Ozone therapy as an adjuvant for endondontic protocols: microbiological - ex vivo study and citotoxicity analyses

Effectiveness of supplementary antimicrobial procedures in disinfecting lateral canals as evaluated by a novel ex vivo analytical approach

This ex vivo study devised an analytical ex vivo method for infection/disinfection of simulated lateral canals located in the middle and apical segments of the root. The antibacterial effects of supplementary approaches were tested in this model. Extracted mandibular premolars had their main root canals enlarged and then two lateral canals (100 μm in diameter) were created in the root, one in the apical and the other in the middle portion. Micro-computed tomography was used for specimen selection and to confirm the quality of the simulated ramifications. The specimens were contaminated with a mixed bacterial culture from subgingival bacterial biofilm added to pure Enterococcus faecalis strain ATCC 29212 grown overnight, using special strategies to facilitate culture medium penetration within the lateral canals. The following procedures were tested for disinfection: NaOCl/passive ultrasonic irrigation (PUI), NaOCl/XP-endo Finisher, ozonated water/continuous ultrasonic irrigation (CUI), and NaOCl/conventional irrigation with 30-G needles (control). Bacteriological samples were taken from the main canal before (S1) and after (S2) each supplementary protocol, and also from each lateral canal after treatment (S3). DNA extracted from the samples was subjected to quantitative real-time polymerase chain reaction. All S1 main canal samples were positive for bacterial presence. Bacterial counts in the main root canal substantially decreased by 99.2% after PUI, 99.1% after ozone/CUI, 99% after XP-endo Finisher, and 96% in the control group (P < 0.01 for all groups). There were no significant differences between groups (P > 0.05). The same was observed when comparing the effects of the supplementary approaches in the apical and middle lateral canals (P > 0.05). Only a few lateral canals showed no detectable bacteria. The method proposed here proved effective for ex vivo infection/disinfection studies. All supplementary approaches induced a substantial bacterial reduction in the main canal, with no significant differences between them. However, in terms of lateral canal disinfection, none of the tested approaches showed significant effects when compared to the control group.

Non-surgical Management of Periapical Lesions With the Use of Newer Modalities in Adjunct to the Conventional: A Case Series

For endodontic therapy to be successful, the root canal space must be sterilized. This is often done using intracanal irrigants and medications. To accomplish periradicular region sterilization and healing, various intracanal medicaments and irrigation techniques have been researched for better treatment outcomes. Ozonated olive oil is the most researched and successful adjunct to other medicaments owing to its antibacterial properties. Triple antibiotic paste (TAP) (metronidazole, ciprofloxacin, and minocycline) was incorporated as an inter-appointment intracanal dressing. Currently, many newer advances are depicting synergistic effects in the elimination of persistent endodontic pathogens. Given this, in the current case series, periapical lesions were managed non-surgically for alternating weeks by the advent of triple antibiotic paste (TAP) and ozonated olive oil (O3-oil) with laser activation. Irrigation and its effects were further enhanced with the use of a laser, aiming for thorough debridement and rendering the canal free of microbes. Once the patient was asymptomatic and there was no sinus drainage seen, final obturation was done. Therefore, this case series depicts that traditional root canal therapy with the use of ozonated olive oil and laser activation can non-surgically heal the lesion, leading to successful treatment outcomes. Periapical lesions in three cases have been observed; on the initial visit, all lesions were accessible, cleansed, and shaped. We administered ozonated olive oil with laser activation and a triple antibiotic paste on the following visit. In all three cases, six-month follow-ups have shown evidence of a successful course of therapy.

Analysis of antimicrobial efficacy of sodium hypochlorite and ozonated water against biofilm in oval canals

This in vitro study compared the antimicrobial efficacy of 2.5% sodium hypochlorite (NaOCl) and 8 µg/mL ozonated water agitated by passive ultrasonic irrigation (PUI) or PUI combined with EndoActivator (EA) against mature multispecies biofilm. One hundred and five oval-shaped mandibular premolars were instrumented, sterilized, and inoculated with Enterococcus faecalis, Candida albicans, and Staphylococcus aureus, divided into: control group - saline; O3 group - ozonated water; O3 PUI group - ozonated water with PUI agitation; O3 PUI+EA group - ozonated water with PUI+EA agitation; NaOCl group - NaOCl; NaOCl PUI group - NaOCl with PUI agitation; and NaOCl PUI+EA group - NaOCl with PUI+EA agitation. Microbiological samples were collected before (S1) and after (S2) the disinfection procedures and the data were statistically analyzed using the Kruskal-Wallis test. In the culture method, there was significant disinfection in the O3 PUI+EA, NaOCl, NaOCl PUI, and NaOCl PUI+EA groups (p˂0.05). The combination of NaOCl with PUI+EA reduced microbial counts to zero (p˂0.05). In the qPCR method, there was a significant reduction in the total count of viable microorganisms in the O3 PUI, O3 PUI+EA, NaOCl, NaOCl PUI, and NaOCl PUI+EA groups (p˂0.05). It can be concluded that 2.5% NaOCl with and without agitation, as well as 8 µg/mL ozonated water with its action enhanced by the agitation techniques, were effective in root canal disinfection, and their antimicrobial efficacy is related to the microorganisms present in the biofilm.

