Effects of long-term cinnamaldehyde immersion on the surface roughness and color of heat-polymerized denture base resin.

STATEMENT OF PROBLEM: Cinnamaldehyde has been successfully used for the short-term disinfection of dentures; however, its long-term effects on the surface and color properties of denture base materials remain unknown. PURPOSE: The purpose of this in vitro study was to evaluate the effects of simulated immersion in cinnamaldehyde for up to 5 years on the surface roughness and color parameters of a heat-polymerized denture resin. MATERIAL AND METHODS: Eighty Ø10×5-mm disk-shaped specimens were prepared from microwave heat-polymerized polymethylmethacrylate (PMMA) and immersed in 4 solutions (n=20): TW-tap water (control), SH - 0.5% sodium hypochlorite, PX-alkaline peroxide, and CA-cinnamaldehyde (27 µg/mL). The immersion protocol simulated 104 cycles (3.5 months), 913 cycles (2.5 years), and 1825 immersion cycles (5 years) of a daily immersion cleaning protocol, with immersion times ranging from 10 to 20-minutes. Surface roughness (Sa) and the color parameters of CIELab (L∗ a∗ b∗, ΔEab), CIEDE2000 (ΔE00), and the National Bureau of Standards (NBS) were analyzed at baseline (t=0) and after the immersion cycles. The data were analyzed by 2-way analysis of variance (ANOVA) for repeated measures and the Tukey post hoc test (α=.01). RESULTS: Sa was significantly increased in all groups after 1825 cycles compared with baseline (P<.01), regardless of the solution. Only the time factor significantly affected ΔEab, ΔE00, and NBS parameters, which were below the perceptibility and acceptability thresholds. After a simulated 5-year immersion, the surface roughness and color values of CA-treated specimens were not statistically different from those of the other groups (P>.01). CONCLUSIONS: Cinnamaldehyde solution (27 µg/mL) produced minor effects on the surface roughness and color parameters of a heat-polymerized denture base resin similar to those of 0.5% sodium hypochlorite and alkaline peroxide after a 5-year simulated immersion.

Effect of local hygiene protocols on denture-related stomatitis, biofilm, microbial load, and odor: A randomized controlled trial.

STATEMENT OF PROBLEM: Denture stomatitis affects complete denture wearers and is frequently treated with antifungals drugs, as well as treating the denture with sodium hypochlorite. Whether the limitations of these treatments can be overcome with local hygiene protocols that do not damage the denture materials or adversely affect the patient is unclear. PURPOSE: The purpose of this randomized controlled trial was to evaluate the effect of denture hygiene protocols on complete denture wearers with denture stomatitis. MATERIAL AND METHODS: For this randomized, double-blind controlled clinical trial, 108 participants were assigned to parallel groups: 0.25% sodium hypochlorite (positive control) 0.15% Triclosan, denture cleaning tablets, or denture cleaning tablets plus gingival cleaning tablets. The participants were instructed to brush the dentures and the palate and immerse the denture in the solutions. The outcomes of denture stomatitis remission, biofilm removal, decrease of microbial load (colony-forming units), and odor level of the mouth and denture were measured at baseline and after 10 days. Descriptive analyses were used for sociodemographic characterization of the participants; the Pearson chi-square test was used to compare participant frequency with different degrees of denture stomatitis. The data were not normally distributed (Shapiro-Wilks test) or homogeneous (Levene test). So, the Kruskal-Wallis and Dunn post hoc tests and Wilcoxon test were used to compare the effects of solutions and time on the variables (α=.05). RESULTS: The frequency of the highest to lowest denture stomatitis scores was significantly different for the 0.15% Triclosan and denture cleaning tablets groups. No significant difference was found among the groups in terms of denture stomatitis scores, biofilm, or colony-forming unit count of Candida spp. or C. albicans and S. mutans; a significant reduction was found in these parameters. The 0.25% sodium hypochlorite and 0.15% Triclosan treatments caused a significant reduction in Gram-negative microorganisms; these 2 protocols, and the denture cleaning tablets showed a significant reduction in Staphylococcus spp.; all protocols had similar effects. Only the S. mutans count of the palate decreased after 10 days. The odor level of the mouth and the denture was not significantly different (P=.778). CONCLUSIONS: The evaluated protocols can be recommended for the hygiene of complete dentures, since they were effective for all the variables studied.

Effect of sodium hypochlorite and Ricinus communis solutions on control of denture biofilm: A randomized crossover clinical trial.

