Inhibition of de novo plaque growth by a new 0.03 % chlorhexidine mouth rinse formulation applying a non-brushing model: a randomized, double blind clinical trial

Combination of Cetylpyridinium Chloride and Chlorhexidine Acetate: A Promising Candidate for Rapid Killing of Gram-Positive/Gram-Negative Bacteria and Fungi

Combined use of the present antimicrobial drugs has been proved to be an alternative approach for antimicrobial agents' development since the co-existed of the drugs working in different mechanism have been demonstrated potentially enhance their antimicrobial activity. In this work, antibacterial and antifungal activity of the cetylpyridinium chloride (CPC)/chlorhexidine acetate (CHA) combination was evaluated for the first time, while a universal concentration for the rapid killing of gram-positive/gram-negative bacteria and fungi was also proposed. The minimum inhibitory concentrations (MIC) of CPC and CHA used alone or in combination were first measured, showing that the combined treatment decreased the MIC against tested gram-positive/gram-negative bacteria and fungi to 1/8-1/2. Growth curve assays demonstrated CPC and CHA had dynamic combined effects against the tested microorganisms at the concentration equal to MIC. Besides, combined use of these two drugs could also enhance their biocidal activity, which was illustrated by fluorescence microscopy and SEM images, as well as soluble protein measurement. More importantly, in vitro acute eye and skin irritation tests showed short-term contact with CPC/CHA combination would not cause any damage to mammalian mucosa and skin. In a word, CPC/CHA combination exhibited broad-spectrum antibacterial and antifungal activity against tested gram-positive/gram-negative bacteria and fungi while without any acute irritation to mammalian mucosa and skin, providing a new perspective on the selection of personal disinfectants.

Effect of Three Chlorhexidine-Based Mouthwashes on Human Gingival Fibroblasts: An In Vitro Study

Mouthwashes containing chlorhexidine (CHX) are deemed to be associated with dose-dependent side effects, including burning sensation and taste alteration. To overcome these drawbacks, mouthwashes with CHX at lower concentrations with or without adjunctive agents are proposed. The aim of this in vitro study was to investigate the effects of three CHX-based mouthwashes on human gingival fibroblasts (HGFs). After 3 days of cell culture, groups were randomly treated for 30 s, 60 s or 120 s with (a) CHX 0.05% in combination with cetylpyridnium chloride (CPC) 0.05%; (b) CHX 0.1%; (c) CHX 0.2%; or (d) NaCl as control. Cell viability, cytotoxicity and apoptosis were evaluated at 2 h, 3 days and 6 days after the exposure to the different solutions. Similar cell viability values were found among the test groups at all time points. At day 0, higher cytotoxicity was measured in the group treated with CHX 0.02%, in particular after long application time (120 s), while no significant difference was found between CHX + CPC and the control group. All the investigated mouthwashes were well tolerated by HGF cells for the tested application times. The highest cytotoxic effect was observed for CHX 0.2%; therefore, clinicians should consider limiting its usage to carefully selected clinical situations.

Differences in chlorhexidine mouthrinses formulations influence the quantitative and qualitative changes in in-vitro oral biofilms

OBJECTIVE

Chlorhexidine mouthrinses are marketed in different formulations. This study aimed at investigating qualitative and quantitative changes in in-vitro multispecies oral biofilms, induced by different chlorhexidine-containing mouthrinses.

BACKGROUND DATA

Earlier studies comparing chlorhexidine mouthrinses are either clinical studies or in-vitro studies assessing the antimicrobial efficacy of the mouthrinses. However, no clear investigations are available regarding ecological impact of different chlorhexidine formulations on in-vitro multispecies oral biofilms after rinsing with different chlorhexidine formulations.

METHODS

Nine commercially available chlorhexidine mouthrinses were selected. Multispecies oral communities (14 species) were grown for 48 h in a Biostat-B Twin bioreactor. After that, they were used to develop biofilms on the surface of hydroxyapatite disks in 24-well pates for 48 h. Biofilms were then rinsed once or multiple times with the corresponding mouthrinse. Biofilms were collected before starting the rinsing experiment and every 24 h for 3 days and vitality quantitative PCR was performed. The experiment was repeated 3 independent times on 3 different days and the results were analyzed using a linear mixed model.