Antimicrobial action of ozonated water and photodynamic therapy with sonic activation in root canals infected with Enterococcus faecalis

Background

New protocols are constantly being tested in the search for complete disinfection of root canals without the undesirable effects of sodium hypochlorite. This study evaluated the antimicrobial effect of ozonated water and photodynamic therapy (PDT) with sonic activation in root canals infected with Enterococcus faecalis.

Material and Methods

Seventy single-rooted canals of human teeth were prepared and contaminated with E. faecalis for 21 days. The teeth were divided into six experimental groups (n=10): ozonized water without (O + S-) and with sonic activation (O + S +); PDT without (PDT + S-) and with sonic activation (PDT + S +); PDT + ozonized water without (PDT + O + S-) and with sonic activation (PDT + O + S +); and two control groups, one positive (n = 5) and one negative (n = 5). Microbial collections were performed before and shortly after treatment, counted in the log of colony-forming units and tested for significant difference between these counts, if any (Student's t-test). The ANOVA two-way test was applied to evaluate whether the Treatment factor (Ozone, PDT and Ozone + PDT) and the Sonic factor (With and without sonic activation) had any effect on microbial reduction.

Results

In all protocols, there was a significant microbial reduction (p=0.025), whereas in the groups in which sonic activation was used, the microbial reduction was significantly greater (p=0.001).

Conclusions

The treatments significantly reduced the number of microorganisms in the root canals. Sonic activation helped to increase the microbial reduction in infected root canals. Key words:Endodontics, ozone, photodynamic therapy, enterococcus faecalis.

Ozonized Water in Microbial Control: Analysis of the Stability, In Vitro Biocidal Potential, and Cytotoxicity

O3 dissolved in water (or ozonized water) has been considered a potent antimicrobial agent, and this study aimed to test this through microbiological and in vitro assays. The stability of O3 was accessed following modifications of the physicochemical parameters of water, such as the temperature and pH, with or without buffering. Three concentrations of O3 (0.4, 0.6, and 0.8 ppm) dissolved in water were tested against different microorganisms, and an analysis of the cytotoxic effects was also conducted using the human ear fibroblast cell line (Hfib). Under the physicochemical conditions of 4 °C and pH 5, O3 remained the most stable and concentrated compared to pH 7 and water at 25 °C. Exposure to ozonized water resulted in high mortality rates for Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Enterococcus faecalis, and Candida albicans. Scanning electron micrograph images indicate that the effects on osmotic stability due to cell wall lysis might be one of the killing mechanisms of ozonized water. The biocidal agent was biocompatible and presented no cytotoxic effect against Hfib cells. Therefore, due to its cytocompatibility and biocidal action, ozonized water can be considered a viable alternative for microbial control, being possible, for example, its use in disinfection processes.

The antimicrobial effect of different ozone protocols applied in severe curved canals contaminated with Enterococcus faecalis: ex vivo study

The aim of this study was to evaluate 3 different irrigation protocols using ozone on monoculture biofilm of Enterococcus faecalis. Fifty disto-buccal roots of maxillary first molars were instrumented up to the size 25.08, sterilized and then incubated with Enterococcus faecalis for 21 days for biofilm maturation in the root canal walls. After contamination, the initial collection (S1) was performed and the 50 samples were divided in 3 experimental groups (n = 15) and 1 positive control group (n = 5) as follows: Group1: Ozonated water (40 µg/ml); Group2: gaseous ozone (40 µg/ml); Group3: Ozonated water (40 µg/ml) under continuous ultrasonic irrigation (CUI) and, Group 4: 2.5% sodium hypochlorite (positive control). The final collection (S2) was performed using hedstroem files # 25 by scraping the root canal wall and absorbed paper cone. The collected samples were analyzed by CFU/ml count and qPCR. To compare the effect of irrigation methods and to investigate E. faecalis count data, Kruskal-Wallis and Wilcoxon nonparametric tests were used at p < 05. The values of the differences between the S1 values and the S2 values revealed that the groups did not differ significantly for either E. faecalis CFU count data (p = 0.713) or q-PCR (p = 0.185), however, it is observed that for all groups, the CFU count of E. faecalis decreased over 99%. For the q-PCR assay, the reduction was on the order of 74-95%. Only the NaOCl positive control group presented total elimination of CFU/mL bacterial counting. The ozone protocols assessed were similar in regard to Enterococcus faecalis reduction.

