Mass loss of four commercially available heat-polymerized acrylic resins after toothbrushing with three different dentifrices

The association between a toothbrush and a dentifrice is the most used denture cleaning method. The purpose of this study was to evaluate the abrasiveness of specific and non-specific denture cleaning dentifrices on different heat-polymerized acrylic resins. Sixteen specimens (90x30x3mm) of each acrylic resin (QC-20, Lucitone 550, Clássico, Vipi-Cril) were prepared and randomly assigned to 4 groups: 1: control (distilled water), 2: Colgate, 3: Bonyplus and 4: Dentu-Creme. The specimens were subjected to simulated toothbrushing in an automatic brushing machine using 35,600 brush strokes for each specimen. Brushing abrasion run at a 200-g load with the specimens immersed in 2:1 dentifrice/water slurry. Specimens were reconditioned to constant mass and the mass loss (mg) was evaluated. Data were analyzed by 2-way ANOVA and Tukey's test (a=0.05). Analysis of dentifrices' abrasive particles was made by scanning electron microscopy. Colgate produced the greatest mass reduction (42.44 mg, p<0.05), followed by Dentu-Creme (33.60 mg). Bonyplus was the less abrasive (19.91 mg), similar to the control group (19.69 mg) (p>0.05). The mass loss values indicated that QC-20 (33.13 mg) and Lucitone 550 (33.05 mg) resins were less (p<0.05) resistant to abrasion than Clássico (26.04 mg) and Vipi-Cril (23.43 mg). In conclusion, Colgate produced the greatest abrasion. Specific dentifrices for dentures tend to cause less damage to acrylic resins.

Prevention of toothbrushing abrasion of acid-softened enamel by CO(2) laser irradiation

Objective: The aim of the present study was to evaluate the effect of CO(2) laser irradiation (10.6 mu m) at 0.3 J/cm(2) (0.5 mu s; 226 Hz) on the resistance of softened enamel to toothbrushing abrasion, in vitro. Methods: Sixty human enamel samples were obtained, polished with silicon carbide papers and randomly divided into five groups (n = 12), receiving 5 different surface treatments: laser irradiation (L), fluoride (AmF/NaF gel) application (F), laser prior to fluoride (LF), fluoride prior to laser (FL), non-treated control (C). After surface treatment they were submitted to a 25-day erosive-abrasive cycle in 100 ml sprite light (90 s) and brushed twice daily with an electric toothbrush. Between the demineralization periods samples were immersed in supersaturated mineral solution. At the end of the experiments enamel surface loss was determined using a contact profilometer and morphological analysis was performed using scanning electron microscopy (SEM). For SEM analysis of demineralization pattern, cross-sectional cuts of cycled samples were prepared. The data were statistically analysed by one-way ANOVA model with subsequent pairwise comparison of treatments. Results: Abrasive surface loss was significantly lower in all laser groups compared to both control and fluoride groups (p < 0.0001 in all cases). Amongst the laser groups no significant difference was observed. Softened enamel layer underneath lesions was less pronounced in laser-irradiated samples. Conclusion: Irradiation of dental enamel with a CO(2) laser at 0.3 J/cm(2) (5 mu s, 226 Hz) either alone or in combination with amine fluoride gel significantly decreases toothbrushing abrasion of softened-enamel, in vitro. (C) 2011 Elsevier Ltd. All rights reserved.

