Oral malodour – a review

Volatile sulfur compounds in asthmatic children and adolescents: A cross-sectional study in breath and saliva

BACKGROUND

Halitosis in children implies psychosocial repercussions. Risk factors associated with this condition are unclear, and detection methods are inaccurate.

AIM

To quantify the levels of sulfur-like compounds in children with asthma and healthy children from a novel validated assay, and to establish the risk factors related to halitosis.

DESIGN

One hundred and twenty-eight individuals (63 healthy and 65 asthmatic) from 3 to 17 years of age were tested using a passive colorimetric sensor to measure the levels of sulfur-like compounds in breath and saliva. Information was collected on oral hygiene habits, gingival and dental health, breathing type, and dental malocclusion.

RESULTS

The mean values of hydrogen sulfide were 4.0 ± 6.8 and 19.7 ± 12.2 ppbv (parts per billion in volume) in the control and asthmatic groups, respectively (p < .001). The presence of higher concentrations of sulfur compounds was significantly associated (p < .05) with the presence of gingival inflammation, tongue coating, dental plaque, mouth breathing, hypomineralization, age, tongue brushing, and the use of dental floss.

CONCLUSION

The level of sulfur in breath and saliva was significantly higher in patients with asthma. These results can serve as a precedent to raise awareness among paediatricians and parents about oral hygiene care in children and adolescents.

Interspecies metabolite transfer fuels the methionine metabolism of Fusobacterium nucleatum to stimulate volatile methyl mercaptan production

The major oral odor compound methyl mercaptan (CH3SH) is strongly associated with halitosis and periodontitis. CH3SH production stems from the metabolism of polymicrobial communities in periodontal pockets and on the tongue dorsum. However, understanding of CH3SH-producing oral bacteria and their interactions is limited. This study aimed to investigate CH3SH production by major oral bacteria and the impact of interspecies interactions on its generation. Using a newly constructed large-volume anaerobic noncontact coculture system, Fusobacterium nucleatum was found to be a potent producer of CH3SH, with that production stimulated by metabolic interactions with Streptococcus gordonii, an early dental plaque colonizer. Furthermore, analysis of extracellular amino acids using an S. gordonii arginine-ornithine antiporter (ArcD) mutant demonstrated that ornithine excreted from S. gordonii is a key contributor to increased CH3SH production by F. nucleatum. Further study with 13C, 15N-methionine, as well as gene expression analysis, revealed that ornithine secreted by S. gordonii increased the demand for methionine through accelerated polyamine synthesis by F. nucleatum, leading to elevated methionine pathway activity and CH3SH production. Collectively, these findings suggest that interaction between S. gordonii and F. nucleatum plays a key role in CH3SH production, providing a new insight into the mechanism of CH3SH generation in oral microbial communities. A better understanding of the underlying interactions among oral bacteria involved in CH3SH generation can lead to the development of more appropriate prophylactic approaches to treat halitosis and periodontitis. An intervention approach like selectively disrupting this interspecies network could also offer a powerful therapeutic strategy.IMPORTANCEHalitosis can have a significant impact on the social life of affected individuals. Among oral odor compounds, CH3SH has a low olfactory threshold and halitosis is a result of its production. Recently, there has been a growing interest in the collective properties of oral polymicrobial communities, regarded as important for the development of oral diseases, which are shaped by physical and metabolic interactions among community participants. However, it has yet to be investigated whether interspecies interactions have an impact on the production of volatile compounds, leading to the development of halitosis. The present findings provide mechanistic insights indicating that ornithine, a metabolite excreted by Streptococcus gordonii, promotes polyamine synthesis by Fusobacterium nucleatum, resulting in a compensatory increase in demand for methionine, which results in elevated methionine pathway activity and CH3SH production. Elucidation of the mechanisms related to CH3SH production is expected to lead to the development of new strategies for managing halitosis.

Accuracy of two methods to detect the presence of halitosis: the volatile sulfur compounds concentration in the mouth air and the information from a close person

This study aimed to analyze the accuracy of two methods for detecting halitosis, the organoleptic assessment by a trained professional (OA) with volatile sulfur compounds (VSC) measurement via Halimeter® (Interscan Corporation) and information obtained from a close person (ICP). Participants were patients and companions who visited a university hospital over one year period to perform digestive endoscopy. A total of 138 participants were included in the VSC test, whose 115 were also included in the ICP test. ROC curves were constructed to establish the best VSC cut-off points. The prevalence of halitosis was 12% (95%CI: 7% to 18%) and 9% (95%CI 3% to 14%) for the OA and ICP, respectively. At the cut-off point >80 parts per billion (ppb) VSC, the prevalence of halitosis was 18% (95%CI: 12% to 25%). At the cut-off point >65 ppb VSC, sensitivity and specificity were 94% and 76%, respectively. At the cut-off point >140 ppb, sensitivity was 47% and specificity 96%. For the ICP, sensitivity was 14% and specificity 92%. VSC presents high sensitivity at the cut-off point of >65 ppb and high specificity at the cut-off point of >140 ppb. ICP had high specificity, but low sensitivity. The OA can express either occasional or chronic bad breath, whereas the ICP can be a potential instrument to detect chronic halitosis.

Revisiting Standard and Novel Therapeutic Approaches in Halitosis: A Review

Halitosis, or bad breath, is an oral health problem characterized by an unpleasant malodor emanating from the oral cavity. This condition can have different origins and causes a negative burden in social interactions, communication and quality of life, and can in uncommon cases be indicative of underlying non-oral non-communicable diseases. Most cases of halitosis are due to inadequate oral hygiene, periodontitis and tongue coating, yet the remaining proportion of cases are due to ear-nose-throat-associated (10%) or gastrointestinal/endocrine (5%) disorders. For this reason, the diagnosis, treatment and clinical management of halitosis often require a multidisciplinary team approach. This comprehensive review revisits the etiology of halitosis as well as standard and novel treatment that may contribute to higher clinical success.