STATEMENT OF PROBLEM: The prevalence of complete edentulism remains high in the elderly, and previous data have shown that poor denture hygiene is common among patients with edentulism. PURPOSE: The purpose of this randomized crossover trial was to evaluate the efficacy of denture cleansers in terms of biofilm removal, antimicrobial action, and the remission of denture stomatitis. MATERIAL AND METHODS: Fifty denture wearers with denture stomatitis were instructed to brush their dentures (brush and soap) and to soak them (20 minutes/14 days) in 4 solutions, as follows: C (control), 0.85% saline; SH1, 0.1% sodium hypochlorite; SH2, 0.2% sodium hypochlorite; and RC, 8% Ricinus communis. The biofilm in the intaglio surface of maxillary dentures was stained, photographed, and quantified by software (Image Tool). It was then collected (brushed with saline solution), and the obtained suspension was diluted (100 to 10-3) and seeded (50 µL) in CHROMagar for Candida spp. After incubation, colony-forming units per milliliter values were calculated. Denture stomatitis remission was classified according to the Newton classification. Data were analyzed by Friedman (α=.05) and Wilcoxon tests and corrected by the Bonferroni test (α=.005). RESULTS: SH1 (mean rank [MR]=1.98) and SH2 (MR=1.64) showed lower biofilm coverage than C (MR=3.73) that was similar to RC (MR=2.92). SH1 (MR=2.43) and SH2 (MR=2.10) showed antimicrobial action for Candida spp, and RC (MR=3.36) showed similar results to C (MR=3.51) and baseline (MR=3.50). Clinical signs of denture stomatitis were reduced by SH1 (MR=2.44), while SH2 (MR=2.56) and RC (MR=2.74) showed intermediate results. CONCLUSIONS: The two sodium hypochlorite solutions were the most effective means of biofilm control. All tested solutions were effective in reducing the signs of denture stomatitis.

Effect of daily use of an enzymatic denture cleanser on Candida albicans biofilms formed on polyamide and poly(methyl methacrylate) resins: an in vitro study.

STATEMENT OF PROBLEM: Candida biofilms on denture surfaces are substantially reduced after a single immersion in denture cleanser. However, whether this effect is maintained when dentures are immersed in cleanser daily is unclear. PURPOSE: The purpose of this study was to evaluate the effect of the daily use of enzymatic cleanser on Candida albicans biofilms on denture base materials. MATERIAL AND METHODS: The surfaces of polyamide and poly(methyl methacrylate) resin specimens (n=54) were standardized and divided into 12 groups (n=9 per group), according to study factors (material type, treatment type, and periods of treatment). Candida albicans biofilms were allowed to form over 72 hours, after which the specimens were treated with enzymatic cleanser once daily for 1, 4, or 7 days. Thereafter, residual biofilm was ultrasonically removed and analyzed for viable cells (colony forming units/mm(2)) and enzymatic activity (phospholipase, aspartyl-protease, and hemolysin). Factors that interfered with the response variables were analyzed by 3-way ANOVA with the Holm-Sidak multiple comparison method (α=.05). RESULTS: Polyamide resin presented more viable cells of Candida albicans (P<.001) for both the evaluated treatment types and periods. Although enzymatic cleansing significantly (P<.001) reduced viable cells, daily use did not maintain this reduction (P<.001). Phospholipase activity significantly increased with time (P<.001) for both materials and treatments. However, poly(methyl methacrylate) based resin (P<.001) and enzymatic cleansing treatment (P<.001) contributed to lower phospholipase activity. Aspartyl-protease and hemolysin activities were not influenced by study factors (P>.05). CONCLUSIONS: Although daily use of an enzymatic cleanser reduced the number of viable cells and phospholipase activity, this treatment was not effective against residual biofilm over time.

Clinical trial of an experimental cleaning solution: antibiofilm effect and integrity of a silicone-based denture liner.

