Antimicrobial Mouthwashes: An Overview of Mechanisms-What Do We Still Need to Know?

Effect of the Darolac® (Oralis SB®) Probiotic Formulation on Oral Health: A Narrative Review

Gingivitis and periodontitis are prevalent periodontal conditions associated with dysbiosis of the oral cavity, which leads to inflammation and bleeding of gums, loss of tooth attachment, and degradation of the underlying bone structure. The standard adjunctive treatment for periodontal conditions, chlorhexidine mouthwash, is effective but is associated with several side effects. Probiotics have been explored as an alternative solution that promotes oral health by restoring homeostasis in the oral cavity. This review presents a summary of clinical trials using the Darolac® (Oralis SB®) probiotic formulation (Lactobacillus acidophilus Rosell®-52, Lactobacillus rhamnosus Rosell®-11, Bifidobacterium longum Rosell®-175 and Saccharomyces boulardii CNCM I-1079) as a mouthwash to support the maintenance of oral health or the restoration of its balance. In reviewed studies, Darolac® is compared to a placebo or other common solutions for periodontal conditions, including chlorhexidine mouthwash. Studies show that Darolac® is as effective or even superior to other available solutions, which supports its use as an effective adjuvant to oral health. The effects of Darolac® on the reduction in oral pathogens and markers of oral dysbiosis are reviewed, and the association between periodontitis, inflammation, and systemic diseases, as well as their implications and the use of probiotics in the periodontal field, are discussed.

Comparative in vitro study of a new silicone mouth swab for soft tissue cleaning under wet and dry brushing conditions

The use of silicone mouth swabs for soft tissue cleaning in elderly care is significant as it offers a gentle yet effective solution for maintaining oral hygiene, particularly in patients with limited dexterity or cognitive impairments, thereby reducing the risk of oral infections and improving overall health. This study aimed to compare the pseudo-plaque cleaning efficiency of a newly designed silicone mouth swab with that of the existing MouthEze (MC3) under both wet and dry brushing conditions. A new silicone mouth swab was designed with both straight and threaded brushing bristles and a longer head length of 24.0 mm, compared to the MC3, which has only straight bristles and an 18.0 mm head. A pseudo-plaque, created by mixing 6.0 g of Thicken Up Clear food additive with 12.0 ml of water and food coloring, was spread onto a NISSIN dentoform silicone rubber sheet with a thickness of 2.0 mm. The MC3 silicone head (n = 12) and the new silicone head (n = 12) were attached to a V.P.2000 tooth brushing machine, operating at 75 rounds per minute with a force of 2.45 N, and each was used to brush the surface 25 times under both wet (n = 12) and dry (n = 12) conditions. The ImageJ program was used to analyze and quantify the area where the pseudo-plaque was removed after brushing. A two-way analysis of variance (ANOVA) was conducted to assess differences in pseudo-plaque removal between groups. The pseudo-plaque removal per head length of the new silicone mouth swab was significantly higher than that of the MC3 under both wet brushing (72.30 ± 10.21 mm2 vs. 53.69 ± 5.66 mm2, p < 0.05) and dry brushing conditions (66.82 ± 11.29 mm² vs. 53.33 ± 8.54 mm2, p < 0.05). The new silicone mouth swab with both straight and threaded brushing bristles and a longer head length was more effective in pseudo-plaque removal than the swab with only straight bristles and a shorter head.

Novel Quaternary Ammonium Urethane-Dimethacrylates for Copolymers with Low Water Sorption and Solubility

Six novel urethane-dimethacrylates with quaternary ammonium groups (QAUDMAs) were successfully synthesized from 2-(methacryloyloxy)ethyl-2-hydroxyethylmethylalkylammonium bromide (QAHAMA-n, where n was 8 and 10) and diisocyanate (isophorone diisocyanate (IPDI), 4,4'-methylenedicyclohexyl diisocyanate (CHMDI), and 4,4'-diphenylmethane diisocyanate (MDI)). Their chemical structures were confirmed through nuclear magnetic resonance spectroscopy (NMR) and Fourier transform infrared spectroscopy (FTIR). The refractive index (RI) and density (dm) were also determined. The novel QAUDMAs were compounded with common dental dimethacrylates and subsequently photopolymerized. The resulting copolymers, comprising QAUDMA 40 wt.%, bisphenol A glycerolate dimethacrylate (Bis-GMA) 40 wt.%, and triethylene glycol dimethacrylate (TEGDMA) 20 wt.%, were tested for water sorption (WS) and solubility (SL). The WS and SL values decreased following these orderings based on the diisocyanate: IPDI > CHMDI > MDI for WS, and MDI > CHMDI > IPDI for SL. The WS values ranged from 11.50 to 13.82 µg/mm3, and were significantly lower than the recommended maximum for dental materials, 40 µg/mm3. The SL values that met the recommended maximum, 7.5 µg/mm3, ranged from 2.67 to 6.75 µg/mm3. Only the copolymer having the QAHAMA-8- and MDI-derived QAUDMA had the SL slightly exceeding 7.5 µg/mm3, at 7.89 µg/mm3.

