Evaluation of surface roughness, wettability and adhesion of multispecies biofilm on 3D-printed resins for the base and teeth of complete dentures.

OBJECTIVE: This study evaluated the surface roughness, wettability and adhesion of multispecies biofilms (Candida albicans, Staphylococcus aureus and Streptococcus mutans) on 3D-printed resins for complete denture bases and teeth compared to conventional resins (heat-polymerized acrylic resin; artificial pre-fabricated teeth). METHODOLOGY: Circular specimens (n=39; 6.0 mm Ø × 2.0 mm) of each group were subjected to roughness (n=30), wettability (n=30) and biofilm adhesion (n=9) tests. Three roughness measurements were taken by laser confocal microscopy and a mean value was calculated. Wettability was evaluated by the contact angle of sessile drop method, considering the mean of the three evaluations per specimen. In parallel, microorganism adhesion to resin surfaces was evaluated using a multispecies biofilm model. Microbial load was evaluated by determining the number of Colony Forming Units (CFU/mL) and by scanning electron microscopy (SEM). Data were subjected to the Wald test in a generalized linear model with multiple comparisons and Bonferroni adjustment, as well as two-way ANOVA (α=5%). RESULTS: The roughness of the conventional base resin (0.01±0.04) was lower than that of the conventional tooth (0.14±0.04) (p=0.023) and 3D-printed base (0.18±0.08) (p<0.001). For wettability, conventional resin (84.20±5.57) showed a higher contact angle than the 3D-printed resin (60.58±6.18) (p<0.001). Higher microbial loads of S. mutans (p=0.023) and S. aureus (p=0.010) were observed on the surface of the conventional resin (S. mutans: 5.48±1.55; S. aureus: 7.01±0.57) compared to the 3D-printed resin (S. mutans: 4.11±1.96; S. aureus: 6.42±0.78). The adhesion of C. albicans was not affected by surface characteristics. The conventional base resin showed less roughness than the conventional dental resin and the printed base resin. CONCLUSION: The 3D-printed resins for base and tooth showed less hydrophobicity and less adhesion of S. mutans and S. aureus than conventional resins.

Anti-biofilm effectiveness of protocols for cleaning complete dentures in hospitalized patients: a randomized controlled trial.

BACKGROUND: Denture biofilm acts as a potential reservoir for respiratory pathogens, considerably increasing the risk of lung infections, specifically aspiration pneumonia, mainly 48h after hospital admission. The establishment of a straightforward, affordable, and applicable hygiene protocol in a hospital environment for the effective control of denture biofilm can be particularly useful to prevent respiratory infections or reduce the course of established lung disease. OBJECTIVES: To evaluate the anti-biofilm effectiveness of denture cleaning protocols in hospitalized patients. METHODOLOGY: The maxillary complete dentures (MCDs) of 340 hospitalized participants were randomly cleaned once using one of the following 17 protocols (n=20): brushing with distilled water, toothpaste, or neutral liquid soap (controls); immersion in chemical solutions (1% sodium hypochlorite, alkaline peroxide, 0.12% or 2% chlorhexidine digluconate), or microwave irradiation (650 W for 3 min) combined or not with brushing. Before and after the application of the protocols, the biofilm of the intaglio surface of the MCDs was evaluated using two methods: denture biofilm coverage area (%) and microbiological quantitative cultures on blood agar and Sabouraud Dextrose Agar (CFU/mL). Data were subjected to the Wilcoxon and Kruskal-Wallis tests (α=0.05). RESULTS: All 17 protocols significantly reduced the percentage area of denture biofilm and microbial and fungal load (P<0.05). The highest percentage reductions in the area of denture biofilm were observed for 1% hypochlorite solution with or without brushing and for 2% chlorhexidine solution and microwave irradiation only in association with brushing (P<0.05). The greatest reductions in microbial and fungal load were found for the groups that used solutions of 2% chlorhexidine and 1% hypochlorite and microwave irradiation, regardless of the association with brushing (P<0.05). CONCLUSIONS: A single immersion for 10 min in 1% sodium hypochlorite, even in the absence of brushing, proved to be a straightforward, rapid, low-cost, and effective protocol for cleaning the dentures of hospitalized patients.

