Evaluation of the antimicrobial effects of sodium benzoate and dichlorobenzyl alcohol against dental plaque microorganisms. An in vitro study

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.

Antimicrobial Efficiency of Aloe arborescens and Aloe barbadensis Natural and Commercial Products

Nowadays, there are many commercial products from natural resources on the market, but they still have many additives to increase their biological activities. On the other hand, there is particular interest in natural sources that would have antimicrobial properties themselves and would inhibit the growth and the reproduction of opportunistic microorganisms. Therefore, a comparative antimicrobial study of natural samples of aloe and its commercial products was performed. Qualitative and quantitative determination of antimicrobial efficiency of Aloe arborescens and Aloe barbadensis and its commercial products on fungi, Gram-negative, and Gram-positive bacteria was performed. Samples exhibited antimicrobial activity and slowed down the growth of all tested microorganisms. Research has shown that natural juices and gels of A. arborescens and A. barbadensis are at higher added concentrations comparable to commercial aloe products, especially against microbial cultures of Bacillus cereus, Candida albicans, and Pseudomonas aeruginosa, whose growths were completely inhibited at a microbial concentration of 600 μg/mL. Of particular importance are the findings of the good antimicrobial efficacy of fresh juice and gel of A. arborescens on tested microorganisms, which is less known and less researched. These results show great potential of A. arborescens for further use in medicine, cosmetics, food, and pharmaceutical industries.

Effect of two herbal mouthwashes on gingival health of school children

This study aimed at determining the effect of indigenously prepared neem and mango chewing stick mouthwashes on plaque and gingival indices. A sample of 105 children aged 12-15 years was randomized into three groups, namely neem, mango, and chlorhexidine mouthwash groups. All the children were examined at baseline and gingival and plaque indices were recorded. Baseline scores for plaque and gingivitis were fair and moderate, respectively, in all the three groups and there existed no statistically significant difference among them. Ten millilitres each of herbal and chlorhexidine mouthwashes (0.2%) were administered according to the group allocation twice daily for 21 days. Indices were reassessed at 21 days (immediately after intervention) and at 1 month, 2 months, and 3 months after discontinuing the mouthwashes. Statistically significant reduction (P < 0.001) in plaque index was found in all the three mouthwash groups at 21 days and at 1 month from discontinuing the mouthwash. Chlorhexidine additionally showed statistically significant reduction in plaque index at 2 months from discontinuing the mouthwash. Statistically significant reduction (P < 0.001) in gingival index was found in all the three mouthwash groups at 21 days (immediately after discontinuing the mouthwash) and at 1 and 2 months from discontinuing the mouthwash. To conclude, all the three mouthwashes were effective antiplaque and antigingivitis agents. Chlorhexidine and neem possess equivalent efficacy in reducing plaque, while chlorhexidine has superior antigingivitis properties.

Action of food preservatives on 14-days dental biofilm formation, biofilm vitality and biofilm-derived enamel demineralisation in situ

AIMS

The aims of this double-blind, controlled, crossover study were to assess the influence of food preservatives on in situ dental biofilm growth and vitality, and to evaluate their influence on the ability of dental biofilm to demineralize underlying enamel over a period of 14 days.

MATERIALS AND METHODS

Twenty volunteers wore appliances with six specimens each of bovine enamel to build up intra-oral biofilms. During four test cycles of 14 days, the subjects had to place the appliance in one of the assigned controls or active solutions twice a day for a minute: negative control 0.9 % saline, 0.1 % benzoate (BA), 0.1 % sorbate (SA) and 0.2 % chlorhexidine (CHX positive control). After 14 days, the biofilms on two of the slabs were stained to visualize vital and dead bacteria to assess biofilm thickness (BT) and bacterial vitality (BV). Further, slabs were taken to determine mineral loss (ML), by quantitative light-induced laser fluorescence (QLF) and transversal microradiography (TMR), moreover the lesion depths (LD).

