This clinical trial evaluated Ricinus communis and sodium hypochlorite solutions in different concentrations for denture cleanliness, regarding biofilm removal capacity, remission of atrophic chronic candidiasis, degree of patient satisfaction and antimicrobial action against specific microorganism. Sixty-four denture wearers with absence (n=40) or presence of Candidiasis (n=24) were selected and oriented to brush their dentures with a specific brush and neutral soap for 3 minutes, 3 times a day and immerse them, once a day, in hygiene solutions (0.25% sodium hypochlorite - S1 and 0.5% - S2, 10% R. communis - S3; Saline - S4: control) during 20 minutes, for 7 days. The solutions were used in a randomized, double blind and cross form with washout periods. To quantify biofilm with software ImageTool 3.0, the inner surface was disclosed (1% neutral red) and photographed at the end of each period. The Candidiasis remission was assessed by scores before and after the use of solutions. Patient satisfaction was assessed by questionnaire. Antimicrobial activity was determined by Colony Forming Units (CFU) counts of Streptococcus mutans, Candida spp., and gram-negative microorganisms. For collecting biofilm, internal surface of each maxillary complete denture was brushed with saline solution, and the biofilm suspension obtained. After serial dilutions (100 - 10-3), 50 uL aliquots were seeded in Petri dishes containing Mitis salivarius agar base, CHROMagar Candida® and MacConkey agar for detecting S. mutans, Candida spp., or gram-negative microorganisms, respectively. After incubation, colonies were counted, and values in CFU/mL were calculated. Biofilm removal was analyzed as a split-plot with two variation factors: inflammation and solutions. The candidiasis remission was analyzed after adjustment using multinomial logistic regression. Logistic regression analysis and compound symmetry was adopted for patient satisfaction. The antimicrobial action was analyzed with Friedman´s test. Antimicrobial action data were processed after transformation - log10 (CFU + 1) - and were analyzed by Friedman test (α = 0.05).

Sixty-four denture wearers with (n=24) and without Candidiasis (n=40) were enrolled and instructed to brush and immerse their dentures in 4 different storage solutions (S1: 0.25% sodium hypochlorite; S2: 0.5% sodium hypochlorite; S3: 10% R. communis; and S4: Saline/Control). The interventions were randomly performed in a double blind and crossover format with washout periods. After 7 days of brushing and storage, the biofilm formed in the inner surfaces of dentures was disclosed and photographed to quantification. Candidiasis remission was assessed by scores and the patient satisfaction by a questionnaire. Antimicrobial activity of the solutions was determined by counting the Colony Forming Units (CFUs) of Streptococcus mutans, Candida spp., and gram-negative microorganisms. For collecting biofilm, each complete upper denture was placed in a Petri dish, its internal surface was brushed (Tek brush) with saline solution for 2 min, and the biofilm suspension was transferred to a test tube. After serial dilutions (100 - 10-3), 50 uL aliquots were seeded in Petri dishes containing Mitis salivarius agar base, CHROMagar Candida® and MacConkey agar for detecting S. mutans, Candida spp., or gram-negative microorganisms, respectively. After incubation, colonies were counted, and values in CFU/mL were calculated.

Inclusion Criteria:

• Edentulous that make regular use of dentures in acrylic resin for at least one year with the presence of biofilm.

Exclusion Criteria:

• Problems in adapting, reline, or repair fractures
• Patients with limited communication or collaboration as the following recommended protocol.