Changes of volatile sulphur compounds during therapy of a case series of patients with chronic periodontitis and halitosis

Hydrogel-based radio frequency H2S sensor for in situ periodontitis monitoring and antibacterial treatment

Periodontitis, a chronic disease, can result in irreversible tooth loss and diminished quality of life, highlighting the significance of timely periodontitis monitoring and treatment. Meanwhile, hydrogen sulfide (H2S) in saliva, produced by pathogenic bacteria of periodontitis, is an important marker for periodontitis monitoring. However, the easy volatility and chemical instability of the molecule pose challenges to oral H2S sensing. Here, we report a wearable hydrogel-based radio frequency (RF) sensor capable of in situ H2S detection and antibacterial treatment. The RF sensor comprises an agarose hydrogel containing conjugated silver nanoparticles-chlorhexidine (AG-AgNPs-CHL hydrogel) integrated with split-ring resonators. Adhered to a tooth, the hydrogel-based RF sensor enables wireless transmission of sensing signals to a mobile terminal and a concurrent release of the broad-spectrum antibacterial agent chlorhexidine without complex circuits. With the selective binding of the AgNPs to the sulfidion, the RF sensor demonstrates good sensitivity, a wide detection range (2-30 μM), and a low limit of detection (1.2 μM). Compared with standard H2S measurement, the wireless H2S sensor can distinguish periodontitis patients from healthy individuals in saliva sample tests. The hydrogel-based wearable sensor will benefit patients with periodontitis by detecting disease-related biomarkers for practical oral health management.

ORGANOLEPTIC AND HALITOMETRIC ASSESSMENTS DO NOT CORRELATE WELL IN INTRA-ORAL HALITOSIS: A SYSTEMATIC REVIEW AND META-ANALYSIS

BACKGROUND

The gold standard method for diagnosing oral halitosis is the subjective organoleptic measurement. Device-supported methods are also widespread worldwide. The challenges and safety concerns around performing organoleptic measurements during pandemics and the diversity of measuring device alternatives raised our clinical question: which halitometer is the most suitable for diagnosing halitosis?

METHODS

This systematic review was registered in PROSPERO (ID CRD42022320024). The search was performed on March 23, 2022 in the following electronic databases: MEDLINE, Embase, Scopus, Web of Science, and CENTRAL. Adult populations with or without halitosis were included, and patients with systemic diseases were excluded. Organoleptic (subjective) measurement and the device-supported (objective) methods were compared; the primary outcome was the correlation coefficient, and the secondary was the specificity and sensitivity of the devices. QUADAS-2 and QUADAS-C were used to evaluate the risk of bias in the studies. Random-effects meta analyses were performed on the outcomes, and the secondary outcomes were plotted on a common ROC plot.

RESULTS

A total of 1231 records were found in the 5 databases. After the selection process, 76 articles were eligible for the systematic review, and 14,635 patients were involved in the qualitative analysis. The pooled Spearman's correlation coefficient (c.c.) for sulfide monitors was 0.65; 95% CIs: [0.53-0.74]; I2 = 95%, P < .01. The pooled Spearman's c.c. for portable gas chromatographs was 0.69; 95% CIs: [0.63-0.74]; I2 = 12%, P < .01. The pooled Spearman's c.c. for gas chromatographs was 0.76; 95% CIs: [0.67-0.83]; I2 = 0%, P < .01.

DISCUSSION

None of the most commonly used halitometers proved to be significantly superior to the others. Halimeter and OralChroma measurements did not correlate well with the organoleptic level of oral halitosis in adults. Therefore, better halitometers need to be developed as an alternative to organoleptic measurements.

Efficacy of probiotics in the management of halitosis: a systematic review and meta-analysis

BACKGROUND

Halitosis is defined as a foul odour emitted from the oral cavity. Many interventions have been used to control halitosis from mouthwashes to chewing gums. Probiotics have been reported as an alternative method to alleviate halitosis.

OBJECTIVE

The present study aimed to investigate the effect of probiotics on halitosis from a time perspective.

