comparison of the antibacterial effect of Ozone gel, Nd: Yag laser and 2.5% Sodium hypochlorite on 6-week-old Enterococcus faecalis biofilm, an invitro study

Abstract

Background for treatment: Microorganisms are the most important cause of pulp and periapical diseases, which are mostly present as biofilms in the root canal. Among the resistant microorganisms, we can mention Enterococcus faecalis. Due to the anatomical complexity and root divisions, mechanical cleaning alone is not enough, and chemical cleaning with a disinfectant that has tissue compatibility, easy access, long shelf life and reasonable price is necessary. Today due to antibiotic resistance, the use of low-risk products has found great popularity among dentists and physicians. The use of new materials and equipments due to the advancement of endodontics such as ozone gel and Nd: YAG laser can help increase the success of endodontic treatment and reduce accidents during treatment. The aim of this study was to compare the antibacterial efficacy of Nd: Yag laser, 2.5% NaOCl and ozone gel as an irrigant to remove 6-week-old biofilm of Enterococcus faecalis. Materials and methods: In this study, 52 single-rooted teeth without abnormalities and root caries were used. After sterilization and cutting their crowns, the canals were prepared and cleaned. Under sterile conditions, one milliliter of standard suspension of Enterococcus faecalis was transferred to each of the microtubes containing the teeth, the microtubes were placed in an incubator for 6 weeks, and the microtubule suspension was changed daily. Then 4 random samples were examined to confirm the formation of biofilm under electron microscopy The rest of the samples were divided into 4 groups (n = 12). The first group was exposed to 2 ml of 2.5% sodium hypochlorite for 1 minute. A wave of 1064 nm, power 2 watts and frequency of 15 Hz, 4 times, each time 10 seconds with a time interval of 5 seconds applied and the fourth group as control group was exposed to normal saline for 1 minute and then dried with aseptic paper cone. Sampling was performed by Gates Gliding No. 4, then each of the debris was dissolved in 500 μl of normal saline and dilution method was used to obtain CFU / ML. Results: The lowest median CFU / ml was for the 2.5% sodium hypochlorite group and the Nd: Yag laser goup (=0), while the highest median was for the ozone group at 43,000 CFU / ml. Conclusion: Considering the limitations of this study, Nd: Yag laser group and 2.5% sodium hypochlorite showed significant antibacterial activity compaired to control group. The ozone gel group showed less antibacterial activity compared to control group, but there was no significant difference. Considering the results obtained, the Nd: Yag laser can be a good alternative to 2.5% sodium hypochlorite, but ozone gel had weak antibacterial properties in vitro and could not compete with 2.5% sodium hypochlorite.

Background for treatment: Microorganisms are the most important cause of pulp and periapical diseases, which are mostly present as biofilms in the root canal. Among the resistant microorganisms, we can mention Enterococcus faecalis. Due to the anatomical complexity and root divisions, mechanical cleaning alone is not enough, and chemical cleaning with a disinfectant that has tissue compatibility, easy access, long shelf life and reasonable price is necessary. Today due to antibiotic resistance, the use of low-risk products has found great popularity among dentists and physicians. The use of new materials and equipments due to the advancement of endodontics such as ozone gel and Nd: YAG laser can help increase the success of endodontic treatment and reduce accidents during treatment. The aim of this study was to compare the antibacterial efficacy of Nd: Yag laser, 2.5% NaOCl and ozone gel as an irrigant to remove 6-week-old biofilm of Enterococcus faecalis. Materials and methods: In this study, 52 single-rooted teeth without abnormalities and root caries were used. After sterilization and cutting their crowns, the canals were prepared and cleaned. Under sterile conditions, one milliliter of standard suspension of Enterococcus faecalis was transferred to each of the microtubes containing the teeth, the microtubes were placed in an incubator for 6 weeks, and the microtubule suspension was changed daily. Then 4 random samples were examined to confirm the formation of biofilm under electron microscopy The rest of the samples were divided into 4 groups (n = 12). The first group was exposed to 2 ml of 2.5% sodium hypochlorite for 1 minute. A wave of 1064 nm, power 2 watts and frequency of 15 Hz, 4 times, each time 10 seconds with a time interval of 5 seconds applied and the fourth group as control group was exposed to normal saline for 1 minute and then dried with aseptic paper cone. Sampling was performed by Gates Gliding No. 4, then each of the debris was dissolved in 500 μl of normal saline and dilution method was used to obtain CFU / ML. Results: The lowest median CFU / ml was for the 2.5% sodium hypochlorite group and the Nd: Yag laser goup (=0), while the highest median was for the ozone group at 43,000 CFU / ml. Conclusion: Considering the limitations of this study, Nd: Yag laser group and 2.5% sodium hypochlorite showed significant antibacterial activity compaired to control group. The ozone gel group showed less antibacterial activity compared to control group, but there was no significant difference. Considering the results obtained, the Nd: Yag laser can be a good alternative to 2.5% sodium hypochlorite, but ozone gel had weak antibacterial properties in vitro and could not compete with 2.5% sodium hypochlorite.