Antibacterial Effect of Red Laser Therapy on Enterococcus faecalis Using Different Photosensitizers: An In Vitro Study.

Franz Torres,Franco Mauricio,Americo Munayco,Adrian Mallma,Oscar Sotomayor,Frank Mayta-Tovalino,Mario Dioguardi

doi:10.1155/2022/7408554

Abstract

Objective To assess the antibacterial effect of red laser using different photosensitizers such as methylene blue and malachite green on monoradicular premolars contaminated with E. faecalis ATCC 29212. Methods This was an in vitro experimental study. Monoradicular premolars (44, 45, 34, and 35) were used, which were treated with ProTaper Next. After instrument change, irrigation, disinfection, and aspiration were performed with 2 ml of 4% NaOCl with a NaviTip 30°G needle (Ultradent, South Jordan, UT, USA). Group 1: RL + MB (red laser associated with methylene blue photosensitizer), group 2: RL + MG (red laser associated with malachite green photosensitizer), and group 3: control (no treatment). The E. faecalis strain was cultured on trypticase soy agar (TSB) (Difco, Detroit, MI, USA) and incubated at 37°C for 24 h. After the incubation period, colony-forming units (CFU/ml) of each group were counted using the plate count method. The ANOVA test was used with a significance level of p < 0.05. Results Group 1 had the lowest antibacterial contamination as it averaged only 530 ± 581.3 CFU/ml, while group 2 had the highest contamination with an average of 1990 ± 542.5 CFU/ml. Comparison revealed that there were statistically significant differences between the RL + MB and RL + MG groups (p < 0.001). Conclusions Group 1 had the best antimicrobial potential because it presented the lowest contamination in CFU/ml of E. faecalis compared to group 2 and group 3.

Highlights

Disinfection is one of the main purposes of endodontics because the reduction in the number of microorganisms in the root canal system will determine the potential success or failure of endodontic treatment, as in other pathologies of the oral cavity [1,2,3,4]
Enterococcus faecalis has the greatest resistance to endodontic treatment because of its ability to survive in very unfavourable conditions within the root canal system, which is why it has become one of the most prevalent bacterial strains in cases of endodontic reinfection [5,6,7,8]. erefore, the search for new alternative and/or complementary methods to conventional endodontic treatment is essential in reducing the rate of occurrence of endodontic failures
RL + MB: red laser associated with methylene blue photosensitizer; RL + MG: red laser associated with malachite green photosensitizer. ∗Shapiro–Wilk test; ∗∗ANOVA test

Summary

Objective

To assess the antibacterial effect of red laser using different photosensitizers such as methylene blue and malachite green on monoradicular premolars contaminated with E. faecalis ATCC 29212. Group 1: RL + MB (red laser associated with methylene blue photosensitizer), group 2: RL + MG (red laser associated with malachite green photosensitizer), and group 3: control (no treatment). E E. faecalis strain was cultured on trypticase soy agar (TSB) (Difco, Detroit, MI, USA) and incubated at 37°C for 24 h. Colony-forming units (CFU/ml) of each group were counted using the plate count method. Comparison revealed that there were statistically significant differences between the RL + MB and RL + MG groups (p < 0.001). Group 1 had the best antimicrobial potential because it presented the lowest contamination in CFU/ml of E. faecalis compared to group 2 and group 3

Introduction

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Conclusion