Tongue-Coating Microbial and Metabolic Characteristics in Halitosis.

Halitosis is a common oral condition, which leads to social embarrassment and affects quality of life. Cumulative evidence has suggested the association of tongue-coating microbiome with the development of intraoral halitosis. The dynamic variations of tongue-coating microbiota and metabolites in halitosis have not been fully elucidated. Therefore, the present study aimed to determine the tongue-coating microbial and metabolic characteristics in halitosis subjects without other oral diseases using metagenomics and metabolomics analysis. The participants underwent oral examination, halitosis assessment, and tongue-coating sample collection for the microbiome and metabolome analysis. It was found that the microbiota richness and diversity were significantly elevated in the halitosis group. Furthermore, species from Actinomyces, Prevotella, Veillonella, and Solobacterium were significantly more abundant in the halitosis group. However, the Rothia and Streptococcus species exhibited opposite tendencies. Eleven Kyoto Encyclopedia of Genes and Genomes pathways were significantly enriched in the halitosis tongue coatings, including cysteine and methionine metabolism. Functional genes related to sulfur, indole, skatole, and cadaverine metabolic processes (such as serA, metH, metK and dsrAB) were identified to be more abundant in the halitosis samples. The metabolome analysis revealed that indole-3-acetic, ornithine, and L-tryptophan were significantly elevated in the halitosis samples. Furthermore, it was observed that the values of volatile sulfur compounds and indole-3-acetic abundances were positively correlated. The multiomics analysis identified the metagenomic and metabolomic characteristics to differentiate halitosis from healthy individuals using the least absolute shrinkage and selection operator logistic regression and random forest classifier. A total of 19 species and 39 metabolites were identified as features in halitosis patients, which included indole-3-acetic acid, Bacillus altitudinis, Candidatus Saccharibacteria, and Actinomyces species. In conclusion, an evident shift in microbiome and metabolome characteristics was observed in the halitosis tongue coating, which may have a potential etiological significance and provide novel insights into the mechanism for halitosis.

The tongue biofilm metatranscriptome identifies metabolic pathways associated with the presence or absence of halitosis.

Intra-oral halitosis usually results from the production of volatile sulfur compounds, such as methyl mercaptan and hydrogen sulfide, by the tongue microbiota. There are currently no reports on the microbial gene-expression profiles of the tongue microbiota in halitosis. In this study, we performed RNAseq of tongue coating samples from individuals with and without halitosis. The activity of Streptococcus (including S. parasanguinis), Veillonella (including V. dispar) and Rothia (including R. mucilaginosa) was associated with halitosis-free individuals while Prevotella (including P. shahi), Fusobacterium (including F. nucleatum) and Leptotrichia were associated with halitosis. Interestingly, the metatranscriptome of patients that only had halitosis levels of methyl mercaptan was similar to that of halitosis-free individuals. Finally, gene expression profiles showed a significant over-expression of genes involved in L-cysteine and L-homocysteine synthesis, as well as nitrate reduction genes, in halitosis-free individuals and an over-expression of genes responsible for cysteine degradation into hydrogen sulfide in halitosis patients.

Accuracy of a portable breath meter test for the detection of halitosis in children and adolescents

OBJECTIVES: This study aimed to determine the accuracy of the Breath-Alert™ portable breath meter (BA) for the detection of halitosis in children and adolescents, considering the organoleptic test (OT) as the gold standard in this assessment. METHODS: A cross-sectional study was conducted on 150 children (aged 6-12 years). OT was performed by three independent examiners on a single occasion, obtaining three scores of 0-5 points on the Rosenberg's organoleptic scale. The median of the three evaluations for each child was used for analysis. BA was used according to the manufacturer's instructions, with breath odor scored from 0-5 points. Scores ≥2 on both tests were considered indicative of halitosis. RESULTS: A total of 26 (17.3%) and 23 (15.3%) children were detected with halitosis on the OT and BA tests, respectively. The sensitivity and specificity of the BA scores for the detection of halitosis were 80.76% and 98.38%, respectively. The positive and negative predictive values for BA were 91.3% and 96.06%, respectively. CONCLUSION: In the present study involving children, who require fast, practical examinations, BA proved to be an auxiliary tool to OT for the detection of halitosis in the practice of pediatric dentistry, demonstrating high sensitivity and specificity.