ANTİ-HALİTOSİS GARGARALARININ REZİN BAZLI RESTORATİF DENTAL MATERYALLERİN YÜZEY ÖZELLİKLERİ ÜZERİNE ETKİSİ

Amaç: Bu in-vitro çalışmanın amacı anti-halitosis etkili beş farklı ağız gargarasının iki farklı restoratif materyalin renk stabilitesi ve yüzey pürüzlülüğü üzerine olan etkisinin araştırılmasıdır. Gereç ve Yöntemler: Çalışmada nano-hibrit (Filtek Z550, 3M ESPE) ve giomer (Beautifill II, Shofu Dental) yapıda olan iki çeşit reçine bazlı restoratif materyal kullanılmıştır. Her iki materyalden test edilmek üzere toplam 120 adet kompozit disk üretici talimatları doğrultusunda 10x2mm ebatlarında silindir kalıplar kullanılarak hazırlanmıştır. Rastgele seçilen örnekler, 5 farklı ağız gargarası (Listerine Fresh Burst, Listerine Total Care, Colgate Plax, Oderol, Halitosil) ve 1 kontrol grubunda (distile su) bekletilmek üzere toplam 6 farklı gruba ayrılmıştır. Başlangıç renk koordinatları CIELAB renk sistemine göre spektrofotometre (Easyshade Compact) ile yüzey pürüzlülük değerleri (Ra) ise kontakt profilometre (Surtronic 25) ile ölçülmüştür. Tüm örnekler 37°C'de ağız gargaralarında 12boyunca bekletilmiş ardından renk ve pürüzlülük ölçüm prosedürleri aynı şekilde gerçekleştirilmiştir. Elde edilen veriler SPSS 24.0 programı ile Kruskal-Wallis H ve Bonferroni Post Hoc testleri kullanılarak 0.05 anlamlılık düzeyinde analiz edilmiştir. Bulgular: Bu çalışmanın sonuçları, yüzey pürüzlülük değerlerinde istatistiksel olarak anlamlı bir artış olmadığını göstermiştir. Ağız gargaralarında bekletilen Beautifil II materyallerinin tamamında CIELAB değerlerinde önemli bir değişiklik olmuştur (P

The Prevalence and Determinant Factors of Oral Halitosis in Northwest Ethiopia: A Cross-Sectional Study

BACKGROUND

Oral halitosis, unpleasant or offensive odor to others, has become a major health concern among the general population, ranking the third most common reason for seeking a dentist behind dental caries and periodontal disease. Even though there have been repeated cases of halitosis in Ethiopia, there is no documented evidence.

OBJECTIVE

The purpose of this study was to determine the prevalence of halitosis in Northwest Ethiopia and to examine the relationship between halitosis and sociodemographic factors, oral habits, and health practices.

METHODS

From December 2019 to March 30, 2020, a hospital-based cross-sectional study was conducted. A systematic random sampling method was used to select study participants. Following informed consent, sociodemographic characteristics were collected using structured questionnaires, and two qualified dental surgeons performed the oral examination. The organoleptic test was used to assess the presence of halitosis.

RESULTS

Six hundred sixty-one people took part in the study, with a mean age of 30.0 ±14.76 years. The prevalence of oral halitosis was 44.2% (95% CI: 40.39-47.96) among the study participants. Participants with no formal education were more prone to oral halitosis. Oral halitosis was common in students (18.5%), low-income individuals (22.2%), rural residents (12.3%), mouth breathers (19.1%), and participants with poor oral hygiene practices (15.3%). Independent factors of halitosis included rural residency (AOR=1.40, 95% CI: 1.18, 1.67), low economic status (AOR=1.81, 95% CI: 1.06,3.09), poor tooth brushing habit (AOR=1.85 (1.31, 2.61), smoking (AOR=2.69 (1.39, 5.21) and dental caries (AOR=8.74 (5.57, 13.71).

CONCLUSION

The prevalence of oral halitosis was 44.2% among the study participants. Rural residency, low monthly income, poor tooth-brushing habit, smoking, and dental caries were independent factors of halitosis.

The role of oral microbiome in pemphigus vulgaris

While the impact of oral microbiome dysbiosis on autoimmune diseases has been partially investigated, its role on bullous diseases like Pemphigus Vulgaris (PV) is a totally unexplored field. This study aims to present the composition and relative abundance of microbial communities in both healthy individuals and patients with oral PV lesions. Ion Torrent was used to apply deep sequencing of the bacterial 16S rRNA gene to oral smear samples of 15 healthy subjects and 15 patients. The results showed that the most dominant phyla were Firmicutes (55.88% controls-c vs 61.27% patients-p, p value = 0.002), Proteobacteria (9.17%c vs 12.33%p, p value = 0.007) and Fusobacteria (3.39%c vs 4.09%p, p value = 0.03). Alpha diversity showed a significant difference in the number of genera between patients and controls (p value = 0.04). Beta diversity showed statistical differences in the microbial community composition between two groups. Fusobacterium nucleatum, Gemella haemolysans and Parvimonas micra were statistically abundant in patients. We noticed the characteristic fetor coming out of oral PV lesions. Most of anaerobic bacteria responsible for oral halitosis are periopathogenic. Though, only F. nucleatum and P. micra were differentially abundant in our patients. Especially, F. nucleatum has been reported many times as responsible for bad breath. Furthermore, Streptococcus salivarius and Rothia mucilaginosa, species mostly associated with clean breath, were found in relative abundance in the healthy group. Consequently, the distinct malodor observed in PV patients might be attributed either to the abundance of F. nucleatum and P. micra and/or to the lower levels of S. salivarius and R. mucilanginosa in oral lesions.

Colorimetric Dye-Loaded Nanofiber Yarn: Eye-Readable and Weavable Gas Sensing Platform

The colorimetric gas sensor offers an opportunity for the simple and rapid detection of toxic gaseous substances based on visually discernible changes in the color of the sensing material. In particular, the accurate detection of trace amounts of certain biomarkers in a patient's breath provides substantial clues regarding specific diseases, for example, hydrogen sulfide (H₂S) for halitosis and ammonia (NH₃) for kidney disorder. However, conventional colorimetric sensors often lack the sensitivity, selectivity, detection limit, and mass-productivity, impeding their commercialization. Herein, we report an inexpensive route for the meter-scale synthesis of a colorimetric sensor based on a composite nanofiber yarn that is chemically functionalized with an ionic liquid as an effective H₂S adsorbent and lead acetate as a colorimetric dye. As an eye-readable and weavable sensing platform, the single-strand yarn exhibits enhanced sensitivity supported by its high surface area and well-developed porosity to detect the breath biomarker (1 ppm of H₂S). Alternatively, the yarn loaded with lead iodide dyes could reversibly detect NH₃ gas molecules in the ppm-level, demonstrating the facile extensibility. Finally, we demonstrated that the freestanding yarns could be sewn into patterned textiles for the fabrication of a wearable toxic gas alarm system with a visual output.

Exploring residential care aide experiences with oral malodour in long-term care

Aim

To determine what experiences do residential care aides (RCAs) have with individuals living with oral malodour in a long-term care (LTC) facility?

Design

Study investigation was done using an interpretive qualitative approach paired with a social constructivism interpretive framework.

Methods

The study was conducted in May of 2015 through face-to-face interviews with RCAs, which were recorded and transcribed verbatim, observations of RCAs in their work environment, as well as RCA personal logs of their daily experiences with odour during caregiving. Thereafter, data were analysed and coded for emerging themes.

Results

Five major themes were identified after grouping the codes: 1) attitudes and behaviours when caring for residents with malodour; 2)RCA knowledge of oral malodour; 3) level of job satisfaction among RCAs that care for residents with malodour; 4) culture and malodour; and 5) challenges of care giving compounded by malodour. These themes depict the overall experiences of study participants.

