The cutting effectiveness of carbide fissure burs on teeth.

The cutting effectiveness of the burs decreased with time. While the multivariate analysis of variance showed an overall difference among the three groups, these differences appeared to be due to the shape of the curves (the linear and quadratic components) rather than to their average location (the mean). Therefore there were no significant differences in cutting among the three types of burs tested. The SEM photomicrographs showed that there was no gross bur damage after the burs were used for cutting tooth structure. The cutting mechanism of a carbide bur on tooth structure needs further investigation.