Denture stomatitis--a review of the aetiology, diagnosis and management

The antimicrobial activity of an antiseptic soap against Candida Albicans and Streptococcus Mutans single and dual-species biofilms on denture base and reline acrylic resins

To evaluate the effect of antiseptic soap on single and dual-species biofilms of Candida albicans and Streptococcus mutans on denture base and reline resins. Samples of the resins were distributed into groups (n = 9) according to the prevention or disinfection protocols. In the prevention protocol, samples were immersed in the solutions (Lifebuoy, 0.5% sodium hypochlorite solution and PBS) for 7, 14 and 28 days before the single and dual-species biofilms formation. Overnight denture disinfection was simulated. In the disinfection protocol, samples were immersed in the same solutions during 8 hours after the single and dual-species biofilms formation. Antimicrobial activity was analyzed by counting colony-forming units (CFU/mL) and evaluating cell metabolism. Cell viability and protein components of the biofilm matrix were evaluated using confocal laser scanning microscopy (CLSM). Data were submitted to ANOVA, followed by Tukey's post-test (α = 0.05) or Dunnett's T3 multiple comparisons test. In the prevention protocol, Lifebuoy solution effectively reduced the number of CFU/mL of both species. In addition, the solution decreased the cell metabolism of the microorganisms. Regarding disinfection protocol, the Lifebuoy solution was able of reduce approximately of 2-3 logs for all the biofilms on the denture base and reline resin. Cellular metabolism was also reduced. The images obtained with CLSM corroborate these results. Lifebuoy solution was effective in reducing single and dual-species biofilms on denture base and reline resins.

Evaluating the antifungal effectiveness, leaching characteristics, flexural strength, and impact strength of polymethyl methacrylate added with small-scale silver nanoparticles - An in vitro study

AIM

(1) To assess the release of stable silver nanoparticles (AgNPs) of small scale dimension added to heat polymerized polymethyl methacrylate (PMMA) in 6 months. (2) Assessing the influence of incorporating minimal concentrations of stable AgNPs with nanoscale dimensions into heat polymerized PMMA over a 6 month period on its antifungal efficacy (AF), flexural strength (FS), and impact strength (IS).

SETTINGS AND DESIGN

Incorporating nanoparticles with a very small scale may have minimal impact on mechanical properties due to their diminutive size. However, the influence of these small scaled nanoparticles on antimicrobial efficacy and potential escalation in toxicity to host cells through leaching remains unexplored. AgNPs were prepared using an Ultrasonic Probe sonicator and the addition of ammonia to obtain stabilized AgNPs (< 0.01 nm) of small scale dimension. The characterization of these AgNPs involved ultraviolet visible spectroscopy, X ray diffraction, Zetasizer, and transmission electron microscopy with energy dispersive spectroscopy (TEM).

MATERIALS AND METHODS

The prepared AgNPs were then added in various percentages by weight (0%-0.5%) to fabricate 252 modified PMMA samples of sizes 10 mm × 3 mm (AF, n = 108), 65 mm × 10 mm × 3 mm (FS, n = 72), and 65 mm × 10 mm × 2.5 mm (IS, n = 72) as per ADA specification no. 12. These samples underwent testing for leaching out of AgNPs and efficacy against Candida albicans for 6 months. The effect on FS and IS was evaluated using the three point bending test and Charpy's Impact Tester, respectively.

STATISTICAL ANALYSIS USED

Intergroup comparison of CFU between various concentrations of AgNP was done using the Kruskal-Wallis ANOVA test succeeded by Mann-Whitney test for pair wise comparisons. Difference in CFU of various concentrations over 6 months was seen using one way ANOVA test. Intergroup comparison of FS and IS was performed using a one way ANOVA test, followed by a post hoc Tukey's test for pair wise comparisons.

RESULTS

Repeated tests showed no leaching out of AgNPs from the denture base resin into the storage medium. All concentrations of AgNPs incorporated in resin showed inhibition of Candida growth. Intergroup comparison of FS and IS revealed highly statistically significant differences (F = 15.076, P < 0.01 and F = 28.266, P < 0.01) between the groups showing a reduction in strength.

CONCLUSION

The AgNPs of small scale dimension incorporated into the denture base resin imparted a strong antifungal effectiveness against C. albicans, which did not decline during the study period and did not cause any release of nanoparticles. 0.5% showed the best antifungal efficacy. This may prove to be a viable and highly effective treatment for the prevention of Candida associated denture stomatitis. However, the inclusion of these particles resulted in a decrease in both FS and IS, and this reduction was directly proportional to the percentage of added AgNPs, with 0.5% demonstrating the least IS and FS.

Interrelationship between Candida Colonization, Dentures, and Mucosal Tissue Inflammation in the Pathogenesis of Denture Stomatitis

Despite being common, the pathogenesis of denture stomatitis (DS) is poorly known; thus, this study was conducted to examine the relationship between candida, dentures, and mucosal tissue inflammation. One hundred and twenty edentulous patients wearing a denture with clinical signs and symptoms of DS and 30 patients without DS as healthy were involved in the study. Patients with DS were divided into three groups according to Newton's classification and fungal colonies, and denture fit was assessed. No significant difference was observed between age, sex, and denture fit between the two groups (P > 0.05). The fungal colonies in patients with DS were significantly more than the controls. The majority of the patients with good denture fit had degree 1 (localized mucosal inflammation), while the majority of the patients with fair denture fit had degree 2 (diffuse inflammation on the denture bearing area) and the majority with poor denture fit had degree 3 (granular type) (P < 0.001). The fungal colonies were negative for the majority of degree 1 patients (57.1%), while they were positive for the majority of patients with degree 2 (61.3%) and degree 3 (63.2%) inflammation (P = 0.003). We concluded that the pathogenesis of DS is elusive. Multiple factors, including lack of hygiene, reduced salivary flow, poor denture care, and fit, provide an easy pathway for Candida strains to colonize dentures.

Are the counts of Streptococcus mutans and Staphylococcus aureus changed in complete denture wearers carrying denture stomatitis? A systematic review with meta-analyses

STATEMENT OF PROBLEM

Despite the importance of Candida spp. on the etiology of denture stomatitis (DS), information on the role of the bacterial component is still scarce.

PURPOSE

The purpose of this systematic review was to evaluate whether the counts of Staphylococcus aureus and Streptococcus mutans were changed in complete denture wearers diagnosed with Candida-associated DS.

MATERIAL AND METHODS

The literature search was performed in 8 databases and by hand searching. The risk of bias was assessed according to the Newcastle-Ottawa qualifier. Meta-analyses were performed considering the microorganism evaluated (S. aureus or S. mutans) and the collection area (mucosa or dentures). The certainty of evidence was assessed according to the grading of recommendations assessment, development and evaluations (GRADE) criteria.

RESULTS

Participants with DS presented higher counts of S. aureus in the mucosa compared with those from the control group (OR, 3.16 [1.62, 6.15]; P<.001). No significant difference between the groups was observed for samples collected from dentures (OR, 0.73 [0.50, 1.07]; P=.110). Conversely, participants without DS presented higher counts of S. mutans both in the mucosa (OR, 0.19 [0.06, 0.63]; P=.006) and dentures (OR, 0.64 [0.41, 1.0]; P=.050).