Microbiological results of improvement in periodontal condition by administration of oral probiotics.

Oral bacteria that degrade sulphur-containing amino acids (cysteine, cystine, and methionine) produce volatile sulphur compounds (VSCs = hydrogen sulphide, methyl mercaptan, and dimethyl sulphide) highly correlated with halitosis. When these bacteria are given the right environment, i.e. periodontal disease, cariogenic biofilm or food source they can grow in number very quickly and will start to convert proteins to VSC that, together with volatile fatty acids are largely responsible for oral malodor. Recently, the prevention of dental caries and periodontal diseases using various probiotics has been attempted. The purpose of this study was to investigate the effects of probiotics based on in vitro analysis, such as antibacterial activity, and to evaluate the neutralizing effect of probiotics on halitosis, the levels of VSCs were measured by gas chromatography. .

In vitro effects of Melaleuca alternifolia essential oil on growth and production of volatile sulphur compounds by oral bacteria

ABSTRACT Objective Halitosis can be caused by microorganisms that produce volatile sulphur compounds (VSCs), which colonize the surface of the tongue and subgingival sites. Studies have reported that the use of natural products can reduce the bacterial load and, consequently, the development of halitosis. The aim of this study was to evaluate the antimicrobial activity of the essential oil of Melaleuca alternifolia on the growth and volatile sulphur compound (VSC) production of oral bacteria compared with chlorhexidine. Material and Methods The effects of these substances were evaluated by the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) in planktonic cultures of Porphyromonas gingivalis and Porphyromonas endodontalis. In addition, gas chromatography analyses were performed to measure the concentration of VSCs from bacterial cultures and to characterize M. alternifolia oil components. Results The MIC and MBC values were as follows: M. alternifolia - P. gingivalis (MIC and MBC=0.007%), P. endodontalis (MIC and MBC=0.007%=0.5%); chlorhexidine - P. gingivalis and P. endodontalis (MIC and MBC=1.5 mg/mL). M. alternifolia significantly reduced the growth and production of hydrogen sulfide (H2S) by P. gingivalis (p<0.05, ANOVA-Dunnet) and the H2S and methyl mercaptan (CH3SH) levels of P. endodontalis (p<0.05, ANOVA-Dunnet). Chlorhexidine reduced the growth of both microorganisms without altering the production of VSC in P. endodontalis. For P. gingivalis, the production of H2S and CH3SH decreased (p<0.05, ANOVA-Dunnet). Conclusion M. alternifolia can reduce bacterial growth and VSCs production and could be used as an alternative to chlorhexidine.

In vitro effects of Melaleuca alternifolia essential oil on growth and production of volatile sulphur compounds by oral bacteria.

OBJECTIVE: Halitosis can be caused by microorganisms that produce volatile sulphur compounds (VSCs), which colonize the surface of the tongue and subgingival sites. Studies have reported that the use of natural products can reduce the bacterial load and, consequently, the development of halitosis. The aim of this study was to evaluate the antimicrobial activity of the essential oil of Melaleuca alternifolia on the growth and volatile sulphur compound (VSC) production of oral bacteria compared with chlorhexidine. MATERIAL AND METHODS: The effects of these substances were evaluated by the Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) in planktonic cultures of Porphyromonas gingivalis and Porphyromonas endodontalis. In addition, gas chromatography analyses were performed to measure the concentration of VSCs from bacterial cultures and to characterize M. alternifolia oil components. RESULTS: The MIC and MBC values were as follows: M. alternifolia - P. gingivalis (MIC and MBC=0.007%), P. endodontalis (MIC and MBC=0.007%=0.5%); chlorhexidine - P. gingivalis and P. endodontalis (MIC and MBC=1.5 mg/mL). M. alternifolia significantly reduced the growth and production of hydrogen sulfide (H2S) by P. gingivalis (p<0.05, ANOVA-Dunnet) and the H2S and methyl mercaptan (CH3SH) levels of P. endodontalis (p<0.05, ANOVA-Dunnet). Chlorhexidine reduced the growth of both microorganisms without altering the production of VSC in P. endodontalis. For P. gingivalis, the production of H2S and CH3SH decreased (p<0.05, ANOVA-Dunnet). CONCLUSION: M. alternifolia can reduce bacterial growth and VSCs production and could be used as an alternative to chlorhexidine.