AIM: This study evaluated the antibiofilm effect of an experimental solution of 2% Ricinus communis (R. communis) on a silicone-based denture liner by means of a randomized clinical trial, as well as the integrity of such liner following a cleansing regimen with such solution. MATERIALS AND METHODS: About 30 complete denture wearers had their lower dentures relined with a silicone-based denture liner and randomly allocated to cleanse their dentures by means of: (A) a specific toothbrush for complete dentures and dentifrice; (B) soaking in an experimental 2% R. communis solution; and (C) association of A and B. Considered outcomes were biofilm coverage area (%), microbial counts by means of the deoxy-ribonucleic acid (DNA) checkerboard hybridization technique and physical integrity of the soft liner, assessed during a time interval of 60 days. Mean group values were compared by analysis of variance (ANOVA) and Tukey tests or generalized linear method (α = 0.05). RESULTS: The mechanical method presented the lowest biofilm percentage (1.45 ± 1.03) if compared to the chemical method (2.96 ± 1.98) and the associated one (2.71 ± 1.76). After 60 days (3.37 ± 2.04), biofilm accumulation was higher than at 15 days (1.28 ± 0.77) and 30 days (2.46 ± 1.54). The denture liner was less deteriorated and kept its physical integrity when the mechanical method was applied. The chemical method presented higher effectiveness against microorganisms, including some Candida species. CONCLUSION: The 2% R. communis solution presented stronger antimicrobial capacity than brushing on a silicone-based denture liner after immersion. However, it was not superior to the mechanical method in preserving the physical integrity of the material and in biofilm removal. CLINICAL SIGNIFICANCE: Soft denture liners hygiene is a very important issue and not conclusive in the literature. The experimental solution of 2% R. communis evaluated presented promising antimicrobial potential and should be more explored to be recommended as cleanser.

Adding denture cleanser to microwave disinfection regimen to reduce the irradiation time and the exposure of dentures to high temperatures.

BACKGROUND: The microwave energy is an efficient disinfection method; however, it can generate high temperatures that can result in distortion of the dentures. OBJECTIVES: To evaluate whether the addition of an enzymatic cleanser to microwave disinfection regimen would disinfect dentures with shorter irradiation time. MATERIALS AND METHODS: Seven resin discs colonized with Candida albicans biofilm were placed on the palatal surface of sterile dentures to be randomly assigned to the following treatments: immersion in distilled water for 3 min with 0 (DW), 1 (DW + M1), 2 (DW + M2), or 3 min (DW + M3) of microwave irradiation; or immersion in denture cleanser for 3 min with 0 (DC), 1 (DC + M1), 2 (DC + M2) or 3 min (DC + M3) of irradiation. After the treatments, the viable cells were counted by a blinded examiner. The temperature was measured immediately after irradiation. The data were analyzed by ANOVA and Tukey post hoc tests (α = 0.05). RESULTS: No viable cells were found after DC + M2, DC + M3, and DW + M3 treatments, of which DC + M2 achieved the lowest temperature. No significant difference was found between the effectiveness of DW, DW + M1 and DC treatments (p > 0.05). CONCLUSION: Within the limits of this study, the association of a denture cleanser and microwave energy is efficient to disinfect dentures in lower irradiation time and temperature.

Trial of experimental toothpastes regarding quality for cleaning dentures.

The aim of this study was to evaluate the efficacy of experimental toothpastes for removing denture biofilm by means of a randomized crossover trial. Thirty volunteers brushed their dentures using a brush and four pastes: (1) Corega refreshing mint (control), (2) 0.2% chloramine T, (3) 1.0% chloramine T, and (4) 0.01% fluorosurfactant. Each paste was used for 7 days, and participants were randomized to use them according to one of four sequences. Biofilm was disclosed (neutral red) after each period, photographed, and quantified by means of a software program. All experimental toothpastes were similar to the control in terms of posttreatment biofilm coverage.

Oral health practices and beliefs among caregivers of the dependent elderly.

BACKGROUND: Caregivers deal with oral health care of the dependent elderly; however, this has a low priority among them, and their education in daily oral care is deficient. Therefore, studying the oral care practices as well as their oral health beliefs is important as these affect the quality of the oral care they perform. OBJECTIVE: To compare formal and informal caregivers' oral care practices and oral health beliefs when taking care of severely dependent elderly. MATERIAL AND METHODS: A cross-sectional study was conducted on a convenience sample of 21 formal caregivers from a long-term residence and 18 informal caregivers from a local primary health care domiciliary programme. Caregivers were surveyed using a questionnaire designed to elicit oral care practices and oral health beliefs. The nursing Dental Coping Beliefs Scale questionnaire was translated and validated in Chile. RESULTS: Significant differences were observed between formal and informal caregivers' performance of some oral health care practices. There were no significant differences between formal and informal caregivers' oral health beliefs. CONCLUSIONS: Although there are some differences in formal and informal caregivers' oral health care practices, we cannot state that one caregiver's performance is better than the other, in fact, negative oral health beliefs were found in both groups.