CONCLUSIONS

Microbial counts in participants with DS changed as a function of the type of microorganism and collection site. The certainty of evidence ranged from very low to low. The findings reinforce the fact that bacteria also play a relevant role in DS and should be more extensively studied. Such information may be useful to guide further therapies to prevent or control DS.

Prospects on Tuning Bioactive and Antimicrobial Denture Base Resin Materials: A Narrative Review

Denture base resin (DBR) materials are used in dentistry in constructing removable dentures and implant-supported prostheses. A plethora of evidence has demonstrated that DBR materials are associated with a high risk of denture stomatitis, a clinical complication where the soft oral tissues underneath the resin-based material are inflamed. The prevalence of denture stomatitis among denture wearers is high worldwide. Plaque accumulation and the infiltration of oral microbes into DBRs are among the main risk factors for denture stomatitis. The attachment of fungal species, mainly Candida albicans, to DBRs can irritate the underneath soft tissues, leading to the onset of the disease. As a result, several attempts were achieved to functionalize antimicrobial compounds and particles into DBRs to prevent microbial attachment. This review article explored the advanced approaches in designing bioactive and antimicrobial DBR materials. It was reported that using monomer mixtures, quaternary ammonium compounds (QACs), and organic and inorganic particles can suppress the growth of denture stomatitis-related pathogens. This paper also highlighted the importance of characterizing bioactive DBRs to be mechanically and physically sustainable. Future directions may implement a clinical translational model to attempt these materials inside the oral cavity.

Influence of Propolis Extract (Caffeic Acid Phenethyl Ester) Addition on the Candida albicans Adhesion and Surface Properties of Autopolymerized Acrylic Resin

Background. Denture stomatitis has been linked to the adhesion and proliferation of Candida albicans (C. albicans) on denture bases, which is a common and recurrent problem in denture wearers. The current study aimed to evaluate the effect of incorporating caffeic acid phenethyl ester (CAPE) into autopolymerized polymethyl methacrylate (PMMA) acrylic resin on C. albicans adhesion, surface roughness, and hardness as well as the correlation between tested properties. Methods. Autopolymerized acrylic resin discs (N = 100, 50/C. albicans adhesion; 50/C. albicans surface roughness and hardness test) were fabricated in dimensions 15 × 2.5 mm, samples were categorized into 5 groups (n = 10) based on CAPE concentrations; unmodified (control), 2.5, 5, 10 and 15% wt of acrylic powder. Specimens were stored in distilled water for 48 h at 37°C. C. albicans adhesion was evaluated via direct culture method. Profilometer and Vickers hardness tester were used for surface roughness and hardness measurement. Post hoc Tukey’s HSD with ANOVA test was performed to compare the difference of means amongst groups. $P$ values were statistically significant at ≤0.05. Results. The addition of 2.5% of CAPE to PMMA has significantly reduced C. albicans counts in comparison to higher CAPE concentrations ( $p<0.001$ ). As for surface roughness, it was noticed that it increased with increased CAPE concentrations ( $p<0.0001$ ). While surface hardness decreased as CAPE concentrations increased ( $p<0.0001$ ). All tested properties showed a significant difference amongst groups for C. albicans colony count and surface parameters. Conclusion. The addition of 2.5% of CAPE to PMMA acrylic resin significantly decreased C. albicans count compared to higher CAPE concentrations. CAPE can be used as an adjunct in the prevention of DS by incorporating in the PMMA acrylic resin.

Efficacy of antimicrobial photodynamic therapy compared to nystatin therapy in reducing Candida colony count in patients with Candida-associated denture stomatitis: a systematic review and meta-analysis

Purpose This meta-analysis assessed the efficacy of antimicrobial photodynamic therapy (aPDT) compared to conventional nystatin therapy (NYT) in reducing Candida colony count in patients with Candida-associated denture stomatitis (CADS) and critically appraised the available literature.Methods This meta-analysis was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) updated guidelines. A literature search was performed in four electronic databases to identify relevant articles up to 15 August 2021. Randomised controlled trials (RCTs) that assessed the efficacy of aPDT compared to NYT in reducing Candida colony count in patients with CADS were investigated. The weighted mean difference (MD) and 95% confidence interval were calculated. The I2 statistic was used to determine heterogeneity at the level of α = 0.10. The Cochrane risk of bias (RoB 2) tool was used to assess the risk of bias. Certainty of the evidence was determined using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) ranking system.Results Only three eligible RCTs with 141 participants were included in this systematic review and meta-analysis. Based on the pooled results, NYT compared to aPDT generally performed better in reducing Candida colony count (Log10 CFU/mL) in patients' palate and patients' denture. The included studies had a moderate risk of bias and the certainty of the evidence was low.Conclusion Although still inconclusive, based on the current evidence, aPDT may be effective in reducing Candida colony count and treating CADS. Nonetheless, it does not appear to be more effective than conventional NYT in this regard. According to the limited number of included studies, more well-designed RCTs with larger sample sizes and standardised methodology should be conducted to validate this conclusion.

Antagonistic effect of isolated and commercially available probiotics on the growth of Candida albicans on acrylic resin denture surfaces

STATEMENT OF PROBLEM

Biofilms can be retained on dental prostheses leading to the development of infections. The indiscriminate use of antifungal drugs can result in the development of microorganisms that are resistant to these antimicrobial agents. Whether probiotics are a suitable alternative for reducing the prevalence of oral candidiasis is unclear.

PURPOSE

The purpose of this in vitro study was to evaluate the influence of 6 different live strains of probiotics and 2 commercially available probiotic supplements used for inhibiting the growth of Candida albicans biofilm in heat-polymerized acrylic resin denture base material and to determine whether biofilm byproducts modify the surface of specimens.

MATERIAL AND METHODS

Biofilms of C. albicans were formed on acrylic resin specimens in the presence of probiotics and quantified by colony-forming units (CFUs), and the surface roughness (Ra) of the specimens was assessed before and after the formation of biofilms. The CFU and roughness data were analyzed by analysis of variance and the Tukey HSD test (α=.05).

RESULTS

A significant decrease in the number (CFU/mL) of C. albicans cells was found when they were cultured with 4 probiotics: B. lactis (P=.045), B. longum (P<.001), L. casei (P<.001), and L. helveticus (P<.001) and with the commercially available probiotic Prolive (P=.05). The Ra of specimens decreased after exposure to different microbial biofilms (P≤.05) except in 3 experimental groups.

CONCLUSIONS

In general, the tested probiotics had an antagonistic effect on the growth of C. albicans, and the surface of acrylic resin was altered after exposure to biofilm byproducts.

Efficacy of photodynamic therapy versus local nystatin in the treatment of denture stomatitis: A randomized clinical study

AIM

The aim of the present randomized clinical study was to compare the efficacies of photodynamic inactivation (PDI) to nystatin (NST) in terms of prevalence of Candida species in cases with denture stomatitis (DS).