BACTERIAL CONTAMINATION AND METHODS OF DECONTAMINATION OF BASES COMPLETE REMOVABLE PROSTHESES DURING THE APPLICATION OF ADHESIVE MATERIALS.

It turned out that the permanent microbiota of surfaces of acrylic bases of complete removable plastic dentures (CRPD) characterized by several features: the presence of aerobic (7) and anaerobic (10) species. Qualitative and quantitative compositions of microbiocenosis in orthopedic treatment stages have been changed. The revealed patterns require further study in the context of the improvement of decolonization of acrylic bases in the stages of orthopedic treatment by CRPD. Deactivation of acrylic bases of CRPD significantly affects the species composition of microbiota, reduces the quantitative parameters of bacterial contamination. The purpose of our work was determination of bacterial contamination of acrylic bases of CRPD in stages of their clinical exploitation and study of changes in the quantitative composition of the acrylic bases microbiota of CRPD under different decontamination modes. Smears from the inner surface of the acrylic base were stained with Gram and microscopic and seeded on blood agar, Endo agar, Chistovich, Saburo. Species belonging to the micro-organisms were identified by the LAHEMA test system and were determined in colonies forming units (CFUs). These data indicate accumulation under the acrylic base in the course of clinical operation of certain types of microbiota, which requires improvement of the methods of their decontamination. We studied the change in the quantitative and specific composition of the microbiota (bacterial contamination) of acrylic bases CRPD under different modes ("A", "B"). Patients in group "A" used the Sideex solution - a two-component system consisting of a liquid component (glutaraldehyde solution) and a powdery activator, mixed before use to obtain a working activated solution. The liquid component is a clear, colorless solution with a specific odor, which is a 2.2-2.7% aqueous solution of glutaraldehyde, which is an active ingredient, pH=3.0 - 4.5. Powdery activator is a pale-yellow powder containing alkaline components, a corrosion inhibitor, and a dye. The activated working solution is a fluorescent green solution with a specific odor and containing 2.2-2.7% glutaraldehyde; pH=8.2-9.2. (Great Britain). Preparation of the activated solution: a powder-activator is added to the container containing the liquid component (avoiding losses). Cleaning is carried out by the method of full immersion of the prosthesis in solution, with a thickness of the drug over it not less than 1 cm. The dentures are soused in solution for 15 minutes, then thorough washing in the same solution for 1-3 minutes. Sideex activated solution is used for sterilization and disinfection of metal, glass, polymeric (plastic, rubber, etc.) medical products. The dentures of patients from group "B" are decontaminated with 0.2% solution of chlorhexidine bigluconate. The dentures were placed in the solution overnight for 14 days, changing the solution every two days. The decontamination of acrylic bases of CRPD should be considered mode "B" as more effective because of the significant decrease in the species composition of the microbiota (the qualitative indicator of reduction of microbial contamination was 72.0%). It is substantiated that decontamination of acrylic bases of CRPD with mode "A" has a small effect on the species composition of the microbiota, although it significantly (p<0.05) reduces quantitative indicators of microbial contamination. Regarding "B" mode, the species composition of aerobes from 31 lgCFU/ml to 8.7 lgCFU/ml and anaerobes from 42.7 lgCFU/ml to 14.6 lgCFU/ml was considered more effective.

Antibacterial and antifungal impacts of combined silver, zinc oxide, and chitosan nanoparticles within tissue conditioners of complete dentures in vitro.