Association Between Oral Hygiene Status and Halitosis Among Smokers and Nonsmokers.

PURPOSE: To study the association of smoking with poor oral hygiene status and halitosis in a comparative cross-sectional study. MATERIALS AND METHODS: 100 smokers and 100 nonsmokers ages 18-50 years were recruited for this study in Kota Bharu, Malaysia. Oral hygiene (good/fair vs poor) was determined using the Simplified Oral Hygiene Index, and the halitosis level was measured using a Halimeter. Subjects were instructed to refrain from consuming foods containing garlic, onions, strong spices, alcohol and using mouthwashes 48 h prior to the examination. The halitosis levels were quantified by recording volatile sulphur compounds (VSCs) three times at 3-min intervals, resulting in a mean halitosis score. Various statistical analyses were performed, ranging from simple frequency analysis to multivariable modelling. RESULTS: The proportions of subjects with poor oral hygiene and high halitosis were 24.0% and 41.5%, respectively. According to bivariate analyses, both problems were significantly less frequent among younger adults (halitosis), females, subjects with higher education, those with adequate habits to maintain good oral hygiene, those who had recent dental visits and those self-reporting fewer health problems. The percentages of poor oral hygiene and high halitosis were significantly higher in smokers (p < 0.001). However, almost all these variables failed to show significance in the multivariate analyses, with the exceptions of smoking for both poor oral hygiene and halitosis, education for poor oral hygiene, and age, self-reported health problems and time since the previous dental visit for halitosis. CONCLUSION: These findings demonstrate a significantly higher level of halitosis and poorer oral hygiene in smokers than nonsmokers.

Deodorization of garlic breath volatiles by food and food components.

The ability of foods and beverages to reduce allyl methyl disulfide, diallyl disulfide, allyl mercaptan, and allyl methyl sulfide on human breath after consumption of raw garlic was examined. The treatments were consumed immediately following raw garlic consumption for breath measurements, or were blended with garlic prior to headspace measurements. Measurements were done using a selected ion flow tube-mass spectrometer. Chlorophyllin treatment demonstrated no deodorization in comparison to the control. Successful treatments may be due to enzymatic, polyphenolic, or acid deodorization. Enzymatic deodorization involved oxidation of polyphenolic compounds by enzymes, with the oxidized polyphenols causing deodorization. This was the probable mechanism in raw apple, parsley, spinach, and mint treatments. Polyphenolic deodorization involved deodorization by polyphenolic compounds without enzymatic activity. This probably occurred for microwaved apple, green tea, and lemon juice treatments. When pH is below 3.6, the enzyme alliinase is inactivated, which causes a reduction in volatile formation. This was demonstrated in pH-adjusted headspace measurements. However, the mechanism for volatile reduction on human breath (after volatile formation) is unclear, and may have occurred in soft drink and lemon juice breath treatments. Whey protein was not an effective garlic breath deodorant and had no enzymatic activity, polyphenolic compounds, or acidity. Headspace concentrations did not correlate well to breath treatments.

Relationship of a turbidity of an oral rinse with oral health and malodor in Vietnamese patients.