Influence of peracetic acid at acrylic resin properties / Influência do ácido peracético nas propriedades de uma resina acrílica

PURPOSE: To evaluate the influence of peracetic acid immersion on water sorption, solubility and microhardness of heat and self-cured acrylic resins. METHODS: Thirty specimens of each type of acrylic resin were produced for sorption, solubility and microhardness evaluation. Sorption and solubility were evaluated based on ISO1567. For the microhardness test, specimens (20.0×5.0×10.0 mm) were made and evaluated under a 100 g load for 15 s. The test groups were submitted to a peracetic acid 0.2% immersion for 10 minutes. Data of sorption and solubility were analyzed by two way ANOVA and, hardness values, by paired t-test. RESULTS: Values of sorption and solubility were in agreement with ISO1567 requirements to both groups and ranged, in µg/mm³, for sorption from 22.28 (±4.40) to 24.25 (±3.27), and from 1.09 (±0.16) to 1.29 (±0.10) for solubility. Solubility showed a statistically significant difference between the two types of resin at test group. There was no statistical significant difference at the microhardness values. CONCLUSION: In this study, immersion in peracetic acid solution 0.2% showed no alterations at acrylic resin properties tested.Peracetic acid could be recommended to replace the conventional agents for the disinfection of acrylic resin devices.

OBJETIVO: Avaliar a influência da imersão em ácido peracético sobre a sorção, solubilidade e microdureza de resinas acrílicas termo e autopolimerizada. METODOLOGIA: Trinta corpos de prova de cada resina acrílica foram confeccionados para avaliação da sorção, solubilidade e microdureza. A sorção e a solubilidade foram avaliadas de acordo com a ISO 1567. Para a determinação da microdureza, os corpos de prova (20×5×10 mm) foram confeccionados e avaliados com uma carga de 100 g por 15 s. Os grupos teste foram imersos em ácido peracético 0,2% por 10 minutos. Os dados de sorção e solubilidade foram analisados com ANOVA de duas vias e de dureza por teste t pareado. RESULTADOS: Os valores de sorção e solubilidade ficaram de acordo com as especificações da ISO 1567 para ambos os grupos e no ensaio de sorção variaram entre 22,28 (±4,40) até 24,25 (±3,27), e de 1,09 (±0,16) até 1,29 (±0,10) para solubilidade, em µg/mm³. A solubilidade apresentou diferença estatisticamente significativa entre os dois tipos de resina após imersão em ácido peracético. Os valores de microdureza não apresentaram diferença estatisticamente significativa entre os grupos. CONCLUSÃO: A imersão em ácido peracético 0,2% não alterou as propriedades avaliadas das resinas acrílicas.

Analysis of the effectiveness of different hygiene procedures used in dental prostheses.

PURPOSE: To compare the effectiveness of bacterial plaque removal of six denture hygiene procedures used by patients to clean their dentures. MATERIALS AND METHODS: Fifteen students randomly divided into groups G1, G2, G3, G4, G5 and G6 used maxillary intraoral appliances for 24 h without cleaning them. Afterwards, the appliances were submitted to the following procedures: P1: washing under running water for 20 s; P2 and P3: cleaning with alkaline peroxide (Corega Tabs®) for 5 and 30 min, respectively; P4: brushing with water and liquid soap for 40 s; P5: alkaline hypochlorite for 10 minutes; P6: home use chlorine solution (Q'boa® at 0.45% for 10 min), throughout a period of 6 consecutive weeks. The procedures followed a circulating scheme, so that all the appliances were submitted to all the hygiene methods studied. After the hygiene procedures, the appliances were stained, photographed and submitted to the weighing method. RESULTS: After ANOVA and Tukey's test, differences were observed: P5 = 0.73 ± 0.3 (b), P6 = 1.27 ± 0.4(b,c), P4 = 1.92 ± 0.5 (b,c), P3 = 2.24 ± 1.0 (b,c), P2 = 7.53 ± 2.5 (c) and P1 = 26.86 ± 15. 3 (a). CONCLUSION: From the results of the study, it could be concluded that the use of alkaline hypochlorite is the best way to remove bacterial plaque, followed by the home-use chlorine solution and brushing with water and liquid soap. Corega Tabs® must be used for 30 min of immersion to have a cleaning effectiveness similar to that of alkaline hypochlorite.

Color stability of chemically activated reline resin after microwave disinfection: a 1-year clinical trial.