METHODS

Thirty-six patients were randomly divided into two groups; 18 in PDI and 18 in NST. Irradiation was carried out by using the GaA1As diode laser with wavelength, mode of transmission, laser output and energy density were standardized at 660 nm, continuous mode, 100 mW power and 28 J/cm2 respectively. The PDI was applied twice a week, with an interval of at least 48 h among the sessions during four weeks. Topical nystatin oral suspension 100,000 IU was used four times daily for 15 days. The existence of Candida spp. was confirmed by employing the microbiological culture technique. Candida colony counts from the palates and dentures surfaces, quantified as colony forming unit (CFU)/mL, measured at baseline, at the end of treatments (day 15), and at follow-up (days 30 and 60) and the prevalence of Candida spp. were identified in the two groups of treatments.

RESULTS

The overall CFU/mL values were higher in the dentures of the patients of both the groups than those from the palates. During all time periods of the study, the CFU/mL values obtained from both NST and PDI groups showed no significant differences. For dentures and palates, a significant reduction in mean CFU/mL values was observed on day 15 compared with baseline (day 0) in both NST and PDI groups. It can be seen that the effect size of treatments was large for the palates of patients in the NST group (1.79) and moderate for the palates of patients in the PDI group (0.63). On the other hand, the effect size was very large for the dentures for both groups (NST group = 3.01; PDI group = 1.58). C. albicans was the most common species on both dentures and palates of patients throughout the study period followed by C. tropicalis and C. glabrata.

CONCLUSION

Out of all the Candida spp., C. albicans showed the highest prevalence among all species. In addition, PDI was equally effective as nystatin for the treatment of DS.

Isolation of Candida spp. from denture-related stomatitis in Pará, Brazil

The aim of this study was to isolate and identify Candida species from the oral cavity of denture wearers with denture-related stomatitis who were attended at the University Federal of Pará (Belém City, Pará State, Brazil). A total of 36 denture wearers with denture-related stomatitis were included, and type I (50%), type II (33%) and type III (17%) stomatitis were observed. Candida spp. were isolated from 89% of the cases and included five different Candida species. C. albicans was the most frequently recovered species (78% of the cases), followed by C. famata and C. tropicalis. We observed a significant association between Candida species isolation and unsatisfactory denture condition (p = 0.0017). Our results demonstrated the highly frequency of Candida species isolation in denture wearers with denture-related stomatitis and showed the relationship between these species and poor denture maintenance.

In Vitro Evaluation of the Inhibitory Activity of Thymoquinone in Combatting Candida albicans in Denture Stomatitis Prevention

Candida albicans adhesion and proliferation on denture bases may lead to denture stomatitis, which is a common and recurrent problem in denture wearers. The goal of this study was to assess the inhibitory effect of thymoquinone incorporated in the polymethyl methacrylate denture base material against Candida albicans. Eighty acrylic resin specimens were fabricated and divided into eight groups (n = 10) according to thymoquinone concentrations of 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, and 5% of acrylic powder. Two methods were used to evaluate the effect of thymoquinone on Candida albicans: the slide count and the serial dilution test. A multivariate analysis of variance (MANOVA) and the post-hoc Tukey’s Honestly Significant Difference (HSD) test were performed to compare the difference of means between the observations taken at various intervals with baseline. The p value was statistically significant at ≤0.05. According to the slide count and the serial dilution test, the mean number of adhered Candida albicans in the control group was 5436.9 ± 266 and 4691.4 ± 176.8; however, this number dramatically decreased to 0 ± 0 and 32.4 ± 1.7 in group 8 (concentration 5%). These results suggest that the incorporation of thymoquinone into the acrylic resin denture base material might be effective in preventing Candida albicans adhesion.

Soluble factors from biofilm of Candida albicans and Staphylococcus aureus promote cell death and inflammatory response

Background

The objective of this study was to better understand the effects of soluble factors from biofilm of single- and mixed-species Candida albicans (C. albicans) and methicillin-sensitive Staphylococcus aureus (MSSA) cultures after 36 h in culture on keratinocytes (NOK-si and HaCaT) and macrophages (J774A.1). Soluble factors from biofilms of C. albicans and MSSA were collected and incubated with keratinocytes and macrophages, which were subsequently evaluated by cell viability assays (MTT). Lactate dehydrogenase (LDH) enzyme release was measured to assess cell membrane damage to keratinocytes. Cells were analysed by brightfield microscopy after 2 and 24 h of exposure to the soluble factors from biofilm. Cell death was detected by labelling apoptotic cells with annexin V and necrotic cells with propidium iodide (PI) and was visualized via fluorescence microscopy. Soluble factors from biofilm were incubated with J774A.1 cells for 24 h; the subsequent production of NO and the cytokines IL-6 and TNF-α was measured by ELISA.

Results

The cell viability assays showed that the soluble factors of single-species C. albicans cultures were as toxic as the soluble factors from biofilm of mixed cultures, whereas the soluble factors of MSSA cultures were less toxic than those of C. albicans or mixed cultures. The soluble factors from biofilm of mixed cultures were the most toxic to the NOK-si and HaCaT cells, as confirmed by analyses of PI labelling and cell morphology. Soluble factors from biofilm of single-species MSSA and mixed-species cultures induced the production of IL-6, NO and TNF-α by J744A.1 macrophages. The production of IL-6 and NO induced by the soluble factors from biofilm of mixed cultures was lower than that induced by the soluble factors from biofilm of single-species MSSA cultures, whereas the soluble factors from biofilm of C. albicans cultures induced only low levels of NO.

Conclusions

Soluble factors from 36-h-old biofilm of C. albicans and MSSA cultures promoted cell death and inflammatory responses.

The antifungal effects and mechanical properties of silver bromide/cationic polymer nano-composite-modified Poly-methyl methacrylate-based dental resin

Poly-methyl methacrylate (PMMA)-based dental resins with strong and long-lasting antifungal properties are critical for the prevention of denture stomatitis. This study evaluated the antifungal effects on Candida albicans ATCC90028, the cytotoxicity toward human dental pulp cells (HDPCs), and the mechanical properties of a silver bromide/cationic polymer nano-composite (AgBr/NPVP)-modified PMMA-based dental resin. AgBr/NPVP was added to the PMMA resin at 0.1, 0.2, and 0.3 wt%, and PMMA resin without AgBr/NPVP served as the control. Fungal growth was inhibited on the AgBr/NPVP-modified PMMA resin compared to the control (P < 0.05), and the antifungal activity increased as the incorporation of the AgBr/NPVP antimicrobial composite increased. Confocal laser scanning microscopy (CLSM) showed that the number of fungal cells attached to the modified PMMA resin was considerably lower than in the control. The relative growth rate of HDPCs of modified groups were higher than 75%. The flexural strength (FS) and flexural modulus (FM) were not significantly different (P > 0.05) between the experimental and control groups. These data indicate that the incorporation of AgBr/NPVP conferred strong and long-lasting antifungal effects against Candida albicans to the PMMA resin, and it has low toxicity toward HDPCs, and its mechanical properties were not significantly affected.

