Interplay between toothbrush stiffness and dentifrice abrasivity on the development of non-carious cervical lesions
Abstract
Objective
This
study investigated the effect of toothbrush stiffness and dentifrice
slurry abrasivity on the development and progression of simulated
non-carious cervical lesions (NCCLs).
Materials and methods
Human
maxillary premolars were allocated to 12 groups generated by the
association between toothbrushes, soft, medium, and hard stiffness, and
simulated dentifrice slurries, lower, medium, and higher; deionized
water (DI) served as negative control. Teeth were mounted on acrylic
blocks, and their root surfaces partially covered with acrylic resin to
simulate gingiva, leaving a 2-mm area apical to the cemento-enamel
junction exposed to toothbrushing. Specimens were brushed with the test
slurries for 35,000 and 65,000 double strokes. Impressions taken at
baseline and after both brushing periods were scanned by a 3D optical
profilometer. Dentin volume loss (mm3) was calculated by image subtraction. Data were analyzed using three-way ANOVA and Fisher’s PLSD tests.
Results
All
toothbrushes caused higher volume loss when associated to higher
abrasive slurry, compared to medium- and lower-abrasive slurries. Medium
caused more volume loss than lower-abrasive slurry, which led to more
volume loss than DI. Hard and medium toothbrushes were not different
when used with medium- or higher-abrasive slurries. There were no
differences among toothbrushes when used with DI and lower-abrasive
slurry. Overall, 35,000 brushing strokes resulted in significantly less
volume loss than 65,000.
Conclusions
Toothbrush
stiffness was an important factor on NCCL development, especially when
brushing with medium- and higher-abrasive slurries.
Clinical relevance
Medium and hard toothbrushes associated with medium- and high-abrasive toothpastes can yield more severe NCCLs.
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