Halitosis: prevalence, risk factors, sources, measurement and treatment - a review of the literature

Halitosis, an offensive breath odour, has multiple sources and negative impacts on people's social interactions and quality of life. It is important for health care professionals, including general physicians and dental professionals, to understand its aetiology and risk factors in order to diagnose and treat patients appropriately. In this study, we have reviewed the current literature on halitosis regarding its prevalence, classification, risk factors, sources, measurement and treatment.

Prevalence of Tongue Cleaning Using a Toothbrush: A Questionnaire Survey in Fukui Prefecture, Japan

Objective

The aim of this study was to investigate the tongue cleaning habits using toothbrushes among outpatients of the University of Fukui Hospital and a private hospital in Fukui Prefecture.

Methods

We administered a questionnaire survey to volunteers detailing tongue cleaning habits using toothbrushes. The content of the questions in this survey were as follows: gender, age, frequency of tongue cleaning, portion of tongue cleaning, and purposes of tongue cleaning.

Results

We had 1,014 volunteers of various ages participating in this study. Regarding the frequency of tongue cleaning, 187 (18.4%) of all participants replied, “Every day”, and 346 (34.1%) replied, “Sometimes”. Regarding tongue cleaning of the 533 participants with active tongue cleaning habits, 242 (45.4%) participants replied, “The center of the dorsum of the tongue”, and 274 (51.4%) replied, “The entire tongue”. When analyzing the purpose of tongue cleaning, 346 (64.9%) participants replied, “To remove the tongue stain”, 192 (36.0%) participants replied, “To remove the tongue coating”, and 240 (45.0%) participants replied, “To manage halitosis”.

Conclusions

This study clarified that a wide range of age groups in the nonhospitalized general public practiced tongue cleaning habits using a toothbrush for various purposes.

Perceptual and cognitive determinants of tactile disgust

Tactile cues are said to be potent elicitors of disgust and reliable markers of disease. Despite this, no previous study had explored what the full range of tactile properties are that cue disgust, nor how interpretation of these sensations influences disgust. To answer these questions, participants were asked to touch nine objects, selected to cover the range of tactile properties, and evaluate their sensory, affective, and risk-based characteristics (primarily how sick they thought the object would make them). Object contact was manipulated in four ways, with participants randomly allocated to corresponding groups-one that could see the objects (i.e., the control) and three that could not (i.e., the blind groups). To manipulate disease risk interpretation of the objects, labelling was used on the blind groups, with one receiving Disgust-Labels, one True-Labels and one no labels. Disgust was strongly associated with sticky and wet textures, and moderately with viscous, cold, and lumpy textures, suggesting adherence-to-skin may predict disgust. The participants in the disgust-labelled condition had the highest disgust ratings, and this was mediated by their increased sickness belief and fear of the objects. Object identification was poor when labels or visual cues were absent. Our findings suggest that tactile disgust may reflect a bottom-up sensory component-skin adhesion-moderated by judgements of disease-related threat.

Efficacy of probiotics: clinical and microbial parameters of halitosis

BACKGROUND & AIM

Halitosis is defined as an offensive breath odour of whatever source and therefore may affect a person's social interactions. Intra-oral halitosis is a result of bacterial activity. Therefore, probiotics may offer an appropriate and biological solution as a part of the therapy of intra-oral halitosis. The aim of this systematic review was to study the effect of the administration of probiotics alone or as an adjunct to other treatments on the level of halitosis as measured by volatile sulphur compound (VSC) levels, organoleptic scores (ORG) or hydrogen sulphide, methyl mercaptan and dimethyl sulphide levels. In addition, the effect of probiotic usage on oral microbial composition was summarised.

METHODS

The MEDLINE-PubMed and Embase databases were searched up to September 2017 with language restricted to English. Eligible papers were selected according to pre-set criteria; the data was extracted and analysed descriptively.

RESULTS

The search resulted in 1104 original research articles and a final six were selected as being eligible including 129 subjects. These studies used different detection methods and combinations thereof to measure halitosis. Five studies were randomised placebo-controlled clinical trials of which two studies reported a significant reduction in ORG between probiotic and placebo groups, and two studies on the basis of total VSC levels. The two studies reporting a significant improvement in ORG did not find an improvement in total VSC levels. Three studies included a microbiological assessment. In these three studies, the probiotic strain was detected at the end of the treatment period, but no detailed data was reported on the abundance of the strain before and after the treatment period.

CONCLUSIONS

Probiotics may be beneficial in treating intra-oral halitosis. However, due to limited data and the heterogeneity of the studies, the efficacy of probiotics remains unclear. Studies with more subjects and standardised protocols need to be designed.

Predicting oral malodour based on the microbiota in saliva samples using a deep learning approach

Background

Oral malodour is mainly caused by volatile sulphur compounds produced by bacteria and bacterial interactions. It is difficult to predict the presence or absence of oral malodour based on the abundances of specific species and their combinations. This paper presents an effective way of deep learning approach to predicting the oral malodour from salivary microbiota.

Methods

The 16S rRNA genes from saliva samples of 90 subjects (45 had no or weak oral malodour, and 45 had marked oral malodour) were amplified, and gene sequence analysis was carried out. Deep learning classified oral malodour and healthy breath based on the resultant abundances of operational taxonomic units (OTUs)

Results

A discrimination classifier model was constructed by profiling OTUs and calculating their relative abundance in saliva samples from 90 subjects. Our deep learning model achieved a predictive accuracy of 97%, compared to the 79% obtained with a support vector machine.

Conclusion

This approach is expected to be useful in screening the saliva for prediction of oral malodour before visits to specialist clinics.

Electronic supplementary material

The online version of this article (10.1186/s12903-018-0591-6) contains supplementary material, which is available to authorized users.

Bioinspired Cocatalysts Decorated WO3 Nanotube Toward Unparalleled Hydrogen Sulfide Chemiresistor

Herein, we incorporated dual biotemplates, i.e., cellulose nanocrystals (CNC) and apoferritin, into electrospinning solution to achieve three distinct benefits, i.e., (i) facile synthesis of a WO₃ nanotube by utilizing the self-agglomerating nature of CNC in the core of as-spun nanofibers, (ii) effective sensitization by partial phase transition from WO₃ to Na₂W₄O₁₃ induced by interaction between sodium-doped CNC and WO₃ during calcination, and (iii) uniform functionalization with monodispersive apoferritin-derived Pt catalytic nanoparticles (2.22 ± 0.42 nm). Interestingly, the sensitization effect of Na₂W₄O₁₃ on WO₃ resulted in highly selective H₂S sensing characteristics against seven different interfering molecules. Furthermore, synergistic effects with a bioinspired Pt catalyst induced a remarkably enhanced H₂S response ( R_air/ R_gas = 203.5), unparalleled selectivity ( R_air/ R_gas < 1.3 for the interfering molecules), and rapid response (<10 s)/recovery (<30 s) time at 1 ppm of H₂S under 95% relative humidity level. This work paves the way for a new class of cosensitization routes to overcome critical shortcomings of SMO-based chemical sensors, thus providing a potential platform for diagnosis of halitosis.