DESIGN AND METHODS

This is a meta-analysis study performed in indexed databases up to February 2021. Randomised controlled trials that compared the effects of probiotics and placebo on primary outcomes (organoleptic (OLP) scores and volatile sulfur compound (VSC) levels) and secondary outcomes (tongue coating scores (TCS) and plaque index (PI)) were included. Data extraction and quality assessment were conducted independently by two reviewers. Publication bias and leave-one-out analyses were performed.

RESULTS

The standardised mean difference (SMD) and 95% CI were calculated to synthesise data. The data were subgrouped and analysed in the short term (≤4 weeks) and long term (>4 weeks) based on the follow-up time. Seven articles were included in this meta-analysis. The primary outcomes, OLP scores (SMD=-0.58; 95% CI -0.87 to -0.30, p<0.0001) and VSC levels (SMD=-0.26; 95% CI -0.51 to -0.01, p=0.04), both decreased significantly in the probiotics group compared with the placebo group in the short term. However, a significant reduction was observed only in OLP scores (SMD=-0.45; 95% CI -0.85 to -0.04, p=0.03) in the long term. No significant differences were observed in secondary outcomes. There was no evidence of publication bias. The leave-one-out analysis confirmed that the pooled estimate was stable.

CONCLUSIONS

According to the results of this work, it seems that probiotics (eg, Lactobacillus salivarius, Lactobacillus reuteri, Streptococcus salivarius and Weissella cibaria) may relieve halitosis in the short term (≤4 weeks). The results of the biased assessment, limited data and heterogeneity of the clinical trials included might reduce the reliability of the conclusions.

Effectiveness of Different Antimicrobial Agents on Malodor Prevention in Two-Stage Dental Implants: A Double-Blinded Randomized Clinical Trial

OBJECTIVE

 Opening of a healing abutment in two-stage implant systems is usually followed by a bad smell. Previous studies have found that presence of bacteria in microleakages of the implant-abutment interface results in further malodor. However, studies focusing on preventive treatments for this issue are scarce. Therefore, the aim of this study is to evaluate the effectiveness of two antimicrobial agents on prevention of malodor followed by opening the healing abutments.

MATERIALS AND METHODS

 Current double-blinded randomized clinical trial was performed on 51 eligible patients who were referred for their exposure surgery. They were divided equally into three parallel groups. In two groups, either chlorhexidine or tetracycline was added to the internal surface of the fixtures before screwing the healing abutments. One group did not receive any intervention. Three to 4 weeks later malodor was scored by sniffing the healing abutments immediately after uncovering them (odorless = 0/odor = 1). The three groups were then compared regarding malodor scores.

RESULTS

 Our findings showed that malodor was more frequent in the control group (58.82%) in comparison with groups of intervention (17.65 and 23.53%). There was a statistically significant difference between malodor in patients in whom antimicrobial agents (chlorhexidine and tetracycline) were used in their implants and the control group (p-value = 0.023). However, malodor in the chlorhexidine group and tetracycline group did not show any significant difference (p-value = 1).

CONCLUSION

 Based upon the data from this study, it appears that local antimicrobial agents including chlorhexidine and tetracycline result in less malodor production within the implant-abutment interface.

CLINICAL SIGNIFICANCE

 A specific type of malodor is commonly seen after opening the healing abutment of a two-stage dental implant. Not only this issue is noticed by the dentist, but also annoyed the patient. Using local antimicrobial agents in the fixtures is likely to be a simple, easily applicable solution that satisfies both patients and dentists, and eliminates the possibility of further inflammation.

Salivary β-galactosidase, halitosis parameters in periodontal health and disease, and their changes after periodontal treatment

BACKGROUND

In this study, we aimed to evaluate the salivary β-galactosidase and Halimeter values (HMV), organoleptic scores (OLS) and Winkel tongue coating index (WTCI) in periodontal health and periodontitis (P), and also their changes after phase I periodontal therapy and tongue cleaning.

