Comparative study of hyperpure chlorine dioxide with two other irrigants regarding the viability of periodontal ligament stem cells

Comparison of antimicrobial efficacy of different disinfectants on the biofilm formation in dental unit water systems using dip slide and conventional methods: A pilot study

OBJECTIVE

Biofilm formation in dental waterlines brings opportunistic infections, especially for immunosuppressive patients. This study aimed to determine biofilm-forming microorganisms by various methods and investigate disinfectants' effects on biofilm.

MATERIALS & METHODS

In the study, samples were obtained from the waterlines of 10-15 aged six dental units, before (0 min.) and after chlorine dioxide (ClO2) and hypochlorous acid (HOCl) treatment (1, 5, 10, 20, and 30 min.), and total colony counts were performed using conventional surface smear method (SSM) and dip slide method (DSM). The Congo red agar and Christensen methods were used to examine the biofilm-forming properties of the isolates. Monitoring of biofilm presence was also visualized by SEM scanning.

RESULTS

When DSM and SSM are compared in all units where ClO2 and HOCl are applied, DSM can detect bacterial growth even during periods of greater exposure to disinfectant application. Although DSM can achieve a value approaching 3% even at the 10th minute in units treated with HOCl; SSM does not show reproduction at the same disinfectant exposure and duration; It was observed that in the units where ClO2 was applied, the growth was no longer observed at the 10th minute with DSM, and SSM, 50% growth in the first minute of the units treated with ClO2 could not be detected in the 5th minute.

CONCLUSIONS

It is concluded that it can be advisable to routinely disinfect the dental unit water systems with non-toxic doses of ClO2 application before patient treatments in clinics and also to perform contamination controls at regular intervals with DSM, which is a sensitive and very practical method.

RESEARCH HIGHLIGHTS

It has been observed that the dip slide method can count bacteria more sensitively than conventional methods in dental water systems without the need for experienced personnel and equipment. The difference between biofilm formation in water systems before and after disinfectant exposure in SEM examinations is remarkable. The effects of ClO2 and HOCl on biofilm were investigated and bacterial growth was inhibited in dental units between 5 and 10 minutes with both disinfectants.

Hyperpure chlorine dioxide versus chlorhexidine in intra-oral halitosis (ODOR trial) - protocol of a double-blinded, double-arm, parallel non-inferiority pilot randomized controlled trial

INTRODUCTION

Intra-oral halitosis (IOH) is the most common type of bad breath; its consequences impair quality of life. However, evidence-based treatment protocols and guidelines are lacking. Our aim is to investigate the effectiveness of chlorine dioxide as an applicable complementary treatment modality in IOH after tongue cleaning.

METHODS AND ANALYSIS

The ODOR trial will be a single-center, double-blinded, parallel-group, double-armed pilot randomized controlled trial with a non-inferiority design. The efficacy of hyperpure chlorine dioxide will be compared to chlorhexidine mouthwash. We plan to investigate the short-term effects of the intervention over a 3-h period. The primary endpoint will be changes in organoleptic test scores. At the end of the pilot investigation of the first 30 patients each, sample size calculation will be performed. If feasible, the investigators will continue the study by enrolling more patients.

TRIAL REGISTRATION

The trial has been registered at ClinicalTrials.gov (NCT06219226).

Antimicrobial efficacy of sodium hypochlorite and hyper-pure chlorine dioxide in the depth of dentin tubules in vitro

OBJECTIVES

The study aimed to compare the antibacterial effect of a novel disinfectant, hyper-pure chlorine dioxide (hClO2) to sodium hypochlorite (NaOCl) in various depths of dentin tubules.

MATERIALS AND METHODS

The distal root of the extracted lower molars was infected artificially with Enterococcus faecalis. The control group was rinsed with saline, and the test groups were irrigated with either 5% NaOCl or 0.12% hClO2. The longitudinally split teeth were stained by viability stain. The coronal third of the root was scanned with a confocal laser scanning microscope. The fluorescent intensities were measured, and the percentage of dead bacteria was calculated at depths up to 950 μm along the dentin tubules. The effect of penetration depth, irrigants, and their interaction on antimicrobial efficacy was determined by the linear mixed model.

RESULTS

The percentage of dead bacteria was higher both in the NaOCl (45.1 ± 2.3%, p < 0.01) and in the hClO2 (44.6 ± 3.8%, p < 0.01) irrigant groups compared to saline (23 ± 4.5%); however, there was no difference between them. The percentage of killed bacteria was not correlated with the depths in any group (p = 0.633).