Influence of Oral Probiotic Streptococcus salivarius K12 on Ear and Oral Cavity Health in Humans: Systematic Review

Traditionally, probiotics are linked to the good health of the intestine and most clinical studies focus on that field. Evidence of oral probiotic use for ear and oral cavity disease prevention with impact on human health is limited. This work reviews existing studies and literature on Streptococcus salivarius K12 as an oral probiotic and effects of S. salivarius K12 on human ear and oral cavity human health. The studies were accessed via database searches: MEDLINE, PubMed, and Elsevier. The search included/focused on/encompassed publications from 2003 to 2016 with keywords related to K12 Streptococcus salivarius, bacteriocin-like inhibitory substances (BLIS) K12, probiotic K12 salivarius, and K12 probiotic health effects. Only a small amount of studies was identified: the total of 68 studies was identified, 35 of which were relevant after screening, and 9 were included in the final analysis. Very little literature is available about the association/correlation between/connection/interrelation of S. salivarius K12 with/and human ear and oral cavity health. S. salivarius K12 may have a role in reducing the occurrence and/or severity of secretory otitis media (SOM) and also in prevention of streptococcal and viral pharyngotonsillitis in children. Research highlights that S. salivarius K12 has shown promising results in treatment of halitosis, but data are still deficient. Further studies need to be initiated to improve understanding of the association of oral probiotic S. salivarius K12 with human ear and oral cavity health.

Quality and readability of internet-based information on halitosis

OBJECTIVE

To evaluate quality and readability of Internet-based information on halitosis.

STUDY DESIGN

An Internet search through 3 engines (Google, Yahoo, and Bing) was done with the terms ("bad breath," "halitosis," "oral malodor," "foul breath," "mouth malodor," "breath malodor," "fetor ex ore," "fetor oris," "ozostomia," and "stomatodysodia"). The first 50 websites from each engine resulting from each search term were screened. Included websites were evaluated using Health on the Net (HON) criteria, Journal of American Medical Association (JAMA) benchmarks, DISCERN, Ensuring Quality Information for Patients (EQIP), Flesch Reading Ease (FRE) score, and Flesch-Kincaid Grade level.

RESULTS

A total of 101 websites were included. HON, DISCERN, EQIP, and FRE score were 42.9%, 37.6%, 37.4%, and 51.9% of the maximum score, respectively. Fewer than 50% of sites displayed attribution, disclosure, and currency according to JAMA benchmarks. HON score, DISCERN score, and EQIP score had significant correlation with each other and were significantly higher in sites displaying the HON seal.

CONCLUSION

The current quality and readability of informative websites on halitosis are generally low and poorly organized. Clinicians should be able to assess the Internet-based information on halitosis, as well as give accurate advice and guide patients concerning this issue.

Comparative Evaluation of Antiplaque Efficacy of Coconut Oil Pulling and a Placebo, Among Dental College Students: A Randomized Controlled Trial

Introduction

Oil pulling, has been extensively used as traditional Indian folk remedy since many years to prevent dental diseases and for strengthening teeth and gums.

Aim

To compare and evaluate antiplaque efficacy of coconut oil pulling with a placebo among dental students, in Hyderabad city of India.

Materials and Methods

A randomized controlled study was carried out among 40 dental students. Out of 40, 20 subjects were randomly assigned to study group and other 20 to control group. Subjects in the study group were given the coconut oil and control group a placebo, and advised to rinse for 10 minutes, once daily in the morning for a period of seven days. Plaque levels were assessed on day zero, third and seventh day using Turesky-Gilmore-Glickman Modification of the Quigley-Hein Plaque Index (1970) for both the groups.

Results

The mean plaque scores showed a significant difference at baseline, third day and seventh day among both study (p<0.001) and control groups (p<0.001). Group wise comparison revealed, though the mean plaque scores were low among study group on third day and seventh day on comparison with the control group, significant difference was noticed only on the seventh day. Furthermore, the mean percentage reduction of plaque scores were also significant only on the seventh day with a high mean plaque reduction among study groups (p<0.001).

Conclusion

Oil pulling is effective in controlling plaque levels.

Association of tongue brushing with the number of fungiform taste buds and taste perception: A preliminary study using confocal laser scanning microscopy in combination with a filter-paper disc method

OBJECTIVE

The aim of this study was to investigate the association of tongue brushing with the number of fungiform taste buds and taste perception using a confocal laser scanning microscopy in combination with a filter-paper disc method (FPDM).

METHODS

Twenty-four subjects with or without a habit of tongue brushing (11 males and 13 females, 20-46 years old) participated in this study. Nine of the 24 subjects had no habit of tongue brushing (Group 1, n=9). Fifteen subjects had a habit of tongue brushing, and the brushing regions of the tongue were as follows: central region (Group 2, n=7), or entire region (Group 3, n=8) of the tongue dorsum. Using confocal laser scanning microscopy, the average number of taste buds per fungiform papilla (FP) was counted. Taste perception was evaluated using an FPDM. These observations were performed in the midlateral region of the tongue since the distribution of fungiform papillae is large in the midlateral region compared to that in the central region.

RESULTS

The subjects in Group 3 showed a significantly decreased number of fungiform taste buds compared to Group 1 and Group 2. Group 3 also showed significantly higher FPDM scores than the other two groups.

CONCLUSIONS

Excessive tongue brushing of the entire tongue dorsum, including the midlateral region, may have an association with the decreased number of FP and taste buds and decreased taste sensation. To avoid these conditions, instituting proper tongue brushing methods, such as limiting it to the central region of the tongue and using a light touch, is suggested and is important for the subjects who are eager to participate in tongue brushing.

Inhibition of malodorous gas formation by oral bacteria with cetylpyridinium and zinc chloride

OBJECTIVE

The antimicrobial efficacy of zinc- (ZnCl₂) and cetylpyridinium-chloride (CPC) and their inhibition capacity on volatile sulfur compound (VSC) production by oral bacterial strains were investigated.

DESIGN

Minimum inhibitory concentrations (MIC) and growth curves were determined for ZnCl₂, CPC, and CPC with ZnCl₂ solutions against eight oral microorganisms (Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, Porphyromonas gingivalis, Prevotella intermedia, Treponema denticola, Tannerella forsythia, Staphylococcus aureus and Streptococcus mutans) known to be involved in the pathophysiology of both halitosis and periodontal disease. Gas chromatography was applied to measure VSCs (H₂S, CH₃SH, (CH₃)₂S) production levels of each strains following exposure to the solutions.