PURPOSE: To evaluate the effect of microwave disinfection on the color stability of a hard chairside reline resin after a 1-year service period. METHODS: 40 adult patients aged between 30-75 years, who required denture reline treatment, participated in this study. Tokuyama Rebase II was used to reline complete maxillary dentures. The edentulous subjects were randomly divided into two groups (n=20) and dentures were cleansed according to two methods: CG (control group) - brushing with coconut soap and soft toothbrush; DG (disinfection group) - brushing according to previous methods and microwave disinfection once a week for 3 minutes at 650W. Color parameters in L*a*b* were recorded by spectrophotometer immediately after the reline, at 7 and 15 days, 1, 3, 6 and 9 months and 1 year post-placement. Data were analyzed by two-way repeated-measures ANOVA and Tukey tests (alpha = 0.05). RESULTS: Color alteration values of DG were significantly lower than those of CG (P<0.05). Color changes observed after 15 days were greater than values obtained at 7 days recall (P<0.05). All color changes observed for the CG were considered noticeable (between 1.5 and 3.0 NBS). In DG, color change was slight (between 0.5 and 1.5 NBS). There were statistically significant differences between L* values obtained initially and after 3 months, between 15 days and 3 months and between 15 days and 1 year (P<0.05). No significant differences were observed between group and time for the parameters a* and b*.

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

OBJECTIVE: To determine the effectiveness of a denture cleanser in reducing the concentration of volatile sulphur compounds (VSC) and its antimicrobial action. BACKGROUND: Micro-organisms from the denture biofilm can cause local and systemic disease and halitosis. Denture cleansers are important adjuncts in oral care, but there is limited investigation on their effect in malodour compounds. MATERIAL AND METHODS: Nineteen institutionalised elderly who wore at least an upper denture were selected; their VSC concentrations were measured and the denture biofilm was collected. In phase 1, the subjects wore their old denture and data were collected before (B0) and after 7(A1), 14(A2), 28(A3) days of continuous daily use of the denture cleanser. In phase 2, new dentures were inserted and measurements were made at 30(A1.1), 60(A2.2), 90(A3.3) days of treatment. RESULTS: The VSC concentration increased from B0 to A1 (p<0.05), but no differences were found for the others intervals of times. Total micro-organism data did not show a statistical difference between times in Phase I, but in Phase II, there was a statistical difference (p<0.05) and a progressive re-colonisation was observed. CONCLUSION: Within the limits of this study, it was concluded that the denture cleanser had no antimicrobial effect and VSC levels were not reduced.

In vivo efficacy of alkaline peroxide tablets and mouthwashes on Candida albicans in patients with denture stomatitis.

OBJECTIVE: Effective cleaning of dentures is important for the maintenance of good oral hygiene for denture stomatitis patients. The in vivo efficacy of three different brands of alkaline peroxide tablets (Polident, Efferdent, and Fittydent) and two mouthwashes (CloSYS II and Corsodyl) to eliminate Candida albicans on dentures was evaluated in this in vivo study. MATERIAL AND METHODS: Ninety denture wearers with clinical evidence of denture stomatitis were randomly divided into 5 test groups and 1 control group. Each group was further divided into three subgroups in which the dentures were subjected to 15-, 30-, and 60-min disinfection procedures. The dentures of each test group were treated with one of the cleaners, while those of the control group were treated with distilled water. Swab samples from the palatal surfaces (2 cm x 2 cm template delimited area) of the upper dentures were obtained before and after 15, 30, and 60 min periods of cleaner use and examined mycologically. RESULTS: The reduction in the number of colony-forming units (CFU) of C. albicans before, and after 15, 30, and 60 min of use of CloSYS II and Corsodyl was significantly greater than that of the control group (p<0.05). Moreover, there was no statistically significant difference (p>0.05) among Polident, Efferdent and the control group in any of the treatment periods. Dentures treated with Fittydent appeared to have a significantly greater reduction in the number of Candida spp. only after 60 min of treatment. CONCLUSIONS: The results of this study showed that the use of mouthwashes significantly reduced the number of microorganisms on dentures.