METHODS

The participants were separated as follows: 25 P with halitosis (Group 1), 25 P without halitosis (Group 2) and 25 healthy controls (Group 3). Periodontal recordings, HMV, OLS and WTCI scores were recorded, and whole saliva β-galactosidase levels were measured colorimetrically in the samples at baseline and 1 month after the therapy.

RESULTS

The baseline values of HMV, OLS, WTCI and salivary β-galactosidase levels were significantly higher in Group 1 than in Group 2 (P < 0.05). There was a statistically significant decrease in periodontal recordings, HMV, OLS, WTCI and salivary β-galactosidase levels in all P patients by the therapy (P < 0.05). However, major reductions in halitosis measurements and saliva enzyme levels were observed in Group 1 after the treatment.

CONCLUSION

Our results showed that salivary β-galactosidase was associated with halitosis parameters and phase I periodontal therapy played an important role to reduce this enzyme level and halitosis parameters in P.

Hydrogen Sulfide Oxidation by Sulfide Quinone Oxidoreductase

Hydrogen sulfide (H2 S) is an environmental toxin and a heritage of ancient microbial metabolism that has stimulated new interest following its discovery as a neuromodulator. While many physiological responses have been attributed to low H2 S levels, higher levels inhibit complex IV in the electron transport chain. To prevent respiratory poisoning, a dedicated set of enzymes that make up the mitochondrial sulfide oxidation pathway exists to clear H2 S. The committed step in this pathway is catalyzed by sulfide quinone oxidoreductase (SQOR), which couples sulfide oxidation to coenzyme Q10 reduction in the electron transport chain. The SQOR reaction prevents H2 S accumulation and generates highly reactive persulfide species as products; these can be further oxidized or can modify cysteine residues in proteins by persulfidation. Here, we review the kinetic and structural characteristics of human SQOR, and how its unconventional redox cofactor configuration and substrate promiscuity lead to sulfide clearance and potentially expand the signaling potential of H2 S. This dual role of SQOR makes it a promising target for H2 S-based therapeutics.

Are Lactobacillus salivarius G60 and inulin more efficacious to treat patients with oral halitosis and tongue coating than the probiotic alone and placebo? A randomized clinical trial

BACKGROUND

The combination of probiotics and prebiotics might be useful to treat oral halitosis. The aim of this study was to assess the effect of Lactobacillus salivarius G60 (LS) and inulin on oral halitosis and tongue coating.

METHODS

In this double-masked, randomized, phase II clinical trial, 45 patients (aged 35 ± 15 years, 66% female) with oral halitosis and tongue coating were allocated to three treatment groups (n = 15) using gums of oral dissolution (one gum every 12 hours) for 10 days. Each gum contained LS (1 billion colony forming units [CFUs]) + inulin (1 g), LS (1 billion CFU) or placebo. Primary outcomes were organoleptic test, Halimeter, and tongue coating, whereas secondary outcomes were quality of life (QOL) and treatment safety. Generalized linear models were used, adjusting for age and sex. In vitro tests were performed to verify whether LS interacts with inulin and whether LS inhibits the growth of Porphyromonas gingivalis and Prevotella intermedia.

RESULTS

Forty-four patients (97%) completed the study. Patients treated with LS + inulin showed greater reduction in halitosis measured by Halimeter compared with placebo (adjusted post-intervention average: 96.7 versus 142.5 ppb; P = 0.003), whereas LS and placebo did not differ (115.7 versus 142.5 ppb; P = 0.097). Organoleptic measurements and coating index showed a similar decrease for all groups. QOL improved in patients treated with LS + inulin compared with placebo (P = 0.029). Side effects were mild and transient in all groups. LS did not metabolize inulin but inhibited the growth of P. gingivalis and P. intermedia after 72 hours.

CONCLUSIONS

Treatment with L. salivarius G60 combined or not with inulin showed significant decrease in the outcomes organoleptic test, Halimeter, and coating index, improving oral halitosis. However, no significant difference was obtained between the groups.