BACKGROUND: Tissue conditioners are suitable places for colonization of microorganisms. A combination of tissue conditioners with antibacterial and antifungal materials inhibits the growth of microorganisms. AIMS: Here, we aimed to investigate the antibacterial and antifungal effects of silver (Ag), zinc oxide (ZnO), and chitosan nanoparticles on tissue conditioners in complete dentures. METHODS: The growth of four microorganisms in six different concentrations of Ag, ZnO, and chitosan nanoparticles was investigated after 24 and 48 h. Nanoparticles were synthesized using optical sequestration and approved by scanning electron microscope, x-ray diffraction, and infrared (FT-IR) methods. Nanoparticles were combined at 0.5, 0.25, and 0.25 ratios (chitosan, Ag, and ZnO, respectively) with 0.625, 1.25, 2.5, 5, 10, and 20 mass percentages. Tissue conditioners with nanoparticles were entered to test tubes containing microorganisms, and the growth rate was measured using the turbidity method by spectrophotometer after 24 and 48 h of incubation at 37 °C. RESULTS: Growth inhibition of Candida albicans occurred at 2.5% concentration. However, the growth inhibition of Streptococcus mutans, Enterococcus faecalis, and Pseudomonas aeruginosa occurred at 5% after both 24 and 48 h. Also, the optimum nanoparticle concentration for Candida albicans was found to be 1.25% for both timings. On the other hand, the optimum nanoparticle concentration for Streptococcus mutans, Enterococcus faecalis, and Pseudomonas aeruginosa was 2.5% for both time scales. CONCLUSIONS: The combination of Ag, ZnO, and chitosan nanoparticles inhibited the growth of fungi and bacteria in tissue conditioners. These nanoparticles inhibited the growth of fungi more effectively than bacteria.

Efficacy of removing Candida albicans from orthodontic acrylic bases: an in vitro study.

BACKGROUND: This study evaluated the efficacy of four methods in removing Candida albicans from the acrylic base material used to fabricate removable orthodontic appliances. METHODS: Heat-processed bars of orthodontic acrylic were incubated in a suspension of C. albicans for 2 h at 37 °C. Samples were allocated into five groups (five bars per group) according to the cleaning method: (1) manual brushing using a toothbrush; (2) soaking in a commercial denture cleaning solution; (3) soaking in a commercial mouthwash solution; (4) using an ultrasonic cleaner; and (5) soaking in distilled water as a negative control. Yeast remaining attached to the bars after cleaning were removed by vortexing in growth medium and plated on Sabouraud dextrose agar. The reduction in yeast colony count after cleaning was calculated and expressed as the number of colony forming units per acrylic bar (CFU/bar). The experiment was carried out three times. RESULTS: All four cleaning methods resulted in a significant decrease in viable yeast cells associated with the acrylic bars compared to the control group. The mean percentage reduction in viable yeast cells affected by the cleaning methods was: brushing 89.9%; chlorhexidine 95.8%; ultrasonic cleaning 99.9%; and denture tablet 100%. CONCLUSIONS: All four methods evaluated in this study were effective, to some extent, in removing C. albicans from orthodontic acrylic samples. The most effective, and readily available, cleaning method was the use of commercial denture sterilizing tablets.

Chemical hygiene protocols for complete dentures: A crossover randomized clinical trial.

STATEMENT OF PROBLEM: Clinical evidence on the best chemical protocol for the disinfection and removal of biofilm from complete dentures is lacking. PURPOSE: The purpose of this crossover randomized clinical trial was to assess the effectiveness of various chemical hygiene clinical protocols in reducing the microbial viability of biofilm formed on complete dentures. MATERIAL AND METHODS: In this triple-blind (participants, dentist, and outcome evaluator) study, complete denture wearers without candidiasis were randomly divided into 4 groups (n=40) according to the chemical hygiene protocol: water (placebo), 0.5% sodium hypochlorite solution, 0.12% chlorhexidine gluconate solution, and 5% sodium bicarbonate solution. The biofilm formed on the palate intaglio and denture teeth was collected and assessed in each experimental phase for quantitative microbial viability at the seventh and 14th day after using the chemical protocol. RESULTS: Two participants were lost. Data were analyzed by MANOVA and Tukey HSD tests. Soaking dentures was not effective in decreasing Candida albicans, C. non-albicans, and lactobacillus counts. The use of sodium hypochlorite and chlorhexidine decreased total microorganisms and Streptococcus mutans counts for both palate and teeth compared with water and sodium bicarbonate. The intaglio of the dentures always presented higher microbial counts than did the denture teeth. CONCLUSIONS: The use of sodium hypochlorite and chlorhexidine and mechanical cleansing with a toothbrush decreased microbial viability in healthy complete denture wearers.