Improving practice guidelines for the treatment of denture-related erythematous stomatitis: a study protocol for a randomized controlled trial

Background

Denture-related erythematous stomatitis (DES) is a chronic biofilm-mediated disease, affecting one in every three complete denture wearers. Antifungals are the treatment most commonly prescribed by oral health professionals, based on the belief that colonization by Candida spp. is the main cause of DES. However, high recurrence rates and adverse effects are commonly observed, prompting the need for practice guidelines regarding treatment. Results from our pilot study demonstrate that palatal brushing can reduce the palatal inflammation and potentially associated Candida carriage without any need for antifungal therapy. The objective of this study is to validate these pilot results by means of a randomized controlled trial (RCT) and provide a practice guideline for clinicians.

Methods/design

A pragmatic, two-parallel-arm, multicenter RCT will be conducted in Canada, Brazil, and Chile. Fifty-two adult complete denture wearers presenting with moderate to severe DES will be allocated randomly to two groups: the Intervention arm will consist of palatal brushing and standard oral and denture hygiene measures, while the Control arm will include only standard oral and denture hygiene measures. The study outcome will be the oral Candida carriage. Participants will be assessed at baseline, and at 3 and 6 months post intervention. Descriptive, bivariate, and mixed models with repeated measures will be performed following the intention-to-treat principle.

Discussion

This pragmatic RCT will serve to provide a clinical practice guideline regarding the use of preventive measures in the treatment of biofilm-mediated oral diseases. Moreover, it will have a great impact on reducing the harm of antifungal overtreatment on patients suffering from DES.

Trial registration

ClinicalTrials.gov, NCT02686632. Registered on 15 February 2016.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-1947-y) contains supplementary material, which is available to authorized users.

Photodynamic inactivation of a multispecies biofilm using Photodithazine(®) and LED light after one and three successive applications

In this investigation, the effectiveness of successive applications of antimicrobial photodynamic inactivation (API) mediated by Photodithazine(®) (PDZ) and LED light was evaluated against a multispecies biofilm formed by Candida albicans, Candida glabrata, and Streptococcus mutans on denture base acrylic resin. Standard cell suspensions (bacteria and yeast) were inoculated on acrylic resin samples, and the biofilm was grown for 48 h (37 °C/75 rpm). API was performed by the administration of PDZ (175 and 200 mg/L) and exposure to 37.5 J/cm(2) of LED light (660 nm). Additional samples were treated with PDZ or LED light only. Untreated control samples were not submitted to light or PDZ. The conditions described were applied once or in three consecutive applications for all groups. Cell viability was determined by colony counts (CFU/mL), metabolic activity, total biomass, and confocal laser scanning microscopy (CLSM). Data were analyzed by a nonparametric two-way ANOVA and Tukey tests (α = 0.05). The results obtained demonstrated a significant effect (p < 0.05) of number of applications and treatment groups for CFU/mL, and S. mutans showed the highest susceptibility to API. The metabolic activity of the multispecies biofilm was significantly reduced (p < 0.05) after API for both numbers of applications, which were also significantly different (p < 0.05) between them. The total biomass of the biofilm was significantly different (p < 0.05) only between groups submitted to one and three API applications. CLSM showed a visual increase of dead cells after API. API-mediated PDZ was effective in reducing the cell viability of multispecies biofilm. Three consecutive applications of API were more effective for reducing the cell viability and the total biomass of multispecies biofilm.

The Oral Microbiome of Denture Wearers Is Influenced by Levels of Natural Dentition

Objectives

The composition of dental plaque has been well defined, whereas currently there is limited understanding of the composition of denture plaque and how it directly influences denture related stomatitis (DS). The aims of this study were to compare the microbiomes of denture wearers, and to understand the implications of these towards inter-kingdom and host-pathogen interactions within the oral cavity.

Methods

Swab samples were obtained from 123 participants wearing either a complete or partial denture; the bacterial composition of each sample was determined using bar-coded illumina MiSeq sequencing of the bacterial hypervariable V4 region of 16S rDNA. Sequencing data processing was undertaken using QIIME, clustered in Operational Taxonomic Units (OTUs) and assigned to taxonomy. The dentures were sonicated to remove the microbial flora residing on the prosthesis, sonicate was then cultured using diagnostic colorex Candida media. Samples of unstimulated saliva were obtained and antimicrobial peptides (AMP) levels were measured by ELISA.

Results

We have shown that dental and denture plaques are significantly distinct both in composition and diversity and that the oral microbiome composition of a denture wearer is variable and is influenced by the location within the mouth. Dentures and mucosa were predominantly made up of Bacilli and Actinobacteria. Moreover, the presence of natural teeth has a significant impact on the overall microbial composition, when compared to the fully edentulous. Furthermore, increasing levels of Candida spp. positively correlate with Lactobacillus spp. AMPs were quantified, though showed no specific correlations.

Conclusions

This is the first study to provide a detailed understanding of the oral microbiome of denture wearers and has provided evidence that DS development is more complex than simply a candidal infection. Both fungal and bacterial kingdoms clearly play a role in defining the progression of DS, though we were unable to show a defined role for AMPs.

Effectiveness of Chemical and Microwave Disinfection on Denture Biofilm Fungi and the Influence of Disinfection on Denture Base Adaptation

The aims of this study were to evaluate the effectiveness of six disinfection methods and the influence of these methods on the adaptation of maxillary dentures. Acrylic resin specimens contaminated with fungi were exposed to the following disinfection treatments: 1. microwave oven (900 W) at full power for 5 min (with soaking the specimen in 250 ml water), 2. microwave oven at medium power for 5 min (with soaking the specimen in 250 ml water), 3. sodium hypochlorite 5.25 % for 5 min, 4. diluted sodium hypochlorite 1:420 for 5 h, 5. Chlorhexidine gluconate for 5 h, 6. effervescent tablets for 15 min, 7. soaking in 250 ml tap water for 15 min. Colony forming units (CFUs) of remaining cells were counted and compared with t test (p ≤ 0.05). Dimensional stability was evaluated using aluminum die simulating the maxillary edentulous arch. Posterior palatal gaps were measured. Data were analyzed using one-way ANOVA test and t test (p ≤ 0.05). Microwave irradiation (at full or medium power) and sodium hypochlorite 5.25 % for 5 min were able to reduce the CFUs of fungi by more than 4 log10 whereas diluted sodium hypochlorite, chlorhexidine gluconate, and effervescent tablets did not achieve a reduction of >2.8, 2.68 and 1.66, respectively. For dimensional stability test, t test revealed significant difference between control group and the microwave at full power group (p = 0.000). Within the limits of this study, microwave oven at medium power and sodium hypochlorite (5.25 %) are effective and safe methods of disinfecting removable dentures.