Randomised-crossover clinical trial on the substantivity of a single application of a gel containing chlorhexidine and o-cymen-5-ol on the oral biofilm and saliva

BACKGROUND

No clinical trials have evaluated the antimicrobial activity and substantivity of gel formulations containing chlorhexidine (CHX) and cymenol.

OBJECTIVE

To compare the in situ antimicrobial effect and substantivity of a new 0.20% CHX + cymenol gel (test) with the current 0.20% CHX gel formulation (control) on salivary flora and dental plaque biofilm up to seven hours after a single application.

METHODS

A randomised-crossover clinical trial was conducted with 29 orally healthy volunteers participating in the development of Experiments 1 (saliva) and 2 (dental plaque biofilm). All subjects participated in both experiments and were randomly assigned to receive either the test or control gels. Samples were collected at baseline and five minutes and one, three, five, and seven hours after a single application of the products. The specimens were processed using confocal laser scanning microscopy after staining with the LIVE/DEAD® BacLight™ solution. Bacterial viability (BV) was quantified in the saliva and biofilm samples. The BV was calculated using the DenTiUS Biofilm software.

RESULTS

In Experiment 1, the mean baseline BV was significantly reduced five minutes after application in the test group (87.00% vs. 26.50%; p < 0.01). This effect was maintained throughout all sampling times and continued up to seven hours (40.40%, p < 0.01). The CHX control followed the same pattern. In Experiment 2, the mean baseline BV was also significantly lower five minutes after applying the test gel for: (1) the total thickness of biofilm (91.00% vs. 5.80%; p < 0.01); (2) the upper layer (91.29% vs. 3.94%; p < 0.01); and (3) the lower layer (86.29% vs. 3.83%; p < 0.01). The reduction of BV from baseline was observed for the full-thickness and by layers at all sampling moments and continued seven hours after application (21.30%, 24.13%, and 22.06%, respectively; p < 0.01). Again, the control group showed similar results. No significant differences between test and control gels were observed in either saliva or dental plaque biofilm at any sampling time.

CONCLUSIONS

A 0.20% CHX + cymenol gel application demonstrates potent and immediate antimicrobial activity on salivary flora and de novo biofilm. This effect is maintained seven hours after application. Similar effects are obtained with a 0.20% CHX-only gel.

The Impact of Oral Microbiome Dysbiosis on the Aetiology, Pathogenesis, and Development of Oral Cancer

Oral squamous cell carcinoma (OSCC) is the most common head and neck cancer. Although the oral cavity is an easily accessible area for visual examination, the OSCC is more often detected at an advanced stage. The global prevalence of OSCC is around 6%, with increasing trends posing a significant health problem due to the increase in morbidity and mortality. The oral cavity microbiome has been the target of numerous studies, with findings highlighting the significant role of dysbiosis in developing OSCC. Dysbiosis can significantly increase pathobionts (bacteria, viruses, fungi, and parasites) that trigger inflammation through their virulence and pathogenicity factors. In contrast, chronic bacterial inflammation contributes to the development of OSCC. Pathobionts also have other effects, such as the impact on the immune system, which can alter immune responses and contribute to a pro-inflammatory environment. Poor oral hygiene and carbohydrate-rich foods can also increase the risk of developing oral cancer. The risk factors and mechanisms of OSCC development are not yet fully understood and remain a frequent research topic. For this reason, this narrative review concentrates on the issue of dysbiosis as the potential cause of OSCC, as well as the underlying mechanisms involved.

