Malodour in denture wearers: an ill-defined problem

Comparative Evaluation of Bacterial Colonization Color Stability and Halitosis of Oral Appliances Fabricated Using Cold Cure Acrylics, Heat Cure Acrylics and Thermoforming Sheets: An In Vivo Study

Aim

Removable oral appliances form an integral part of interceptive orthodontic procedures. Bacterial colonization leading to halitosis and poor color stability are the major disadvantages of the same in spite of patient acceptability. The aim of the present study was to evaluate bacterial colonization, color stability, and halitosis from the oral appliances fabricated using cold cure, cold cure under pressure pot, heat cure acrylics, thermoforming sheet, Erkodur and antibacterial thermoforming sheet, Erkodur-bz.

Materials and methods

A group of 40 children was divided into five groups and the appliances were delivered. Bacterial colonization and halitosis were evaluated before giving the appliance to the patient after 1 and 2 months. Color stability was evaluated before giving the appliance to the patient and then after 2 months. This study was designed as a single-blinded randomized clinical trial.

Results

Results have shown that after 1 and 2 months, bacterial colonization was higher from the appliances fabricated with cold cure and was lower for the Erkodur group, which was statistically significant. Color stability was more from the appliances fabricated with Erkodur and was less for cold cure, which was statistically significant. Halitosis after 1 month was more from the appliances fabricated with cold cure and less from Erkodur group, which was statistically significant. After 2 months, halitosis was more from the cold cure group and less from Erkodur group, which was not statistically significant.

Conclusion

Thermoforming sheet, Erkodur showed better results than other groups in terms of bacterial colonization, color stability, and halitosis.

Clinical significance

When removable appliances are indicated for minor orthodontic tooth movement, Erkodur is preferable due to the advantages of easy fabrication and less bacterial colonization.

How to cite this article

Madhuri L, Puppala R, Kethineni B, et al. Comparative Evaluation of Bacterial Colonization Color Stability and Halitosis of Oral Appliances Fabricated Using Cold Cure Acrylics, Heat Cure Acrylics and Thermoforming Sheets: An In Vivo Study. Int J Clin Pediatr Dent 2022;15(5):499-503.

The denture microbiome in health and disease: an exploration of a unique community

The United Nations suggests the global population of denture wearers (an artificial device that acts as a replacement for teeth) is likely to rise significantly by the year 2050. Dentures become colonized by microbial biofilms, the composition of which is influenced by complex factors such as patient’s age and health, and the nature of the denture material. Since colonization (and subsequent biofilm formation) by some micro‐organisms can significantly impact the health of the denture wearer, the study of denture microbiology has long been of interest to researchers. The specific local and systemic health risks of denture plaque are different from those of dental plaque, particularly with respect to the presence of the opportunist pathogen Candida albicans and various other nonoral opportunists. Here, we reflect on advancements in our understanding of the relationship between micro‐organisms, dentures, and the host, and highlight how our growing knowledge of the microbiome, biofilms, and novel antimicrobial technologies may better inform diagnosis, treatment, and prevention of denture‐associated infections, thereby enhancing the quality and longevity of denture wearers.

Removable Denture Wearing as a Risk Predictor for Pneumonia Incidence and Time to Event in Older Adults

INTRODUCTION

Older adults are more susceptible to a common respiratory infection: pneumonia. Nearly 1 million older adults per year are hospitalized for community-acquired pneumonia in the United States.

OBJECTIVE

To examine whether wearing removable dentures are associated with an increased risk of pneumonia incidence in a geriatric population.

METHODS

We conducted a retrospective cohort study among patients >65 y of age within a large academic health system (University of Rochester Medical Center). The medical and dental electronic records from 2010 to 2018 were reviewed and used for data collection. The exposure was removable denture wearing. The main outcome variables were the incidence of pneumonia and time to event of pneumonia. A Cox proportional hazards regression was used to examine the association between pneumonia onset and wearing removable dentures, adjusting for demographics, socioeconomic status, and medical and dental conditions.