Influence of a new denture cleaning technique based on photolysis of H(2)O(2) the mechanical properties and color change of acrylic denture base resin

The purpose of this study was to evaluate the influence of a disinfection technique based on photolysis of H2O2 on the mechanical properties and color change of acrylic denture base resin. Resin specimens were immersed in 1 M H2O2 irradiated with light-emitting diode (LED) light at 400 nm for 1 week. The immersion duration of 1 week (168 h) corresponded to performing approximately 500 times of 20-min cleaning. Hydroxyl radicals are potent oxidants and they were generated via the photolysis of H2O2. Oxidative damage caused by these radicals included reduced flexural strength and altered color for the acrylic resin. Nonetheless, the degraded flexural strength and altered color of acrylic resin after 500 times of cleaning in the disinfection system would be within clinically acceptable levels.

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.

Identificação das espécies de Candida em portadores de estomatite protética e avaliação da susceptibilidade ao miconazol e à terapia fotodinâmica

INTRODUÇÃO: Próteses mucossuportadas são consideradas facilitadoras, em potencial, da estomatite protética (EP), condição caracterizada pelo aspecto eritematoso, difuso ou pontilhado da mucosa palatina sob a base das próteses. A etiologia da doença é multifatorial, embora a infecção por Candida seja uma causa bastante comum. OBJETIVO: Relacionar a EP com a presença de Candida, identificar as espécies de Candida mais prevalentes, a partir do meio CHROMagar Candida(r), e caracterizar o perfil de sensibilidade das colônias ao miconazol e à terapia fotodinâmica (TFD). MATERIAL E MÉTODO: A amostra foi constituída por 45 usuários de prótese total, sendo 30 com diagnóstico clínico de EP e 15 sem a doença. Realizou-se raspagem com swab da mucosa palatina e das próteses, e as amostras foram semeadas em CHROMagar Candida(r), para identificação de espécies de C. albicans, C. krusei e C. tropicalis. Após incubação e leitura das placas, as colônias foram reisoladas em Ágar Sabouraud, para caracterização da sensibilidade ao miconazol e à TFD. RESULTADO: Espécies de Candida estiveram presentes em 53,33% das amostras dos pacientes com EP e em 6,67% das amostras dos pacientes sem EP, considerando-se o total de amostras de mucosa (p=0,008) e próteses (p=0,001). As espécies mais prevalentes foram C. albicans (36,67% e 53,33%), seguida de C. tropicalis (13,33% e 16,67%) e C. krusei (13,33% e 6,67%), em mucosa e prótese, respectivamente. As amostras mostraram maior sensibilidade ao miconazol que à TFD (p<0,0001). CONCLUSÃO: Existiu uma associação entre a presença de Candida e EP, sendo C. albicans a espécie mais prevalente. Miconazol proveu melhores resultados na eliminação in vitro de colônias de Candida quando comparado à TFD.

Relationship among local and functional factors in the development of denture stomatitis in denture wearers in northern Brazil

OBJECTIVE: The aim of this study was to evaluate the relationship among functional and qualitative factors in the development of denture stomatitis (DS) (according to Newton's classification) in acrylic-based denture wearers residents from northern Brazil.MATERIAL AND METHOD: A total of 99 patients who wore partial or total acrylic resin-based upper dentures were included in this study. The subjects completed an epidemiological data form that includes the patient's gender, age, local factors (hygiene habits, remove denture to sleep, use of mouthwash, present condition of the denture, age of the denture) and functional factors (vertical dimension at rest, vertical dimension of occlusion, occlusion, retention, and static and dynamic stability). To detect yeasts, samples were collected from the inner surface of the dentures and from the palatal mucosa in contact with it. Subsequently, the samples were cultured on Sabouraud dextrose agar, observing macro and microscopic characteristics.RESULT: In the present study, we did not find any significant relationship between the gender and disease onset. Based on the Newton classification, 36.3% of the patients presented with DS and 89.0% were colonized by yeasts; of these subjects, 50% had type I lesions, 33.3% had type II lesions, and 16.6% had type III lesions. All of the qualitative and local factors, except the use of mouthwash, were clinically relevant to the development of disease.CONCLUSION: Denture stomatitis in denture users in northern Brazil was multifactorial, involving local, functional and microbiological factors.

Antifungal activity, biofilm-controlling effect, and biocompatibility of poly(N-vinyl-2-pyrrolidinone)-grafted denture materials

Colonization and biofilm-formation of Candida species on denture surfaces cause Candida-associated denture stomatitis (CADS), a common, recurring disease affecting up to 67% of denture wearers. We developed poly(N-vinyl-2-pyrrolidinone)-grafted denture materials that can be repeatedly recharged with various antifungal drugs to achieve long-term antifungal and biofilm-controlling effects. The monomer, N-vinyl-2-pyrrolidinone (NVP), was grafted onto poly(methyl methacrylate) denture resins through plasma-initiated grafting polymerization. The physical properties and biocompatibility of the resulting resins were not negatively affected by the presence of up to 7.92% of grafted poly (N-vinyl-2-pyrrolidinone) (PNVP). Miconazole and chlorhexidine digluconate (CD) were used as model antifungal drugs. PNVP grafting significantly increased the drug absorption capability of the resulting denture materials. Further, the new materials showed sustained drug release and provided antifungal effects for weeks (in the case of CD) to months (in the case of miconazole). The drug-depleted resins could be recharged with the same or a different class of antifungal drug to further extend antifungal duration. If needed, drugs on the PNVP-grafted denture materials could be "washed out" (quenched) by treating with PNVP aqueous solutions to stop drug release. These results point to great potentials of the new materials in controlling biofilm-formation in a wide range of device-related applications.

Prevalence of oral mucosal lesions in a group of Iranian dependent elderly complete denture wearers

AIM

Oral mucosal lesions are frequently observed in institutionalized elderly patients more than other age groups. The aim of this study was to determine the prevalence of epulis fissuratum and denture stomatitis and their associated causes in dependent elderly complete denture wearers.

MATERIALS AND METHODS

This study was conducted in dependent elderly complete denture's wearers living in four randomly selected nursing homes located in Tehran. Associated factors such as gender, age, use of medication, site of nursing home, denture quality and denture-wearing habit were studied.

RESULTS

Overall, 674 patients were examined; 201 had complete denture. The prevalence of denture stomatitis was 36%. There was significant relationship among the prevalence of denture stomatitis with gender and denture wearing period (p < 0.05). The prevalence of epulis fissuratum was 16.4%. There was significant relationship among the prevalence of epulis fissuratum with gender, denture quality and denture wearing habit (p < 0.05).

CONCLUSION

In this particular dependent age group, the prevalence of oral mucosal lesions is high and the mentioned associated factors should be noticed.

CLINICAL SIGNIFICANCE

Dependent elderly complete denture wearers need more support and motivation for reducing the prevalence of these particular denture-associated oral mucosal lesions.

Clinical and histological findings of denture stomatitis as related to intraoral colonization patterns of Candida albicans, salivary flow, and dry mouth

PURPOSE

Multifactorial etiological factors contribute to denture stomatitis (DS), a type of oral candidiasis; however, unlike other oral candidiasis, DS can occur in a healthy person wearing a denture. In this study, we therefore attempt to explore the association between candida, denture, and mucosal tissue using (1) exfoliative cytology, (2) the candidal levels present in saliva, on mucosal tissues and on denture surfaces, and (3) the salivary flow rate and xerostomic symptoms.