Prevalence and relevant factors of halitosis in Chinese subjects: a clinical research

BACKGROUND

The aim of this study was to investigate the prevalence of halitosis among Chinese subjects and to analyze the associated factors that influence halitosis.

METHODS

This study included subjects complaining of halitosis who came to the clinic between 2014 and 2016. Questionnaires were used to obtain general information from patients. An organoleptic test was conducted, and volatile sulfur compounds measurement was obtained to assess halitosis. In conjunction with these tests, the oral health status of each patient was recorded.

RESULTS

In total, there were 205 samples entered into data analysis, and the patients' age ranged from 18 to 71 years (mean ± SD: 32.44 ± 10.31). Of these patients, 65.9% had an organoleptic score ≥ 2, and 41% of patients had a volatile sulfur compound level ≥ 110 ppb. The findings indicated that the prevalence of halitosis was higher in males than in females (55.6% vs. 44.4%, respectively, P = 0.018). Several factors including the duration of bad breath, rhinitis, tongue coating and periodontal conditions were found to be associated with the organoleptic score. Tongue coating was also associated with the volatile sulfur compound level.

CONCLUSIONS

Among these subjects, 65.9% had halitosis. Oral health status was strongly associated with halitosis, and tongue coating was the most important factor.

A randomized cross-over short-term study on the short-term effects of a zinc-lactate containing mouthwash against oral malodour

AIM

This randomized controlled cross-over-design-study investigated short-term effects on oral malodour of a zinc-lactate-containing mouthwash.

MATERIALS AND METHODS

Sixteen subjects (18-65 years) with an organoleptic score (OLS) ≥2 were included. Following rinses were used: (A) a zinc-lactate-containing mouthwash (10 ml/30 s); (B) a zinc-lactate-containing mouthwash (15 ml/60 s); (C) a rinse without zinc-lactate (3 droplets/10 ml tap water/30 s) and (D) tap water (10 ml/30 s). Each formulation was evaluated by two blinded examiners comparing OLS and three volatile-sulphur-compounds (VSC; H₂S (hydrogen sulphide), CH₃SH (methyl mercaptan) and (CH₃)₂S (dimethyl sulphide)) before, 1 and 3 h after rinsing. Subject's perception was investigated with a visual-analogue-scale. Linear mixed models were used to compare all parameters simultaneously with respect to the four treatment groups with a significance level α < 0.05.

RESULTS

OLS was significantly reduced by A and B compared to C and D after 3 h (p < 0.006). The sum of the 3 VSCs as well as H₂S alone were significantly reduced by rinses A and B after 1 and 3 h compared to rinses C and D (p < 0.05). Significant differences were found between the four rinses for 'Taste' (p = 0.003), for 'Change of mouth feeling' (p = 0.001), for 'Feeling of freshness' (p = 0.002) and for 'Effectiveness' (p = 0.002) in favour of A & B.

CONCLUSION

A zinc-lactate-containing mouthwash reduced OLS and VSC over a period of 3 h with favourable patient reported outcomes.

Modulation of Catalytic Promiscuity during Hydrogen Sulfide Oxidation

The mitochondrial sulfide oxidation pathway prevents the toxic accumulation of hydrogen sulfide (H₂S), a signaling molecule that is maintained at low steady-state concentrations. Sulfide quinone oxidoreductase (SQR), an inner mitochondrial membrane-anchored protein, catalyzes the first and committing step in this pathway, oxidizing H₂S to persulfide. The catalytic cycle comprises sulfide addition to the active site cysteine disulfide in SQR followed by sulfur transfer to a small molecule acceptor, while a pair of electrons moves from sulfide, to FAD, to coenzyme Q. While its ability to oxidize H₂S is well characterized, SQR exhibits a remarkable degree of substrate promiscuity in vitro that could undermine its canonical enzyme activity. To assess how its promiscuity might be contained in vivo, we have used spectroscopic and kinetic analyses to characterize the reactivity of alternate substrates with SQR embedded in nanodiscs ( ndSQR) versus detergent-solubilized enzyme ( sSQR). We find that the membrane environment of ndSQR suppresses the unwanted addition of GSH but enhances sulfite addition, which might become significant under pathological conditions characterized by elevated sulfite levels. We demonstrate that methanethiol, a toxic sulfur compound produced in significant quantities by colonic and oral microbiota, can add to the SQR cysteine disulfide and also serve as a sulfur acceptor, potentially interfering with sulfide oxidation when its concentrations are elevated. These studies demonstrate that the membrane environment and substrate availability combine to minimize promiscuous reactions that would otherwise disrupt sulfide homeostasis.

