Untargeted metabolomics of the bacterial tongue coating of intra-oral halitosis patients.

Intra-oral halitosis (IOH) refers to an unpleasant odor from the oral cavity that is mainly caused by the tongue coating. Although the tongue coating microbiome is thought to play an essential role in IOH, the exact aetiology of IOH remains unclear. Here we investigated and compared the metabolic profiles of the tongue coating microbiomes of patients with IOH versus healthy control. The metabolic profiles were significantly different in IOH patients than in healthy controls. Healthy controls showed higher selenoamino acid and nicotinamide metabolism; these metabolic pathways are mainly involved in maintaining the oxidation-reduction potential and redox state. A total of 39 putative metabolites were associated with IOH. Remarkably, 3 of the metabolites, branched-chain fatty acids (BCFA), 3-fumaryl pyruvate, and acetyl phosphate, are potential key players in IOH. Interestingly, the predominant metabolite in IOH is BCFAs, which might underlie tongue coat formation. In addition, the key metabolite acetyl phosphate has a clear association with the hydrogen sulfide- (H2S-) producing metabolic pathway and anaerobic fermentation. These novel metabolomic findings provide insights into the formation of the tongue coating and the production of H2S, which causes bad breath.

Tongue coating: its characteristics and role in intra-oral halitosis and general health-a review.

Tongue coating (TC), a grayish-white deposit on the tongue, is the main cause of intra-oral halitosis (IOH), a socially unacceptable condition. This review covers the general features of TC, including its formation and the factors that influence it. Volatile sulfur compounds (VSCs) are the principal elements of IOH, and TC and periodontal diseases are the two main sources of VSCs. This review covers the relationship between VSCs, TC, and periodontal disease. We comprehensively discuss the methods employed to quantify TC, its microbial composition, its influence on general health and its importance in general medicine.

Mutations in SELENBP1, encoding a novel human methanethiol oxidase, cause extraoral halitosis.

Selenium-binding protein 1 (SELENBP1) has been associated with several cancers, although its exact role is unknown. We show that SELENBP1 is a methanethiol oxidase (MTO), related to the MTO in methylotrophic bacteria, that converts methanethiol to H2O2, formaldehyde, and H2S, an activity not previously known to exist in humans. We identified mutations in SELENBP1 in five patients with cabbage-like breath odor. The malodor was attributable to high levels of methanethiol and dimethylsulfide, the main odorous compounds in their breath. Elevated urinary excretion of dimethylsulfoxide was associated with MTO deficiency. Patient fibroblasts had low SELENBP1 protein levels and were deficient in MTO enzymatic activity; these effects were reversed by lentivirus-mediated expression of wild-type SELENBP1. Selenbp1-knockout mice showed biochemical characteristics similar to those in humans. Our data reveal a potentially frequent inborn error of metabolism that results from MTO deficiency and leads to a malodor syndrome.

The tongue microbiome in healthy subjects and patients with intra-oral halitosis.

Intra-oral halitosis (IOH) is an unpleasant odor emanating from the oral cavity. It is thought that the microbiota of the dorsal tongue coating plays a crucial role in this condition. The aim of the study was to investigate the composition of the tongue microbiome in subjects with and without IOH. A total of 26 subjects, 16 IOH patients and 10 healthy subjects were recruited based on their organoleptic score and volatile sulfur compound (VSC) measurements. The composition of the tongue microbiome was studied using the 16s amplicon sequencing of the V3-V4 hyper variable region with an Illumina MiSeq. The sequenced data were analyzed using QIIME, and the sequences obtained were distributed across 7 phyla, 27 genera and 825 operational taxonomic units (OTUs). At a higher taxon level, TM7 was associated with IOH patients whereas Gemellaceae was significantly abundant in the healthy subjects. At OTU level, we found several significant OTUs that differentiated the IOH patients from the controls. These included Aggregatibacter (OTU id 4335776), Aggregatibacter segnis (A. segnis), Campylobacter, Capnocytophaga, Clostridiales, Dialister, Leptotrichia, Parvimonas, Peptostreptococcus, Peptococcus, Prevotella, Selenomonas, SR1, Tannerella, TM7-3 and Treponema in the IOH group. In the control group, Aggregatibacter (OTU id 4363066), Haemophilus, Haemophilus parainfluenza (H. parainfluenza), Moryella, Oribacterium, Prevotella, several Streptococcus, Rothia dentocariosa (R. dentocariosa) and OTU from Gemellaceae were significantly abundant. Based on our observation, it was concluded that the bacterial qualitative composition of the IOH and the control group was almost the same, except for the few above-mentioned bacterial species and genera.