MATERIALS AND METHODS

A cross-sectional study enrolled 32 edentulous participants, 17 without DS as controls and 15 with DS (Newton's classification type II and III). Participants with systemic or other known oral conditions were excluded. Participants completed a xerostomia questionnaire, and salivary flow rates were measured. Samples of unstimulated whole saliva (UWS) and stimulated whole saliva (SWS) were collected. UWS was used for fungal culturing. Periodic acid-Schiff (PAS) stain and quantitative exfoliative cytology were performed on samples from affected and unaffected mucosa from each participant. Levels of Candida species (albicans and non-albicans) were determined in salivary samples (expressed as colony-forming units, CFU), as well as from swab samples obtained from denture fitting surfaces, in addition to affected and unaffected mucosa.

RESULTS

There were no significant differences in salivary flow rates, mucosal wetness, or frequency of reported dry mouth comparing participants with and without DS. Exfoliative cytology of mucosal smears demonstrated significantly higher (p= 0.02) inflammatory cell counts in DS patients, as compared with smears of healthy denture-wearers. Candida albicans was significantly more prevalent in saliva (p= 0.03) and on denture surfaces (p= 0.002) of DS participants, whereas mucosal candidal counts and the presence of cytological hyphae did not show significant difference comparing DS to healthy participants.

CONCLUSIONS

In this investigation, we presented a unique group of healthy edentulous patients. This population may reflect the general DS population without systemic or other oral diseases. The prominent etiological factor for DS in this population is the presence of candida in denture and saliva. We found that other factors such as saliva flow/xerostomia, fitting of the denture, and the presence of candida in the mucosa, are less important in this population. Therefore, DS treatments in healthy patients should first focus on sanitization of an existing denture and/or fabrication of a new denture.

A study of factors contributing to denture stomatitis in a north Indian community

Factors like oral and denture hygiene, presence of saliva, age of the denture, and degree of colonization with Candida albicans are to be evaluated as local contributing factors for causing denture stomatitis. 100 patients aged 30 to 70 years were selected for the study. Among these, 70 patients were labeled test group showing signs of stomatitis and 30 patients as control group as they showed no inflammatory signs. Clinical tests included oral and denture hygiene evaluation, salivary measurements, and age of the dentures, and microscopic investigations were done. Results showed no significant differences between the two groups in terms of saliva, oral and denture hygiene habits, and denture age. Test group showed stomatitis in patients who were wearing dentures for 5 to 10 years compared to control group who were wearing dentures for 10 years and above. Denture age was proportional to Candida colonization and not to degree of inflammation. Significant differences were found in Candida colonization of the fitting surface of the denture between stomatitis and control groups. Poor denture hygiene habits are the most prominent contributing factor for denture stomatitis and colonization.

Silver distribution and release from an antimicrobial denture base resin containing silver colloidal nanoparticles

PURPOSE

The aim of this study was to evaluate a denture base resin containing silver colloidal nanoparticles through morphological analysis to check the distribution and dispersion of these particles in the polymer and by testing the silver release in deionized water at different time periods.

MATERIALS AND METHODS

A Lucitone 550 denture resin was used, and silver nanoparticles were synthesized by reduction of silver nitrate with sodium citrate. The acrylic resin was prepared in accordance with the manufacturers' instructions, and silver nanoparticle suspension was added to the acrylic resin monomer in different concentrations (0.05, 0.5, and 5 vol% silver colloidal). Controls devoid of silver nanoparticles were included. The specimens were stored in deionized water at 37°C for 7, 15, 30, 60, and 120 days, and each solution was analyzed using atomic absorption spectroscopy.

RESULTS

Silver was not detected in deionized water regardless of the silver nanoparticles added to the resin and of the storage period. Micrographs showed that with lower concentrations, the distribution of silver nanoparticles was reduced, whereas their dispersion was improved in the polymer. Moreover, after 120 days of storage, nanoparticles were mainly located on the surface of the nanocomposite specimens.

CONCLUSIONS

Incorporation of silver nanoparticles in the acrylic resin was evidenced. Moreover, silver was not detected by the detection limit of the atomic absorption spectrophotometer used in this study, even after 120 days of storage in deionized water. Silver nanoparticles are incorporated in the PMMA denture resin to attain an effective antimicrobial material to help control common infections involving oral mucosal tissues in complete denture wearers.

Effectiveness of photodynamic therapy for the inactivation of Candida spp. on dentures: in vitro study

OBJECTIVE

This in vitro study evaluated the effectiveness of photodynamic therapy (PDT) for the inactivation of different species of Candida on maxillary complete dentures.

BACKGROUND DATA

The treatment of denture stomatitis requires the inactivation of Candida spp. on dentures. PDT has been reported as an effective method for Candida inactivation.

METHODS

Reference strains of C. albicans, C. glabrata, C. tropicalis, C. dubliniensis and C. krusei were tested. Thirty-four dentures were fabricated in a standardized procedure and subjected to ethylene oxide sterilization. The dentures were individually inoculated with one of the strains and incubated at 37°C for 24 h. Dentures submitted to PDT (P+L+) were individually sprayed with 50 mg/L of Photogem(®) (PS) and, after 30 min, illuminated by LED light for 26 min (37.5 J/cm(2)). Additional dentures were treated only with PS (P+L-) or light (P-L+) or neither (P-L-). Samples of serial dilutions were spread on Sabouraud dextrose agar and incubated at 37°C for 48 h. The colonies were counted and the values of log (cfu/mL) were analyzed by Kruskall-Wallis and Dunn tests (p<0.05).

RESULTS

For all species of Candida, PDT resulted in significant reduction (p<0.05) of cfu/mL values from dentures when compared with P-L- (reductions from 1.73 to 3.99 log(10)). Significant differences (p<0.05), but lower reductions, were also observed for P+L- and P-L+when compared with P-L- for some species of Candida.

CONCLUSIONS

PDT was an effective method for reducing Candida spp. on dentures.

Denture stomatitis treated with photodynamic therapy: five cases

OBJECTIVE

Photodynamic therapy (PDT) is an effective method for Candida spp. inactivation in vitro and in vivo, but as yet, no clinical trial has been conducted. This report describes 5 cases of denture stomatitis (DS) treated with PDT.

STUDY DESIGN

Five subjects with clinical and microbiologic diagnosis of DS were submitted to 6 sessions of PDT 3 times a week for 15 days. In each session, patients' dentures and palates were sprayed with 500 mg/L Photogem, and, after 30 minutes of incubation, irradiated by light-emitting diode light source at 455 nm (37.5 and 122 J/cm(2), respectively). Cultures of Candida spp. from dentures and palates and standard photographs of the palates were taken at baseline (day 0), at the end of the treatment (day 15), and at follow-up time intervals (days 30 and 60).

RESULTS

Four patients showed clinical resolution of DS (no inflammation) after PDT sessions, and only 1 subject demonstrated reduction in palatal inflammation. Recurrence of DS was observed in 2 patients during the follow-up period.

CONCLUSIONS

PDT appears to be an alternative treatment for DS.