RESULTS

A total of 2,364 patients were included, with 1,189 (50.29%) in the denture-wearing group and 1,175 (49.70%) in the non-denture wearing group. The annual pneumonia incidence rate per 100,000 persons was 1,191 in the denture-wearing group and 128 per 100,000 persons in the non-denture wearing group, with a crude incidence rate ratio of 9.33 (95% CI, 5.41 to 18.81; P < 0.0001). The mean ± SD age of the pneumonia onset was 78.0 ± 10.0 and 78.6 ± 9.0 y among denture-wearing and nonwearing groups (P = 0.84). The time to event of pneumonia was associated with removable denture wearing (yes/no; hazard ratio, 7.68 [95% CI, 3.91 to 15.08]; P < 0.001) after adjusting for covariates.

CONCLUSIONS

Wearing removable dentures was found to be a risk predictor for pneumonia incidence among the geriatric population even after accounting for other risk factors.

KNOWLEDGE TRANSFER STATEMENT

Wearing removable dentures was found to be a risk predictor of pneumonia incidence among older adults. Although the current study does not imply a causal relationship between denture wearing and pneumonia, clinicians and older patients could reference the study results when choosing dental prostheses to restore missing teeth.

Treatment of halitosis with photodynamic therapy in older adults with complete dentures: A randomized, controlled, clinical trial

BACKGROUND

Halitosis of oral origin is mainly caused by the release of H₂S (hydrogen sulfide) by bacteria lodged on the tongue. Antimicrobial photodynamic therapy (aPDT) has been evaluated for the treatment of halitosis, but there are no previous reports of the use of this treatment modality in older people with dentures. The aim of the present study was to compare the effect of aPDT and tongue scraping (standard treatment) in older people with complete dentures diagnosed with halitosis (H2S gas concentration>112 ppb).

METHODS

The participants were divided into two groups: G1- treatment with a tongue scraper (n = 20); G2- treatment with aPDT (n = 20). Halimeter testing was performed before and after treatments using gas chromatography and was repeated after seven days.

RESULTS

After treatment, the group treated with aPDT had a lower mean concentration of H2S gas (18.5 ppb) than the tongue scraping group (185.3 ppb). After one week, the mean concentration of H2S increased to 218.2 ppb in the tongue scraping group and 39 ppb in the PDT group.

CONCLUSIONS

Both treatments were able to reduce the concentration of H2S but only treatment with aPDT was able to decrease halitosis to socially unnoticeable levels. Moreover, this normal breath condition remained for seven days only in the aPDT group.

Does Peritoneal Dialysis Affect Halitosis in Patients with End-Stage Renal Disease?

Objective

There are various causes of halitosis, one of which is chronic renal failure. The objective of this study was to investigate halitosis levels in end-stage renal disease (ESRD) patients before and after peritoneal dialysis (PD) therapy.

Methods

42 subjects with ESRD were included in this study. The presence of halitosis was assessed using an organoleptic measurement and compared with blood urea nitrogen (BUN) levels and salivary flow rates. Decayed, missing, and filled teeth (DMFT) index and Community Periodontal Index (CPI) were calculated. All measurements were done before and after patients had received 3 months of PD therapy.

Results

Mean serum BUN level was found to be lower (46.05 ± 13.30 vs 91.24 ± 31.28 mg/dL), salivary flow rate higher (0.34 ± 0.07 vs 0.26 ± 0.04 mL/minute), and halitosis level lower (2.39 ± 0.60 vs 3.90 ± 0.37) at the end of 3 months of PD therapy than at the beginning of PD therapy. There was no significant difference in CPI or DMFT index before and after PD therapy (p > 0.05). There was statistically significant positive correlation between the presence of halitosis and BUN levels ( r = 0.702, p = 0.001 before PD; r = 0.45, p = 0.002 after PD) and a negative correlation between the presence of halitosis and salivary flow rates ( r = -0.69, p = 0.000 before PD; r = -0.37, p = 0.01 after PD).

Conclusion

High BUN levels and low salivary flow rates were found to be associated with halitosis. PD may play an important role in decreasing the level of halitosis in ESRD patients.

Evaluation of the treatment of halitosis with photodynamic therapy in older patients with complete denture: Protocol for a randomized, controlled trial

BACKGROUND

Halitosis is the term used to define an unpleasant odor emanating from the mouth. However, no studies have evaluated the causes and treatment of halitosis in the population of older adults with denture.