Prognostic indicators for surgical peri-implantitis treatment.

OBJECTIVES: Objective of this study was to identify prognostic indicators for the outcome of resective peri-implantitis treatment, by an analysis of the pooled data of two previously conducted randomized controlled trials. MATERIAL AND METHODS: Data of 74 patients with peri-implantitis (187 implants) who had received resective surgical treatment were available. Primary outcome variable was failure of peri-implantitis treatment after 12 months. Multilevel univariable and multiple logistic regression analyses were performed to evaluate the effect of various potentially prognostic indicators on the primary outcome. RESULTS: Peri-implantitis treatment was unsuccessful in 106 implants (57%) and 48 patients (67%) after 12 months. In the multiple regression analysis, the variables "order of inclusion" (P = 0.016) and mean bone loss at baseline (P = 0.030) were significant prognostic indicators for treatment failure. To eliminate the effect of "order of inclusion," post hoc analyses were carried out in a subgroup of patients. The univariable post hoc analysis showed a significant association for smoking (P = 0.015), maximum pocket depth at baseline (P = 0.073), mean bone loss at baseline (P = 0.003), and presence of plaque (P = 0.100). In the multiple regression post hoc analysis, only the variables smoking (P = 0.044) and mean bone loss (P = 0.043) remained statistically significant. CONCLUSIONS: The outcome of surgical peri-implantitis treatment is influenced by the experience of the surgical team with the surgical procedure. The observed learning effect has consequences for clinical practice and for conducting and interpreting clinical trials on peri-implantitis treatment. Other prognostic indicators are amount of peri-implant bone loss at baseline and smoking, and to a lesser extent, probing pocket depth at baseline and presence of plaque during follow-up. Early diagnosis of peri-implantitis and control of behavioral factors are crucial in achieving peri-implantitis treatment success.

Java project on periodontal diseases: causes of tooth loss in a cohort of untreated individuals.

OBJECTIVE: To assess the relative contribution of caries and periodontal disease to tooth loss over 24 years in a cohort deprived of regular dental care. MATERIAL & METHODS: The study population consisted of 98 subjects from a tea estate on West Java, Indonesia, that had been part of a prospective longitudinal study and provided full datasets of clinical assessments between 1987, 1994 and 2002. In 2011, complete sets of dental radiographs were made which was combined with the survey forms and clinical slides from the previous assessments in order to estimate reasons for tooth loss. RESULTS: Thirty-seven subjects lost no teeth, whereas 61 subjects lost 185 teeth. In this group, 45.9% lost ≤2 teeth, 32.8% lost 3 to 4 teeth and 19.7% lost ≥5 teeth. The majority of teeth were lost due to caries. In five subjects, tooth loss could be attributed solely to periodontitis, whereas in four subjects teeth were lost due to both caries and periodontits. Analyses of the predictor variables age, gender, smoking, education, presence of caries and severe periodontitis showed that male gender and caries were significantly associated with tooth loss. CONCLUSION: The majority of teeth in this population were lost due to caries.

[Halitosis management by the general dental practitioner- results of an International Consensus Workshop*]. / Halitosismanagement für die Zahnarztpraxis. Ergebnisse eines internationalen Konsunsus-Workshops*.

Clinical investigations on patients suffering from halitosis clearly reveal that in the vast majority of cases the source for an offensive breath odor can be found within the oral cavity (90%). Based on these studies, the main sources for intra-oral halitosis where tongue coating, gingivitis/periodontitis and a combination of the two. Thus, it is perfectly logical that general dental practitioners (GDPs) should be able to manage intra-oral halitosis under the conditions found in a normal dental practice. However, GDPs who are interested in diagnosing and treating halitosis are challenged to incorporate scientifically based strategies for use in their clinics. Therefore, the present paper summarizes the results of a consensus workshop of international authorities held with the aim to reach a consensus on general guidelines on how to assess and diagnose patients’ breath odor concerns and general guidelines on regimens for the treatment of halitosis.