In vivo efficacy of alkaline peroxide tablets and mouthwashes on Candida albicans in patients with denture stomatitis

OBJECTIVE: Effective cleaning of dentures is important for the maintenance of good oral hygiene for denture stomatitis patients. The in vivo efficacy of three different brands of alkaline peroxide tablets (Polident, Efferdent, and Fittydent) and two mouthwashes (CloSYS II and Corsodyl) to eliminate Candida albicans on dentures was evaluated in this in vivo study. MATERIAL AND METHODS: Ninety denture wearers with clinical evidence of denture stomatitis were randomly divided into 5 test groups and 1 control group. Each group was further divided into three subgroups in which the dentures were subjected to 15-, 30-, and 60-min disinfection procedures. The dentures of each test group were treated with one of the cleaners, while those of the control group were treated with distilled water. Swab samples from the palatal surfaces (2 cm x 2 cm template delimited area) of the upper dentures were obtained before and after 15, 30, and 60 min periods of cleaner use and examined mycologically. RESULTS: The reduction in the number of colony-forming units (CFU) of C. albicans before, and after 15, 30, and 60 min of use of CloSYS II and Corsodyl was significantly greater than that of the control group (p<0.05). Moreover, there was no statistically significant difference (p>0.05) among Polident, Efferdent and the control group in any of the treatment periods. Dentures treated with Fittydent appeared to have a significantly greater reduction in the number of Candida spp. only after 60 min of treatment. CONCLUSIONS: The results of this study showed that the use of mouthwashes significantly reduced the number of microorganisms on dentures.

Detecção da expressão dos genes HWP1, ALS1 e ALS3 de C. albicans, por meio de RT-PCR em tempo real, após desinfecção química e por microonda, de resina acrílica para confecção de dentaduras / HWP1, ALS1 and ALS3 genes expression in Candida albicans after chemical or microwave disinfection of acrylic resin for denture prosthesis using real time PCR

A desinfecção de dentaduras promove o controle do biofilme microbiano e previne doenças, como a estomatite por uso de dentadura, associada à presença de Candida albicans. A expressão dos genes HWP1, ALS1, ALS3 deste fungo está relacionada à adesão das células fúngicas às do hospedeiro. O objetivo deste estudo foi detectar e quantificar a expressão desses genes em células planctônicas e biofilme de Candida albicans, desenvolvidos sobre superfícies de resina acrílica, após tratamento com dois métodos de desinfecção. Corpos de prova de resina acrílica, previamente tratados por hipoclorito de sódio 1%, microondas, e um grupo não tratado, foram inoculados com Candida albicans para desenvolvimento de biofilme. O biofilme e as células planctônicas foram coletados em três tempos distintos, correspondentes às etapas de desenvolvimento do biofilme: inicial (6h), intermediária (12h) e madura (48h) e a expressão gênica foi quantificada pelo ensaio de RT-PCR em tempo real. Os dados obtidos foram submetidos ao teste estatístico ANOVA two-way e pós-teste de Bonferroni; valores de p<0,05, p<0,01 e p<0,001 foram considerados significantes. Os três genes avaliados foram detectados e quantificados por RT-PCR em tempo real, em biofilmes e células planctônicas, independente do grupo de tratamento ou tempo de desenvolvimento do biofilme. A expressão dos genes ALS1 e ALS3 variou de acordo com o tempo de desenvolvimento do biofilme e, e com o tratamento da superfície. Ocorreu diferença significativa (p<0,001) entre a expressão desses genes nas superfícies tratadas por hipoclorito de sódio e microondas, além de diferenças significativas (p<0,001) na expressão gênica entre células planctônicas e biofilme, para os tratamentos avaliados. Concluiu-se que os tratamentos de desinfecção alteram o padrão da expressão dos genes ALS1 e ALS3 em biofilmes desenvolvidos sobre superfície de resina acrílica e em células planctônicas e este padrão foi diferente entre os tratamentos de desinfecção.

Complete dentures disinfection promotes biofilm control and prevents diseases such as denture stomatitis associated with the presence of Candida albicans infection. The expression of the genes HWP1, ALS1, ALS3 in this fungus is related to the adhesion of fungal cells to the host tissues. Therefore, the aim of this study was to detect and quantify the expression of these genes in planktonic cells and biofilms of Candida albicans, developed on acrylic resin surfaces, after treatment with two disinfection methods. Specimens of acrylic resin, previously treated by 1% sodium hypochlorite or microwave, and an untreated group were inoculated with Candida albicans for biofilm development. Biofilm and planktonic cells were collected at three different time points corresponding to biofilm development stages: initial (6 h), intermediate (12h) and mature (48h). The total RNA of these samples was obtained and the gene expression for mRNA of HWP1, ALS1 and ALS3 were quantified by Real-Time RT-PCR assay. The data obtained were assessed throught two-way ANOVA and Bonferroni post-test. Significant levels were determined for p values at <0.05. The three genes were detected and quantified in both biofilms and planktonic cells regardless of treatment condition or time of biofilm development. ALS1 and ALS3 expression varied according to the time point, and surface treatment. Significant differences (p <0.001) were showed between gene expression on surfaces treated with sodium hypochlorite and microwave, and significant differences (p <0.001) were showed in gene expression between planktonic and biofilm cells. It can be concluded that the disinfection procedures affect the ALS1 and ALS3 expression patterns in Candida albicans denture biofilms and planktonic cells. Additionaly, differential gene expression patterns were observed among the disinfection treatments.