METHODS

A randomized, controlled trial is proposed. The patients will be divided into 2 groups: G1: older adults who wear complete dentures and will be treated with tongue scraper (n = 20); G2 older adults who wear complete dentures and will be treated with PDT (n = 20). If the halitosis persists, the participants will be submitted to hygiene procedures for the mucosa and dentures. The evaluation of halitosis will be made before and after treatments, with OralChroma. If the halitosis is solved, the participants will return after 1 week for an additional evaluation. Oral Health Impact Profile (OHIP-14) will be administered by a calibrated examiner on the day the patient history is taken (baseline) and 1 week after treatment for halitosis.

DISCUSSION

This protocol will determine the effectiveness of photodynamic therapy regarding the reduction of halitosis in older adults with complete denture.

TRIAL REGISTRATION

This protocol was registered in ClinicalTrial.gov, under number NCT03960983. It was first posted and last updated in May 23, 2019. https://clinicaltrials.gov/ct2/show/NCT03960983.

Randomized Controlled Clinical Study to Determine the Oral and Dermal Tolerability of an Experimental Denture Wipe

Purpose

To evaluate oral and dermal tolerance following use and user acceptability of an experimental denture‐cleansing wipe. An exploratory objective was to develop a method to assess denture wipe effectiveness in removing debris from denture surfaces.

Materials and Methods

This was a single‐center, randomized, controlled, parallel‐group, examiner‐blind study in participants with ≥1 full/partial denture. Participants were randomized to clean their dentures with the denture wipe (n = 76) or water (n = 76) up to 4 times per day for 14 days. Tolerability was assessed by treatment‐emergent adverse events (TEAEs), oral soft tissue examination, and lead hand dermatological assessment. Acceptability was assessed by questionnaire. The feasibility of a methodology to assess the efficacy of the wipe at removing food particles was also evaluated through determination of the mass of chewed peanut particles that the wipe removed after a single use (n = 31).

Results

The proportion of participants experiencing oral TEAEs by day 14 was 0.039% with the denture wipe (lip injury [n = 1], mouth injury [n = 2]) and 0.013% with the water rinse (coated tongue [n = 1]). There were no dermal TEAEs and no TEAE‐related study withdrawals. Skin irritation scores with the denture wipe remained unchanged from baseline. Comparing before vs. after cleaning with the denture wipe, a higher proportion of participants rated their dentures as feeling extremely/very fresh (28.9% pre‐/85.5% post‐cleaning), feeling extremely/very clean (34.2%/86.8%) and looking extremely/very clean (43.5%/85.5%). More denture‐wipe group participants than water‐rinse group participants were extremely/very satisfied with the amount of debris removed from their dentures (88.1% vs 72.4%). The methodology used to assess the weight of peanut particles captured from the wipes/dentures appeared to be a feasible investigation technique.

Conclusions

The denture wipe was generally well‐tolerated and had good user acceptability. The methodology for assessing the mass of peanut particles removed by denture wipes was successful.

Isolation and Identification of Nonoral Pathogenic Bacteria in the Oral Cavity of Patients with Removable Dentures

Aims and Objectives:

Dentures in the oral cavity may act as a reservoir of microorganisms, which may be related to systemic infections. The aim of this study was to investigate the nonoral pathogenic bacteria in the oral cavity of patients with removable dentures in Shiraz, Southern Iran.

Materials and Methods:

The bacterial flora of saliva samples from 50 men and 50 women with removable dentures and 100 age- and sex-matched controls with normal dentate were compared using culture, Gram staining, and API20E Kit methods. All data were analyzed using SPSS software.

Results:

Except for Enterobacter cloacae isolate (P = 0.03), there was no significant difference between both groups for the presence of Escherichia coli, Klebsiella pneumoniae, nonfermenting Gram-negative bacilli, Raoultella ornithinolytica, Raoultella planticola, Kluyvera spp., and Enterobacter aerogenes. No significant correlation was noticed between age and presence of bacteria in the oral cavity. The Gram-negative rod bacteria were more in males, but the difference was not significant. When a total of Gram-negative rods were considered, there was a significant difference between case and control groups (P = 0.004).

Conclusions:

Based on our findings that nonoral pathogenic bacteria are detected from the saliva of the denture wearers, general and oral health measures in patients with removable dentures should be adopted to decrease the risk of cross infection.