Changes in oral microflora after full-mouth tooth extraction: a prospective cohort study.

AIM: The aim of the study was to evaluate the effect of full-mouth tooth extraction on the oral microflora, with emphasis on the presence and load of Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis. MATERIAL AND METHODS: Adult patients (n = 30), with moderate to advanced periodontitis and scheduled for full-mouth tooth extraction, were consecutively selected. Prior to and 1 and 3 months after full-mouth tooth extraction saliva, tongue, buccal and gingival mucosa and subgingival plaque/prosthesis samples were obtained. Aerobic and anaerobic culture techniques and quantitative real-time polymerase chain reaction (qPCR) were employed for the detection of oral pathogens. RESULTS: Full-mouth tooth extraction resulted in reduction below detection level of A. actinomycetemcomitans and P. gingivalis in 15 of 16 and 8 of 16 previously positive patients using culture techniques and qPCR, respectively. Those patients remaining qPCR positive showed a significant reduction in load of these bacteria. CONCLUSION: Full-mouth tooth extraction significantly changes the oral microflora. These changes include reduction of A. actinomycetemcomitans and P. gingivalis, frequently to levels below detection threshold. In some patients, A. actinomycetemcomitans and P. gingivalis can persist in the edentulous oral cavity up to 3 months after full-mouth tooth extraction.

Differences in peri-implant microflora between fully and partially edentulous patients: a systematic review.

BACKGROUND: The current evidence suggests that the oral microflora differs between individuals who are fully edentulous (FES) and those who are partially edentulous (PES). It is unknown whether this leads to differences in peri-implant microflora when implants are installed. The aim of the study is to compare the submucosal peri-implant microflora between FES and PES. METHODS: A systematic review was conducted. The MEDLINE, Embase, and Cochrane databases were searched for publications up to September 1, 2012. To reduce methodologic variations, only studies reporting in the same article about the submucosal peri-implant microflora of FES and PES were selected. RESULTS: Eleven publications describing 10 studies were selected. Because of numerous differences among the selected studies, no meta-analysis could be performed. Six of 10 studies showed a significant difference in the composition of the submucosal peri-implant microflora in healthy and peri-implant mucositis conditions between FES and PES, with the latter showing a potentially more pathogenic composition. However, microbiologic results were not unanimous among the studies. CONCLUSIONS: In healthy and peri-implant mucositis conditions, PES harbor a potentially more pathogenic peri-implant microflora than FES. The current data are insufficient for a clear conclusion regarding peri-implantitis cases. Overall, because of the lack of a meta-analysis, the variability in microbiologic outcomes and the limited number of studies available, the current evidence seems not to be robust.

Differences in peri-implant conditions between fully and partially edentulous subjects: a systematic review.

AIM: The aim of this study was to compare peri-implant conditions between fully edentulous (FES) and partially edentulous subjects (PES). MATERIAL AND METHODS: A systematic review was conducted. The MEDLINE, EMBASE and COCHRANE databases were searched for publications up to January 1st 2012. Studies reporting on the bleeding tendency of the peri-implant mucosa and/or studies reporting on the prevalence of peri-implant mucositis and/or peri-implantitis were considered. RESULTS: Fifty-five publications describing 46 studies were selected. One study described both FES and PES, and all other studies described either FES or PES. Subgroup analyses were performed according to dental status (fully/partially edentulous), follow-up time (≥5 years and ≥ 10 years) and study design (prospective/cross-sectional). FES harboured more plaque at their implants than PES. Modified bleeding index scores were significantly higher in FES, but no differences in bleeding on probing, implant loss and probing pocket depth were observed between FES and PES. No meta-analysis could be performed on prevalence of peri-implant mucositis and peri-implantitis. Overall prevalence of peri-implantitis was 0-3.4% after 5 years and 5.8-16.9% after 10 years of implant evaluation. CONCLUSION: FES and PES show comparable implant survival rates. However, no conclusion can be drawn regarding differences in prevalence of peri-implant mucositis and peri-implantitis between FES and PES.