AIM: In the present study, the relationship between the turbidity of mouth-rinse water and oral health conditions, including oral malodor, in patients with (n = 148) and without (n = 231) periodontitis was examined. METHODS: The turbidity of 20 mL distilled water that the patients rinsed in their mouths 10 times was measured using a turbidimeter. Oral malodor was evaluated using an organoleptic test and Oral Chroma. Oral health conditions, including decayed teeth, periodontal status, oral hygiene status, proteolytic activity of the N-benzoyl-dl-arginine-2-napthilamide (BANA) test on the tongue coating, and salivary flow rate, were assessed. RESULTS: Turbidity showed significant correlations with oral malodor and all oral health parameters in the periodontitis group. In the non-periodontitis group, turbidity showed significant correlations with oral malodor and oral health parameters, including dental plaque, tongue coating, BANA test, and salivary flow rate. The regression analysis indicated that turbidity was significantly associated with methyl mercaptan and the BANA test in the periodontitis group, and with hydrogen sulfide, dental plaque, tongue coating, and salivary flow rate in the non-periodontitis group. CONCLUSION: The findings of the present study indicate that the turbidity of mouth-rinse water could be used as an indicator of oral health conditions, including oral malodor.

Efficacy of different mouthrinse formulations in reducing oral malodour: a randomized clinical trial.

AIMS: The aim of this study was to assess the efficacy of mouthrinses formulations in oral malodour. MATERIAL & METHODS: This single-centre, double-blind, randomized, parallel group clinical trial compared the efficacy of Halita™ and meridol(®) with and without zinc lactate versus negative and positive control. Volunteers with confirmed oral malodour (18/group) rinsed with one mouthrinse during 7 days (15 ml, 2x/day for 1 min.). 15 min. after a first rinse (masking effect), and after 7 days (therapeutic effect) the change in organoleptic scores and level of sulphur compounds was recorded. RESULTS: All rinses showed a masking effect (OLS 1 to 2 values reduced), only the rinses with antimicrobial ingredients showed a therapeutic effect (OLS 1 to 1.5 value less). The addition of zinc resulted in a more pronounced masking effect. Halita™ and meridol(®) with zinc showed the best therapeutic effect. CONCLUSION: Although the masking effect of the rinses can be attributed partially to a dilution and the effect of aromas, the therapeutic effect should be linked to the anti-microbial action of active ingredients and counter action of zinc ions on VSC. A complete resolution of the unpleasant breath by additional mechanical intervention remains to be proven.

Halitosis in obese patients and those undergoing bariatric surgery.

BACKGROUND: Patients undergoing bariatric surgery often complain of bad breath. However, the relationship between bariatric surgery and halitosis is relatively unknown. The purpose of the present study was to evaluate and compare the occurrence of halitosis among patients before and after a specific type of bariatric surgery, Roux-en-Y gastric bypass, and its relationship with the tongue coating index, plaque index, and salivary flow rate. METHODS: A total of 62 patients with good oral health and in treatment for obesity at the walk-in clinic of Santa Casa Hospital, Belo Horizonte, Brazil, were selected. Of this sample, 31 were bariatric surgery candidates (control group) and 31 had already undergone Roux-en-Y gastric bypass surgery (case group). After completing a questionnaire, all patients underwent an oral clinical examination. Halitosis was measured using an organoleptic scale and a portable sulfide monitor. RESULTS: The Spearman correlation demonstrated a strong positive relation between the organoleptic rates and the concentration of volatile sulfur compounds determined using the sulfide monitor (rs = .58; P = .0001). No difference was found in the prevalence of halitosis between the 2 groups (P = .48). Only the salivary flow rate was significantly reduced in the control group compared with the case group (P = .02). In the case group, the concentration of volatile sulfur compounds correlated negatively with the salivary flow rate (P = .04) and positively with the tongue coating index (P = .005). The tongue coating index was significantly increased in those patients who did not brush the tongue (P < .04) and who had had episodes of vomiting (P = .02). CONCLUSION: These data suggest that no significant association exists between halitosis and Roux-en-Y gastric bypass. However, they do highlight the possible effect of this surgery on the oral cavity.