Detecção da expressão dos genes HWP1, ALS1 e ALS3 de C. albicans, por meio de RT-PCR em tempo real, após desinfecção química e por microonda, de resina acrílica para confecção de dentaduras / HWP1, ALS1 and ALS3 genes expression in Candida albicans after chemical or microwave disinfection of acrylic resin for denture prosthesis using real time PCR

A desinfecção de dentaduras promove o controle do biofilme microbiano e previne doenças, como a estomatite por uso de dentadura, associada à presença de Candida albicans. A expressão dos genes HWP1, ALS1, ALS3 deste fungo está relacionada à adesão das células fúngicas às do hospedeiro. O objetivo deste estudo foi detectar e quantificar a expressão desses genes em células planctônicas e biofilme de Candida albicans, desenvolvidos sobre superfícies de resina acrílica, após tratamento com dois métodos de desinfecção. Corpos de prova de resina acrílica, previamente tratados por hipoclorito de sódio 1%, microondas, e um grupo não tratado, foram inoculados com Candida albicans para desenvolvimento de biofilme. O biofilme e as células planctônicas foram coletados em três tempos distintos, correspondentes às etapas de desenvolvimento do biofilme: inicial (6h), intermediária (12h) e madura (48h) e a expressão gênica foi quantificada pelo ensaio de RT-PCR em tempo real. Os dados obtidos foram submetidos ao teste estatístico ANOVA two-way e pós-teste de Bonferroni; valores de p<0,05, p<0,01 e p<0,001 foram considerados significantes. Os três genes avaliados foram detectados e quantificados por RT-PCR em tempo real, em biofilmes e células planctônicas, independente do grupo de tratamento ou tempo de desenvolvimento do biofilme. A expressão dos genes ALS1 e ALS3 variou de acordo com o tempo de desenvolvimento do biofilme e, e com o tratamento da superfície. Ocorreu diferença significativa (p<0,001) entre a expressão desses genes nas superfícies tratadas por hipoclorito de sódio e microondas, além de diferenças significativas (p<0,001) na expressão gênica entre células planctônicas e biofilme, para os tratamentos avaliados. Concluiu-se que os tratamentos de desinfecção alteram o padrão da expressão dos genes ALS1 e ALS3 em biofilmes desenvolvidos sobre superfície de resina acrílica e em células planctônicas e este padrão foi diferente entre os tratamentos de desinfecção.

Complete dentures disinfection promotes biofilm control and prevents diseases such as denture stomatitis associated with the presence of Candida albicans infection. The expression of the genes HWP1, ALS1, ALS3 in this fungus is related to the adhesion of fungal cells to the host tissues. Therefore, the aim of this study was to detect and quantify the expression of these genes in planktonic cells and biofilms of Candida albicans, developed on acrylic resin surfaces, after treatment with two disinfection methods. Specimens of acrylic resin, previously treated by 1% sodium hypochlorite or microwave, and an untreated group were inoculated with Candida albicans for biofilm development. Biofilm and planktonic cells were collected at three different time points corresponding to biofilm development stages: initial (6 h), intermediate (12h) and mature (48h). The total RNA of these samples was obtained and the gene expression for mRNA of HWP1, ALS1 and ALS3 were quantified by Real-Time RT-PCR assay. The data obtained were assessed throught two-way ANOVA and Bonferroni post-test. Significant levels were determined for p values at <0.05. The three genes were detected and quantified in both biofilms and planktonic cells regardless of treatment condition or time of biofilm development. ALS1 and ALS3 expression varied according to the time point, and surface treatment. Significant differences (p <0.001) were showed between gene expression on surfaces treated with sodium hypochlorite and microwave, and significant differences (p <0.001) were showed in gene expression between planktonic and biofilm cells. It can be concluded that the disinfection procedures affect the ALS1 and ALS3 expression patterns in Candida albicans denture biofilms and planktonic cells. Additionaly, differential gene expression patterns were observed among the disinfection treatments.

Oral health care in private and small long-term care facilities: a qualitative study.