RESULTS

Nineteen subjects completed all test cycles. Use of SA, BA and CHX resulted in a significantly reduced BV compared to NaCl (p < 0.001). Only CHX exerted a statistically significant retardation in BT as compared to saline. Differences between SA and BA were not significant (p > 0.05) for both parameters. TMR analysis revealed the highest LD values in the NaCl group (43.6 ± 44.2 μm) and the lowest with CHX (11.7 ± 39.4 μm), while SA (22.9 ± 45.2 μm) and BA (21.4 ± 38.5 μm) lay in between. Similarly for ML, the highest mean values of 128.1 ± 207.3 vol% μm were assessed for NaCl, the lowest for CHX (-16.8 ± 284.2 vol% μm), while SA and BA led to values of 83.2 ± 150.9 and 98.4 ± 191.2 vol% μm, respectively. With QLF for both controls, NaCl (-33.8 ± 101.3 mm(2) %) and CHX (-16.9 ± 69.9 mm(2) %), negative values were recorded reflecting a diminution of fluorescence, while positive values were found with SA (33.9 ± 158.2 mm(2) %) and BA (24.8 ± 118.0 mm(2) %) depicting a fluorescence gain. These differences were non-significant (p > 0.05).

CONCLUSION

The biofilm model permited the assessment of undisturbed oral biofilm formation influenced by antibacterial components under clinical conditions for a period of 14 days. An effect of BA and SA on the demineralization of enamel could be demonstrated by TMR and QLF, but these new findings have to be seen as a trend. As part of our daily diet, these preservatives exert an impact on the metabolism of the dental biofilm, and therefore may even influence demineralization processes of the underlying dental enamel in situ.

2,4-Dichloro-benzyl 2-meth-oxy-benzoate

In the title compound, C₁₅H₁₂Cl₂O₃, the aromatic rings make a dihedral angle of 10.78 (4)°. In the molecule, there is a short C—H⋯O contact. In the crystal, C—H⋯O contacts connect the mol­ecules into C(7)C(8) chains along the b axis. The shortest inter­centroid distance between two benzoic acid aromatic systems is 3.7416 (8) Å.

Evaluation of the subgingival microbiota of alcoholic and non-alcoholic individuals

OBJECTIVES

The aim of this study was to evaluate the composition of the subgingival microbiota of alcoholic and non-alcoholic individuals.

METHODS

The study was conducted with 49 alcoholic and 49 non-alcoholic males of the Philippe Pinel Institute, Rio de Janeiro, Brazil. The subjects were selected by convenience and two criteria were used to diagnose alcohol dependence: the CAGE (cut-down, annoyed, guilt, eyes-opener) questionnaire and the International Statistical Classification of Diseases, 10th edition (WHO). Subgingival biofilm samples were obtained from 4 sites, 2 with probing depth (PD) ≥ 4 mm and 2 sites with PD < 4 mm. The presence and levels of 45 bacterial taxa were analysed using the checkerboard technique.

RESULTS

The prevalence of bacterial species was not significantly different between groups. However, alcoholics showed significantly higher mean counts of Aggregactibacter actinomycetemcomitans, Fusobacterium nucleatum nucleatum, and Porphyromonas gingivalis (adjusted p < 0.001). Moreover, alcoholics harboured significantly higher mean levels of Capnocytophaga sputigena, Fusobacterium nucleatum vincentii, F. nuc. nucleatum, Gemella morbillorum, Neisseria mucosa, P. gingivalis, Streptococcus gordonii, and Tannerella forsythia at sites with PD < 4 mm or ≥ 4 mm compared to non-alcoholics (p ≤ 0.001). Of interest, shallow sites of alcoholics presented significantly higher mean levels of F. nuc. vincentii, F. nuc nucleatum, P. gingivalis, and T. forsythia than sites with PD ≥ 4 mm of non-alcoholics (p ≤ 0.001).

CONCLUSIONS

Alcoholics and non-alcoholics present a diverse and complex microbiota; however, alcoholics harbour significantly higher levels of periodontopathic species in the subgingival microbiota than non-alcoholics.