CONCLUSIONS

Our results suggest that the functional penetration depth of NaOCl is at least 2-3 times more than published to date. There is no difference in disinfection effectiveness along the dentin tubules between NaOCl and hClO2 until at least the measured 950 μm. However, both were only able to eradicate the intratubular bacteria partially.

CLINICAL RELEVANCE

Hyper-pure ClO2 could be used as an alternative or final adjuvant irrigant in endodontic treatment.

Short- and long term antibacterial effects of a single rinse with different mouthwashes: A randomized clinical trial

Objectives

Reducing the microbial level in the aerosol created during dental procedures is essential to avoiding infections. The aim of this study was to examine the change in Streptococcus mutans (S. mutans) and the total bacterial load in human saliva in vivo after a single rinse with different mouthwashes.

Material and methods

One mL of unstimulated saliva was collected from volunteers with poor oral hygiene at baseline and 5 min after a 1-min rinsing with diluted Solumium Oral® (hyper-pure 0.0015% chlorine dioxide; ClO₂), Listerine Total Care®, Corsodyl® (0.2% chlorhexidine-digluconate; CHX), or BioGate Si*CLEAN for bacterial investigation. In a second study, volunteers rinsed with 0.003% ClO₂ or CHX for 1 min, and saliva was collected at baseline, after 5 min, and after 90 min. After plating, the total plate and S. mutans colony numbers were determined.

Results

In the first study, ClO₂ and CHX similarly reduced both total germ and S. mutans numbers, while Listerine Total Care® decreased only the S. mutans counts. BioGate Si*Clean had no effect on either the total germ or S. mutans numbers. In the second study, an increasing tendency toward bacterial regrowth was observed with CHX after 90 min compared to the 5-min value, while no change was measured after ClO₂ rinsing.

Conclusion

Hyper-pure ClO₂ rinsing may be a new promising preventive and therapeutic adjuvant in dental practice, as it is similar in effectiveness to the gold standard CHX-containing mouthwashes, especially in patients concerned with taste or tooth discoloration during oral health therapy.

Daily use of chlorine dioxide effectively treats halitosis: A meta-analysis of randomised controlled trials

OBJECTIVES

We aimed to conduct a systematic review on published data in order to investigate the efficacy of mouthwash products containing chlorine dioxide in halitosis.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

Our search was conducted on 14th October 2021. We searched the following electronic databases: MEDLINE, Embase, Scopus, Web of Science, and CENTRAL. We analysed data on adults with halitosis, included only randomised controlled trials and excluded in vitro and animal studies. The interventional groups used chlorine dioxide, and the comparator groups used a placebo or other mouthwash. Our primary outcomes were changes in organoleptic test scores (OLS) and Volatile Sulfur Compound (VSC) levels from baseline to the last available follow-up.

RESULTS

We found 325 articles in databases. After the selection process, ten articles were eligible for qualitative synthesis, and 7 RCTs with 234 patients were involved in the meta-analysis. Our findings showed a significant improvement in the parameters of the chlorine dioxide group compared to the placebo group in OLS one-day data (mean difference (MD): -0.82; 95% confidence intervals (95% CIs): [-1.04 --0.6]; heterogeneity: I2 = 0%, p = 0.67); and one-week OLS data (MD: -0.24; 95% CIs: [-0.41 --0.07]; I2 = 0%, p = 0.52); and also changes in H2S one-day data (standardised mean difference (SMD): -1.81; 95% CIs: [-2.52 --1.10]); I2 = 73.4%, p = 0.02).

CONCLUSION

Our data indicate that chlorine dioxide mouthwash may be a good supportive therapy in oral halitosis without known side effects.

The effects of mouthwashes in human gingiva epithelial progenitor (HGEPp) cells

OBJECTIVES

The gingiva epithelium accounts for a significant proportion of the surface around the tooth. An inflammatory reaction occurs in the presence of bacterial biofilm, adhesion is reduced, and the depth of the sulcus gingivalis increases. The most common antiseptic agents in oral rinses are chlorhexidine digluconate (CHX) and cetylpyridinium chloride. We examined long-lasting effects of residual concentrations of eight commercially available rinses. Our main goals were (i) to analyze the effect of different chemical compositions on cell proliferation, (ii) to examine apoptosis, and (iii) cell morphology on human epithelial progenitor cell line (HGEPp).