Halitosis Assessment and Changes in Volatile Sulfur Compounds After Chewing Gum: A Study Performed on Dentistry Students

OBJECTIVE

The objective of this study is to estimate the prevalence of halitosis (with subjective and objective methods), evaluate the immediate effect of chewing gum on volatile sulfur compounds (VSCs), assess the perception of halitosis by dentistry students, and estimate the distribution of positive and negative frequencies, when comparing objective and subjective methods for the diagnosis of halitosis.

METHODS

The study was performed on a sample of dentistry students attending the Faculty of Medicine and Health Sciences at the University of Barcelona. A questionnaire about halitosis perception was provided and a clinical examination, organoleptic test (OT), and gas chromatography were performed to determine the presence of halitosis. The subjects were also given chewing gum to modify their breath, and gas chromatography was carried out to evaluate possible changes in VSCs.

RESULTS

The sample comprised 80 individuals. Twenty-seven (33.75%) self-perceived halitosis during the period of evaluation; the OT was positive in 38 subjects (47.5%); and individuals positive for halitosis on gas chromatography were distributed as follows: H₂S in 25 (31.25%), CH₃SH in 28 (35%), and (CH₃)₂S in 70 individuals (87.5%). A statistical difference before and after chewing gum (P < .05) was found for each VSC; a difference in frequencies was observed between the variable OT and H₂S (P < .05) and between the OT and (CH₃)₂S (P < .001). There was no significant difference (P > .05) between the positive and negative frequencies retrieved between the variable OT and CH₃SH and between the OT and the student's halitosis perception.

CONCLUSION

Prevalence of halitosis in the studied sample is high, considering that it comprised healthy individuals. The relationship between the OT and gas chromatography is not completely established. Chewing gum could be considered a therapeutic alternative to decrease or neutralize the amount of VSCs present in oral breath.

Comparison of oral malodors before and after nonsurgical periodontal therapy in chronic periodontitis patients

Background/purpose

Periodontal diseases have been considered as a source of oral malodor or halitosis. Improvement of oral malodor in chronic periodontitis patients has recently been observed after nonsurgical periodontal therapy in combination with tongue cleaning and/or chlorhexidine mouth rinsing. The present study, however, evaluated the impact of nonsurgical periodontal therapy alone on the oral malodor in chronic periodontitis patients by comparing the intraoral concentrations of volatile sulfur compounds (VSCs) before and after nonsurgical therapy.

Materials and methods

Using a sulfide monitor, the total VSCs in exhaled breath were measured in 80 patients with chronic periodontitis prior to and 1 month after nonsurgical periodontal therapy (re-evaluation phase). Malodor was defined as a VSC score > 75 parts per billion (ppb) and > 110 ppb, respectively.

Results

Significantly lower level of VSCs was recorded at periodontal re-evaluation (55 ± 9.7 ppb) than before treatment (89 ± 16.3 ppb). Before treatment, 27 (34%) patients were considered to have malodor, defined as VSCs > 75 ppb. After treatment, 16 patients (20%) had VSC scores > 75 ppb, including 10 of 27 patients with baseline VSC scores > 75 ppb and six of 53 patients with baseline scores ≤ 75 ppb. The risk of malodor differed significantly before and after treatment (P = 0.035, McNemar's test). However, when malodor was defined as VSCs > 110 ppb, the difference in risk showed only borderline significance (P = 0.077).

Conclusion

On the basis of our findings, we suggest that nonsurgical periodontal therapy has a mild impact on oral malodor.