RESULTS

ZnCl₂ and CPC effectively inhibited growth of all eight strains. ZnCl₂ was generally more effective than CPC in suppressing bacterial growth excluding A. actinomycetemcomitans, P. intermedia, and T. forsythia. Synergism between CPC and ZnCl₂ was shown in A. actinomycetemcomitans. The MIC for CPC was significantly lower than ZnCl₂. VSC production was detected in five bacterial strains (A. actinomycetemcomitans, F. nucleatum, P. gingivalis, T. denticola, and T. forsythia). Each bacterial strain showed unique VSCs production profiles. H₂S was produced by F. nucleatum, P. gingivalis, and T. denticola, CH₃SH by all five strains and (CH₃)₂S by A. actinomycetemcomitans, F. nucleatum, P. gingivalis, and T. denticola. Production of CH₃SH, the most malodorous component among the three major VSCs from mouth air was evident in F. nucleatum and T. forsythia.

CONCLUSION

Both ZnCl₂ and CPC effectively inhibit bacterial growth causative of halitosis and periodontal disease, resulting in a direct decrease of bacterial VSCs production.

Mesoporous SnO2 Nanotubes via Electrospinning-Etching Route: Highly Sensitive and Selective Detection of H2S Molecule

We report the facile synthesis of thin-walled SnO₂ nanotubes (NTs) with numerous clustered pores (pore radius 6.56 nm) and high surface area (125.63 m²/g) via selective etching of core (SiO₂) region in SiO₂-SnO₂ composite nanofibers (NFs), in which SnO₂ phase preferentially occupies the shell while SiO₂ is concentrated in the center of the composite NFs. The SiO₂-etched SnO₂ NTs are composed of ultrasmall crystallites (∼6 nm in size) originating from crystal growth inhibition by small SiO₂ domains, which are partially segregated in the polycrystalline SnO₂ shell during calcination. These features account for efficacious diffusion and innumerable active sites, which maximize interaction between background gas (air) and analyte gas (H₂S). Evaluation of gas-sensing performance of the porous SnO₂ NTs before and after decorating the exterior and interior walls with Pt nanoparticles (NPs) reveals exceptional selectivity and superior response (R_a/R_g) of 154.8 and 89.3 to 5 and 1 ppm of H₂S, respectively. Excellent gas-sensing characteristics are attributed to the porous topography, nanosized crystallites, high surface area, and the catalytic activity of Pt/PtO_x NPs.

Use of traditional plants in management of halitosis in a Moroccan population

Introduction:

The use of medicinal plants was a very spread therapeutic way. At present, several studies are moving toward this ancestral option, seen the emergence of several bacterial resistance and for the large number of side effects of some synthetic drugs.

Objective:

The objective of this study was to collect and evaluate information on medicinal plants commonly used in five Moroccan cities: Rabat, Salé, Témara, Khémisset, and Tiflet for the management of halitosis.

Methods:

This is a cross-sectional survey; conducted among 171 herbalists. The tool of the study was a questionnaire filled by herbalists. SPSS in its version 13 was used for statistical calculations. Quantitative variables were expressed as a mean and standard deviation. Categorical variables were expressed as numbers and percentage.

Results:

Analysis of the results of this study identified 23 plants that are used the most. The herbal knowledge herbalists prescribed on the toxicity of plants and their side effects were appreciated.

Conclusions:

Preliminary results presented in this work allow knowing the plants used by this population. This data could be the basis for experimental and clinical studies to promote the use of natural agents in the treatment of bad breath.

Investigation of bacterial viability from incubated saliva by application of flow cytometry and hyphenated separation techniques

The aim of the study was determination of bacterial viability in saliva samples and finding a correlation between microbiological and volatile profiles of saliva depending on incubation time. Bacteria colonizing healthy oral cavities were also identified. Twelve healthy adults donated unstimulated saliva samples. Flow cytometry, optical density measurements and colony-forming unit (CFU) counting method were employed for analyses of native and inoculated saliva after 0, 1, 2, 24, and 48 h of incubation. Volatile profiles were acquired using headspace-solid phase microextraction-gas chromatography/mass spectrometry (HS-SPME-GC/MS). Oral bacteria were the most viable within 2 h after collection of saliva. Extension of incubation time to 48 h caused considerable decrease in live bacteria counts and sharp increase in dead bacteria counts. The most prevalent strain was Sphingomonas paucimobilis (26.67%). The number of volatiles raised from 5 to 27 with incubation time and most of them were putrefaction products, such as methanethiol, indole and pyrrole. HS-SPME-GC/MS method is insufficient for volatile profiling of "fresh" saliva and should be directed rather to investigation of bacterial metabolites.

Recombinant Sox Enzymes from Paracoccus pantotrophus Degrade Hydrogen Sulfide, a Major Component of Oral Malodor

Hydrogen sulfide (H₂S) is emitted from industrial activities, and several chemotrophs possessing Sox enzymes are used for its removal. Oral malodor is a common issue in the dental field and major malodorous components are volatile sulfur compounds (VSCs), including H₂S and methyl mercaptan. Paracoccus pantotrophus is an aerobic, neutrophilic facultatively autotrophic bacterium that possesses sulfur-oxidizing (Sox) enzymes in order to use sulfur compounds as an energy source. In the present study, we cloned the Sox enzymes of P. pantotrophus GB17 and evaluated their VSC-degrading activities for the prevention of oral malodor. Six genes, soxX, soxY, soxZ, soxA, soxB, and soxCD, were amplified from P. pantotrophus GB17. Each fragment was cloned into a vector for the expression of 6×His-tagged fusion proteins in Escherichia coli. Recombinant Sox (rSox) proteins were purified from whole-cell extracts of E. coli using nickel affinity chromatography. The enzyme mixture was investigated for the degradation of VSCs using gas chromatography. Each of the rSox enzymes was purified to apparent homogeneity, as confirmed by SDS-PAGE. The rSox enzyme mixture degraded H₂S in dose- and time-dependent manners. All rSox enzymes were necessary for degrading H₂S. The H₂S-degrading activities of rSox enzymes were stable at 25–80°C, and the optimum pH was 7.0. The amount of H₂S produced by periodontopathic bacteria or oral bacteria collected from human subjects decreased after an incubation with rSox enzymes. These results suggest that the combination of rSox enzymes from P. pantotrophus GB17 is useful for the prevention of oral malodor.

Determination of salivary urea and uric acid of patients with halitosis

Background:

Halitosis is the presence of unpleasant or foul smelling breath. The origin of halitosis may be related to both systemic and oral conditions, but a large percentage of cases, about 90%, is generally related to an oral cause. The aim of this study was to compare the concentration of urea and uric acid in patients with halitosis and people without halitosis.

Materials and Methods:

In this case–control study, concentration of urea and uric acid was compared between two groups: (1) persons suffering halitosis (2) control group without halitosis. Each group includes fifty patients. Unstimulated saliva was collected in both groups. Then, concentration of urea, uric acid, and creatinine was determined. The results were statistically analyzed with SPSS software version 14 (SPSS Inc., Chicago, Illinois, USA) by t-test (α = 0.05).

Results:

Results showed that salivary urea and uric acid concentration in halitosis group were significantly greater than control group (P < 0.05). Salivary creatinine concentration in halitosis group was significantly lower compared to control group (P < 0.05). Salivary urea and uric acid concentration to creatinine ratios were higher in halitosis group than control group, and significant differences between them were existed (P < 0.05).