The role of p53 in an apoptotic process caused by an oral malodorous compound in periodontal tissues: a review.

Oral malodor is caused by volatile sulfur compounds (VSCs) composed mainly of hydrogen sulfide (H(2)S) and methyl mercaptan. In particular, H(2)S is an important compound, since it is a major component of physiologic halitosis. The toxicity of VSCs is similar to that of hydrogen cyanide, and is well investigated. The role of VSCs in reducing collagen in human gingival fibroblasts is one of the main sources of their toxicity to human oral tissues. It has been reported recently that H(2)S may cause apoptosis in several periodontal tissues. In human gingival fibroblasts, H(2)S inhibits not only cytochrome c oxidase activity but also superoxide dismutase activity. The levels of reactive oxygen species are markedly increased, which causes the release of cytochrome c into the cytoplasm, resulting in caspase-9 activation; finally, the executor caspase, caspase-3, is activated. This pathway is commonly observed in cells from all periodontal tissues. Moreover, p53, an apoptotic factor, and phosphorlylated p53, which is the activated form, are increased by H(2)S in keratinocyte stem cells and osteoblasts. H(2)S also increases the expression of Bax, a primary response gene playing an important role in p53-mediated apoptosis, but maintains a lower expression of Bcl-2, an anti-apoptotic factor, in osteoblasts. It is concluded that the Bax apoptotic pathway and the mitochondrial pathway are activated by H(2)S.

Oral malodorous compound causes caspase-8 and -9 mediated programmed cell death in osteoblasts.

BACKGROUND AND OBJECTIVE: Hydrogen sulfide (H(2) S) is one of two volatile sulfur compounds that are known to be the main cause of oral malodor; the other is methyl mercaptan. Other known volatiles existing in mouth air do not contribute significantly to oral malodor originating in the oral cavity. Hydrogen sulfide is also known to be an etiological factor in periodontal disease. However, the effects of H(2) S on alveolar bone remain unclear. The objectives of this study were to determine the apoptotic effects of H(2) S on osteoblasts and to verify the apoptotic molecular pathways. MATERIAL AND METHODS: A clonal murine calvaria cell line was incubated with 50 ng/mL of H(2) S. To detect apoptosis, the cells were analysed by flow cytometry and ELISA. Mitochondrial membrane depolarization was assessed using flow cytometry as well. ELISA was used to evaluate the release of cytochrome c into the cytosol and to assess Fas ligand, p53, tumor necrosis factor α, interleukin IL1-α IL-ß, IL-2, IL-4, IL-10, interferon-γ, granulocyte-colony stimulating factor and granulocyte-macrophage colony stimulating factor. Caspase-3, -8 and -9 activities were estimated. Expression of BAX and Bcl-2 was assessed by real-time quantitative RT-PCR. DNA fragmentation was detected by single-cell gel electrophoresis. Fas receptors were evaluated by western blotting. RESULTS: After H(2) S incubation, apoptotic levels increased significantly in a time-dependent manner. Mitochondrial membrane depolarization, the release of cytochrome c, p53 and caspase-3, -8 and -9 and DNA fragmentation were all significantly greater. BAX gene activity was upregulated, whereas Bcl-2 remained low. Fas ligand/Fas receptor, tumor necrosis factor α and other cytokines were not increased to a significant degree. CONCLUSION: At less-than-pathological concentrations in gingival crevicular fluid, H(2) S induces apoptosis in osteoblasts. The molecular mechanisms underlying the apoptotic process include p53, a mitochondrial pathway and caspase-8 activation.

Effect of a single brushing with two Zn-containing toothpastes on VSC in morning breath: a 12 h, randomized, double-blind, cross-over clinical study.

