Patrícia Costa Cruz

Effect of Three Methods for Cleaning Dentures on Biofilms Formed In Vitro on Acrylic Resin

PURPOSE The aim of this study was to evaluate the effect of three denture hygiene methods against different microbial biofilms formed on acrylic resin specimens. MATERIALS AND METHODS The set (sterile stainless steel basket and specimens) was contaminated (37 degrees C for 48 hours) by a microbial inoculum with 10(6) colony-forming units (CFU)/ml (standard strains: Staphylococcus aureus, Streptococcus mutans, Escherichia coli, Candida albicans, Pseudomonas aeruginosa, and Enterococcus faecalis; field strains: S. mutans, C. albicans, C. glabrata, and C. tropicalis). After inoculation, specimens were cleansed by the following methods: (1) chemical: immersion in an alkaline peroxide solution (Bonyplus tablets) for 5 minutes; (2) mechanical: brushing with a dentifrice for removable prostheses (Dentu Creme) for 20 seconds; and (3) a combination of chemical and mechanical methods. Specimens were applied onto a Petri plate with appropriate culture medium for 10 minutes. Afterward, the specimens were removed and the plates incubated at 37 degrees C for 48 hours. RESULTS Chemical, mechanical, and combination methods showed no significant difference in the reduction of CFU for S. aureus, S. mutans (ATCC and field strain), and P. aeruginosa. Mechanical and combination methods were similar and more effective than the chemical method for E. faecalis, C. albicans (ATCC and field strain), and C. glabrata. The combination method was better than the chemical method for E. coli and C. tropicalis, and the mechanical method showed intermediate results. CONCLUSION The three denture hygiene methods showed different effects depending on the type of microbial biofilms formed on acrylic base resin specimens.

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.

The effectiveness of chemical denture cleansers and ultrasonic device in biofilm removal from complete dentures

Adequate denture hygiene can prevent and treat infection in edentulous patients. They are usually elderly and have difficulty for brushing their teeth. Objective This study evaluated the efficacy of complete denture biofilm removal using chemical (alkaline peroxide-effervescent tablets), mechanical (ultrasonic) and combined (association of the effervescent and ultrasonic) methods. Material and Methods Eighty complete denture wearers participated in the experiment for 21 days. They were distributed into 4 groups (n=20): (1) Brushing with water (Control); (2) Effervescent tablets (Corega Tabs); (3) Ultrasonic device (Ultrasonic Cleaner, model 2840 D); (4) Association of effervescent tablets and ultrasonic device. All groups brushed their dentures with a specific brush (Bitufo) and water, 3 times a day, before applying their treatments. Denture biofilm was collected at baseline and after 21 days. To quantify the biofilm, the internal surfaces of the maxillary complete dentures were stained and photographed at 45º. The photographs were processed and the areas (total internal surface stained with biofilm) quantified (Image Tool 2.02). The percentage of the biofilm was calculated by the ratio between the biofilm area multiplied by 100 and the total area of the internal surface of the maxillary complete denture. Results The Kruskal-Wallis test was used for comparison among groups followed by the Dunn multiple-comparison test. All tests were performed respecting a significance level of 0.05. Significant difference was found among the treatments (KW=21.18; P<0.001), the mean ranks for the treatments and results for Dunn multiple comparison test were: Control (60.9); Chemical (37.2); Mechanical (35.2) and Combined (29.1). Conclusion The experimental methods were equally effective regarding the ability to remove biofilm and were superior to the control method (brushing with water). Immersion in alkaline peroxide and ultrasonic vibration can be used as auxiliary agents for cleaning complete dentures.

Effervescent tablets and ultrasonic devices against Candida and mutans streptococci in denture biofilm.

OBJECTIVE To evaluate the antimicrobial action of effervescent tablets and ultrasound on Candida spp. and mutans streptococci from denture biofilm. BACKGROUND It is not uncommon for edentulous patients to be elderly and find it difficult to brush their dentures. Hence, auxiliary methods are required for cleansing dentures as well as treating oral infections. MATERIALS AND METHODS Seventy-seven complete denture wearers were randomly assigned into four groups: (A) Brushing with water (control); (B) Effervescent tablets; (C) Ultrasonic device (Ultrasonic Cleaner, model 2840 D); (D) Effervescent tablets and ultrasonic device. All groups brushed their dentures with a specific brush and water, three times a day, before applying their treatments. Denture biofilm was collected at baseline and after 21 days. The samples were collected by brushing the dentures with saline and the detached microbial cells were quantified by plating. Counts [log (CFU+1) ml(-1) ] of total aerobes, Candida spp. and mutans streptococci were compared by one-way anova or Kruskal-Wallis test (α = 0.05). RESULTS No significant difference was found among the methods from C. albicans (p = 0.76), C. tropicalis (p = 0.94) and C. glabrata (p = 0.80). Lower counts were found for methods B and D when compared with the other methods against mutans streptococci (p < 0.001). Method B showed lower total aerobic counts than A, whereas C and D showed intermediate results (p = 0.011). CONCLUSION The effervescent tablets significantly reduced mutans streptococci and total aerobes from denture biofilm. However, they was not as effective against C. albicans. Ultrasonic cleansing presented a discrete antimicrobial effect and was less effective than the tablets for complete denture disinfection.

Effect of Chlorhexidine on Denture Biofilm Accumulation

PURPOSE Adequate denture hygiene can prevent and treat infection in edentulous patients, who are frequently elderly and have difficulty brushing their teeth. This study evaluated the efficacy of complete denture biofilm removal using a chlorhexidine solution in two concentrations: 0.12% and 2.0%. MATERIALS AND METHODS Sixty complete denture wearers participated in a trial for 21 days after receiving brushing instructions. They were distributed into three groups, according to the tested solution and regimen (n = 20): (G1) Control (daily overnight soaking in water); (G2) daily immersion at home in 0.12% chlorhexidine for 20 minutes after dinner; and (G3) a single immersion in 2.0% chlorhexidine for 5 minutes at the end of the experimental period, performed by a professional. Biofilm coverage area (%) was quantified on the internal surface of maxillary dentures at baseline and after 21 days. Afterward, the differences between initial and posttreatment results were compared by means of the Kruskal-Wallis test (α= 0.05). RESULTS Median values for biofilm coverage area after treatment were: (G1) 36.0%; (G2) 5.3%; and (G3) 1.4%. Differences were significant (KW = 35.25; p < 0.001), although G2 and G3 presented similar efficacy in terms of biofilm removal. CONCLUSIONS Both chlorhexidine-based treatments had a similar ability to remove denture biofilm. Immersion in 0.12% or 2.0% chlorhexidine solutions can be used as an auxiliary method for cleaning complete dentures.