Conclusion:

According to the results, urea and uric acid concentration show increase in patient suffering halitosis, and this increase may result in oral malodor.

Effects of fixed and removable space maintainers on halitosis

Background

The current study evaluated the effects of fixed and removable space-maintainers on halitosis and oral health of children.

Methods

Forty-three patients randomly selected between the ages 4–10 whom fixed or removable space maintainers were indicated in Gazi University, Faculty of Dentistry, Department of Pedodontics. The inclusing criteria were: caries-free (with/without restorations), with absence of periodontal diseases, without systematic disease, no mouth breathing and no use of antibiotics the 2-months period before the study. The patients were subdivided into two groups: the group treated with fixed space maintainers (group 1, n = 27), the group treated with removable space maintainers (group 2, n = 16). The the plaque index (PI), gingival index (GI), periodontal screening index (PSI), tongue coating index (TCI) records and the halitosis measurements were obtained at three time periods (T1: immediately after application, T2: 1 week after application, T3: 5 weeks after application). The measurement values of T1 served as control.

Results

No statistically significant difference was found in the PI, GI, PSI, TCI and halitosis measurements between T1–T2, T2–T3 and T1–T3 in both appliance groups and between the groups (p > 0.05).

Conclusions

The fixed and removable space maintainers did not affect oral health status and halitosis significantly.

Self-perceived halitosis and related factors among adults residing in Riyadh, Saudi Arabia. A cross sectional study

Objectives

This cross-sectional observational study was conducted to determine the prevalence of self-perceived halitosis among adults in Riyadh, Saudi Arabia and to assess the relation of halitosis with some socio-demographic factors, oral habits and health practices.

Materials and methods

A questionnaire was distributed to randomly selected subjects including senior high school students, college students and employees working in governmental offices. High schools and governmental offices were selected using systematic random sampling from each of the main five regions of Riyadh. The college students were selected from the major universities in Riyadh. One hundred questionnaires were randomly distributed in each of the 15 locations for males and 15 for females (5 schools, 5 universities and 5 governmental offices for each gender) giving a total of 3000 questionnaires.

Results

The prevalence of self-perceived halitosis was 22.8% among the participants. The majority of the subjects with self-perceived halitosis experienced bad breath on waking up (83.5%). Nearly half of the sample with self-perceived halitosis was told by others that they had bad breath, 25.8% visited a doctor regarding that, 23.8% received treatment for their bad breath and 54.1% made trials to control their problem by using some aids. Self-perceived halitosis was found to be more prevalent among males compared to females (P < 0.000), whereas, no statistically significant differences were found among the different age groups (P = 0.317). A statistically significant relationship was found between self-perceived halitosis and times of mouth cleaning, use of tooth brush, use of tooth paste, tongue cleaning (P < 0.000), and the use of dental floss (P = 0.004). A statistically significant relationship was also found between self-perceived halitosis and shisha (P < 0.000) and cigarette smoking (P = 0.045).

Conclusion

The prevalence of self-perceived halitosis among the population in Riyadh is within the range reported in other countries. Self-perceived halitosis is related to gender, inadequate oral hygiene practices and cigarettes and shisha smoking however, it is not related to age.

Factors Associated with Halitosis in White-Collar Employees in Shanghai, China

Objective

To investigate the factors associated with halitosis in Chinese white-collar employees.

Materials and Methods

Subjects in three randomly selected office buildings in Shanghai, China, were enrolled in this cross-sectional study using cluster random sampling. Oral malodor was assessed by measuring volatile sulfur compounds (VSCs) with a portable sulfide monitor. Subjects’ oral health, including dental caries, periodontal status, and tongue coating, was evaluated clinically. A questionnaire was used to obtain information about participants’ demographic characteristics, oral hygiene habits, and health behaviors.

Results

Of the 805 subjects invited to participate in this study, 720 were enrolled (89.4% response rate). Data from these subjects were used for statistical analyses. The prevalence of halitosis was 33.2%. In the final regression model, halitosis was significantly related to tongue coating thickness, periodontal pocket depth, no food consumption within 2 hours prior to oral examination, and less intake frequency of sweet foods.

Conclusions

In this Chinese white-collar population, tongue coating and periodontal disease were associated with halitosis. Oral hygiene education should be provided at the population level to encourage the maintenance of oral health and fresh breath. Consumption of sweet foods may reduce VSC production, although this finding requires further investigation.

Self-perceived halitosis influences social interactions

Background

To determine the impact of self-perceived halitosis on social interactions, and the effect of using an oral rinse for management of halitosis.

Methods

A survey among a representative sample of the Dutch population (n = 1082), and a pre-post study among a sample of consecutive coming-by volunteers (n = 292).

Results

Participants of the representative sample rated their oral odor as 66.8 ± 17.2 and the consecutive volunteers as 70.9 ± 16.7 (range: 0–100). Sizable proportions (15.3 % and 38.1 %, respectively) indicated to always take into account their (bad) oral odor when meeting a person for the first time. The worse people perceived their oral odor, the more likely they were to take into account to keep a certain distance.

Following the use of the oral rinse, a significant decline was found of the extent to which the participants reported to take into account their oral odor when meeting a person for the first time. Both studies identified a subgroup of individuals (9.1 % and 28.1 % respectively) who reported to keep a certain distance when meeting other people, despite a “fresh” self-perceived oral odor.

Conclusion

The results suggest that self-perceived oral odor negatively affects social interactions, and that adequate management of halitosis has the potential to improve such interactions.

Attitudes towards individuals with halitosis: an online cross sectional survey of the Dutch general population

OBJECTIVE

To derive an estimate of encounters with halitosis and to assess the impact of halitosis on their psychosocial interactions with halitosis patients.

METHODS

Participants were 1,006 members of an online panel, being representative of the population of the Netherlands with regard to gender, age, family situation, education level and labour participation. They were invited to participate in a survey using an online questionnaire with four questions on becoming faced with people having halitosis.

RESULTS

Almost 90% of the participants indicated being faced with a person having halitosis regularly, 40% at least once a week, and men significantly more frequently than women. Halitosis was reported to be a strong 'downer' when meeting a person for the first time. Whether one would draw a person's attention to his breath malodour proved to be related to the kind of person involved and appeared to decrease with the increase of the social distance to the person. Drawing a person's attention to his breath malodour would virtually always be performed personally.

CONCLUSION

Halitosis is considered to be one of the most unattractive aspects of social interactions and has potentially damaging effects on psychosocial interactions and relationships.

