A comparison of two-dimensional and three-dimensional measurements of wear in a laboratory investigation

Objectives. The aim of this research was to compare two-dimensional (2D) and three-dimensional (3D) tooth measuring techniques after subjecting enamel samples to tooth wear in vitro on an erosionabrasion model. Method. 80 polished mid-coronal enamel sections were subjected to 10 wear cycles. Each cycle consisted of remineralization for 2h in artificial saliva, followed by 10min immersion in one of four acidic fruit drinks or distilled water and finally toothbrush abrasion with a non-fluoridated tooth paste. The resulting wear scars were measured using 2D and 3D techniques using surface matching software. Results. The 2D step heights measurements from the exposure to the four acidic drinks showed no statistically significant differences (median wear range=22.432.5 mu m) between them (p=0.99) but there were differences with distilled water (median wear=10.0 mu m) (p=0.01). The 3D measurements showed that two drinks produced more wear compared to the others and water when the whole surface and volume exposed to wear was accounted for (p=0.01). Significance. The difference in data from the two techniques showed that 3D measurements gave a more accurate assessment of the impact of the wear regime.