Author/Authors :
Hendi, Sareh Department of Endodontics - Dental School - Hamadan University of Medical Sciences, Hamadan, Iran , Shiri, Maryam General Dentist - Hamadan University of Medical Sciences, Hamadan, Iran , Poormoradi, Banafsheh Dental Research Center - Department of Periodontology - Dentistry Faculty - Hamadan University of Medical Sciences, Hamadan, Iran , Alikhani, Mohammad Yousef Faculty of Medicine - Microbiology Department - Hamadan University of Medical Sciences, Hamadan, Iran , Afshar, Saeid Department of Molecular Medicine and Genetics - School of Advanced Technologies in Medicine, Molecular Medicine Research Center - Hamadan University of Medical Sciences, Hamadan, Iran , Farmani, Abbas Dental Research Center - Hamadan University of Medical Sciences, Hamadan, Iran.
Abstract :
Introduction: The final goal of root canal therapy is to remove of the most bacteria from the root
canal. This study aimed at comparing the antibacterial effects of a diode laser with a wavelength
of 940nm and silver nanoparticles and the synergic effects of both techniques on Enterococcus
faecalis.
Methods: Ninety single-rooted human teeth were decoronated and prepared with rotary files. The
samples were irrigated with sodium hypochlorite and EDTA17%. Then they were autoclaved and
contaminated with E. faecalis suspension (1.5 × 108
CFU/mL) for 21 days. The samples were fixed in
a microtube and were randomly divided into 4 experimental (n=20) groups and a negative control
group (n=10) as follows: Group 1: hypochlorite sodium 5%, Group 2: silver nanoparticle, Group
3: diode laser, and Group 4: diode laser and silver nanoparticle. The samples were obtained from
dentin chips before and after the intervention. The data were analysed using the Kruskal-Wallis
nonparametric test. Furthermore, alterations in bacterial colonies were entered using the Wilcoxon
signed ranks test (α=0.05).
Results: There was a significant decrease in colony counts for all groups after interventions (P
value<0.05). Also, all groups showed more reductions in colony counts compared with the negative
control group (P value
<0.004). There was a significant reduction for group 1 in comparison with other
groups (P value
<0.001) and this group had an extreme decrease of colony counts (RCC=100%).
There was an important differential between silver nanoparticles and diode laser groups in bacterial
counts (P value<0.001) and silver nanoparticles (RCC=83.15%) had more efficiency than the diode
laser (RCC=41/33%). RCC of group 4 was 68/52%.
Conclusion: Followed by sodium hypochlorite 5%, silver nanoparticles were the most effective
antibacterial substances. The 940 nm laser diode had less antibacterial effect compared to its use
with silver nanoparticles.
Keywords :
Root Canal Therapy , Laser Diode , Silver Nanoparticles , Hypochlorite Sodium , Enterococcus faecalis