Activity of N-Chlorotaurine against Periodontal Pathogens

Dental plaque bacteria play an important role in the pathogenicity of periodontitis and peri-implantitis. Therefore, antimicrobial agents are one means of treatment. N-chlorotaurine (NCT) as an endogenous well-tolerated topical antiseptic could be of advantage for this purpose. Accordingly, its microbicidal activity against some dental plaque bacteria was investigated at therapeutic concentrations in vitro. In quantitative killing assays, the activity of NCT against planktonic bacteria and against biofilms grown for 48 h on implantation screws was tested. Electron microscopy was used to demonstrate the formation of biofilm and its morphological changes. The killing of planktonic bacteria of all tested species, namely Streptococcus sanguinis, Streptococcus salivarius, Streptococcus oralis, Streptococcus cristatus, Rothia aeria, and Capnocytophaga ochracea, was shown within 10-20 min by 1% NCT in 0.01 M phosphate-buffered saline at 37 °C. Bacteria grown on screws for 24 h were inactivated by 1% NCT after 15-20 min as well, but the formation of biofilm on the screws was visible in electron microscopy not before 48 h. The killing of biofilms by 1% NCT was demonstrated after 30 min (streptococci) and 40 min (R. aeria). As expected, NCT has broad activity against dental plaque bacteria as well and should be further investigated on its clinical efficacy in periodontitis and peri-implantitis.

Are Mouthwashes Really Effective against Candida spp.?

Oral candidiasis is an opportunistic infection caused by fungi of the genus Candida. Nystatin, fluconazole, and miconazole are the most widely used antifungal drugs in dentistry, but in recent years, they have been shown to be less effective due to the increase in the resistance to antifungal drugs. The growing challenge of antifungal resistance emphasizes the importance of exploring not only alternative strategies in the fight against Candida spp. infections but also supportive treatment for pharmacological treatment for oral candidiasis. This review aims to evaluate and compare the in vitro reports on antifungal efficacy against Candida spp. exhibited by mouthwashes distributed on the European market. The research question was elaborated through the PEO framework recommended by PRISMA 2020. A bibliographic search strategy was developed for the scientific online databases Pubmed and ScienceDirect. According to the eligibility criteria, 21 papers were included in this study over a 27-year period. Mouthwashes containing chlorhexidine digluconate, cetylpyridinium chloride, hexetidine, and fluorine compounds among others, and natural antimicrobials, such as menthol, thymol, eucalyptol, and Glycyrrhiza glabra extracts, have demonstrated antifungal effectiveness. Nonetheless, the methodological variance introduces ambiguity concerning the comparative efficacy of distinct molecules or mouthwash formulations and complicates the evaluation and the comparison of results between studies. Some mouthwashes commercially available in Europe have the potential to be used in anti-Candida therapy and prevention since they have shown antifungal effect.

Satisfaction with government recommended pre-procedural mouth rinses in the mitigation of Covid-19 in Hong Kong SAR: A triple blind randomized controlled clinical trial

OBJECTIVE

To evaluate satisfaction and acceptability with three pre-procedural mouthrinses recommended by the Government of Hong Kong Special Administrative Region (HKSAR) during the COVID-19 pandemic.

MATERIAL AND METHODS

A triple-blind parallel-arm randomised controlled clinical trial was conducted. Following eligibility assessment, participants were block-randomised to the three intervention pre-procedural mouthrinses groups: Povidone-iodine, Hydrogen Peroxide and Chlorhexidine Digluconate. Participants rinsed with one of the mouthrinses assigned prior to any dental treatment. Participants, operators and assessors were blind to the assigned mouthrinses (triple blind). Satisfaction ratings were assessed on a 10 cm visual analogue scale (VAS) and acceptability of the mouthrinses were determined.

RESULTS

Following clinical screening, 228 participants were involved in the trial. The mean overall VAS satisfaction was 7.35 (SD 1.68). There was no significant difference in VAS satisfaction ratings among the three groups (p>0.05) nor in between groups. Acceptability of the mouthrinses was high with the vast majority (89.5 %, 204) willing to use the mouthrinses again if pre-procedural mouthrinsing is required. There was no significant difference in acceptability ratings (p>0.05). There were some aspects such as taste and smell that participants commented on (on average, 24.6 %, 56), although no significant difference in prevalence of reports among groups (p>0.05).

CONCLUSIONS

There were high rates of satisfaction and acceptability of the HKSAR Government recommended pre-procedural mouthrinses for the mitigation of COVID-19 transmission in the dental setting. There was no significant difference in satisfaction and acceptability rates among the three recommended pre-procedural mouthrinses.

CLINICAL RELEVANCE

The high satisfaction and acceptability rates of the HKSAR Government recommended pre-procedural mouthrinses in the mitigation of COVID-19 in this clinical trial lends support for the HKSAR's policy on pre-procedural mouthrinses in the dental setting and this has implications for practice and policy during pandemics.

Caries preventing efficacy of new Isomalt-containing mouthrinse formulations: a microbial study

OBJECTIVES

The effectiveness of an Isomalt-containing mouthrinse to prevent caries development was investigated.