This randomized, double-blind, 12 h clinical study tested the effect of a single brushing with two Zn-containing toothpastes on volatile sulfur compound (VSC) levels in morning breath. The following toothpastes were each tested by all 28 participants: A-Zn toothpaste, B--experimental toothpaste (Zn citrate + PVM/MA copolymer) and C--control toothpaste without Zn. The evening prior to test days participants brushed their teeth for 2 min with 1 g toothpaste. 12 h later and prior to eating or performing oral hygiene, morning breath levels of VSC (H(2)S, CH(3)SH) were analysed by gas chromatography. Subjects then rinsed for 30 s with 5 ml cysteine and breath samples were analysed for H(2)S (H(2)S(cys)). Median VSC (area under the curve) values were compared for A, B and C and the effects of A and B on VSC were compared with C. Toothpaste B was more effective than both toothpastes A and C in reducing H(2)S, CH(3)SH and H(2)S(cys) (p < 0.05). Compared with toothpaste C, toothpastes A and B reduced H(2)S by 35% and 68%, respectively (p = 0.003), and CH(3)SH by 12% and 47%, respectively (p = 0.002). Toothpaste B reduced H(2)S(cys) by 48% compared with toothpaste C (p = 0.001). It is suggested that the superior effect of the experimental toothpaste was most likely due to a higher Zn concentration combined with longer retention of Zn due to the PVM/MA copolymer.

Correlations between health status and OralChroma™-determined volatile sulfide levels in mouth air of the elderly.

Dimethyl sulfide (DMS), a volatile sulfur compound (VSC) found in mouth air, is thought to be associated with systemic diseases; this in contrast to the two other VSCs found in mouth air: hydrogen sulfide and methyl mercaptan (MM). This study aimed to validate the relationship between DMS in mouth air and oral and systemic factors. The subjects were 393 elderly Japanese volunteers participating in an oral and systemic health survey. They were surveyed for the concentration of VSC components in their mouth air and for their oral and systemic health status. Using logistic regression models, the prevalence of DMS in mouth air above the organoleptic threshold level (OTL) was found to be significantly associated with high-density lipoprotein (HDL) cholesterol level, medical history of colon polyps and asthma, being female, and the presence of MM in mouth air above the OTL. Our data suggest that systemic factors, such as a high serum HDL cholesterol level and a medical history of asthma and colon polyps, might be more prominent in subjects with elevated DMS. The differences, although statistically significant, are quite small. They also indicate that an oral factor, such as a high MM mouth-air level also influences the DMS mouth-air level in addition to systemic factors.

Volatile sulphur compounds in morning breath of human volunteers.

OBJECTIVE: morning breath contains elevated concentrations of volatile sulphur components (VSCs). Therefore, morning breath is recognised as a surrogate target for interventions on breath quality. Nevertheless, factors influencing morning breath are poorly understood. Our aim was to evaluate concentrations of VSC at the time of awakening. METHODS: a procedure was developed to collect breath samples at home. Intra- and inter-person variations were determined in two small studies based on measurements of hydrogen sulphide, methyl mercaptan and dimethyl sulphide in healthy volunteers. RESULTS: highest levels of VSC were found directly after waking up, followed by a significant decline afterward. Considerable day-to-day variation was found, but could not be linked to dietary intake. A significantly higher concentration of H(2)S and CH(3)SH was observed in the group of female subjects compared to males. CONCLUSIONS: when morning breath is used as a target for interventions, breath collected at the time of or shortly after waking up is preferred over breath collected later during the morning. Gender plays an important role in VSC levels, and should be taken into account.

Effects of a composition containing lactoferrin and lactoperoxidase on oral malodor and salivary bacteria: a randomized, double-blind, crossover, placebo-controlled clinical trial.