Cytotoxicity assessment of different doses of ozonated water on dental pulp cells

Background

The purpose of this study was to assess the cytotoxicity of various concentrations of ozonated water (OW) on human primary dental pulp cells.

Methods

Human primary dental pulp cells were isolated from exfoliated primary canine teeth of an 11-year-old patient with good systemic and oral health. Afterwards, cells were divided into 6 experimental groups; four groups of OW in concentrations of 2 mg/L, 4 mg/L, 8 mg/L, and 16 mg/L, untreated control group, and cell culture without cells. Cytotoxicity was evaluated after exposure for 5-min exposure using Mosmann’s Tetrazolium Toxicity (MTT) assay at 0 h and 48 h time points. Data were analyzed using a repeated measures analysis of variance and Post-hoc tests were performed using Bonferroni correction for multiple comparisons.

Results

All experimental groups showed proliferation at 0 h time point. However, all groups also experienced a decrease in overtime at 48 h time point (p < 0.05). At both time points 2 mg/L OW showed the highest cell viability as well as proliferation. At 0 h time point, the increase in cell viability for all experimental groups was found statistically significant when compared to positive control group (p < 0.05). At 48 h time point, although 8 mg/L and 16 mg/L OW showed statistically significant reduction in compare to 0 h time point, 2 mg/L and 4 mg/L OW groups didn’t experience any statistically significant difference (p < 0.05).

Conclusion

Considering our findings, due to ozonated water's induced a higher proliferation rate of dental pulp cells, indicating their biocompatibility and a possible adjuvant on irrigating agent in regenerative endodontic procedures.

Antimicrobial efficacy of 2.5% sodium hypochlorite, 2% chlorhexidine, and ozonated water as irrigants in mesiobuccal root canals with severe curvature of mandibular molars

Objective

The aim of this study is to evaluate the antimicrobial efficacy of 2.5% sodium hypochlorite, 2% chlorhexidine, and ozonated water on biofilms of Enterococcus faecalis, Streptococcus mutans, and Candida albicans in mesiobuccal root canals with severe curvature of mandibular molars.

Materials and Methods

This was an experimental ex vivo study in microbiologic laboratory. Sixty mesiobuccal root canals with severe curvature of mandibular molars were contaminated with standard strains of E. faecalis, S. mutans, and C. albicans. The specimens were randomly divided into four groups (n = 15) according to irrigating solution: SH: 2.5% sodium hypochlorite; CH: 2% chlorhexidine; O₃: ozonated water; and control: double-distilled water. The mesiobuccal root canals of all groups were instrumented with the WaveOne Gold Primary reciprocating system. Three cycles of instrumentation with three short in-and-out brushing motions were performed: (1) in the coronal third, (2) in the middle third, and (3) in the apical third of the canal. A ProGlider file was used before the first cycle.

Statistical Analysis

Statistical analysis was performed using one-way analysis of variance followed by Tukey's multiple comparison test. Samples were collected for viable bacterial counts before and after instrumentation.

Results

All groups showed significant biofilm reduction after irrigation (P < 0.01). After instrumentation, sodium hypochlorite (98.07%), chlorhexidine (98.31%), and ozonated water (98.02%) produced a significantly reduction in bacterial counts compared with double-distilled water (control, 72.98%) (P < 0.01).

Conclusion

All irrigants tested in this study showed similar antimicrobial activity. Thus, ozonated water may be an option for microbial reduction in the root canal system.

Associations between ambient air pollution and mortality from all causes, pneumonia, and congenital heart diseases among children aged under 5 years in Beijing, China: A population-based time series study

BACKGROUND

Previous studies have mainly focused on the associations between particulate matters and infant mortality. However, evidence regarding the associations between gaseous pollutants and mortality among children aged <5 years remains sparse.

OBJECTIVES

The aim of this study was to investigate the associations between ambient air pollution and death among children aged <5 years in Beijing, China, and explore the impact of age, gender and specific causes of death on these associations.