METHODS

Human enamel blocks were randomly assigned to five groups (n = 30/group): De-ionized distilled water (DDW), and mouthrinse containing either (IFC) 1% Isomalt, 225 ppm fluoride, and 0.05% cetylpyridinium chloride (CPC), (IF) 1% Isomalt and 225ppm fluoride, (FC) 225 ppm fluoride and 0.05% CPC or (F) 225 ppm fluoride. During 7-day demineralization in a Microbial Caries Model, mouthrinses were applied once daily for 1 min. Demineralization was assessed using Surface Microhardness testing for percentage change in SMH (%ΔSMH) and Transverse Microradiography for mineral loss (ΔZ). Data analysis (α = 0.05) used paired t-test (Intra-group comparison using SMH) and ANOVA/Tukey's for inter-group comparisons (%ΔSMH and ΔZ).

RESULTS

With SMH, relative to sound enamel baseline, demineralization was significant (P < 0.001) in all groups, except in IFC. Intergroup comparison with %ΔSMH showed significantly (p < 0.001) greater demineralization in DDW compared to other groups, and in IF, FC, and F compared to IFC (P < 0.001). With ΔZ, relative to DDW, all groups significantly (p < 0.0001) inhibited demineralization at varying percentages.

CONCLUSIONS

Mouthrinse containing Isomalt, fluoride, and CPC inhibited demineralization amidst cariogenic biofilm; thus, highlighting its potential as a more effective caries control tool than mouthrinse with only fluoride.

A Low-Cost Protocol Using the Adjunctive Action of Povidone-Iodine Irrigations and Sodium Hypochlorite Rinsing Solution in Step 2 of Periodontal Therapy for Patients with Stage III-IV Periodontitis: A Single-Blind, Randomized Controlled Trial

In severe stages of periodontitis, conventional periodontal therapy and maintenance care are usually insufficient due to the viral and bacterial etiology; thus, a mechanical approach alone may not be sufficient to eliminate a substantial portion of subgingival pathogens, especially in deep periodontal sites. Background and Objectives: This single-blind, randomized clinical trial aimed to compare the clinical and microbiological efficacy of a low-cost protocol using povidone-iodine and sodium hypochlorite formulations as adjuncts to non-surgical therapy for patients with stage IV periodontitis when compared with chlorhexidine, the most commonly employed substance to date for antimicrobial regimens in periodontal therapy. Materials and Methods: Forty-five patients were randomly divided into two groups: control (subgingival instrumentation, chlorhexidine-assisted) and test (antiviral medication, subgingival instrumentation with povidone-iodine, sodium hypochlorite rinsing solution, and antibiotics). Clinical measurements and microbiological analyses were performed at baseline and after three months. Results: After three months, notable differences were found in the bacterial detection scores for Porphyromonas gingivalis (a significant reduction in detection frequency was observed in the test compared to the control (p = 0.021)), and there were significant reductions in detection in the test group for Tannerella forsythia and Treponema denticola, showing undetectable levels (p < 0.0001 for both). In the test group, the pocket probing depth median value was reduced significantly (p = 0.0005); similarly, bleeding on probing showed a marked decrease (p < 0.0001). However, changes in clinical attachment loss and full-mouth plaque score were not statistically significant. Conclusions: Using the proposed protocol, substantial improvements in clinical and microbiological parameters were obtained when compared with the current antimicrobial recommendations.

Impact of various solutions on the oral health status of critically ill patients

Oral care is a crucial challenge of nursing care in orally intubated patients. Oropharyngeal colonization with microorganisms is probably the first step in the pathogenesis of most bacterial pulmonary infections. This study aimed to investigate the effect of different oral care solutions on the oral health status of critically ill patients. We conducted a quasi-experimental study involving a convenience sample of 60 adult orally intubated patients, distributed equally into three groups: 20 patients received 0.12% chlorhexidine gluconate (CHX) solution as an oral rinse; 20 patients received 0.1% hexetidine (HEX) solution as an oral rinse; and a control group of 20 patients received routine hospital oral care with 0.9% normal saline (NS) solution. Oropharyngeal and tracheal cultures were obtained from patients within 24-48 h of admission, before the administration of topical oral antimicrobial solutions and then repeated on day 4 and day 7 after the oral solutions. The study revealed that CHX has a more powerful effect than HEX and NS in improving the oral mucosa and decreasing colonization of both the oropharynx and trachea. On day 7, the improvements were statistically significant in the CHX group and the HEX group (P = 0.02 and P = 0.03, respectively), but not in the NS group. This research confirms the effect of CHX and HEX in lowering the risk of tracheal and oropharyngeal colonization, and recommends the use of a CHX solution as oral mouth care in critically ill patients.