The role of surface sealants in the roughness of composites after a simulated toothbrushing test

Objectives: To evaluate the influence of two surface sealants (BisCover/Single Bond) and three application techniques (unsealed/conventional/co-polymerization) on the roughness of two composites (Filtek Z250/Z350) after the toothbrushing test. Methods: Seventy-two rectangular specimens (5 mm x 10 mm x 3 mm) were fabricated and assigned into 12 groups (n = 6). Each sample was subjected to three random roughness readings at baseline, after 100,000 (intermediate), and 200,000 (final) toothbrushing strokes. Roughness (R) at each stage was obtained by the arithmetic mean of the reading of each specimen. Sealant removal was qualitatively examined (optical microscope) and classified into scores (0-3). Data were analyzed by Student`s paired t-test, two-way ANOVA/Tukey`s test, and by Wilcoxon, Kruskal-Wallis and Miller`s test (alpha = 0.05). Results: Z250 groups at baseline did not differ statistically from each other. Unsealed Z350 at baseline had lower R values. All the unsealed groups presented gradual decrease in R from baseline to final brushing. From baseline to the inter-mediate stage, Z250 co-polymerized groups presented a significant reduction in R (score 3). Conventionally sealed groups had no significant changes in R (scores 2-0.8). From baseline to the intermediate stage, the conventionally sealed Z350 Single Bond group had an increase in R (score 1.5). In the final stage, all the conventionally sealed groups presented a reduction in R (scores 0.7-0). Co-polymerized Single Bond groups had a significant reduction in R (scores 2.5-2.7), and co-polymerized BisCover groups an increase in R (scores 2.8-3). Conclusions: At any brushing stage, sealed composites presented superior performance when compared with unsealed composites. (C) 2009 Elsevier Ltd. All rights reserved.

Surface deterioration of dental materials after simulated toothbrushing in relation to brushing time and load.

OBJECTIVES: (1) To evaluate the changes in surface roughness and gloss after simulated toothbrushing of 9 composite materials and 2 ceramic materials in relation to brushing time and load in vitro; (2) to assess the relationship between surface gloss and surface roughness. METHODS: Eight flat specimens of composite materials (microfilled: Adoro, Filtek Supreme, Heliomolar; microhybrid: Four Seasons, Tetric EvoCeram; hybrid: Compoglass F, Targis, Tetric Ceram; macrohybrid: Grandio), two ceramic materials (IPS d.SIGN and IPS Empress polished) were fabricated according to the manufacturer's instructions and optimally polished with up to 4000 grit SiC. The specimens were subjected to a toothbrushing (TB) simulation device (Willytec) with rotating movements, toothpaste slurry and at three different loads (100g/250g/350g). At hourly intervals from 1h to 10h TB, mean surface roughness Ra was measured with an optical sensor and the surface gloss (Gl) with a glossmeter. Statistical analysis was performed for log-transformed Ra data applying two-way ANOVA to evaluate the interaction between load and material and load and brushing time. RESULTS: There was a significant interaction between material and load as well as between load and brushing time (p<0.0001). The microhybrid and hybrid materials demonstrated more surface deterioration with higher loads, whereas with the microfilled resins Heliomolar and Adoro it was vice versa. For ceramic materials, no or little deterioration was observed over time and independent of the load. The ceramic materials and 3 of the composite materials (roughness) showed no further deterioration after 5h of toothbrushing. Mean surface gloss was the parameter which discriminated best between the materials, followed by mean surface roughness Ra. There was a strong correlation between surface gloss and surface roughness for all the materials except the ceramics. The evaluation of the deterioration curves of individual specimens revealed a more or less synchronous course suspecting hinting specific external conditions and not showing the true variability in relation to the tested material. SIGNIFICANCE: The surface roughness and gloss of dental materials changes with brushing time and load and thus results in different material rankings. Apart from Grandio, the hybrid composite resins were more prone to surface changes than microfilled composites. The deterioration potential of a composite material can be quickly assessed by measuring surface gloss. For this purpose, a brushing time of 10h (=72,000 strokes) is needed. In further comparative studies, specimens of different materials should be tested in one series to estimate the true variability.