Implant decontamination during surgical peri-implantitis treatment: a randomized, double-blind, placebo-controlled trial.

AIM: The objective of this randomized, double-blind, placebo-controlled trial was to study the effect of implant surface decontamination with chlorhexidine (CHX)/cetylpyridinium chloride (CPC) on microbiological and clinical parameters. MATERIAL & METHODS: Thirty patients (79 implants) with peri-implantitis were treated with resective surgical treatment consisting of apically re-positioned flap, bone re-contouring and surface debridement and decontamination. Patients were randomly allocated to decontamination with 0.12% CHX + 0.05% CPC (test-group) or a placebo-solution (without CHX/CPC, placebo-group). Microbiological parameters were recorded during surgery; clinical and radiographical parameters were recorded before (pre-) treatment (baseline), and at 3, 6 and 12 months after treatment. RESULTS: Nine implants in two patients in the placebo-group were lost due to severe persisting peri-implantitis. Both decontamination procedures resulted in significant reductions of bacterial load on the implant surface, but the test-group showed a significantly greater reduction than the placebo-group (log 4.21 ± 1.89 versus log 2.77 ± 2.12, p = 0.006). Multilevel analysis showed no differences between both groups in the effect of the intervention on bleeding, suppuration, probing pocket depth and radiographical bone loss over time. CONCLUSION: Implant surface decontamination with 0.12% CHX + 0.05% CPC in resective surgical treatment of peri-implantitis leads to a greater immediate suppression of anaerobic bacteria on the implant surface than a placebo-solution, but does not lead to superior clinical results. The long-term microbiological effect remains unknown.

Standardization of clinical protocols in oral malodor research.

The objective of this study is to standardize protocols for clinical research into oral malodor caused by volatile sulfur compounds (VSCs). To detect VSCs, a gas chromatograph (GC) using a flame photometric detector equipped with a bandpass filter (at 393 nm) is the gold standard (sensitivity: 5 × 10(-11) gS s(-1)). The baselines of VSC concentrations in mouth air varied considerably over a week. When the subjects refrained from eating, drinking and oral hygiene including mouth rinsing, the VSC concentrations remained constant until eating. Over a 6 h period after a meal, VSC concentrations decreased dramatically (p < 0.01). These results point to optimal times and conditions for sampling subjects. Several portable devices were compared with the measurements by the GCs. Portable GCs demonstrated capabilities similar to those of the GCs. We also applied the recommended protocols described below to clinical research testing the efficacy of ZnCl(2) products, and confirmed that using the recommended protocols in a randomized crossover design would provide very clear results. Proposed protocols include: (a) a short-term study rather than a long-term study is strongly recommended, since the VSC concentrations are constant in the short term; (b) a crossover study would be the best design to avoid the effects of individual specificities on each clinical intervention; (c) measurements of VSCs should preferably be carried out using either a GC or portable GCs.

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.

Intra- and extra-oral halitosis: finding of a new form of extra-oral blood-borne halitosis caused by dimethyl sulphide.

AIM: The aim of this study was to unravel the origen and cause of intra-oral and extra-oral halitosis. MATERIAL AND METHODS: We studied 58 patients complaining of halitosis, using gas chromatography of volatile sulphur compounds (VSCs) in mouth and nose breath, organoleptic scoring of mouth and nose breath, Halimeter readings of mouth air and tongue-coating inspection. Subjects had no precence or history of periodontitis. RESULT: Of 58 patients, 47 patients had halitosis of oral origin, six had halitosis of extra-oral origin and five had no halitosis (halitophobia). A strong correlation was found between the degree of intra-oral halitosis as measured by organoleptic scoring of mouth breath and the concentration of the VSCs hydrogen sulphide (H(2)S) and methyl mercaptan (CH(3)SH) in mouth breath. Taking into account the much larger odour index of CH(3)SH, it was concluded that CH(3)SH is the main contributor to intra-oral halitosis. In all six cases of extra-oral halitosis, halitosis was caused by the presence of elevated levels of dimethyl sulphide (CH(3)SCH(3)) in mouth and nose breath. CONCLUSION: Our study provides evidence that the VSC, CH(3)SH and to a lesser extent H(2)S are the main contributors to intra-oral halitosis and that CH(3)SCH(3) is the main contributor to extra-oral or blood-borne halitosis, due to a hitherto unknown metabolic disorder.

