Oral Malodour Research Articles

Review of the treatment strategies for oral malodour

Breath malodour, a significant social and/or psychological handicap, may be caused by several intra- and extraoral factors. Malodour of intraoral origin is the result of microbial putrefaction, during which volatile sulphur compounds (VSC) and other volatile compounds are produced. The treatment of oral malodour can therefore be focused on the reduction of the intraoral bacterial load and/or the conversion of VSC to nonvolatile substrates. This article outlines the efficacy and mechanisms of different antimalodour approaches. Most approaches were found to be inefficient and/or short lasting. The most successful treatment involves mechanical debridement (including toothbrushing, flossing, and tongue cleaning), possibly combined with the use of an antimicrobial mouthrinse.

The oral anti-volatile sulphur compound effects of zinc salts and their stability constants.

Volatile sulphur compounds (VSC) produced in the oral cavity, are a major cause of oral malodour. Zinc (Zn) ions inhibit VSC formation. The objective of this study was to examine whether Zn salts with low stability constants were more suitable as sources of Zn in lozenges than salts with high stability constants. The former provide free Zn ions upon dissolution in water, whereas the latter provide almost no free Zn. Identical lozenges containing Zn-acetate and -gluconate, which have low stability constants, and Zn citrate and amino acid-chelated Zn, which have extremely high stability constants, were tested. All the lozenges contained 0.9% w/w Zn. Ten volunteers sucked the lozenges until dissolved, and oral VSC were measured by gas chromatography. Zn-acetate, -gluconate and -chelate had an impressive anti-VSC effect even 3 h after the lozenges were taken. Zn citrate had significantly less effect than the other lozenges except Zn acetate after 2 and 3 h. It was concluded that the anti-VSC effect was not related to the stability constants of the Zn compounds tested. Alternative ligands. with stronger affinity for Zn than the ligands in the lozenges, must be present in the oral cavity to explain these results. It is suggested that the sulphide ion may serve this function.

Variation in oral volatile sulphur compound formation

It has been suggested that the level of orally produced volatile sulphur compounds (VSCs) can be of use when monitoring oral malodour or in determining patients at risk of periodontal disease in longitudinal studies. It is not known, however, to what extent the level of VSC in mouth air is a stable, individual characteristic over time. Aim: The hypothesis to be tested was that the level of VSC in mouth air is an individual trait that is stable over time. Methods: Two groups of dental students participated in the study (n = 30 and n = 11). The amount of available substrate for VSC formation was standardized by rinses with 6 mM aqueous solutions of cysteine (pH 7.2). Part 1 used a Halimeter® to measure 'morning breath' and response to cysteine rinses. Part 2 measured response to cysteine rinsing using a gas chromatograph. Repeated measurements provided information concerning the longitudinal intra-individual variations in level of oral VSC formation. Results: Both groups showed large intra-individual variations in oral VSC. The differences were enhanced by cysteine rinses. Conclusion: The hypothesis was not supported. Oral VSC levels cannot be taken as diagnostic criteria in a normal population because of marked intra-individual variations over time.

Oral microbial flora and oral malodour of the institutionalised elderly in Japan.

To determine the oral health status, especially the level of oral microbial flora and oral malodour, of institutionalised elderly people compared with non-institutionalised elderly people. Three institutions and numerous private homes. 56 institutionalised and 56 non-institutionalised elderly people. Institutionalised elderly people had higher levels of candida, staphylococci, and oral malodour. Institutionalised elderly people had a higher level of candida in denture wearers, and a higher level of staphylococci and oral malodour compared with the non-institutionalised elderly. The institutionalised elderly have a higher risk of opportunistic infections and oral health care should be improved to protect them from these infections and to reduce oral malodour.

A multifactorial investigation of the ability of oral health care products (OHCPs) to alleviate oral malodour.