Technologies that motivates healthy toothbrushing: practices through social translucence

Fifty percent of the European Union’s population suffers from an oral disease. Studies have repeatedly shown that while acquiring healthy toothbrushing practices early on in one’s life is of significance, children and adults often fail to adhere to those. In this thesis we attempt to design and prototype interactive technologies that motivate healthy tooth brushing habits on individuals. Rather than focusing on the technologies’ persuasive power over individuals, we tap on the social mechanisms employed by families. In this sense, we think of these technologies as social translucent rather than persuasive, whose goal is to raise awareness within the family on each other’s habits and that aim at leveraging families’ existing social mechanisms for behavior change, rather than replacing them. More specifically, we aim to gain insights with respect to the following questions: a) What are the drivers and barriers towards adhering to healthy tooth brushing behaviors? b) Can we effectively measure toothbrushing behaviors? c) How can technologies leverage family communication practices in motivating proper toothbrushing behaviors? First, we present two studies about children and adults’ tooth brushing behaviors and how these are influenced by social interactions within the family. Secondly, we present the design and prototyping of two systems that sense toothbrushing practices and provide feedback, using the Social Translucence Framework as a design lens. We conclude with an overview of lessons learnt from the prototyping of these systems supported by an analysis of the strengths and pitfalls of the developed technologies.

Noncarious Cervical Lesions and Their Association With Toothbrushing Practices: In Vivo Evaluation

Objectives: This pilot study aims to investigate the prevalence of noncarious cervical lesions (NCCLs) in a student population at the Faculty of Dentistry of Aracatuba-UNESP and to assess the potential relation between buccal hygiene habits and the presence and number of NCCLs.Methods: This study was conducted with a sample of 58 young volunteers (15 men and 43 women; mean age, 23.6 +/- 1.8 years and 22.3 +/- 2.4 years, respectively). The research was divided into three steps: 1) clinical assessment; 2) oral-hygiene practices self-report questionnaire; and 3) analysis of toothbrush filament deformations. After the clinical exam the participants were divided into two groups, a control group (without NCCLs) and a test group (NCCLs), according to NCCL presence. The data were statistically analyzed with SPSS 16.0 software, using t-test, chi(2), Fisher exact test, and Spearman correlation.Results: NCCLs were present in 53% of the subjects. The presence of NCCLs was marginally statistically associated with age (p=0.15) and proportionally more prevalent in male (80%) subjects (p=0.01). NCCLs were more concentrated in the posterior-superior quadrant (93%) in both the right (90%) and left (55%) sides of the mouth. The direct rank correlation was presented between presence of NCCLs and toothbrush firmness; and between number of NCCLs and age and force applied during toothbrushing.Conclusion: Within the limitations of this pilot study, the use of medium and hard toothbrushes and greater force applied during toothbrushing might contribute to the development and/or aggravation of NCCLs.

Weight loss and changes in surface roughness of denture base and reline materials after simulated toothbrushing in vitro

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Toothbrushing with vegetable oil: a clinical and laboratorial analysis.

The dentifrices currently available in the marketplace contain many anticariogenic substances, fluoride and abrasives aimed to better clean the dental surface, remove dental plaque, improve salivary flow and its buffer capacity and reduce colonies of bacteria such as S. mutans, the causative agent of dental caries. The objective of this study was to evaluate the possibility of adequately removing dental plaque using an experimental almond oil dentifrice (Titoil) with no abrasives or antiplaque agents. This study was carried out with 80 volunteers, all of them 18-year-old recruits from the military training school of Araçatuba -- SP. Saliva sampling and dental plaque disclosing were undertaken both before and after 28 days of toothbrushing with a low abrasive dentifrice (Group 1: 40 volunteers) or with Titoil (Group 2: 40 volunteers). Statistical analysis of the results revealed that the experimental dentifrice (Titoil) did not interfere with salivary flow and reduced dental plaque more than the low abrasive dentifrice, improved the salivary buffer capacity and decreased salivary S. mutans (Caritest-SM) as much as regular dentifrices. It was concluded that if the dental industry replaces abrasive by vegetable oil in dentifrices, these will be more effective in maintaining oral health and will cause less dental abrasion.