The effect of preprocedural mouthrinses against COVID-19 before acid etching on the microleakage of a resin-based sealant in permanent molars: An in vitro experimental study

Aim

To determine whether rinsing with preprocedural mouthrinses against coronavirus disease before acid etching affects resin-based sealant microleakage.

Materials and Methods

A presented in vitro experimental study was performed on 15 extracted permanent third molars. Samples were randomly allocated into five groups: Group 1-distilled water (control); Group 2-1% hydrogen peroxide; Group 3-1.5% hydrogen peroxide; Group 4-0.5% povidone-iodine; and Group 5-1% povidone-iodine. After the teeth were immersed in the assigned mouth rinses for 60 s, they were sealed with Concise™ white sealant. Subsequently, the teeth were thermocycled for 500 cycles, immersed in 2% methylene blue solution for 24 h, and sectioned with two parallel cuts in the buccolingual direction. Sixty surfaces (12 surfaces in each group) were examined for microleakage under a 40× light microscope and scored as described by Zyskind et al. Welch's one-way analysis of variance test and the Games-Howell test were used to analyze the results at a significance level of P < 0.05 for all tests.

Results

The intergroup comparisons indicated that the 0.5% povidone-iodine group and the 1% povidone-iodine group had significantly higher microleakage compared with the control group. The 1% and 1.5% hydrogen peroxide groups demonstrated no significant difference in mean microleakage scores compared with the control group. There was no significant difference between the povidone groups and the hydrogen peroxide groups.

Conclusions

Preprocedural rinsing with 0.5% and 1% povidone-iodine before acid etching caused higher microleakage of resin-based sealant, while hydrogen peroxide rinsing gave comparable microleakage compared with the control group.

The LiaSR Two-Component System Regulates Resistance to Chlorhexidine in Streptococcus mutans

Chlorhexidine (CHX) is widely considered to be the gold standard for preventing dental caries. However, it is possible to induce resistance to CHX. The LiaSR two-component system has been identified that contributed to CHX resistance in Streptococcus mutans, which is one of the major pathogens in dental caries. However, the underlying mechanisms remain unclear. In this study, an MIC assay and a viability assessment demonstrated that after deleting the liaS and liaR genes, the sensitivity of mutants could increase. The Nile Red efflux assay exhibited that the efflux rates of mutants were significantly decreased. The RT-qPCR results indicated that the LiaSR two-component system-mediating influence on the expression of lmrB in S. mutans contributed to the efflux rate. The hydrophobicity assay and membrane potential assay showed that the mutants had higher levels of hydrophobicity and depolarization, suggesting that their membranes were more easily disturbed. The TEM graphs revealed that the border of the cell membrane was unclear in mutants compared with the wild-type strain, indicating that the cell envelope's stress response may have been inhibited. While the surface charge of mutants showed no significant difference in the wild-type strain according to the result of cytochrome c-based charged determination. This study provides valuable novel insights into the mechanisms of the LiaSR two-component system in the CHX resistance of S. mutans.

Cetylpyridinium chloride and chlorhexidine show antiviral activity against Influenza A virus and Respiratory Syncytial virus in vitro

BACKGROUND

The oral cavity is the site of entry and replication for many respiratory viruses. Furthermore, it is the source of droplets and aerosols that facilitate viral transmission. It is thought that appropriate oral hygiene that alters viral infectivity might reduce the spread of respiratory viruses and contribute to infection control.

MATERIALS AND METHODS

Here, we analyzed the antiviral activity of cetylpyridinium chloride (CPC), chlorhexidine (CHX), and three commercial CPC and CHX-containing mouthwash preparations against the Influenza A virus and the Respiratory syncytial virus. To do so the aforementioned compounds and preparations were incubated with the Influenza A virus or with the Respiratory syncytial virus. Next, we analyzed the viability of the treated viral particles.

RESULTS

Our results indicate that CPC and CHX decrease the infectivity of both the Influenza A virus and the Respiratory Syncytial virus in vitro between 90 and 99.9% depending on the concentration. Likewise, CPC and CHX-containing mouthwash preparations were up to 99.99% effective in decreasing the viral viability of both the Influenza A virus and the Respiratory syncytial virus in vitro.

CONCLUSION

The use of a mouthwash containing CPC or CHX alone or in combination might represent a cost-effective measure to limit infection and spread of enveloped respiratory viruses infecting the oral cavity, aiding in reducing viral transmission. Our findings may stimulate future clinical studies to evaluate the effects of CPC and CHX in reducing viral respiratory transmissions.