AIM, BACKGROUND: Oral malodour (halitosis) is generally ascribable to oral microbial putrefaction generating malodorous volatile sulphur compounds which predominantly comprise dihydrogen sulphide and methyl mercaptan. This study assesses the relative effectiveness of 6 oral health care products in reducing oral cavity volatile sulphur compound concentrations. A mixed model 3-factor factorial experimental design involving 6 volunteers, 7 treatment regimens (products I-VI* and water placebo) and 5 time-points (0.00-5.29 h) was undertaken. Electron-donating volatile sulphur compound levels were determined in triplicate using a sulphide monitor (Interscan model 1170) both prior to (0.00 h) and following oral rinsing (20 ml of 5 of the products) or chewing (2 capsules of the remaining product) episodes with each product examined (0.29, 1.29, 2.29 and 5.29 h post-administration). Results were recorded as peak and steady-state volatile sulphur compound equivalents (ppb). With the exception of one of the products, each oral health care product tested was found to reproducibly reduce volatile sulphur compound concentrations within 20 min of treatment; the mean % decreases in peak (and corresponding steady-state) levels ranging from 3.6 (0.0) to 16.8 (16.4)%. Subsequently, volatile sulphur compound concentrations returned to their zero-control (baseline) values within 5 h, the rate of this regression being in the reverse of the order observed for the magnitude of the primary 20 min reduction for both peak and steady-state measurements. As expected, the water placebo exerted no influence on oral cavity volatile sulphur compound levels. The most effective oral health care products contained admixtures of chlorite anion and chlorine dioxide (both of these agents have the ability to directly oxidise volatile sulphur compounds to non-malodorous products and the latter is also powerfully cidal towards odourigenic micro-organisms). We therefore conclude that oral health care products containing such oxohalogen oxidants may provide a useful therapeutic strategy for the treatment of oral malodour.

The benefits of toothpaste--real or imagined? The effectiveness of toothpaste in the control of plaque, gingivitis, periodontitis, calculus and oral malodour.

Toothbrushing with toothpaste is the most widely used method of home dental care for the populations of the Western world. The traditional role of toothpaste is primarily cosmetic, in aiding the cleaning of teeth and producing fresh breath. Today, however, formulations contain ingredients which may also help oral health by way of reducing dental plaque and improving gingival/periodontal health. This article provides a short review on the usefulness of these chemicals when used primarily in toothpastes.

Tongue Microbiota and Malodour

Thirty-two healthy, dentate volunteers with unexplained non-systemic halitosis took part in this blind, 2-cell (metronidazole and quinine control), randomised, single rinse, crossover study. The effects of both mouthwashes on the tongue bacterial microbiota, salivary microbiota, breath odour and the odour generating potentials of subjects’ saliva were measured. Metronidazole mouthwash reduced both breath odour and incubated salivary odour to a significantly greater extent ( p <0.05) than did the quinine control. The odour reduction was associated with a significant reduction in the bacterial counts per unit area of tongue surface. In particular, the reductions in the strict anaerobic species (up to 1.5 log-fold) and proportions of sulphide-producing organisms, were highly significant ( p <0.001), even up to 24 hours post-rinse. This study confirmed the highly selective nature of metronidazole. The concomitant reduction of both breath odour and recovery of strict anaerobes from the tongue (correlation, r2=0.776; p <0.005) supports the theory that this group of organisms are the major contributors to oral malodour production. Keywords: Metronidazole mouthrinse, oral malodour, salivary malodour, tongue microbiota, strict anaerobes.

Simple detector for oral malodour based on spectrofluorimetric measurements of hydrogen sulphide in mouth air

A sensing phase for spectrofluorimetric determination of hydrogen sulphide in mouth air, by immobilizing in a silica gel support the complex formed between Hg(II) and 2,2′-Pyridylbenzimidazole, has been developed. The sensing scheme is based on the fluorescence intensity increase of the solid phase upon reaction of hydrogen sulphide with the Hg(II), present in the non-fluorescent binary complex, with release of the fluorescent reagents. The developed sensing phase exhibits a response time of less than 2 min for hydrogen sulphide concentrations in the linear range. The 3σ detection limit is 4 ppb (v/v) of hydrogen sulphide and the linear range extends up to 200 ppb. The system has been successfully assayed for the measurement of human oral malodour and the results validated by comparison with those obtained for the same patients using a commercially available instrument based on electrochemical measurements.