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.

Effect of opposing implant prostheses on periodontal pathogens in dentures: A pilot study.

STATEMENT OF PROBLEM: An understanding of the presence of periodontal pathogens in denture plaque is important for the treatment of patients with edentulism. However, current data are limited and inconclusive. PURPOSE: The purpose of this pilot clinical study was to investigate whether opposing implant prostheses affect the presence of periodontal pathogens in maxillary complete dentures. MATERIAL AND METHODS: Twenty adult participants were enrolled in the study. The complete denture (CD/CD) group included 7 participants with complete maxillary and mandibular dentures. The implant overdenture (CD/IOD) group included 13 participants with maxillary complete-denture opposing implant overdentures. Plaque from maxillary complete dentures was collected and genomic DNA was extracted. Periodontal pathogens included Aggregatibacter actinomycetemcomitans, Eikenella corrodens, Fusobacterium nucleatum, Porphyromonas gingivalis, Prevotella intermedia, and Tannerella forsythia, and the total bacteria numbers were determined by real-time polymerase chain reaction (PCR) assay. A comparison of the detection rates and levels of periodontal pathogens between the 2 groups was performed using the chi-square test and the Mann-Whitney U test, respectively. Associations among these pathogens were determined using the Spearman rank correlation coefficient. RESULTS: No significant differences (P>.05) in detection rates were found between the CD/CD and CD/IOD groups for A actinomycetemcomitans (100% versus 100%, respectively), E corrodens (71.4% versus 76.9%, respectively), F nucleatum (100% versus 69.2%, respectively), Porphyromonas gingivalis (100% versus 100%, respectively), P intermedia (57.1% versus 84.6%, respectively), and T forsythia (100% versus 92.3%, respectively). No significant differences in periodontal pathogen levels (P>.05) were observed between the 2 groups. Significant positive associations were observed (P<.05) between F nucleatum and P intermedia, F nucleatum and T forsythia, F nucleatum and P gingivalis, P intermedia and P gingivalis, P intermedia and A actinomycetemcomitans, T forsythia and P gingivalis, T forsythia and A actinomycetemcomitans, and P gingivalis and A actinomycetemcomitans. CONCLUSIONS: Six investigated periodontal pathogens were widely present in denture plaque. Wearing opposing implant overdentures did not affect the presence and levels of the periodontal pathogens.

Does the Prevalence of Periodontal Pathogens Change in Elderly Edentulous Patients after Complete Denture Treatment?

PURPOSE: To determine if wearing complete dentures can cause changes in prevalence of some of the most common periodontal pathogens in elderly edentulous patients. The need for understanding the composition of oral microflora in edentulous patients has been recognized by some authors, but no studies have dealt with the changes that occur in periodontal pathogens' prevalence as a result of complete dentures. MATERIALS AND METHODS: A total of 30 edentulous elderly (average age 71) patients participated in the study. Complete dentures were fabricated for each patient, and the residual alveolar ridges were swabbed before denture insertion. After a period of 6 months swabs were taken again. Identification of P. intermedia, A. actinomycetemcomitans, P. gingivalis, T. forsythia, T. denticola, and F. nucleatum was done by the polymerase chain reaction (PCR) method and primers specific for each microorganism. RESULTS: A noticeable increase in the presence of periodontal pathogens was observed after 6 months of denture wearing; targeted bacteria were identified in 17 pre-insertion samples compared to 28 post-insertion samples. The McNemar test was used to compare the prevalence of periodontal pathogenic bacteria before and after dental treatment. p<0.05 indicated statistical significance. Three microorganisms showed a statistically significant difference between the first and second swabbing-A. actinomycetemcomitans (6.7% vs. 40.0%, p = 0.006), P. intermedia (30.0% vs. 73.3%, p = 0.004), and T. forsythia (6.7% vs. 30.0%, p = 0.004). There was also an increase in bacteria co-associations 6 months post-insertion of complete dentures. CONCLUSIONS: The results of the present study suggested that wearing complete dentures caused a considerable increase of periodontopathic bacteria prevalence in elderly patients. Better understanding of oral microflora and the impact dental treatment has on bacterial colonies is important in modern dentistry.