Silver colloidal nanoparticles: antifungal effect against adhered cells and biofilms of Candida albicans and Candida glabrata

The aim of this study was to evaluate the effect of silver nanoparticles (SN) against Candida albicans and Candida glabrata adhered cells and biofilms. SN (average diameter 5 nm) were synthesized by silver nitrate reduction with sodium citrate and stabilized with ammonia. Minimal inhibitory concentration (MIC) tests were performed for C. albicans (n = 2) and C. glabrata (n = 2) grown in suspension following the Clinical Laboratory Standards Institute microbroth dilution method. SN were applied to adhered cells (2 h) or biofilms (48 h) and after 24 h of contact their effect was assessed by enumeration of colony forming units (CFUs) and quantification of total biomass (by crystal violet staining). The MIC results showed that SN were fungicidal against all strains tested at very low concentrations (0.4-3.3 μg ml(-1)). Furthermore, SN were more effective in reducing biofilm biomass when applied to adhered cells (2 h) than to pre-formed biofilms (48 h), with the exception of C. glabrata ATCC, which in both cases showed a reduction ∼90%. Regarding cell viability, SN were highly effective on adhered C. glabrata and respective biofilms. On C. albicans the effect was not so evident but there was also a reduction in the number of viable biofilm cells. In summary, SN may have the potential to be an effective alternative to conventional antifungal agents for future therapies in Candida-associated denture stomatitis.

Salivary levels of TNF-alpha and IL-6 in patients with denture stomatitis before and after laser phototherapy

OBJECTIVE

The aim of this study was to monitor therapeutic response by determining the level of proinflammatory cytokines TNF-alpha and IL-6 in whole unstimulated saliva in patients with denture stomatitis (DS), before and after laser phototherapy (LPT).

BACKGROUND

DS is an inflammatory condition that occurs in subjects who wear dentures, and it is a common oral mucosal lesion. A potential noninvasive treatment for DS patients is LPT.

MATERIALS AND METHODS

A sample consisting of 40 consecutive subjects was selected on a voluntary basis from patients who presented for the diagnosis and treatment of DS at the Oral Medicine Unit of the Medical Faculty at the University of Rijeka. A clinical examination was performed according to the standard clinical criteria. Lesions described as palatal inflammation were diagnosed as Newton type II denture stomatitis. The patients were randomly assigned to either an experimental group (20 patients receiving real LPT) or a control group (20 patients receiving inactive/placebo laser treatment). In order to determine the salivary levels of TNF-alpha and IL-6, ELISA (Sigma Immunochemicals, St Louis, MO) was performed.

RESULTS

Following treatment with LPT for 4 wk, the levels of TNF-alpha and IL-6 decreased significantly (p < 0.001) and were significantly different from controls (p < 0.001).

CONCLUSION

The results of this study suggest that LPT may be an efficacious choice of therapy.

Interspecies variation in Candida biofilm formation studied using the Calgary biofilm device

An in vitro assay to study multiple Candida biofilms, in parallel, has been carried out using the Calgary biofilm device (CBD). We here report: i) standardization of the CBD for Candida albicans biofilm formation, ii) kinetics of C. albicans biofilm formation, iii) biofilm formation by five Candida species, and iv) effect of dietary carbohydrates on biofilm formation. The biofilm metabolic activity on all CBD pegs was similar (p=0.6693) and C. albicans biofilm formation revealed slow growth up to 36 h and significantly higher growth up to 48 h (p<0.001). Significant differences in total biofilm metabolic activity were seen for glucose, fructose and lactose grown C. albicans compared with sucrose and maltose grown yeasts. Candida krusei developed the largest biofilm mass (p<0.05) relative to C. albicans, C. glabrata, C. dubliniensis and C. tropicalis. Scanning electron microscopy revealed that C. krusei produced a thick multilayered biofilm of pseudohyphal forms embedded within the polymer matrix, whereas C. albicans, C. dubliniensis and C. tropicalis biofilms consisted of clusters or chains of cells with sparse extracellular matrix material. We conclude that CBD is a useful, simple, low cost miniature device for parallel study of Candida biofilms and factors modulating this phenomenon.

Feasibility of using collagen as the base of the antifungal drug, miconazole

The feasibility of using collagen as the base of miconazole was investigated. The addition of 33% collagen to a miconazole solution did not affect the minimal inhibitory concentration (MIC80) of the miconazole solution for Candida albicans. When 1 microg mL(-1) of miconazole in 33% collagen solution was plated on resin discs and dried to yield a thin membrane, the growth of C. albicans on the resin discs was nearly completely inhibited. In addition, we compared the antifungal effect of this collagen solution that contained 1 microg mL(-1) miconazole, with the antifungal effect of miconazole gel that had been diluted with glycerol (the main component of miconazole gel) to yield a final concentration of 1 microg mL(-1) of miconazole; as a result, we found that the collagen solution containing 1 microg mL(-1) miconazole had a stronger antifungal effect. In conclusion, our results demonstrated that it may be feasible to use collagen as the base of miconazole instead of glycerol, and suggest that a collagen-based miconazole solution would have a stronger antifungal effect than commercially available miconazole gel. Collagen-based miconazole solution may be useful for the treatment of Candida-associated denture stomatitis.

Miconazole gel compared withZataria multiflora Boiss. gel in the treatment of denture stomatitis

An open, randomized, controlled study with two parallel treatment groups was done to evaluate the efficacy of a miconazole 2% gel compared with Zataria multiflora 0.1% gel applied four times daily for 2 weeks, in the treatment of Candida-associated denture stomatitis. Twenty four patients were included in the study. The efficacy variables were the colony count of Candida from the palatal mucosa and the denture surface and the erythema surface of the palatal mucosa on days 0, 7, 14, 21 and 28 after commencement of therapy. Twelve patients received miconazole gel and twelve Z. multiflora gel. The erythema surface was significantly reduced by both gels. No significant difference was seen between the two groups (p < 0.05). There was a significant reduction in the colony count of the palatal mucosa in both groups (except on days 21 and 28 in the Zataria group p = 0.07 and 0.08). Miconazole treatment reduced the number of denture colonies more efficiently than Z. multiflora except for day 21 when the efficacy of both groups was similar (p = 0.17). The results indicate that Z. multiflora gel reduced the surface erythema of the palate more efficiently than miconazole gel but did not reduce the colony count of the denture surface as efficiently as miconazole.

Intra-oral findings and general health conditions among institutionalized and non-institutionalized elderly in Greece

BACKGROUND

The aim of the study was to record the findings from intra-oral examination and the general health conditions encountered in a group of Greek individuals 65 years of age or older.

PATIENTS AND METHODS

The study subjects were derived from the elderly attending 12 randomly selected community centres located in Athens and neighbouring municipalities, consisting the non-institutionalized study group and from the elderly living in three ecclesiastical nursing homes, consisting the institutionalized study group. The research data comprised information from the subjects' interviews, self-defined health status, medical records and intra-oral examination on the following variables: sex, age, general health condition, dentate or not, use of dentures and oral conditions. Fisher's exact two-sided test was used for statistical analysis.