Prevalence and Associated Factors of Subjective Halitosis in Korean Adolescents

This study was conducted to estimate the prevalence and associated factors of subjective halitosis in adolescents. In total, 359,263 participants were selected from the Korea Youth Risk Behavior Web-based Survey (KYRBWS) from 2009 through 2013. Demographic data including age, sex, obesity and residency; psychosocial factors such as subjective health, stress, and economic levels; and dietary factors such as alcohol consumption; smoking; and fruit, soda, fast food, instant noodle, confection, and vegetable consumption were analyzed for correlations with halitosis using simple and multiple logistic regression analyses with complex sampling. In total, 23.6% of the participants reported the presence of halitosis. The following subjectively assessed factors were related to halitosis: poor health status (adjusted odds ratio [AOR] = 2.56), overweight or obese (AOR = 1.37), stress (AOR = 2.56), and lower economic levels (AOR = 1.85). The high intake of fast food (AOR = 1.15), instant noodles (AOR = 1.17), and confections (AOR = 1.17) and the low intake of fruits (AOR = 1.22) and vegetables (AOR = 1.19) were also related to halitosis. The prevalence of subjective halitosis in the studied adolescents was 23.6%. Specific psychosocial factors and dietary intake were related to halitosis.

Green tea extract and its major constituent epigallocatechin-3-gallate inhibit growth and halitosis-related properties of Solobacterium moorei

Background

Solobacterium moorei is a volatile sulfide compound (VSC)-producing Gram-positive anaerobic bacterium that has been associated with halitosis. The aim of this study was to investigate the effects of green tea extract and its major constituent epigallocatechin-3-gallate (EGCG) on growth and several halitosis-related properties of S. moorei.

Methods

A microplate dilution assay was used to determine the antibacterial activity of green tea extract and EGCG against S. moorei. Their effects on bacterial cell membrane integrity were investigated by transmission electron microscopy and a fluorescence-based permeability assay. Biofilm formation was quantified by crystal violet staining. Adhesion of FITC-labeled S. moorei to oral epithelial cells was monitored by fluorometry. The modulation of β-galactosidase gene expression in S. moorei was evaluated by quantitative RT-PCR.

Results

The green tea extract as well as EGCG inhibited the growth of S. moorei, with MIC values of 500 and 250 μg/ml, respectively. Transmission electron microscopy analysis and a permeabilization assay brought evidence that the bacterial cell membrane was the target of green tea polyphenols. Regarding the effects of green tea polyphenols on the S. moorei colonization properties, it was found that biofilm formation on EGCG-treated surfaces was significantly affected, and that green tea extract and EGCG can cause the eradication of pre-formed S. moorei biofilms. Moreover, both the green tea extract and EGCG were found to reduce the adherence of S. moorei to oral epithelial cells. The β-galactosidase activity of S. moorei, which plays a key role in VSC production, was dose-dependently inhibited by green tea polyphenols. In addition, EGCG at ½ MIC significantly decreased the β-galactosidase gene expression.

Conclusion

Our study brought evidence to support that green tea polyphenols possess a number of properties that may contribute to reduce S. moorei-related halitosis. Therefore, these natural compounds may be of interest to be used to supplement oral healthcare products.

Volatile sulphur compound measurement with OralChroma(TM): a methodological improvement

The instrumental measurement of volatile sulphur compounds is a common practice to assess halitosis. One of the most widespread devices for that purpose is OralChroma(TM), a combination of a semiconductor gas sensor and a compact gas chromatograph (GC) system. Several lines of evidence indicate that although the hardware of OralChroma(TM) is fit for the precise measurement of volatile sulphur compounds (VSCs), its software needs revision to allow that precision. In this study we sought to develop software to solve this problem, and to test the utility of the new software in a population of patients and controls. The results were also compared with VSC measurements performed with Halimeter(®), another widespread device, so as to assess the correlation. A set of measurements involving volunteers (21 controls and 14 oral cancer patients) were conducted. The analysis of the chromatograms recorded by OralChroma(TM) indicated that the majority of the studied breath samples contained significant amounts of isoprene (the peak was around 100 s) and acetaldehyde (the peak was around 350 s), therefore OralChroma(TM) was also calibrated for both isoprene and acetaldehyde. A linear relationship was found between the concentration (in the range of 80-1400 ppbv for acetaldehyde and 40-560 ppbv for isoprene) and the area under the corresponding peak. In numerous cases the concentrations of VSCs calculated by the software of OralChroma(TM) required revision. In the new software, the concentrations of the VSCs, isoprene and acetaldehyde were determined by fitting the chromatograms with the sum of six Gaussian functions. Based on the findings of the present study we conclude that our new software allows an improved and instantaneous evaluation of OralChroma(TM) chromatograms with the additional possibility of determining the isoprene and acetaldehyde concentrations from breath samples.

Halitosis: a review of the etiologic factors and association with systemic conditions and its management

Halitosis is a general term defined as an unpleasant or offensive odor emanating from the breath, arising from either oral or nonoral sources. Extraoral factors, such as ear-nose-throat conditions or gastrointestinal, respiratory, and systemic diseases, may also contribute to oral malodor. Although, halitosis has a multifactorial etiology, local factors play an important role in the majority of cases. Halitosis may lead to significant personal discomfort and social embarrassment. Assessment of halitosis can be performed using organoleptic measurements, sulfide monitoring, gas chromatography, microbial testing and chemical test strips. Management approaches are based on masking oral malodor, reducing the levels of volatile organic compounds (VOCs) and volatile sulfur compounds (VSCs), and mechanical and/or chemical treatment. This review aims to identify the etiology of oral halitosis, describe the methods available for assessment and differential diagnosis and introduce a variety of management strategies. The importance of a multidisciplinary approach for the improvement of overall health and for the management and prevention of halitosis is highlighted.

Taking your breath away: metabolomics breathes life in to personalized medicine

Breath-based metabolomics (breathomics) is an exciting developing area of biotechnology that centers on the capture, identification, and quantification of volatile organic compound (VOC) patterns in human breath and their utilization as tools in the diagnosis of a broad spectrum of medical problems. With the age of personalized medicines demanding rapid bespoke diagnosis and treatment, this area of molecular diagnostics is beginning to see an upsurge in biotechnological advancement. Here, we discuss recent improvements and directions in the development of breath VOC analysis and diagnosis platforms that offer the potential for disease biomarker discovery and disease prognosis.

Prevalence of halitosis in children considering oral hygiene, gender and age

BACKGROUND

To date, few studies have addressed halitosis in the paediatric population. As such, the aim of the present study was to investigate symptoms, signs and risk factors associated with halitosis in healthy children and to present a model based on the clinical data that predicts the presence of halitosis.

METHODS

A total of 101 individuals were included. All patients received a questionnaire that queried on sociodemographic characteristics, self-reported halitosis and dental treatment history. Individuals received a thorough intra-oral examination, and the volatile sulphur compounds (VSC) were measured to test the presence of halitosis with a portable sulphide monitor (Halimeter(®); Interscan Co., Chatsworth, CA, USA). The distribution of the sociodemographic characteristics, self-reported halitosis, dental treatment history and other oral features was evaluated. Finally, a statistical model was constructed with the best set of features to predict halitosis in children.

