Aim: The aim of the present study was to evaluate and compare the antimicrobial efficiency of different irrigating solutions against Enterococcus faecalis with or without the use of 980 nm diode laser in infected root canals.
Materials and methods: A total of 100 freshly extracted human single-rooted teeth were divided into three experimental groups (n = 30) and one control group (n = 10). Experimental group was subdivided into two subgroups A and B (n = 15), whereas control group was subdivided into positive and negative controls (n = 5). After access cavity preparation, the root canals were prepared using ProTaper rotary instruments. A volume of 5 ml of 5.25% sodium hypochlorite and 17% Ethylenediaminetetraacetic acid, 1.2 ml of 2% chlorhexidine gluconate, and 2 ml of neem solution was used for irrigation in Group I, II, and III, respectively. E. faecalis (ATCC 29212) was inoculated into each canal of experimental groups and incubated for 2 weeks under aerobic conditions at 37°C. In all the subgroups B, laser irradiation was performed, whereas, in subgroup A, no laser irradiation was done. In negative control, E. faecalis was not inoculated in samples, but in positive control, E. faecalis inoculation and incubation procedure was followed. With circumferential filing using #40 reamer, dentinal chips were collected using sterile paper points, vortexed in sterile saline, was then applied to UTI Hicrome agar culture plates and incubated at 37°C for 48 h. The cfu/ml for each plate was calculated using a bacterial colony counter. The data obtained were subjected to statistical analysis using SPSS software version 20.0.
Results: The study showed that the least number of bacterial cfu/ml was observed in Group IB. The order of bacterial colony count (cfu/ml) was observed as Group IB <IA <IIB <IIA <IIIB <IIIA.
Conclusion: The study concluded that the groups with laser irradiation along with irrigation protocols were more efficient as compared with irrigation protocol alone.
Keywords: 980 nm diode laser; Enterococcus faecalis; antimicrobial efficiency; irrigating solutions.