RESULTS

Overall, 316 patients were examined; 120 male (38%), 196 female (62%), mean age 78 years (range: 65-99). Of those, 150 were non-institutionalized (59 male, 91 female) and 166 institutionalized (61 male and 105 female). The vast majority (90%) of the patients had at least one general health problem, for which they were taking daily medication. Twenty-three different medical conditions were recorded. The most frequent medical problems were hypertension (56%), cardiovascular problems (41%), depression/anxiety (39%), arthritis (18.5%) and visual problems (16%). The vast majority of the study patients (79%) were edentulous, while 33% were not wearing or using their dentures. Almost half of them (47%) had at least one oral condition. Twenty-seven different oral conditions were recorded. The most frequent oral findings were denture-induced stomatitis (17.2%), dry mouth (14.6%), atrophy of tongue papillae (10.5%), fissured tongue (9.8%) and haemangioma (6.8%). No cases of malignant lesions were observed.

CONCLUSIONS

The present study confirms that in this particular age group, general health problems are frequent, variable, coexistent, necessitating the daily administration of multiple medications, while oral examination by a specialist is an essential part of the multidisciplinary medical care in this group of individuals.

Fluconazole and/or hexetidine for management of oral candidiasis associated with denture-induced stomatitis

OBJECTIVE

The aim of the present study was to compare the influence of fluconazole capsules and/or hexetidine mouthrinses for the management of oral candidiasis associated with denture stomatitis. DESIGN RELEVANT: Sixty-one patients (ages 43-76 years, mean: 61) admitted to the Department of Oral Surgery and Medicine and diagnosed as suffering from oral candidiasis associated with denture stomatitis by microbiological examination were involved.

MATERIALS AND METHODS

Patients in group 1 (n = 21) were given only fluconazole capsules (Zolax 50 mg once a day), those in group 2 (n = 18) were given only hexetidine mouthrinses (Heksoral 0.1%, twice daily), whereas those in group 3 (n = 22) were given both fluconazole capsules and hexetidine mouthrinses for 14 days. The yeast colonies of the saliva samples were counted and calculated as the number of colony forming units per milliliter. The presence of yeasts in the lesion and denture samples were evaluated as present/absent according to their growth on cultures. Candida albicans was identified by means of germ tube analysis.

RESULTS

Patients in groups 1, 2 and 3 had a statistically significant decrease in the amount of C. albicans in saliva, lesions and dentures after treatment, when compared with pretreatment results (P < 0.05). Candida albicans counts in saliva, lesion and denture after treatment detected no statistically significant difference when the three groups were compared.

CONCLUSION

Of the three study groups, group 2, where hexetidine was the only medication prescribed, was found to be superior on account of fewer potential complications. We conclude that dentists should employ a more conservative intervention with oral mouthrinses rather than risk adverse effects and complications of systemic drugs for the management of oral candidiasis.

Improving the oral health of older people: the approach of the WHO Global Oral Health Programme

The proportion of older people continues to grow worldwide, especially in developing countries. Non-communicable diseases are fast becoming the leading causes of disability and mortality, and in coming decades health and social policy-makers will face tremendous challenges posed by the rapidly changing burden of chronic diseases in old age. Chronic disease and most oral diseases share common risk factors. Globally, poor oral health amongst older people has been particularly evident in high levels of tooth loss, dental caries experience, and the prevalence rates of periodontal disease, xerostomia and oral precancer/cancer. The negative impact of poor oral conditions on the quality of life of older adults is an important public health issue, which must be addressed by policy-makers. The means for strengthening oral health programme implementation are available; the major challenge is therefore to translate knowledge into action programmes for the oral health of older people. The World Health Organization recommends that countries adopt certain strategies for improving the oral health of the elderly. National health authorities should develop policies and measurable goals and targets for oral health. National public health programmes should incorporate oral health promotion and disease prevention based on the common risk factors approach. Control of oral disease and illness in older adults should be strengthened through organization of affordable oral health services, which meet their needs. The needs for care are highest among disadvantaged, vulnerable groups in both developed and developing countries. In developing countries the challenges to provision of primary oral health care are particularly high because of a shortage of dental manpower. In developed countries reorientation of oral health services towards prevention should consider oral care needs of older people. Education and continuous training must ensure that oral health care providers have skills in and a profound understanding of the biomedical and psychosocial aspects of care for older people. Research for better oral health should not just focus on the biomedical and clinical aspects of oral health care; public health research needs to be strengthened particularly in developing countries. Operational research and efforts to translate science into practice are to be encouraged. WHO supports national capacity building in the oral health of older people through intercountry and interregional exchange of experiences.

Denture-related oral mucosal lesions in a Brazilian school of dentistry

The purpose of this study was to survey the frequency of denture-related lesions of the oral mucosa in patients treated at a Brazilian dental school and to determine if the oral lesions were related to age, sex, denture type, length of denture use and denture cleaning methods. The denture-related lesions observed in this study were chronic atrophic candidiasis, chronic hyperplastic candidiasis, denture-induced fibrous inflammatory hyperplasia (FIH), traumatic ulcer, angular cheilitis and flabby ridge. The most frequent lesion, chronic atrophic candidiasis, occurred more frequently in females, in complete maxillary denture wearers, with denture use for 16-20 years. The most common method of cleaning dentures was a toothbrush and toothpaste. These results suggest that dentures can cause a wide range of lesions of the oral mucosa, that could be prevented with follow-up to evaluate dentures and provide instructions on how to maintain oral tissues healthy.

Candida-associated denture stomatitis

Candida-associated denture stomatitis was demonstrated by its cultivation in 171 out of 240 patients examined with partial or total dentures. After taking smears from lesions of the oral mucosa (tongue, cheeks, palate) and the contiguous denture surface by cotton wool swabs and inoculating them onto Sabouraud glucose agar and CHROMagar Candida, individual yeast species were identified by a germ tube, filamentous, and assimilation tests employing the commercial kit AuxaColor. Seven Candida species were identified in smears from the oral mucosa lesions and the contiguous denture surface: C. albicans (95 patients), C. tropicalis (26), C. parapsilosis (20), C. krusei (14), C. guilliermondii (12), C. lusitaniae (1) and C. freyschusii (1). Diabetes mellitus, neoplastic diseases, chemotherapy, radiotherapy, and broad-spectrum antibiotic therapy were identified as some of the large number of factors predisposing patients to stomatitis prothetica.

Antifungal and antiviral chemotherapy

Fungal and viral infections are difficult to treat, since fungal infections commonly rebound after suppression by the antifungal agent and current antiviral drugs are only virustatic, allowing the virus to reassert its pathogenicity if not eliminated by the host defenses. In addition, fungal infections commonly are associated with significant biofilms, retarding drug penetration, and the fluid nature of the oral cavity does not promote drug-fungus contact for long periods of time. Both mycotic and viral pathogens are developing sophisticated methods to elude the toxic effects of drugs intended to eliminate their existence. The drug therapy of oral fungal and viral infections is therefore limited but occasionally successful (more with fungal than viral infections) and is often relegated to palliative care. The specter of drug resistance and its promotion by prolonged, repetitive and frivolous use must always be foremost in the clinician's mind.