Status of Removable Dentures and Relationship with Oral Candida-Associated Factors in a Geriatric Population in Catalonia.

PURPOSE: Colonization by Candida is related to wearing a denture. How denture type, status, and maintenance play a role in determining Candida colonization remains unknown. This work evaluated removable denture status in an elderly population and explored the association between denture-related factors and oral Candida colonization as determined by systemic and local factors. MATERIALS AND METHODS: Socio-demographic, general health, and behavioral data and oral factors were registered by means of a questionnaire. Oral, dental, and denture-related factors were assessed by clinical examination, and yeasts were isolated from oral and denture specimens. Multiple logistic regression analysis was used to explore the relative relevance of risk factors. RESULTS: Overall, 52.4% of subjects used complete dentures in both lower and upper arches, and 90% of the prostheses were in good condition. Denture plaque index was high in most cases, and 75% of subjects had yeasts in their oral cavities. Oral Candida colonization was significantly associated with low saliva pH, sugar consumption, and the fault of a denture component; however, only sugar consumption was found to be an independent factor related with oral Candida colonization, showing an odds ratio of 3.04 in a multiple logistic regression model. CONCLUSIONS: Elderly people in this study used a complete denture in good condition, with a median age of 15 years. Daily or weekly sugar consumption was found to be highly associated with oral colonization by Candida.

Correlation between age and gender in Candida species infections of complete denture wearers: a retrospective analysis.

AIM: Denture-related stomatitis is a disorder that often affects denture wearers. The purpose of this study was to evaluate the intensity, genera, and frequency of yeasts in the oral cavity of complete denture wearers in terms of subject gender and age. MATERIALS AND METHODS: Nine hundred twenty patients (307 males and 613 females) with complete upper dentures were selected for the study and divided into four age groups: ≤50 years, 51-60, 61-70, and >70 years. Yeast samples were taken as a smear from the palate. The data were collected from January 15, 2007 to January 15, 2012. RESULTS: The distribution of the number of yeast colonies by gender was statistically significant (P=0.02). Across all subjects, there was a statistically significant relationship between the intensity of yeast growth and the gender (P=0.01). In every age group, the number of infection-free individuals was greater among males than females. Intermediate, intense, and abundant growth of yeast occurred most frequently in the youngest group of females. CONCLUSION: The genera of Candida species and the frequency of yeast infection in denture wearers appear to be influenced by both age and gender. The complete denture wearers ≤50 years of age appeared to have the greatest proclivity to oral Candida infections.

Identificação de micro-organismos do gêneroCandida na saliva de usuários de prótese total convencional e prótese total fixa sobre implantes / Identification of Candida genus microorganisms in saliva of conventional denture and fixed dentures on implants users