Effect of food preservatives on in situ biofilm formation

The aim of this double-blind, controlled crossover study was to evaluate the influence of food preservatives on in situ dental biofilm growth. Twenty-four volunteers wore appliances with six specimens each of bovine enamel to build up intra-oral biofilms. During three test cycles, the subjects had to put one half of the appliance twice a day in one of the assigned active solutions (0.1% benzoate, BA; 0.1% sorbate, SA or 0.2% chlorhexidine, CHX) and the other into NaCl. After 5 days, the developed biofilms were stained with two fluorescent dyes to visualise vital (green) and dead bacteria (red). Biofilms were scanned by confocal laser scanning microscopy and biofilm thickness (BT) and bacterial vitality (BV%) were calculated. After a washout period of 7 days, a new test cycle was started. The use of SA, BA and CHX resulted in a significantly reduced BT and BV compared to NaCl (p<0.001). Differences between SA and BA were not significant (p>0.05) for both parameters, while CHX showed significantly lower values. Both preservatives showed antibacterial and plaque-inhibiting properties, but not to the extent of CHX. The biofilm model enabled the examination of undisturbed oral biofilm formation influenced by antibacterial components under clinical conditions.

The effect of alcohol consumption on periodontal disease

BACKGROUND

Alcohol consumption, like smoking, may be related to periodontal disease independently of oral hygiene status. This study assessed the relationship between alcohol consumption and severity of periodontal disease.

METHODS

A cross-sectional study of 1,371 subjects ages 25 to 74 in the Erie County, NY population was performed. Alcohol intake was assessed by means of previously validated self-reported questionnaires. Outcome variables were gingival bleeding, clinical attachment loss, alveolar bone loss, and presence of subgingival microorganisms.

RESULTS

Logistic regression analyses adjusting for age, gender, race, education, income, smoking, diabetes mellitus, dental plaque, and presence of any of 8 subgingival microorganisms showed that those consuming > or =5 drinks/week had an odds ratio (OR) of 1.65 (95% CI: 1.22 to 2.23) of having higher gingival bleeding, and OR of 1.36 (95% CI: 1.02 to 1.80) of having more severe clinical attachment loss compared to those consuming <5 drinks/week. Those consuming > or =10 drinks/week had an odds ratio (OR) of 1.62 (95% CI: 1.12 to 2.33) of having higher gingival bleeding and OR of 1.44 (95% CI: 1.04 to 2.00) of having more severe clinical attachment loss compared to those consuming <10 drinks/week. Alcohol consumption was not significantly related to alveolar bone loss nor to any of the subgingival microorganisms.

CONCLUSIONS

The results suggest that alcohol consumption is associated with moderately increased severity of periodontal disease. Longitudinal studies are needed to determine whether alcohol is a true risk factor for periodontal disease.

Using the DMF gender difference to assess the "major" role of fluoride toothpastes in the caries decline in industrialized countries: a meta-analysis

The regular use of fluoridated toothpastes has been ascribed a major role in the observed decline in caries prevalence in industrialized countries during the last 20 to 25 years, but only indirect evidence supports this claim. The purpose of this study was to test the hypothesis that the more frequent use of fluoride toothpastes by girls than by boys has reduced the relative age-specific D(M)FT gender difference, and that this difference should decrease with increasing age and fluoride toothpaste exposure among adolescents. The material comprised 8,777 subjects 12 to 17 years of age from the pre-fluoride toothpaste era (1946-1959) and 39,903 from the period when use of fluoride toothpaste had become common (1983-1993) in industrialized countries. Meta-analyses were done using the relative age-specific mean D(M)FT difference between girls and boys. Separate analyses were carried out for subgroups of studies/countries to check for confounding. Regardless of analytical approach, no evidence was found to support the hypothesis. It is concluded that the gender difference in fluoride exposure due to tooth brushing frequency is too small to matter, that the study lacked power, or that the role of fluoride toothpastes in the caries decline has been overrated.