Comparison of subgingival bacterial sampling with oral lavage for detection and quantification of periodontal pathogens by real-time polymerase chain reaction.

BACKGROUND: Saliva has been studied for the presence of subgingival pathogens in periodontitis patients. With the anaerobic culture technique, the discrepancy between salivary recovery and subgingival presence has been significant, which makes this approach not suitable for practical use in the microbial diagnosis of periodontitis patients. The real-time polymerase chain reaction (PCR) technique represents a very sensitive technique to detect and quantify bacterial pathogens. The aim of the study was to compare the presence and numbers of Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythensis, Prevotella intermedia, and Micromonas micros in subgingival plaque and mouthwash samples by the anaerobic culture and real-time PCR techniques. METHODS: Pooled subgingival plaque samples and 10-ml mouthwash samples were collected from 21 adult patients with periodontitis and analyzed by quantitative anaerobic culture and real-time PCR for A. actinomycetemcomitans, P. gingivalis, T. forsythensis, P. intermedia, and M. micros. RESULTS: The detection frequency of A. actinomycetemcomitans, P. gingivalis, and T. forsythensis in subgingival plaque was identical by culture and real-time PCR and was higher for P. intermedia and M. micros by real-time PCR. The highest detection frequencies for the target bacteria were found in mouthwash samples by real-time PCR. The additional value of the real-time PCR to detect target bacteria was 38% for P. gingivalis, 73% for T. forsythensis, 77% for P. intermedia, and 71% for M. micros. The sensitivity to detect target species in mouthwash by real-time PCR was 100% for all test species except for P. intermedia (93.8%). CONCLUSIONS: Rapid detection and quantification of periodontal pathogens in mouthwash samples are possible by real-time PCR. The procedure is significantly less time-consuming than subgingival sampling with paper points. This approach to detect major periodontal pathogens in mouthwash samples may simplify microbial diagnosis in periodontitis patients and may be used to monitor periodontal treatment.

IL-1RN gene polymorphism is associated with peri-implantitis.

OBJECTIVES: Interleukin (IL)-1alpha, IL-1beta and their natural specific inhibitor IL-1 receptor antagonist (IL-1ra) play a key role in the regulation of the inflammatory response in periodontal tissues. Polymorphisms in the IL-1 gene cluster have been associated with severe adult periodontitis. We aimed to investigate the IL-1 gene cluster polymorphisms in patients with peri-implantitis. MATERIAL AND METHODS: The study included 120 North Caucasian individuals. A total of 71 patients (mean age 68 years, 76% smokers) demonstrating peri-implantitis at one or more implants as evidenced by bleeding and/or pus on probing and bone loss amounting to >3 threads on Brånemark implants and 49 controls (mean age 66 years, 45% smokers) with clinical healthy mucosa and no bone loss around the implants were recruited for the study. The titanium implants, ad modum Brånemark, had been in function for at least 2 years. Mouthwash samples were collected and used for genotyping of the bi-allelic polymorphisms IL-1A(-889), IL-1B(+3953), IL-1B(-511) and a variable number of tandem repeat IL-1RN gene polymorphisms using PCR technique. RESULTS: Significant differences were found in the carriage rate of allele 2 in the IL-1RN gene between peri-implantitis patients and controls (56.5% vs. 33.3%, respectively; odds ratios (OR) 2.6; 95% confidence interval (CI) 1.2-5.6; P=0.015). Logistic regression analysis taking smoking, gender and age into account confirmed the association between the IL-1RN allele 2 carriers and peri-implantitis (OR 3; 95% CI 1.2-7.6; P=0.02). CONCLUSIONS: Our results provide evidence that IL-1RN gene polymorphism is associated with peri-implantitis and may represent a risk factor for this disease.