Candida albicans é a espécie mais encontrada em relação às demais em pacientes usuários de próteses dentárias acrílicas. Colonização por espécies do gêneroCandida comumente associam-se à estomatite protética. O objetivo desse estudo foi isolar, quantificar e identificar espécies do gêneroCandidaem amostras de saliva em usuários de prótese total convencional e prótese total fixa sobre implantes. Foram coletados 20 ml de saliva não estimulada de indivíduos voluntários sistemicamente saudáveis. 100 µ de cada amostra de saliva foram semeados separadamente no meio Agar Sabouraud dextrose cloranfenicol (Difco) e no Chromagar. Após o período de incubação, foi feita a contagem das Unidades Formadoras de Colônias (UFC). As colônias foram transferidas para tubos contendo caldo Sabouraud Dextrose, para posterior identificação. No grupo de usuários de prótese total convencional, foram encontradas duas espécies: Candida albicans (50%) e Candida tropicalis (50%), no grupo de usuários de prótese fixa sobre implantes foram encontradas as espécies C. tropicalis (70%) e C. krusei (30%). Conclui-se que: micro-organismos do gênero Candida estão presentes na saliva de usuários de prótese total convencional e fixa sobre implantes (AU).

Candida albicans is the species most commonly found in relation to other species in patients users of acrylic denture. Colonization by species of the genus Candida are commonly associated with denture stomatitis. The aim of this study was to isolate, quantify and identify species of the genus Candida in saliva samples in conventional denture and fixed dentures on implants users. It was collected 20 ml of unstimulated saliva of systemically healthy volunteers. 100 µ of each saliva sample were seeded separately in the middle Sabouraud Agar chloramphenicol dextrose (Difco) and Chromagar. After the incubation period the counting of Colony Forming Units (CFU) was performed. The colonies were transferred to tubes containing Sabouraud Dextrose broth, for later identification. In the conventional denture user group two species were found: Candida albicans (50%) and Candida tropicalis (50%), in the fixed dentures on implants user group were found the C. tropicalis species (70%) and C. krusei (30%). In conclusion: microorganisms of Candida genus are present in the saliva of conventional and fixed denture on implants users (AU).

Antimicrobial activity of complete denture cleanser solutions based on sodium hypochlorite and Ricinus communis: a randomized clinical study

ABSTRACT To preserve oral health and to maintain the prosthetic devices, it is important not only to improve the properties of commonly known hygiene products, but also to investigate new materials with antimicrobial action. Objectives This study evaluated the antimicrobial activity of sodium hypochlorite (0.25% and 0.50%) and 10% Ricinus communis’ solutions against specific microorganisms. Material and Methods Sixty four maxillary complete denture wearers were instructed to brush their dentures three times a day and to soak them (20 min/day) in the solutions: SH1: 0.25% sodium hypochlorite; SH2: 0.5% sodium hypochlorite; RC: 10% R. communis oil; and C: 0.85% saline (control). The solutions were used for 7 days in a randomized sequence. Following each period of use, there was a 1-week washout period. Antimicrobial activity was determined by Colony Forming Units (CFU) counts of Streptococcus mutans, Candida spp., and gram-negative microorganisms. For collecting biofilm, the internal surface of maxillary dentures was brushed with saline solution, and biofilm suspension obtained. After dilutions (100 - 10-3), aliquots were seeded in Mitis salivarius, CHROMagar Candida®, and MacConkey agar for detecting S. mutans, Candida spp., or gram-negative microorganisms, respectively. After incubation, colonies were counted, and CFU/mL values were calculated. Then, transformation - log10 (CFU+1) - data were analyzed using the Friedman test (α=0.05). Results showed significant differences between the solutions (p<0.001). Results All three solutions showed antimicrobial activity against S. mutans. Against Candida spp., RC and SH1 solutions showed similar effect while SH2 showed superior activity. SH1 and SH2 solutions showed antimicrobial action against gram-negative microorganisms. The Candida species most frequently isolated was C. albicans, followed by C. tropicalis and C. glabrata. Conclusions The 0.5% sodium hypochlorite solution was the most effective and might be used to control denture biofilm. C. albicans was the most frequently isolated Candida sp.

Evaluation of sodium hypochlorite as a denture cleanser: a clinical study.