RESULTS

The median age was 12.0 years (mean: 11.7 ± SD 2.7) with 54.5% males. Halitosis (VSC > 100 parts per billion, or ppb) was objectively measured in 37.6% of patients. For comparison purposes, Bayesian network was obtained using clinical and demographic data. The model consisted of four variables (sex, age, oral hygiene status and self-reported halitosis) directly related to the presence of halitosis (VSC > 100 ppb). This model achieved 76.4% area under receiver operating characteristics curve (AUROC). Overall, female patients or individuals with dental plaque on more than 25% of the dental surfaces or patients older than 13 year old were more prone to present with halitosis.

CONCLUSIONS

The results suggest that halitosis in the paediatric population is related to poor oral hygiene and may be more common in females and older individuals. This specific predictive model may be useful to identify subgroups to target for intervention to treat oral halitosis.

Characteristics of patients complaining of halitosis and factors associated with halitosis

OBJECTIVES

To describe the characteristics of patients who visited halitosis clinic and to investigate the factors that may associate with halitosis.

MATERIALS AND METHODS

Nine hundred and eleven patients, who visited halitosis clinic for consultations, underwent organoleptic tests and volatile sulfur compound (VSC) measurements with a portable sulfide monitor. The oral health of patients, including dental caries, oral hygiene, and gingival inflammation status, was assessed. Questionnaires were used to obtain information on demographics, oral hygiene practices, and dietary habits.

RESULTS

Of the 911 patients, more females than males visited the clinic. Patients' age ranged from 18 to 82 years (mean ± s.d.: 40.8 ± 14.1). Almost 30% of patients had complained of halitosis for over 5 years before looking into treatments. Approximately half of the patients self-perceived that they were unable to get close to others. Around 77% of patients had halitosis. Results of multiple logistic regressions for organoleptic scores and VSC values showed that tongue coating and tongue scraping were significantly associated with halitosis (P < 0.05).

CONCLUSIONS

Among these Chinese patients, over three-quarters of patients had halitosis, and negative impacts on social communications were observed. Tongue coating was the most important factor responsible for halitosis.

Antimicrobial activity of common mouthwash solutions on multidrug-resistance bacterial biofilms

Background

Periodontal bacteria occur in both planktonic and biofilm forms. While poor oral hygiene leads to accumulation of bacteria, reducing these microbes is the first step toward good oral hygiene. This is usually achieved through the use of mouthwash solutions. However, the exact antibacterial activity of mouthwash solution, especially when bacteria form biofilms, is yet to be determined. In this study, we evaluated the antibacterial activity of common mouthwash solutions against standard bacteria in their planktonic and biofilm states.

Methods

Standard bacterial strains were cultured, and biofilm were formrd. Thereafter, using standard method for determination of minimum inhibitory concentrations (MIC) values of various mouthwash solutions were determined.

Results

Results show that common mouthwash solutions have variable antibacterial activity depending on their major active components. Only mouthwash solutions containing chlorohexidine gluconate or cetylpyridinum chloride exhibited activity against majority, but not all tested bacterial strains in their biofilm state. Additionally, bacteria are generally less susceptible to all mouthwash solutions in their biofilm as compared to planktonic state.

Conclusions

While mouthwash solutions have variable antibacterial activity, bacteria in their biofilm state pose a challenge to dental hygiene/care where bacteria become not susceptible to majority of available mouthwash solutions.

Relationship between halitosis and periodontal disease - associated oral bacteria in tongue coatings

AIM

The objective of our study was to investigate the relationship between halitosis and oral bacteria in tongue coating (TC) and saliva samples from patients with halitosis, and to evaluate the effect of tongue cleaning on halitosis.

METHODS

Ninety-four participants complaining of oral malodour were included in the study. Organoleptic (OR) values, volatile sulphur compound (VSC) concentrations determined by gas chromatography and TC scores were used as clinical parameters of halitosis. Quantitative real-time polymerase chain reactions were used to determine the numbers of periodontal disease-associated oral bacteria.

RESULTS

There was a significant correlation between TC scores and OR values, methylmercaptan (CH3 SH) concentrations and VSC concentrations (Spearman's rank-correlation coefficient test, P < 0.01). There was also a positive correlation between the clinical parameters of halitosis and total bacterial numbers and Prevotella intermedia, Fusobacterium nucleatum and Campylobacter rectus concentrations in the TC samples. However, there was no similar correlation with respect to the saliva samples. The participants were sub-divided into two groups based on whether they had the habit of tongue cleaning or not. The participants with the habit of tongue cleaning had significantly lower OR scores, VSC concentrations and P. intermedia, F. nucleatum and C. rectus levels than the other participants (Mann-Whitney U-test, P < 0.05).

CONCLUSION

These results suggested that periodontal disease-associated oral bacteria in TCs are closely related to halitosis and that tongue cleaning may be an effective method for improving halitosis.

The potential impact of washing machines on laundry malodour generation

A multidisciplinary approach has been adopted to investigate and identify the source of malodour in washing machines and the potential for cross-contamination of laundry. Four washing machines were olfactively graded, and the number of colony-forming units (CFUs) bacteria was determined in four specific locations. Then, samples of terry-towel and fleece were washed, without the use of detergent, in the machines, and the occurrence of malodour over a 52-h period was assessed. Analysis of the scrapings from the four locations in the two malodorous machines identified a plethora of volatile organic compounds (VOCs) by either olfactory detection or mass spectral identification post-gas chromatographic separation. In addition, microbiological analysis from the swabs from the four locations within all four washing machines was carried out. Quantitative analysis of VOCs from 66 microbiological isolates from either the washing machines or fabrics was carried out. In total, 10 VOCs were identified: dimethyl disulfide, 3-methyl-1-butanol, 2,4-dithiapentane, dimethyl trisulfide, 2-tridecanone, indole, 2-phenylethanol, isovaleric acid, isobutyric acid and 1-undecene.

Characterization of volatile sulfur compound production by Solobacterium moorei

OBJECTIVE

Solobacterium moorei is a Gram positive bacterium that has been specifically associated with halitosis. The aim of this study was to characterize volatile sulfur compound (VSC) production by S. moorei.

METHODS

S. moorei was either grown or incubated in the presence of various supplements prior to determining VSC production with a Halimeter sulfide monitor. The effect of exogenous proteases or glycosidase inhibitors on VSC production by S. moorei was examined.

RESULTS

We first showed that S. moorei can convert cysteine into hydrogen sulfide. The capacity of S. moorei to produce VSCs from serum, saliva, and mucin was dependent on the presence of an exogenous source of proteases such as pancreatic trypsin or Porphyromonas gingivalis gingipains. VSC production from mucin was inhibited by the presence of a β-galactosidase inhibitor, thus suggesting that deglycosylation of mucin by S. moorei is critical for VSC production.

CONCLUSION

Our study suggests that S. moorei can be a major source of malodorous compounds in halitosis by producing VSCs through a process involving the β-galactosidase activity of the bacterium and an exogenous source of proteases.