RESULTS

The mouthrinses provoked different effects in terms of change in total viable bacterial load (VBL), ecology, and community structure of the multispecies biofilms. There was no relation between chlorhexidine concentrations, presence, or absence of cetylpyridinium chloride and/or alcohol, and the observed effects. Some tested chlorhexidine mouthrinses (MC, HG, HH, and HI) strongly lowered the total VBL (≈10⁰⁷ Geq/ml), but disrupted biofilm symbiosis (≥40% of the biofilms communities are pathobionts). On the other hand, other tested chlorhexidine mouthrinses (MD, ME, and HF) had limited impact on total VBL (≥10¹⁰ Geq/ml), but improved the biofilm ecology and community structure (≤10% of the biofilms communities are pathobionts).

CONCLUSION

Not all chlorhexidine mouthrinses have the same effect on oral biofilms. Their effect seems to be strongly product dependent and vary according to their compositions and formulations.

Efficacy of 0.05% Chlorhexidine and 0.05% Cetylpyridinium Chloride Mouthwash to Eliminate Living Bacteria on In Situ Collected Biofilms: An In Vitro Study

Chlorhexidine (CHX) mouthwashes are frequently used as an adjunctive measure for the treatment of periodontitis and peri-implantitis, as well as in patients on maintenance therapy. However, their prolonged use is associated with several side effects. This study aimed at evaluating if a mouthwash with a reduced concentration of CHX combined with cetylpyridnium chloride (CPC) was as effective as a conventional CHX mouthwash in the reduction in living cells in oral biofilms attached to hydroxyapatite (HA) and micro-rough titanium (Ti) surfaces. Four healthy volunteers wore a customized acrylic appliance containing HA and Ti discs for in situ plaque accumulation. Biofilms were grown on the discs for 24 or 48 h and then randomly exposed for 60 s to: 0.05% CHX + 0.05% CPC, 0.1% CHX (positive control) or sterile saline (negative control). Viability assay and live-dead staining were performed to quantify bacterial viability and to distinguish live and dead cells, respectively. At both time points, contrary to saline, CHX, both alone and in combination with CPC, exhibited high antibacterial properties and induced a significant reduction in biofilm viability. This study demonstrates the potential of mouthwashes containing a low concentration of CHX combined with CPC as effective antibacterial agents for long-term applications with reduced undesired side effects.

Tetracycline and multidrug resistance in the oral microbiota: differences between healthy subjects and patients with periodontitis in Spain

Introduction: Antibiotic resistance is widely found even among bacterial populations not having been exposed to selective pressure by antibiotics, such as tetracycline. In this study we analyzed the tetracycline-resistant subgingival microbiota of healthy subjects and of patients with periodontitis, comparing the prevalence of tet genes and their multidrug resistance profiles.

Methods: Samples from 259 volunteers were analyzed, obtaining 813 tetracycline-resistant isolates. The prevalence of 12 antibiotic resistance genes was assessed, and multidrug profiles were built. Each isolate was identified by 16S rRNA sequencing. Differences in qualitative data and quantitative data were evaluated using the chi-square test and the Mann-Whitney-U test, respectively.

Results: tet(M) was the most frequently detected tet gene (52.03%). We observed significant differences between the prevalence of tet(M), tet(W), tet(O), tet(32) and tet(L) in both populations studied. Multidrug resistance was largely observed, with resistance to kanamycin being the most detected (83.64%). There were significant differences between the populations in the prevalence of kanamycin, chloramphenicol, and cefotaxime resistance. Resistant isolates showed significantly different prevalence between the two studied groups.

Conclusion: The high prevalence of multidrug resistance and tetracycline resistance genes found in the subgingival microbiota, highlights the importance of performing wider and more in-depth analysis of antibiotic resistance in the oral microbiota.

Evaluation of new Seawater-based Mouth Rinse Versus Chlorhexidine 0.2% Reducing Plaque and Gingivitis Indexes. A Randomized Controlled Pilot Study