OBJECTIVES: To evaluate the effect of sodium hypochlorite (NaOCl) on biofilms, colour stability (ΔE) and surface roughness (Ra) of complete dentures and patient acceptability. BACKGROUND: Denture cleansers should be able to reduce the accumulation of biofilms without affecting the acrylic resin properties. Patient satisfaction is important to maintaining their daily use. MATERIALS AND METHODS: Fifteen participants were instructed to keep their dentures immersed daily in a 0.5% NaOCl solution for 3 min over 90 days. Swabs were taken from dentures and inoculated on CHROMagar and blood agar. The number of colony-forming units (cfu) was counted after a 48-h incubation period. ΔE was assessed using the CIE L*a*b* system. Ra was measured using a profilometer. Patient acceptability was checked based on their degree of satisfaction. Cell counts, ΔE and Ra were analysed using anova, Friedman's and Kruskal-Wallis tests, respectively (α = 0.05). RESULTS: A significant reduction in the total number of microorganisms (p = 0.001) and Candida spp. was noticed. No significant differences were found for ΔE (p = 0.68) and for Ra (p = 0.47). The level of the patient satisfaction increased throughout the follow-up period. CONCLUSION: The 0.5% NaOCl solution was effective in reducing microorganisms without significant changes in colour or roughness of denture resin. The participants reported satisfaction with the cleaning results.

Dry mouth and denture plaque microflora in complete denture and palatal obturator prosthesis wearers.

OBJECTIVE AND BACKGROUND: The purpose of this study was to investigate the association of dry mouth with denture plaque microflora in patients with palatal obturator prostheses from the viewpoint of infection control. METHODS: Thirty palatal obturator prosthesis wearers were compared with 30 healthy maxillary complete denture wearers. Dry mouth was examined using a moisture-checking device and was diagnosed by the measured moisture levels. Denture plaque was collected by rubbing the mucosal surface of the denture with a swab; collected microorganisms were cultured and identified using culture-dependent methods. The number of colonising microorganisms and prevalence of microorganisms were examined according to the type of prostheses and presence of dry mouth using nonparametric tests and frequency analysis (α = 0.05). RESULTS: The prevalence of Candida spp. and Staphylococcus spp. in palatal obturator prostheses was significantly higher than that in complete dentures. In palatal obturator prostheses, the total number of colonising microorganisms showed no significant differences between the groups with and without dry mouth on each side of the prostheses. However, the prevalence of Candida spp. and Staphylococcus spp. in the group with dry mouth was significantly higher than that in the group without dry mouth. The number of microorganisms and moisture levels of palatal obturator prosthesis wearers showed a significantly negative correlation with Candida spp. and Staphylococcus spp., but a positive correlation with Neisseria spp. CONCLUSION: It was concluded that palatal obturator prosthesis wearers with a dry mouth have greater colonisation by Candida spp. and Staphylococcus spp. than do complete denture wearers.

Effect of green tea extract and mouthwash without alcohol on Candida albicans biofilm on acrylic resin.

OBJECTIVE: To evaluate the effect of aqueous extract of green tea and the oral antiseptic without alcohol, on Candida albicans biofilm formation to heat-curing acrylic resin plates. BACKGROUND: Candida is associated with oral candidiasis in poorly cleaned dentures. MATERIAL AND METHODS: Standardised specimens of heat-cured (Conv; n = 30) or microwave-cured acrylic resin (Mw; n = 30) were obtained and divided into six groups (n = 10): G1 = Conv resin and green tea aqueous extract, G2 = Conv resin and mouthwash, G3 = control of Conv resin, G4 = Mw resin and green tea aqueous extract, G5 = Mw resin and mouthwash and G6 = control of Mw-cured resin. The specimens were contaminated with 10 ml of Sabouraud dextrose broth inoculated with 0.1 ml of standard suspension containing 1 × 10(6) cells/ml of C. albicans and incubated for 24 h at 37°C. After this period, they were immersed in the aqueous extract or in mouthwash for 15 min. The control groups were treated with sterile distilled water. Aliquots of 0.1 ml were plated on Sabouraud dextrose agar and incubated at 37°C for 24 h. The numbers of colony-forming units per test specimen (CFU/TS) were calculated, and the results statistically analysed by two-way anova and Tukey's tests (5%). RESULTS: Statistically significant difference was observed for the aqueous extract groups (G1; 33.65%) and mouthwash (G2; 17.06%), when compared to control (G3; 100%), for Conv resin. For the Mw resin, there was significant difference between mouthwash (G5; 43.16%) and control (G6; 100%). CONCLUSION: The aqueous extract of green tea and mouthwash led to a reduction in the number of viable fungal cells in biofilm formed on acrylic resin.

