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.

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.

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.

Survival of microorganisms on complete dentures following ultrasonic cleaning combined with immersion in peroxide-based cleanser solution.

OBJECTIVES: To compare ultrasonic cleaning combined with immersion in a commercially available peroxide-based cleanser solution (Polident(®) ) with other denture cleaning methods, we examined the quantity of micro-organisms that survived on dentures before and after various cleaning methods. SUBJECTS AND METHODS: One hundred complete dentures belonging to 50 nursing home residents (mean age, 84.6 years) were randomly assigned to five groups according to the cleaning method employed: (A) immersion in Polident(®) solution alone, (B) brushing with water, (C) ultrasonic cleaning with water, (D) method (A) followed by method (B) and (E) ultrasonic cleaning combined with immersion in Polident(®) solution. Before and after the dentures had been cleaned, denture biofilm was collected from the mucosal surface of each lateral half of the examined dentures. The collected micro-organisms were cultured, presumptively identified by standard methods and quantified. Comparisons between the five cleaning methods were carried out using the Kruskal-Wallis test and Dunn's multiple comparisons test. RESULTS: The denture cleaning methods involving the use of Polident(®) solution (methods A, D and E) were significantly more effective at denture disinfection than the other methods (p < 0.05); in particular, the quantity of Candida spp. was lowest after method E (median, 0.00; significantly lower than those observed after methods A, B and C; p < 0.05). CONCLUSION: It was concluded that ultrasonic cleaning combined with immersion in a peroxide-based cleanser solution effectively reduces the quantity of micro-organisms surviving on dentures and is a suitable method for elderly individuals who find brushing their dentures difficult.

Ricinus communis treatment of denture stomatitis in institutionalised elderly.

This study compared the effectiveness of Ricinus communis (RC) with Nystatin (NYS) and Miconazole (MIC) in the treatment of institutionalised elderly with denture stomatitis (DS). They (n = 30) were randomly distributed into three groups: MIC, NYS or RC. Clinical and mycological evaluations were performed prior to the use of the antifungal (baseline) and repeated after 15 and 30 days of treatment. The sample was clinically examined for oral mucosal conditions. Standard photographs were taken of the palate, and the oral candidiasis was classified (Newton's criteria). Mycological investigation was performed by swabbing the palatal mucosa, and Candida spp. were quantified by counting the number of colony-forming units (cfu mL⁻¹). The clinical and mycological data were analysed, respectively by Wilcoxon and Student's t-test (α = 0.05). Significant improvement in the clinical appearance of DS in the MIC and RC groups was observed between the 1st and 3rd collections (MIC - P = 0.018; RC - P = 0.011) as well as between the 2nd and 3rd collections (MIC - P = 0.018; RC - P = 0.011). Neither groups showed a statistically significant reduction in cfu mL⁻¹ at any time. Although none of the treatments decreased the cfu mL⁻¹, it was concluded that Ricinus communis can improve the clinical condition of denture stomatitis in institutionalised elderly patients, showing similar results to Miconazole.

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.

Differential diagnosis of denture-induced stomatitis, Candida, and their variations in patients using complete denture: a clinical and mycological study.

Denture-induced stomatitis usually occurs in persons who wear a complete or a partial denture. Among the many aetiological and predisposing factors, Candida spp. are believed to play an important role in the initiation and progression of the infection. Seventy cases who attended the clinics of the Dental Faculty, University of Atatürk, Turkey were investigated from the viewpoint of denture-induced stomatitis. After questioning the patients for their personal information, they were examined clinically and smears were obtained from lesions of the palatal mucosa and the contiguous denture surface by calcium aliginate swabs, and inoculated onto Sabouraud dextrose agar supplemented with 1% chloramphenicol, and CHROMagar Candida. Individual yeast species were identified by a germ tube test, development of blastospores, chlamydospores and pseudohyphae and assimilation tests employing the commercial kit API 20C AUX system. According to the results obtained, 70% of the cases had denture-induced stomatitis, and in 68% of them mycological culture results were positive. Candida albicans was the most frequently isolated fungus (68.75%). On the other hand, fungal growth was much more pronounced in the cultures made from the inner surface of the dentures. In conclusion, this study showed that candidal infections are not the predisposing factor in the occurrence of denture-induced stomatitis, but they play a major role, as also some other factors, especially those related with dentures.

Application of a diagnostic-therapeutic procedure using implant-supported dental prosthesis as a preventive therapy for candidiasis of upper gastrointestinal tract in complete denture users.

Our previous studies demonstrated that the use of acrylic based prosthesis in edentulous patients had a direct impact on the increased incidence of oral mycosis and further episodes of mycosis in the digestive tract. This dependency is associated with formation of a space between the surface of the prostheses and adhering mucosal membrane, where a specific micro environment is being formed, which - as stated - creates a superior breeding ground mainly for microorganisms of the genus Candida.