OBJECTIVE: Elderly people who are institutionalised receive qualified care. Among the services supplied, oral health care has not always been a priority. The aim of this study was to identify the characteristics of oral health care provided to the elderly residents in long-term care facilities (LTC) in Porto Alegre/RS city. METHODS: Twelve private and small-size LTCs (less than 20 residents) participated in this study. All supervisors and 36 carers were interviewed. The data obtained were organised according to the offer of oral health under the following categories: responsibility for oral care, oral care routines, difficulties carrying out oral care routines. RESULTS: The procedures used most often in order of frequency were tooth brushing, prostheses cleaning, use of mouthwashes, soaking of prostheses and cleaning of the tongue. Among the difficulties mentioned were the high cost of dental assistance, the lack of co-operation both by family members and by the elderly themselves, the oral and general health status of the elderly and the limited time available for carers to carry out the tasks. Oral care is conducted empirically, and the responsibility is left to the carers. CONCLUSIONS: Analysis of the statements given reveals that oral care does not follow any kind of protocol or standardisation. The persistence of this situation could lead to unsatisfactory oral health care in private and small LTC facilities.

In vitro and clinical evaluation of specific dentifrices for complete denture hygiene.

OBJECTIVES: To study the physical properties of two experimental dentifrices for complete denture hygiene, their effect on denture biofilm removal and antimicrobial properties by means of a clinical trial. MATERIALS AND METHODS: The experimental dentifrices comprised two compositions. One was based on the addition of 1% chloramine T (D1) and the other on the presence of 0.01% fluorosurfactant (D2). Measurements of density, pH, consistency, rheological features and abrasiveness were conducted. Sixty complete denture wearers were randomly assigned to three groups and were instructed to brush their dentures with a specific toothbrush: (1) Water (control); (2) D1; or (3) D2. Each method was used for 21 days. Denture biofilm was disclosed by a 1% neutral red solution and quantified by means of digital photos taken from the internal surface. Microbiological assessment was conducted to quantify Candida sp. and mutans streptococci. Data were evaluated by one-way anova and Tukey HSD, or Kruskal-Wallis (alpha = 0.05). RESULTS: Both dentifrices decreased biofilm coverage when compared with the control group. D1 was the most efficacious treatment to reduce mutans streptococci, whereas D2 showed an intermediate outcome (ANOVA, p < 0.040). No treatment influenced Candida albicans or non-albicans species (Kruskal-Wallis, p = 0.163 and 0.746, respectively). CONCLUSION: It can be concluded that brushing complete dentures with the experimental dentifrices tested could be effective for the removal of denture biofilm.

Biofilm formation of Candida albicans on the surface of a soft denture-lining material.

BACKGROUND: Soft denture lining-materials are more susceptible to microbial adhesion than hard denture base acrylic resin. Poor oral hygiene and Candida albicans infection are common among elderly denture wearers as these patients usually have difficulty in keeping them clean. PURPOSE: To evaluate the influence of the oral hygiene methods on the formation of a biofilm over a soft denture-lining material. MATERIAL AND METHODS: Twenty volunteers were randomly separated into two groups: G1 and G2. Ten volunteers performed daily hygiene of the prostheses with a soft toothbrush and toothpaste. The G2 performed a treatment identical to G1 but also immersed the prostheses in sodium hypochlorite 0.5% for 20 min, once a week. Quantification of the mean score values of biofilm formation at different times were statistically analysed using analysis of variance and Tukey's test (alpha = 0.05). RESULTS: G1 (0.65 +/- 0.52) showed the lowest mean score values of biofilm formation. There was statistical difference between G1 and G2. The highest mean score values were found at 6 weeks (1.3 +/- 1.08) and were statistically different from other times. CONCLUSION: The oral hygiene methods had a significant effect in the formation of the biofilm over a soft denture-lining material.

Vinegar as an antimicrobial agent for control of Candida spp. in complete denture wearers.

The use of denture is known to increase the carriage of Candida in healthy patients, and the proliferation of Candida albicans strains can be associated with denture-induced stomatitis. The aim of this study was to evaluate the use of vinegar as an antimicrobial agent for control of Candida spp. in complete upper denture wearers. Fifty-five patients were submitted to a detailed clinical interview and oral clinical examination, and were instructed to keep their dentures immersed in a 10% vinegar solution (pH less than 3) overnight for 45 days. Before and after the experimental period, saliva samples were collected for detection of Candida, counting of cfu/mL and identification of species by phenotypical tests (germ tube formation, chlamidoconidia production, and carbohydrate fermentation and assimilation). The results were analyzed using Spearman's correlation and Student's t-test (p