Antimicrobial activity of complete denture cleanser solutions based on sodium hypochlorite and Ricinus communis - a randomized clinical study.

UNLABELLED: To preserve oral health and to maintain the prosthetic devices, it is important not only to improve the properties of commonly known hygiene products, but also to investigate new materials with antimicrobial action. Objectives This study evaluated the antimicrobial activity of sodium hypochlorite (0.25% and 0.50%) and 10% Ricinus communis' solutions against specific microorganisms. MATERIAL AND METHODS: Sixty four maxillary complete denture wearers were instructed to brush their dentures three times a day and to soak them (20 min/day) in the solutions: SH1: 0.25% sodium hypochlorite; SH2: 0.5% sodium hypochlorite; RC: 10% R. communis oil; and C: 0.85% saline (control). The solutions were used for 7 days in a randomized sequence. Following each period of use, there was a 1-week washout period. Antimicrobial activity was determined by Colony Forming Units (CFU) counts of Streptococcus mutans, Candida spp., and gram-negative microorganisms. For collecting biofilm, the internal surface of maxillary dentures was brushed with saline solution, and biofilm suspension obtained. After dilutions (100 - 10-3), aliquots were seeded in Mitis salivarius, CHROMagar Candida, and MacConkey agar for detecting S. mutans, Candida spp., or gram-negative microorganisms, respectively. After incubation, colonies were counted, and CFU/mL values were calculated. Then, transformation - log10 (CFU+1) - data were analyzed using the Friedman test (α=0.05). Results showed significant differences between the solutions (p<0.001). RESULTS: All three solutions showed antimicrobial activity against S. mutans. Against Candida spp., RC and SH1 solutions showed similar effect while SH2 showed superior activity. SH1 and SH2 solutions showed antimicrobial action against gram-negative microorganisms. The Candida species most frequently isolated was C. albicans, followed by C. tropicalis and C. glabrata. CONCLUSIONS: The 0.5% sodium hypochlorite solution was the most effective and might be used to control denture biofilm. C. albicans was the most frequently isolated Candida sp.

Assessment of Candida species colonization and denture-related stomatitis in bar- and locator-retained overdentures.

The aim of this study was to assess the prevalence of denture-related stomatitis (DRS) in different attachment-retained overdenture wearers and its association with particular colonizing Candida species. Thirty-seven edentulous patients with implant-supported maxillary or mandibular overdentures were enrolled. A full clinical history was obtained, including details of patients' oral hygiene practices and the levels of erythema based on Newton's classification scale. Swabs were taken from the palate and investigated mycologically to identify the yeast colonies. Quantitative and qualitative microbiological assessments were performed, which included recording the total numbers of colonies (cfu), their color, and their morphological characteristics. Significant differences were found in cfu values between the attachment and inner surfaces of locator- and bar-retained overdentures (P < .05). Candida albicans was the most common species in both evaluations, being isolated from 81.3% of bar-retained overdentures and 38.1% of locator-retained overdentures. DRS developed in all patients using bar-retained overdentures but in only 71.4% of those using locator-retained overdentures. No statistically significant relationship was found between bar and locator attachments according to smoking habit, overnight removal, or plaque and gingival indices (P > .05).