Application of a new mechanical properties microprobe to study hardness of eroded bovine enamel in vitro

A mechanical properties microprobe technique was used to study bovine tooth specimens that had been immersed in 50 ml of either cola beverage or sports drink for 1 min, 5 min, and 15 min. A Vickers diamond was used to analyze the test and control surfaces at 7V input. This corresponds to a 100 g load of a conventional indentation microhardness apparatus which was used for comparison. The results showed good agreement between the conventional and the microprobe hardness analyses. Enamel softening was found to be significant after 5 min immersion in both acidic drinks, while 1 min immersion did not cause softening. This shows that shorter immersion times than previously used can be applied in dental erosion studies in vitro. Compared with the conventional indentation microhardness measurements, however, the microprobe technique did not offer any advantage, such as assessment of the microelastic properties of enamel, probably because the biologic tissue did not allow reliable data collection during the loading and unloading phases of the instrument.