Interaction between toothpaste abrasivity and toothbrush filament stiffness on the development of erosive/abrasive lesions in vitro

Abstract

5425, E-Mail flippert@iu.edu 2 Objectives: To investigate the enamel and dentin surface loss caused by the interaction between abrasives in toothpaste and toothbrush filament stiffness. Methods:The study followed a 2 (high/low-level abrasive; silica) × 3 (filament stiffness; soft/medium/hard) × 2 (cycling time; 3/5d) factorial design. Polished bovine enamel and dentin specimens (n=8 each per group) were subjected to 5d of erosion/abrasion cycling: erosion (5min, 4×/d, 0.3% citric acid, pH 3.75), abrasion (15s, 2×/d, 45 strokes each, 150g load, automated brushing machine), fluoride treatment (15s with abrasion and 45s without abrasion; 275ppm F as NaF in abrasive slurry) with exposure to artificial saliva between erosion and abrasion/F exposure (1h) and all other times (overnight).Non-contact profilometry was used to determine surface loss (SL) after 3 and 5d of cycling. Data were analyzed using three-way ANOVA (factors: abrasive/filament stiffness/time) with separate analyses conducted for enamel and dentin.Results: For enamel, only 'cycling time' was found to affect surface loss with 5>3d. Overall, there was little SL (mean range: 0.76-1.85µm). For dentin (mean SL range: 1.87-5.91µm), significantly higher SL was found for 5 vs. 3d, with particularly large differences for hard stiffness/high-level abrasive, and medium stiffness/medium abrasive. Hard stiffness resulted in significantly higher SL than medium stiffness for high abrasive after 5d, with no other significant stiffness differences. High abrasive had significantly higher SL than medium abrasive overall with strong effects for all combinations, except medium stiffness after 5d. Conclusion:The interplay between abrasivity and filament stiffness appears to be more relevant for dentin than enamel.3

3D-Image analysis of the impact of toothpaste abrasivity on the progression of simulated non-carious cervical lesions

“…Approximately a 200 g load was applied on the toothbrush head. Although filament stiffness likely follows toothpaste abrasivity in terms of relevance in the abrasion process for dentine [24], the controversial findings in the literature with some authors finding more abrasion with increased bristle stiffness [25,26], whereas others the opposite [27,28], call for further studies.…”

Piezo-catalysis for nondestructive tooth whitening

“…The use of toothpaste with water-insoluble abrasives is safe, time-and costeffective, but decontamination of tooth stains is realized only by the mechanical friction between tooth and abrasive elements, such as aluminium hydroxide, calcium carbonate, and silicas. Thus, abrasive cleaning exhibits limited efficacy and, furthermore, causes slight scratches to the surface of teeth 5 . Tooth bleaching is a chemical method that generally uses high-concentration hydrogen peroxide as an agent 6 .…”

Baking soda as an abrasive in toothpastes

“…Although there are equivocal findings on how toothbrush stiffness affects abrasion, 27,29-32 its combination with toothpaste abrasivity seems to be important. 12 In another laboratory simulation (Binsaleh and colleagues, unpublished data, November 2015), we observed that toothbrush bristle stiffness seems irrelevant when brushing with low-abrasive toothpaste. In addition, the choice of a soft, medium, or hard toothbrush is of lesser relevance to enamel than to dentin abrasion.…”

“…In addition, the choice of a soft, medium, or hard toothbrush is of lesser relevance to enamel than to dentin abrasion. 12 However, one should bear in mind that filament stiffness is likely to follow toothpaste abrasivity in terms of relevance in the abrasion process, even for dentin substrates. 12 Investigators have speculated that abrasion of dental hard tissues may be minimized if filaments are round ended and smooth.…”

“…12 However, one should bear in mind that filament stiffness is likely to follow toothpaste abrasivity in terms of relevance in the abrasion process, even for dentin substrates. 12 Investigators have speculated that abrasion of dental hard tissues may be minimized if filaments are round ended and smooth. 33,34 In a laboratory simulation, however, flat-ended filaments entrain and trap fewer particles at the filament tip region than do filaments with rounded tips, 35 which might imply increased wear with the latter.…”