We report a clinical trial of the effects of test tablets containing bovine lactoferrin and lactoperoxidase on oral malodor and salivary bacteria. Fifteen subjects with volatile sulfur compounds (VSCs) in mouth air above the olfactory threshold (H(2)S >1.5 or CH(3)SH >0.5 ng/10 ml) as detected by gas chromatography were enrolled in the trial. Either a test or a placebo tablet was ingested twice at 1-h intervals in two crossover phases. Mouth air was monitored for VSC levels at the baseline before ingestion of a tablet, 10 min after the first ingestion, 1 h (just before the second ingestion), and 2 h after the first ingestion. Whole saliva was analyzed at the baseline and at 2 h for bacterial numbers. At 10 min, the level of CH(3)SH was significantly lower in the test group (median [interquartile range] = 0.28 [0.00-0.68] ng/10 ml) compared to that in the placebo group (0.73 [0.47-1.00] ng/10 ml; P = 0.011). The median concentration of CH(3)SH in the test group was below the olfactory threshold after 10 min until 2 h, whereas the level in the placebo group was above the threshold during the experimental period. No difference in the numbers of salivary bacteria was detected by culturing or quantitative PCR, but terminal restriction fragment length polymorphism detected one fragment with a significantly lower copy number at 2 h in the test group (mean ± standard error, 4.89 ± 0.11 log(10) copies/10 µl) compared to that in the placebo group (5.38 ± 0.15 log(10) copies/10 µl; P = 0.033). These results indicate a suppressive effect of the test composition on oral malodor and suggest an influence on oral bacteria.

Oral malodorous compound induces osteoclast differentiation without receptor activator of nuclear factor κB ligand.

BACKGROUND: Hydrogen sulfide (H(2)S), the main component of halitosis, is one of the etiologic factors for periodontitis. We recently reported that H(2)S may induce pathologic changes in rat alveolar bone. The objective of this study is to determine the effect of H(2)S on osteoclast differentiation. METHODS: Murine macrophage cells RAW264 were cultured in medium lacking nuclear factor κB ligand (receptor activator of nuclear factor κB ligand) in 5% CO(2) with air at 37°C for 24 hours; then 0.05, 0.5, or 5 ng/ml H(2)S was added to the CO(2)-air mix for 4 days. The controls received the CO(2)-air mix with no H(2)S. Cell differentiation was evaluated by counting the tartrate-resistant acid-phosphatase (TRAP)-positive cells. Extracellular signaling-regulated kinase1/2 (ERK1/2) and mitogen-activated protein kinase p38 phosphorylation were examined by Western blotting. The bone-resorption activity was determined with the resorption assay of calcium phosphate. RESULTS: There were significantly more TRAP-positive cells at a concentration of 0.05 ng/ml H(2)S than at the other concentrations (P <0.001). Cathepsin K protein, a specific marker for osteoclasts, was expressed in the H(2)S-induced multinuclear cells. Resorption of calcium phosphate significantly increased in the H(2)S-induced TRAP-positive cells cultured on plates coated with calcium phosphate apatite (P <0.01). The phosphorylation of ERK1/2 and p38 were accelerated by H(2)S, and increased with time. PD98059 and SB203580, specific inhibitors of ERK1/2 and p38, suppressed the activation of these enzymes and osteoclast differentiation by H(2)S. CONCLUSION: Results demonstrate that H(2)S at physiologic concentrations in mouth air induces osteoclasts from RAW264 cells.

Comparison of breath and in-mouth collection for the measurement of oral malodorous compounds by gas chromatography using sulfur chemiluminescence detection.

Volatile sulfur compounds (VSCs), specifically hydrogen sulfide, methyl mercaptan and dimethyl sulfide, are generally considered to be the primary volatiles responsible for 'morning' malodors in breath. To date, the 'gold standard' for detecting VSC concentrations in breath is the use of gas chromatography coupled with sulfur chemiluminescence detection. Breath gas is often collected in a polypropylene syringe and then aliquots are injected into a gas chromatograph for analysis. The objective of this work was to compare the Twister™ bar in-mouth extraction methodology for measurement of VSCs with the gas syringe breath-sampling collection technique. The Twister bar technology captures malodorous compounds in the mouth as opposed to breath gas. Using these techniques, comparable results were obtained in studies demonstrating the efficacy of a proprietary oral malodor counteraction system.