Negative correlation between oral malodour and numbers and activities of sulphate-reducing bacteria in the human mouth

The majority of cases of oral malodour are thought to be due to bacterial activities in the mouth, but many of the bacterial species responsible have not been identified. Volatile sulphide compounds have been proposed as constituents of oral malodour. Therefore, the relation between intensity of odour and numbers of bacteria in the mouth that are sulphide-producing from sulphate was investigated. Numbers of such dissimilatory sulphate-reducing bacteria (SRB) and sulphide reduction rates were evaluated in samples from different oral sites in relation to measures of oral malodour. Results showed that sulphate-reducing bacterial numbers and activities were negatively correlated with malodour, as determined by organoleptic assessment and measurement with a sulphide-monitoring instrument, the Halimeter. The data indicate that sulphide produced by oral SRB may not be an important contributor to oral malodour. A rather poor correlation was observed between Halimetric and organoleptic values, indicating that these methods may measure different aspects of oral malodour intensity.

Multicomponent Spectroscopic Investigations of Salivary Antioxidant Consumption by an Oral Rinse Preparation Containing the Stable Free Radical Species Chlorine Dioxide (CIO2)

A multicomponent evaluation of the oxidative consumption of salivary biomolecules by a commercially-available oral rinse preparation containing an admixture of the stable free radical species chlorine dioxide (ClO2.) with chlorite anion (ClO2-) has been investigated using high resolution 1H NMR spectroscopy. The results obtained demonstrated that ClO2. and/or ClO2- present in this preparation effected the oxidative decarboxylation of salivary pyruvate (to acetate and CO2). Experiments conducted on chemical model systems confirmed the oxidative decarboxylation of pyruvate by this oral rinse, and also demonstrated that urate, thiocyanate anion, and the amino acids cysteine and methionine (precursors to volatile sulphur compounds responsible for oral malodour), were oxidatively consumed. The biochemical, periodontal and therapeutic significance of the results are discussed.

The Tongue Microbiota of Low Odour and Malodorous Individuals

The tongue bacterial microbiota of 50 individuals was identified and enumerated to group or genus level. Possible relationships between these data and the oral malodour status of each individual were explored. When subjects were grouped into low or high odour producers, significant increases in the total bacterial load and key bacterial groups, namely gram-negative anaerobes, which include Porphyromonas/Prevotella species and fusiforms, were related to high odour. However, on an individual basis the extensive variation between subjects reduced the correlation between bacterial groups and odour. Two phenotypic characteristics of the microbiota, volatile sulphur production and proteolytic activity, were also assessed. These were strongly associated with odour; in particular, the proportions of hydrogen sulphide producing organisms were significantly related to the odour levels of the individuals, despite the interpersonal variation. Thus it appears that it is the metabolic activity of the mixed microbiota rather than the bacterial load, or genus types present, that most contributes to oral malodour. Keywords: oral malodour, tongue microbiota, oral bacteria, sulphide production, proteolytic activity.

Stimulation of enzyme and cytokine production by methyl mercaptan in human gingival fibroblast and monocyte cell cultures

The volatile sulphur compound methyl mercaptan (CH 3SH) is a by-product of protein metabolism and a principal component of oral malodour. This investigation examines the effect of CH 3SH on the enzymatic activities of cathepsins B and G and elastase, and on the production by human gingival fibroblasts of two key factors, prostaglandin E (PGE) and cAMP, of the PGE 2-cAMP-dependent pathway, which may contribute to the increased production of collagenase and tissue destruction in human periodontal dnsease. The results demonstrate that CH 3SH alone, or in combination with interleukin-1 (IL-1) or lipopolysaccharide, can significantly enhance the secretion of PGE 2, cAMP and procollagenase by human gingival fibroblasts. CH 3SH also stimulated mononuclear cells to produce IL-1, which can increase cAMP production, and act in synergism with the direct effect of CH 3SH on cAMP. CH 3SH also significantly enhanced the activity of cathepsin B, moderately suppressed that of cathepsin G, but did not significantly affect elastase. These results provide evidence that CH 3SH could be a contributing factor in the enzymatic and immunological cascade of events leading to tissue degradation in periodontal diseases.

