Effects of cyclic loading and toothbrush abrasion on cervical lesion formation.

This study sought to determine the effect of cyclic loading and toothbrush abrasion (with and without abrasive slurries) on cervical lesion formation. The roots of extracted human third molars were embedded in acrylic resin, leaving 2 mm of root structure and crowns exposed. Teeth were divided into 6 groups (n = 10) with the following treatments: no treatment (control), cyclic load in distilled water, brushing with distilled water, cyclic load followed by brushing with distilled water, brushing with toothpaste slurry, and cyclic load followed by brushing with toothpaste slurry. Cyclic loading and toothbrushing machines subjected the teeth to 1.6 million cyclic loads and 30,000 brushing strokes, the equivalent of 4 years of function and brushing for an average patient. The teeth were scanned with a 3-dimensional optical profilometer to determine the volumetric loss of tooth structure. Load cycling had no significant effect on cervical tooth loss. Brushing with toothpaste resulted in significantly greater cervical tooth loss than brushing with water, which in turn was significantly greater than no treatment at all.