Dental materials and their performance for the management of screw access channels in implant-supported restorations

Unsuccessfully sealed screw access channels of prosthetic implant abutments may lead to malodor or peri-implant diseases in gingival tissues adjacent to implant-supported restorations. Therefore, 72 sets of screw channel analogs with six different materials incorporated (Polytetrafluoroethylene (PTFE), wax, gutta-percha, cavit, endofrost-pellets and cotton pellets) were exposed (2.5 h, 37°C) to Streptococcus mutans, oralis and Candida albicans suspensions. Bacterial adherence was quantified by using the fluorescence dye, Alamar Blue/resazurin, and an automated multifunctional reader. For quantification of fungal adherence the ATP-based bioluminescence approach was used. High relative fluorescence and luminescence intensities (>10,000), indicating high adhesion of streptococci and fungi were found for cotton and endofrost-pellets and low intensities (<5,000) for wax, gutta-percha, cavit and PTFE. The quantity of bacterial and fungal adhesion differed significantly between the assessed various sealing materials. In conclusion and within the limitations of this study, wax, gutta-percha, cavit and PTFE should be preferred as sealing materials.

Antimicrobial activity of a quaternary ammonium methacryloxy silicate-containing acrylic resin: a randomised clinical trial

Quaternary ammonium methacryloxy silicate (QAMS)-containing acrylic resin demonstrated contact-killing antimicrobial ability in vitro after three months of water storage. The objective of the present double-blind randomised clinical trial was to determine the in vivo antimicrobial efficacy of QAMS-containing orthodontic acrylic by using custom-made removable retainers that were worn intraorally by 32 human subjects to create 48-hour multi-species plaque biofilms, using a split-mouth study design. Two control QAMS-free acrylic disks were inserted into the wells on one side of an orthodontic retainer, and two experimental QAMS-containing acrylic disks were inserted into the wells on the other side of the same retainer. After 48 hours, the disks were retrieved and examined for microbial vitality using confocal laser scanning microscopy. No harm to the oral mucosa or systemic health occurred. In the absence of carry-across effect and allocation bias (disks inserted in the left or right side of retainer), significant difference was identified between the percentage kill in the biovolume of QAMS-free control disks (3.73 ± 2.11%) and QAMS-containing experimental disks (33.94 ± 23.88%) retrieved from the subjects (P ≤ 0.001). The results validated that the QAMS-containing acrylic exhibits favourable antimicrobial activity against plaque biofilms in vivo. The QAMS-containing acrylic may also be used for fabricating removable acrylic dentures.

Development of In Vitro Denture Biofilm Models for Halitosis Related Bacteria and their Application in Testing the Efficacy of Antimicrobial Agents

Objective : Since dentures can serve as a reservoir for halitosis-causing oral bacteria, halitosis development is a concern for denture wearers. In this study, we surveyed the prevalence of four selected halitosis-related species (Fusobacterium nucleatum, Tannerella forsythia, Veillonella atypica and Klebsiella pneumoniae) in clinical denture plaque samples, and developed denture biofilm models for these species in vitro to facilitate assessment of antimicrobial treatment efficacy. Design : Denture plaque from ten healthy and ten denture stomatitis patients was screened for the presence of aforementioned four species by PCR. Biofilm formation by these halitosis-associated species on the surfaces of denture base resin (DBR) discs was evaluated by crystal violet staining and confocal laser scanning microscopy. The efficacy of denture cleanser treatment on these mono-species biofilms was evaluated by colony counting. Results : 80% of the subjects in the denture stomatitis group and 60% in the healthy group contained at least one of the targeted halitosis-related species in their denture plaque. All halitosis species tested were able to form biofilms on DBR disc surfaces to varying degrees. These in vitro mono-species resin biofilm models were used to evaluate the efficacy of denture cleansers, which exhibited differential efficacies. When forming biofilms on resin surfaces, the halitosis-related species displayed enhanced resistance to denture cleansers compared with their planktonic counterparts. Conclusion : The four selected halitosis-related bacterial species examined in this study are present on the majority of dentures. The mono-species biofilm models established on DBR discs for these species are an efficient screening tool for dental product evaluation.