Effect of Japanese Green Tea Extract on Canine Periodontal Diseases

Asaccharolytic pigmented Porphyromonas strains were isolated from the plaque of dogs with gingivitis and periodontitis. Various species of Porphyromonas, including P. endodontalis, P. gingivalis, P. circumdentaria and unclassified species, were detectable. Canine Porphyromonas were sensitive to Japanese green tea extract (JGTE). We examined the effects of dietary JGTE on periodontal diseases. A special diet was prepared on the basis of the minimum inhibitory concentration (MIC: 0.8 mg/ml) of JGTE to several canine Porphyromonas species. Growth of all Porphyromonas isolates was inhibited at this concentration. After 2 mths, the percentage of canine Porphyromonas significantly decreased in the plaque microbiota. Concurrently with the observed decrease in percentage of these bacteria, gingival inflammation was inhibited. However, no change in the calculus index was recorded during the observation period. Levels of oral malodour varied among the dogs and diet with JGTE was effective in the inhibition of oral malodour. We concluded that JGTE was effective in the inhibition of canine periodontal diseases.

Effect of Japanese Green Tea Extract on Canine Periodontal Diseases

Asaccharolytic pigmented Porphyromonas strains were isolated from the plaque of dogs with gingivitis and periodontitis. Various species of Porphyromonas , including P. endodontalis , P. gingivalis , P. circumdentaria and unclassified species, were detectable. Canine Porphyromonas were sensitive to Japanese green tea extract (JGTE). We examined the effects of dietary JGTE on periodontal diseases. A special diet was prepared on the basis of the minimum inhibitory concentration (MIC: 0.8 mg/ml) of JGTE to several canine Porphyrmonas species. Growth of all Porphyromonas isolates was inhibited at this concentration. After 2 mths, the percentage of canine Porphyromonas significantly decreased in the plaque microbiota. Concurrently with the observed decrease in percentage of these bacteria, gingival inflammation was inhibited. However. no change in the calculus index was recorded during the observation period. Levels of oral malodour varied among the dogs and diet with JGTE was effective in the inhibition of oral malodour. We concluded that JGTE was effective in the inhibition of canine periodontal diseases. Keywords: green tea extract; canine Porphyromonas : periodontal disease

The effect of zine chloride mouthwash on the production of oral malodour, the degradations of salivary cellular elements, and proteins.

The effect of zine chloride mouthwash on the production of oral malodour, the degradations of salivary cellular elements, and proteins.

Halitosis: a serious social problem

Halitosis means an unpleasant odor of the expired air, regardless of the source of this odor. The foul breath originating from the oral cavity itself is termed as oral malodor and it is usually the main contributor of unpleasant breath in an otherwise healthy individual. The most predominant causes of halitosis are gingivitis, periodontitis, and tongue coating. However, several non-oral pathologic conditions have also been related to halitosis, including infection of the upper and lower respiratory tracts, the gastrointestinal tract, and some metabolic diseases involving the kidneys and the liver, which should never be overlooked. Though this complaint of bad breath has existed from time immemorial, it has only recently come to scientific platforms of analysis and is being increasingly recognized as a social stigma in an ever-growing sensitive society. Breath malodor has important socio-economic consequences. Literature reveals almost $1 billion a year is spent in the United States on deodorant-type mouth rinses and mints which provide only short-term masking effects, instead of spending the money on a proper diagnosis and etiologic care to manage bad breath. Sulfur containing volatiles are the main constituent of oral malodor and that their levels correlate with the intensity as determined organoleptically. The treatment of intraoral halitosis consists of scaling/root planing and daily removal of tongue coating, and for extraoral halitosis, treatment of underlying systemic disease by a specialist. Keywords: halitosis; bad breath; oral malodour DOI: http://dx.doi.org/10.3126/hren.v9i2.4983 Health Renaissance 2011: Vol.9 (No.2): 106-111