were determined. Results: After the two time periods, all four disinfection protocols reduced the bacterial load when compared to the pretreatment load. None of the techniques predictably generated negative samples, but diode laser and PIPS with Er,Cr:YSGG was superior, when compared to needle irrigation and EndoActivator in this aspect. No statistically significant difference was found between needle irrigation and EndoActivator. Conclusion: Diode laser disinfection demonstrated significant elimination of E. faecalis in minimally instrumented canals. PIPS with Er,Cr:YSGG and EndoActivator reduced the bacterial load when compared with needle irrigation.