The effect of a commercial probiotic drink on oral microbiota in healthy complete denture wearers

Background

It is acknowledged that oral and general health status declines with age. The global population of denture wearers is increasing, so is the incidence of denture biofilm-related problems, such as denture-associated stomatitis, aspiration pneumonia and malodour. It has been suggested that consumption of probiotic bacteria may improve oral health. However, the effects of probiotics on the oral microbiota of denture wearers have received little attention.

Methods

The aim of this study was to investigate the effect of consumption of a commercial probiotic product (Yakult) on microbiota of saliva, tongue and denture biofilm in healthy complete denture wearers. Eight healthy complete denture-wearing National Health Service (NHS) patients undertook a 7-week trial comprising three phases: baseline; 4-week consumption of one bottle of Yakult per day, each containing a minimum 6.5×10⁹ viable cells of Lactobacillus casei strain Shirota (LcS); 4-week washout period. The microbial viability and composition of saliva, tongue dorsum coating and denture biofilm were assessed using a range of solid selective and indicator media. Questionnaires were used to explore participants’ denture cleaning habits and impact of wearing dentures on their life quality and well-being [modified oral health impact profile (OHIP-14)] prior to and after the study.

Results

Seven volunteers (1 male, 6 females) completed the trial. LcS temporarily colonised oral cavity and denture surface. There was no significant change in the viability of Streptococcus mutans, acidogenic microorganisms, total anaerobic species and Gram-negative obligate anaerobes between study phases. There was no obvious effect of LcS on occurrence and viability of Candida. Participants presented a good general knowledge of denture hygiene and their responses to OHIP-14 questionnaires improved after completing the study (p=0.16).

Conclusion

It appeared that 4-week consumption of probiotic drink had no overall effect on selected oral parameters in healthy denture wearers despite temporary presence of LcS.

In vitro colonization of an experimental silicone by Candida albicans

Denture soft-lining materials are exposed to the oral cavity for long periods and are in continuous contact with saliva, subject to inhibition of liquid molecules, and susceptible to colonization by microorganisms. The opportunist yeast Candida albicans is of particular concern in this context, being associated with denture plaque and denture-related stomatitis. In this study, penetration of C. albicans into an experimental silicone elastomer soft-lining material was investigated under batch and continuous culture conditions. A model "denture plaque" microcosm was also used. Increasing the filler concentration within the elastomer decreased penetration under both batch and continuous culture conditions. In continuous culture, C. albicans penetration was significantly greater in pure culture than in the presence of bacteria after 72-h incubation (p < 0.05).

Effect of a denture cleanser on the concentration of volatile sulphur compounds and denture biofilm in institutionalised elderly

OBJECTIVE

To determine the effectiveness of a denture cleanser in reducing the concentration of volatile sulphur compounds (VSC) and its antimicrobial action.

BACKGROUND

Micro-organisms from the denture biofilm can cause local and systemic disease and halitosis. Denture cleansers are important adjuncts in oral care, but there is limited investigation on their effect in malodour compounds.

MATERIAL AND METHODS

Nineteen institutionalised elderly who wore at least an upper denture were selected; their VSC concentrations were measured and the denture biofilm was collected. In phase 1, the subjects wore their old denture and data were collected before (B0) and after 7(A1), 14(A2), 28(A3) days of continuous daily use of the denture cleanser. In phase 2, new dentures were inserted and measurements were made at 30(A1.1), 60(A2.2), 90(A3.3) days of treatment.

RESULTS

The VSC concentration increased from B0 to A1 (p<0.05), but no differences were found for the others intervals of times. Total micro-organism data did not show a statistical difference between times in Phase I, but in Phase II, there was a statistical difference (p<0.05) and a progressive re-colonisation was observed.

CONCLUSION

Within the limits of this study, it was concluded that the denture cleanser had no antimicrobial effect and VSC levels were not reduced.

