The Effect of Diode Laser on Planktonic Enterococcus faecalis in Infected Root Canals in an Ex Vivo Model

Comparison of the Enterococcus faecalis Colony Reduction Effect of Two Wavelengths of Diode Lasers With Three Methods of Root Canal Irrigation: An In Vitro Study

Introduction: The basis of successful root canal therapy is the reduction of microorganisms. The aim of this in vitro study was to compare the antibacterial effect of three different irrigation methods with two laser wavelengths on Enterococcus faecalis biofilm. Methods: Ninety-five single-canal teeth were prepared, sterilized, and divided randomly into a negative control, a positive control, and five test groups. They were inoculated with the standard strain of E. faecalis. The test groups were conventional irrigation (group 1), Passive ultrasonic irrigation (group 2), Gentle file finisher brush (group 3), 810 nm diode laser (group 4), and 980 nm diode laser (group 5). Microbial sampling, cultivation, and colony counting were done. Data were analyzed with the Kruskal-Wallis test and a negative binomial regression model. Results: There was a significant difference in the colony count between the groups (P<0.001). the 810 nm diode had the highest and the conventional irrigation group had the lowest reduction in the microbial load. Passive ultrasonic, 980 nm diode laser, and Gentle file finisher brush groups were also ranked respectively from the highest to the lowest in terms of decreasing effect on the number of colonies. Conclusion: The 810 nm diode laser and conventional irrigation were respectively the most and the least effective methods for reducing the number of E. faecalis colonies.

The efficacy of 2780 nm Er,Cr;YSGG and 940 nm Diode Laser in root canal disinfection: A randomized clinical trial

OBJECTIVES

Effective disinfection of the root canals is the cornerstone of successful endodontic treatment. Diminishing the microbial load within the root canal system is crucial for healing in endodontically treated teeth. The aim of this study was to evaluate the effect of 2780 nm Er,Cr:YSGG and 940 nm diode lasers on the eradication of microorganisms from single-rooted teeth with asymptomatic apical periodontitis.

MATERIALS AND METHODS

Thirty participants conforming to the inclusion criteria were randomly divided into 3 groups according to the disinfection protocol used; Conventional group: 2.5% Sodium Hypochlorite (NaOCl) and 17% EDTA solution NaOCl/EDTA, Dual laser group: 2780 nm Erbium, chromium: yttrium scandium-gallium-garnet (Er,Cr:YSGG) laser and 940 nm diode laser Er,CrYSGG/Diode, and Combined group: 17% EDTA and 940 nm diode laser EDTA/Diode. Bacterial samples were collected before and after intervention. The collected data were statistically analyzed using Friedman's test and Kruskal-Wallis test (P ≤ 0.05).

RESULTS

The results of the study showed that both dual laser Er,CrYSGG/Diode and combined laser EDTA/Diode groups showed significantly less mean Log10 CFU/ml of aerobic and anaerobic bacterial counts than the conventional NaOCl/EDTA group.

CONCLUSIONS

In this study we evaluated in vivo the bactericidal efficacy of three disinfection protocols for endodontic treatment of single-rooted teeth with apical periodontitis. The results indicated that both dual laser Er,CrYSGG/Diode and combined laser EDTA/Diode groups provide superior bactericidal effect compared to the conventional NaOCl/EDTA group.

CLINICAL RELEVANCE

The integration of lasers into root canal disinfection protocols has demonstrated significant bacterial reduction which might promote healing and long-term success.

Physico-chemical and antimicrobial properties and the shelf life of experimental endodontic sealers containing metal methacrylates

The objective of this study was to evaluate the physico-chemical and antimicrobial properties of a dual polymerization experimental endodontic sealer (E) and experimental sealers containing dibutyltin methacrylate (Sn²⁺) (ETs) or calcium methacrylate (Ca²⁺) (ECs). The pH and ion release levels of the sealers were measured. The dimensional stability was evaluated in accordance with ISO 6876. Biofilm growth inhibition was evaluated using confocal laser scanning microscopy (CLSM). Biofilm viability analysis was performed using the SYTO 9 technique. The shelf life was evaluated through the degree of conversion and film thickness tests after the sealers had been stored for different periods of time. For statistical analysis, ANOVA and Tukey's post hoc test were used, with a significance level of 5%. ETs revealed better anti-biofilm potential after 15 days than that of the controls. The degree of conversion was reduced after the shelf-life period. The addition of calcium and dibutyltin methacrylate improved the anti-biofilm properties of the experimental endodontic sealer without impairing their physico-chemical properties.