METHODS

Concentrations of ambient air pollution and the number of deaths among children aged <5 years in Beijing from January 2014 to September 2016 were extracted from authoritative electronic databases. The associations were estimated for a single-month lag from the current month up to the previous 5 months (lag0-lag5) and moving averages of the current and previous months (lag01-lag05) using generalized additive Poisson regression (adjusted for time trends, season, meteorological variables and holidays). Subgroup analyses related to age, gender and specific diseases were performed. Two-pollutant models were used to evaluate the possible role of single pollutants.

RESULTS

Sulfur dioxide (SO₂), nitrogen dioxide (NO₂) and carbon monoxide (CO) demonstrated the strongest associations with death among children aged <5 years at lag0, and the estimates decreased or even turned negative with the increasing lag periods. For an interquartile range increase in SO₂, NO₂ and CO at lag0, the odds ratios (OR) were 1.332 (95% CI 1.152-1.539), 1.383 (95% CI 1.113-1.718) and 1.273 (95% CI 1.028-1.575). However, CO lost significance after adjusting for SO₂ and NO₂, and PM_2.5 gained significance (OR 1.548, 95% CI 1.061-2.258) after adjusting for PM₁₀. The ORs for SO₂ and NO₂ remained the most stable across all two-pollutant models. The associations for children aged 1-5 years were stronger than those reported for infants at lag0 but lower at the other lag months. The pollutant associations were stronger for congenital heart disease-related death than overall and pneumonia-related death. We did not find significant differences in terms of gender.

CONCLUSION

Exposure to air pollution may increase the incidence of death among children aged <5 years. SO₂ and NO₂ may be the most stable pollutants reflecting associations between air pollution and death, deserving further attention. Children with congenital heart diseases are more susceptible to air pollution. Therefore, it is urgent to implement the clean air targets established by WHO and reduce the exposure of children to air pollution.

Ozone ultrafine bubble water induces the cellular signaling involved in oxidative stress responses in human periodontal ligament fibroblasts

Periodontitis is a chronic inflammatory disease caused by oral microorganisms in the subgingival biofilm. Stable aqueous ozone ultrafine bubble water (OUFBW) has recently begun to be used as an antiseptic in the treatment of periodontitis. The effectiveness of OUFBW is thought to depend on the bactericidal actions of dissolved ozone exerted via its oxidizing effect. On the other hand, the effects of ozone on the periodontal tissues are largely unknown. In this paper we examined the cellular responses after OUFBW treatment. Human primary periodontal ligament fibroblasts (hPDLFs) or Ca9-22 human gingival epithelial cells were treated with OUFBW or UV-inactivated OUFBW. The production of reactive oxygen species (ROS), the activation of mitogen-activated protein kinase (MAPK) and the nuclear factor-kappa B (NF-κB) activation were analyzed. The transcript profiles of hPDLFs after OUFBW treatment were also analyzed by RNA sequencing (RNA-seq). Our results showed that OUFBW induces oxidative stress by generating ROS, which, in turn, activated the MAPK pathway. OUFBW triggered activation of c-Fos, a major component of the transcription factor activator protein 1 (AP-1), and also nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2), which possessed a high sensitivity to oxidative stress. The results of RNA-seq analysis revealed that the numerous genes involved in oxidative stress responses or MAPK signaling pathway were up-regulated after OUFBW treatment. Investigation of the signaling pathways activated by OUFBW highlights another aspect of the biological roles of OUFBW, in addition to its bactericidal activity, in the treatment of periodontitis.

Ozone therapy induced sinus arrest in a hypertensive patient with chronic kidney disease: A case report

RATIONALE

Ozone autohemotherapy as an alternative treatment method has been applied to the treatment of several diseases. Here, we report a patient used ozone autohemotherapy to treat her hypertension and diabetes. Nevertheless, the patient occurred sudden dizziness and black haze due to hyperkalemia.

PATIENT CONCERNS

A 54-year-old woman who was admitted to our emergency department complaining of sudden dizziness and black haze for 5 hours.

DIAGNOSES

The blood potassium test showed hyperkalemia. Upon further inquiry of her medical history, the patient received ozone autohemotherapy to treat hypertension and diabetes for 9 days prior to admission.

INTERVENTIONS

The ozone therapy had been asked to stop. Insulin, sodium bicarbonate, and sodium polystyrene sulfonate were administered to the patient.

OUTCOMES

After treatment, blood potassium remained in the normal range. After 3 days of treatment, the 24-hour dynamic electrocardiogram revealed sinus rhythm with an average heart rate of 82 beats/min, occasional ventricular premature beats, occasional ventricular premature beats, and no ST segment depression.

LESSONS

Although ozone therapy is widely used in the treatment of several diseases, adverse reactions should be given attention in clinical practice, especially in patients with chronic kidney disease.