Methods: Eighty polished mid-coronal enamel sections were subjected 10 wear cycles. Each cycle consisted of initial remineralisation in artificial saliva for 2 hours followed by 10 minutes immersion in one of four acidic fruit drinks or distilled water and abrasion on a tooth-brushing on a machine under a load of 200 grams for 200 strokes using an artificial saliva/fluoride free toothpaste slurry (1:3 ratio by weight). The samples were reproduced in light bodied impression material before and after wear cycles. Impressions were scanned on a non-contacting laser profilometer and before and after impressions were superimposed using surface matching software. Tooth wear was measured using 2D (step height and surface area of the wear scar) and 3D (volume, mean step height and normalised data) techniques.
Results: The 2D step heights measurements showed no statistically significant differences (22.4-32.5um) between the four experimental drinks but they were statistically significant different to distilled water (10.0um) (p>0.05). The 3D measurements showed that two drinks produced more wear compared to the others and water when surface area exposed to wear, volumetric loss and normalised data were accounted for (p>0.05) and was directly related to the surface area exposed to the wear cycles. This was not evident with 2D measurements.
Conclusion: Three-dimensional step height measurements were more indicative of overall wear potential of acidic drinks. This study was supported by the Guy's and St Thomas' Charity Grant No G050202.