MATERIALS AND METHODS

Cell proliferation was measured in a real-time system (0-48 h) by impedimetry (xCELLigence). Apoptosis was measured with labeled Annexin-V (BD-FACScalibur).

RESULTS

Changes in proliferation were measured at certain concentrations: (i) H₂O₂ proved to be cytotoxic at almost all concentrations; (ii) low concentrations of CHX (0.0001%; 0.0003%) were proliferation inducers, while higher concentrations were cytotoxic; (iii) for ClO₂, advantageous proliferative effect was observed over a broad concentration range (0.06-6 ppm). In mouthwashes, additives in the formulation (e.g., allantoin) appeared to influence cellular responses positively. Apoptosis marker assay results suggested a low-level activation by the tested agents.

CONCLUSIONS

Mouthwashes and their reference compounds proved to have concentration-dependent cytotoxic effects on human gingival epithelial cells.

CLINICAL RELEVANCE

A better understanding of the effects of mouthwashes and their reference compounds is particularly important. These concentration-dependent effects (cytotoxic or proliferation inducing) interfere with human cells physiology while being used in the fight against the pathogenic flora.

Type 1 Diabetic Patients After Simultaneous Pancreas and Kidney Transplantation Have Less Intense Periodontal Inflammation Compared to Kidney Recipients Treated with Insulin

BACKGROUND Long-term diabetes predisposes to pathological changes in periodontal tissues. Improvement in this respect can be expected in patients after pancreas transplantation. The aim of this study was to assess and compare the intensity of periodontium pathological lesions and inflammation markers concentration in gingival crevicular fluid (GCF) in patients with type 1 diabetes (T1D) after kidney (KTx) or simultaneous pancreas and kidney transplantation (SPK). MATERIAL AND METHODS The study included 20 T1D patients after SPK and 16 after KTx, and 15 non-diabetic kidney recipients (control). Periodontal clinical parameters and concentration of selected biochemical markers of inflammation in GCF were assessed. The following tests were used in statistical data analysis: Shapiro-Wilk test, the t test, the Mann-Whitney U tests, one-way ANOVA with Tukey's post hoc test, and χ² test (also with Yate's correction). Moreover, linear regression and Pearson or Spearman correlation coefficient was used. RESULTS There were no differences in modified Sulcus Bleeding Index (mSBI) and GCF volume between the SPK group and control group, whereas values of these parameters in the KTx group were higher than in the SPK and control groups. Maximal clinical attachment loss and pocket depth and Periotest values were higher in diabetic recipients compared to controls, and did not differ between SPK and KTx. The concentration of IL-1ß, MMP-8, resistin, TNFalpha, and YKL40 in the GCF in the KTx group was higher than in the SPK and control groups. In the combined group of T1D patients, there was a correlation between blood HbA1c and mSBI, GCF volume, and resistin, TNF-alpha and YKL40 concentrations, and between resistin concentration and mSBI. CONCLUSIONS T1D patients after SPK show lower levels of inflammatory markers in GCF and present reduced intensity of periodontitis compared to kidney recipients treated with insulin. The severity of morphological changes in periodontium in T1D patients after KTx or SPK is higher than in non-diabetic kidney recipients.

The cytotoxic effects of various endodontic irrigants on the viability of dental mesenchymal stem cells

This study aimed to evaluate cytotoxic effects of various irrigation solutions used in regenerative endodontic treatments (RETs) on mesenchymal stem cells, and further examine the long-term effect of hypochlorous acid (HOCl) on the cell viability and alkaline phosphatase (ALP) activity. Stem cells were exposed to various concentrations of NaOCl, EDTA, chlorhexidine (CHX), etidronic acid (HEDP)/NaOCl combination and HOCl. HOCl was tested for its effects on ALP activity up to 21 days. Additionally, cell viability was measured fluorescently using calcein AM. The most cytotoxic irrigant was CHX even with the lowest concentration. NaOCl and HEDP/NaOCl with 1:100 dilution decreased viability to around 40%. HOCl showed the lowest cytotoxicity among all tested irrigants. HOCl also showed no significant reduction in ALP activity compared with the controls. The cytotoxicity of endodontic irrigants was time and concentration dependent. HOCl demonstrated promising results regarding viability and ALP activity, since RETs require host stem cell survival.