Differences in abrasion capacity of four soft toothbrushes.

OBJECTIVES: This study evaluated the flexibility and abrasion capacity of the bristles of four soft toothbrush brands. METHODS: Toothbrushes from groups: 1: Aquafresh Flex; 2: Oral-B Indicator; 3: Colgate Classic; 4: Johnson and Johnson Reach were used for the buckling deformation flexibility assay with of load (40 g) for a 5-s period and the measurement of the diameter of the bristles using a comparison gauge (precision: 1 µm), and for the abrasion assay in a brushing machine in 100-min cycles with a standard dentifrice in a 1:1 solution with distilled water and load of 200 g. The data were normalized due to the difference in the size of the toothbrush heads and analysed by the anova and the Tukey test to adjust for multiple comparisons (α = 0.05). RESULTS: A significant difference in the flexibility of the bristles (toothbrushes from groups 2, 3 and 4 were more flexible than 1) was observed. There was no correlation between the increase in the diameter of the bristles and the reduction in flexibility. The statistical analysis revealed loss of mass due to abrasion, varying according to the flexibility of the bristles, with group 1 causing lower wear than groups 2, 3 and 4. CONCLUSIONS: The results of this study showed that there are variations in bristle flexibility abrasion potential of soft-classified toothbrushes.

Effects of the domestic use of a disclosing solution on the denture biofilm: a preliminary study.

To investigate the effect of the home use of a disclosing agent on the microbial composition of denture biofilm, by means of a cross-over randomized clinical trial. Two interventions were tested during 7 days each: (I) oral and denture hygiene instructions and (II) instructions associated with the home use of a disclosing agent (1% neutral red). Eleven participants with visible biofilm deposits over their maxillary complete dentures were randomly assigned to one of the two sequences of interventions: (i) I followed by II, and (ii) II followed by I. A washout period of 7 days was established. After each intervention, samples of denture biofilm were evaluated by DNA checkerboard hybridization for the detection of Candida spp. and 17 bacterial species. Counts were low for all the tested species, and no significant difference was found between the tested interventions (Wilcoxon test, P > 0.05). The home use of a disclosing agent does not remarkably change the composition of denture biofilm.

Effects of mechanical and chemical methods on denture biofilm accumulation.

The aim of this study was to quantify biofilm on the internal surface of upper complete dentures following six possible cleansing methods. Thirty-six edentulous subjects were submitted to a time-series trial and dentures were cleansed according to six methods: (i) rinsing with water; (ii) soaking in an alkaline peroxide solution (Bonyplus); (iii) brushing with dentifrice (Dentu-Creme) and soft Johnson and Johnson's toothbrush; (iv) combination between soaking and brushing according to methods 2 and 3; (v) brushing with dentifrice (Dentu-Creme) and soft Oral B toothbrush; (vi) combination between soaking and brushing according to methods 2 and 5. Each method was randomly used throughout 21 days. Denture biofilm was disclosed by 1% neutral red solution and quantified by means of digital photos taken from the internal surface. The six methods presented significant differences in percentage of biofilm coverage (repeated measures anova, P < 0.0001). Method 1 showed the highest values, 2 was intermediate and other results were the lowest. The most efficacious approach was 6. Biofilm tended to accumulate predominantly over specific zones of the denture base, but this pattern did not change regardless of the method employed. It can be concluded that brushing alone was more effective than the chemical method employed. The best results were obtained by a combination of methods.