Rate of removal of root structure by the use of the Prophy-Jet device.

The effects of a constant blast from the Prophy-Jet directed at enamel, dentin, and cementum over 5-, 10-, 15-, 20-, 30-, 40-, 50- and 60-second periods were evaluated to determine what effects the spray had on tooth structure. There was no visible effect on enamel when the spray was directed at the surface for as long as 60 seconds. It was shown, however, that as little as 5 seconds of continuous spray caused a substantial loss of structure when the spray was directed at dentin and cementum. This structural loss was linearly related to the amount of time the area was subjected to the spray. Substitution of flour of pumice for the Prophy-Jet powder resulted in approximately the same rate of loss of root structure. The results suggest that the manufacturers should provide more explicit warnings regarding the abrasiveness of the device on exposed dentin and cementum areas.