Abstract The development of opportunistic infections due to poor denture hygiene conditions justified the search for effective hygiene protocols for controlling denture biofilm. Objective This study evaluated Ricinus communis and sodium hypochlorite solutions in terms of biofilm removal ability, remission of candidiasis, antimicrobial activity, and participant satisfaction. Material and Methods It was conducted a controlled clinical trial, randomized, double-blind, and crossover. Sixty-four denture wearers with (n=24) and without candidiasis (n=40) were instructed to brush (3 times/day) and immerse their dentures (20 min/day) in different storage solutions (S1 / S2: 0.25% / 0.5% sodium hypochlorite; S3: 10% R. communis; S4: Saline).The trial period for each solution was seven days and a washout period of seven days was used before starting the use of another solution. The variables were analyzed at baseline and after each trial period. The biofilm of inner surfaces of maxillary dentures was disclosed, photographed, and total and dyed areas were measured (Image Tool software). The percentage of biofilm was calculated. Remission of candidiasis was assessed by visual scale and score were attributed. Antimicrobial activity was assessed by the DNA-Checkerboard hybridization method. Patient satisfaction was measured using a questionnaire. Results S1 (4.41±7.98%) and S2 (2.93±5.23%) were more effective then S3 (6.95±10.93%) in biofilm remotion(P<0.0001). All solutions were different from the control (11.07±11.99%). S3 was the most effective solution in remission of candidiasis (50%), followed by S1 (46%). Concerning antimicrobial action, S1/S2 were similar and resulted in the lowest microorganism mean count (P=0.04), followed by S3. No significant differences were found with patient’s satisfaction. Conclusions 10% R. communis and 0.25% sodium hypochlorite were effective in biofilm removal, causing remission of candidiasis and reducing the formation of microbial colonies in denture surfaces. All solutions were approved by patients.

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.

Abstract Aim: To evaluate the sorption, solubility and color change in two lining materials after 120 days of immersion in either sodium perborate or artificial saliva. Methods: Thirty disk-shaped specimens (15×3 mm) of each material, Mucopren(r) soft (MS) and Elite(r) soft (ES) were manufactured and divided into two groups. The specimens in the control group (CG, n=15) were stored in artificial saliva at 37 °C. The specimens in the experimental group (EG, n=15) were stored in artificial saliva at 37 °C and immersed in sodium perborate daily for 5 min. The analysis of sorption and solubility was based on the initial dry weight and on the wet and dry weights after immersion. The color was assessed with a portable spectrophotometer and the NBS system. ANOVA and Tukey test (p<0.05) were used to analyze color and sorption. The solubility was analyzed by KruskalWallis test (p<0.05). Results: Sorption was higher in the EG group (0.31±0.08) than in the control group (0.26±0.05), and higher in Elite(r) soft relining (0.34±0.07) than in Mucopren(r) soft (0.23±0.06). There was no interaction between the factors. Elite(r) Soft presented a higher solubility when immersed in artificial saliva (CG: 0.16±0.07 and EG: 0.13±0.06; p=0.00). Mucopren(r) soft showed no solubility in either treatment. Regarding the color changes, there was a significant difference between the groups (CG: 9.2±1.2 and EG: 9.9±1.2; p=0.025) but not between the materials (Mucopren(r) soft: 9.4±1.3 and Elite(r)soft: 9.7±1.0; p=0.34). Using the NBS system, we verified that both materials presented a high color change. Conclusions: The daily use of sodium perborate promoted changes in the liners' sorption and color. Elite(r) soft relining was more prone to changes than Mucopren(r) soft.

Este estudo avaliou a atividade antimicrobiana de um dentifrício experimental a base de Ricinus communis para higiene de prótese contra as seguintes cepas padrão: Staphylococcus aureus, Escherichia coli, Streptococcus mutans, Enterococcus faecalis, Candida albicans e Candida glabrata. O ensaio de concentração inibitória mínima foi realizado com R. communis em óleo puro a 2,5 % . Apenas a E. coli não foi inibida por R. communis, no entanto, a concentração mínima (0,0781%) foi eficaz contra os outros microrganismos. A partir destes resultados foram determinadas as concentrações dos dentifrícios experimentais: 1, 2, 5 e 10 %, as quais foram avaliadas pelo teste de difusão em Agar. Os dentifrícios comerciais Colgate, Trihydral e Corega Brite foram testados para fins comparativos. O diâmetro dos halos de inibição do crescimento bacteriano, em torno dos poços, foi medido (em mm) com uma régua sob uma luz refletida. Os dados foram analisados estatisticamente por meio de análise de variância e teste post-hoc de Tukey (α=0,05). Nem os dentifrícios comerciais nem os experimentais foram eficazes contra E. coli. Os dentifrícios experimentais contendo R. communis a 2 , 5 e 10 % apresentaram ação contra S. mutans, S. aureaus e E. faecallis. Os dentifrícios experimentais não mostraram atividade antimicrobiana contra Candida spp e E. coli em nenhuma das concentrações testadas . O Trihydral foi o mais eficaz. Comparando os dentifrícios experimentais, o produto com 10% de R. communis produziu os maiores halos de inibição do crescimento microbiano e apresentou atividade antimicrobiana.

This study evaluated the antimicrobial activity of a Ricinus communis-based experimental dentifrice for denture hygiene against the following standard strains: Staphylococcus aureus, Escherichia coli, Streptococcus mutans, Enterococcus faecalis, Candida albicans and Candida glabrata. The minimum inhibitory concentration (MIC) assay was performed with R. communis in pure oil at 2.5%. Only E. coli was not inhibited by R. communis, but the MIC (0.0781%) was effective against the other microorganisms. From these results it was determined the R. communis concentrations for experimental dentifrices, 1, 2, 5 and 10%, which were evaluated by the test-well diffusion in agar. The commercial dentifrices Colgate, Trihydral and Corega Brite were tested for comparative purposes. The diameter of the zones of bacterial growth inhibition produced around the wells was measured (in mm) with a rule under reflected light. Data were analyzed statistically by analysis of variance and Tukey's post-hoc test (α=0.05). Neither the commercial nor the experimental dentifrices were effective against E. coli. The experimental dentifrices containing R. communis at 2, 5 and 10% presented action against S. mutans, S. aureaus and E. faecallis. The experimental dentifrices showed no antimicrobial activity against Candida spp. and E. coli in any of the tested concentrations. Trihydral was the most effective. Comparing the experimental dentifrices, the product with 10% R. communis produced the largest zones of bacterial growth inhibition and had similar antimicrobial activity to the commercial dentifrices, except against S. aureus.