A review of the current literature on management of halitosis

Halitosis is an unpleasant or offensive odour, emanating from the oral cavity. In approximately 80% of all cases, halitosis is caused by microbial degradation of oral organic substrates. Major degradation products are volatile sulphur-containing compounds. In this review, the available management methods of halitosis and their effectiveness and significance are presented and discussed. Undoubtedly, the basic management is mechanically reducing the amount of micro-organisms and substrates in the oral cavity. Masking products are not, and antimicrobial ingredients in oral healthcare products are only temporary effective in reducing micro-organisms or their substrates. Good short-term results were reported with chlorhexidine. Triclosan seems less effective, essential oils and cetylpyridinium chloride are only effective up to 2 or 3 h. Metal ions and oxidizing agents, such as hydrogen peroxide, chlorine dioxide and iminium are active in neutralizing volatile sulphur-containing compounds. Zinc seems to be an effective safe metal at concentrations of at least 1%. The effectiveness of active ingredients in oral healthcare products is dependent on their concentration and above a certain concentration the ingredients can have unpleasant side effects. Tonsillectomy might be indicated if (i) all other causes of halitosis are managed properly; (ii) halitosis still persists and (iii) crypts in tonsils are found to contain malodorous substrates.

Development of an in vitro denture plaque biofilm to model denture malodour

This study aimed to develop an in vitro denture plaque biofilm to model denture malodour. No previous studies have attempted to characterize the malodour associated with dentures and the effect of Candida spp. (main aetiological agent of denture-related stomatitis) on malodour. Pooled denture plaque microcosms and 'model' denture plaque biofilms (pooled saliva supplemented with additional microbial species) with and without addition of candida were grown aerobically at 37 °C for up to 13 days in a constant depth film fermenter (CDFF) on denture acrylic discs. Sample discs were removed, rinsed in sterile water and placed in phosphate buffered saline (PBS). The discs were vortex mixed to remove the biofilms, diluted in PBS and plated in duplicate onto general and selective media. The composition and stability of the biofilms over time were assessed. CDFF-grown microcosms and 'model' denture plaque biofilms were relatively stable in composition, with streptococci remaining the dominant microbial group. Model denture plaque biofilms were comparable in composition to denture plaque microcosms. This model system has the potential for evaluation of agents that might affect these parameters such as denture cleansers and other oral hygiene treatments.

The microbiological origin of fluorescence observed in plaque on dentures during QLF analysis

The aim of this study was to determine the microbiological origin of plaque fluorescence observed during quantitative light-induced fluorescence (QLF) analysis. Plaque was sampled from dentures, because of easy accessibility and the homogeneous background provided by the denture tooth during imaging, and the acknowledged comparability to occlusal plaque. Forty removable poly(methyl methacrylate) dentures were screened for the presence of fluorescent plaque deposits during QLF analysis. Dentures were photographed, QLF images were recorded and samples of fluorescent plaque were taken. Plaque samples were cultured on fastidious anaerobe agar, Wilkins Chalgren agar and Sabourauds dextrose agar. Plates were screened under QLF and fluorescent colonies were subcultured and identified. Areas of red, orange and green fluorescence were detected on the fitting and non-fitting surfaces of dentures. The red and orange fluorescing species were Prevotella melaninogenica, Actinomyces israelii and Candida albicans, which are generally acknowledged to be secondary colonisers, present in more mature plaque. Green fluorescence was observed in streptococcal species (early colonisers) and Fusobacterium nucleatum (important organism in plaque development). Non-fluorescent colonies were also cultured. Plaque which accumulates on susceptible surfaces tends to be associated with caries, but it may be its maturity, rather than the presence of cariogenic streptococci, that is more likely to provide a microbiological link between red fluorescence and caries.

Factors affecting microbial adhesion to stainless steel and other materials used in medical devices

The role of biofilm in medical device associated infections is well documented. Biofilms are more resistant to antibiotics than planktonic cells, these are extremely difficult to treat. Prevention strategies include efforts to insert implants under stringent aseptic conditions, and also encompass the development of novel materials which interfere with the initial attachment of microorganisms to the surface of the device. Microbial cells also attach onto hygienic surfaces in the hospital setting, and thereby pose a cross-infection problem. In this case, vigorous cleaning and sanitizing regimes may be employed in addition to any surface modifications. Many factors affect the initial attachment of organisms to inert substrata, and their subsequent retention or removal/detachment, including the physical and chemical nature and location of the substratum, the type of organic material and microorganisms potentially fouling the surface, and the nature of the interface (solid-liquid in the body; solid-air on environmental surfaces). Focusing on one factor, surface topography, it is apparent that many further variables need to be defined in order to fully understand the interactions occurring between the cell and surface. It is therefore important when modifying one substratum surface property in order to reduce adhesion, to also consider other potentially confounding factors.