For a long time, Chlorhexidine digluconate (CHX) has been considered the most used mouth-rinse for reducing plaque and gingivitis. Sea4® Encias is a new seawater-based mouth rinse with a similar action to CHX. Its prolonged use produces fewer side effects. This study compared the effects of two oral rinses: Chlorhexidine 0.20% and Sea 4® Encias (seawater) for reducing plaque and gingivitis indices. This double-blind crossover study recruited and monitored 93 volunteer dental students, hygienists and doctors from the Universidad Católica de Murcia (UCAM), for 1 month, and compared the efficacy of Chlorhexidine 0.20% (Group A); Sea4® Encías (Group B); and a placebo saline solution (Group C) mouth-rinses for reducing plaque and gingivitis indices. Plaque and gingival inflammation (Löe and Silness test) were evaluated at baseline and after each study stage. Group A reduced plaque growth and gingivitis significantly compared with Groups B and C; Group B was more effective than Group C. The mean P.I. decreased similarly in groups A and B. However, Group A showed the statistically significant value compared with other groups. Group A and group B, showed greater reduction in Gingival Indexes compared with group C. The Sea4 mouthwash showed better inhibitory activity on plaque (1.32 ± 0.22) compared with CHX (1.97 ± 0.34) and saline (2.78 ± 0.11). Sea4 Encias and Chlorhexidine 0.20% mouth-rinses significantly reduce plaque growth and G.I. compared with saline mouth-rinse; Sea4 Encías mouth-rinse is more effective against plaque regrowth than Chlorhexidine in this pilot study.

The clinical evaluation of Vi-one chlorhexidine mouthwash on plaque-induced gingivitis: A double-blind randomized clinical trial

Background

Chlorhexidine (CHX) is the most effective antiseptic mouthwash to date. Essential oil such as thymol, have inhibitory and biocidal effects a range of bacteria.

Objective

To determine the effect of mouthwash containing CHX and thymol on plaque induced gingivitis.

Methods

This double-blind randomized clinical trial study was performed on 60 patients with plaque induced gingivitis who were randomly divided into two groups: Group I (CHX/thymol mouthwash-Vi-one) and Group II (CHX mouthwash-Behsa). Patients in each group underwent scaling and root planning and polishing, then were educated about BASS-Method brushing, and were recommended Oral-B toothbrushes and Pooneh toothpaste. The two groups were asked to rinse their mouths for 60 seconds twice a day, once in the morning and once at night, after brushing their teeth. Plaque index, gingival index, bleeding index and stain index were evaluated at baseline and 14 days later in Ramfjord teeth. Data analysis was conducted using SPSS version 21. Independent-samples t-test and paired-samples t-test were used for data analysis.

Results

The results showed that plaque index and gingival index significantly reduced in two groups (p<0.001). However, group I was significantly more efficient than group II (p<0.001, p=0.021 respectively). Similar results were observed in terms of bleeding index with the difference that the two groups did not differ significantly from each other (p=0.879). Both groups significantly increased the stain index. No remarkable difference was also observed between the two groups (p=0.754).

Conclusion

Based on the results of this study, we can conclude that the CHX/thymol mouthwash can be offered to patients with dental plaque-induced gingivitis, because it appears to be more effective in controlling dental plaque and gingivitis.

Trial registration

The trial was registered at the Iranian Registry of Clinical Trials (http://www.irct.ir) with the Irct ID: IRCT201602231760N45.

Funding

This study was part of a thesis and research project (Grant No: 9440921) supported and funded by Babol University of Medical Sciences. The authors received no financial support from Behsa pharmaceutical company (Behsa mouthwash manufacturer) or Rojin cosmetic laboratory (Vi-one mouthwash manufacturer) for this study.

Antibiofilm and Anti-Inflammatory Activities of Houttuynia cordata Decoction for Oral Care

Dental biofilms that form in the oral cavity play a critical role in the pathogenesis of several infectious oral diseases, including dental caries, periodontal disease, and oral candidiasis. Houttuynia cordata (HC, Saururaceae) is a widely used traditional medicine, for both internal and external application. A decoction of dried HC leaves (dHC) has long been consumed as a health-promoting herbal tea in Japan. We have recently reported that a water solution of HC poultice ethanol extract (wHCP) exerts antimicrobial and antibiofilm effects against several important oral pathogens. It also exhibits anti-inflammatory effects on human keratinocytes. In our current study, we examined the effects of dHC on infectious oral pathogens and inflammation. Our results demonstrated that dHC exerts moderate antimicrobial effects against methicillin-resistant Staphylococcus aureus (MRSA) and other oral microorganisms. dHC also exhibited antibiofilm effects against MRSA, Fusobacterium nucleatum (involved in dental plaque formation), and Candida albicans and inhibitory effects on interleukin-8, CCL20, IP-10, and GROα productions by human oral keratinocytes stimulated by Porphyromonas gingivalis lipopolysaccharide (a cause of periodontal disease), without cytotoxic effects. This suggests that dHC exhibits multiple activities in microorganisms and host cells. dHC can be easily prepared and may be effective in preventing infectious oral diseases.