The effects of some vaso-active drugs on the eruption of the rabbit mandibular incisor

Abstract

Because the forces of tooth eruption may be generated by vascular/tissue hydrostatic pressures, the effects on the rabbit incisor of hypotensive agents (hexomethonium, guanethidine and hydrallazine) and of noradrenaline and acetylcholine were investigated using a technique for continuously monitoring tooth movements. Following the intravenous administration of hexomethonium (10 mg/kg), guanethidine (3 mg/kg) or hydrallazine (1 mg/kg), the rates of eruption-like movements increased for approximately 2 h and then the hexomethonium ones returned to control values, the other two showed a similar trend to return. In some rabbits treated with guanethidine or hydrallazine, however, the initial response was an intrusion of the incisor. Injection of noradrenaline (0.003 mg/kg) was associated with intrusive movements initially. Acetylcholine (0.01 mg/kg) was associated with a rapid extrusive movement initially where there was little or no prior eruption. Where eruption was present, reactions were difficult to show. These initial effects of noradrenaline and acetylcholine were occasionally followed by eruption-like movements, the rates of which were much higher than expected. Changes in periodontal tissue hydrostatic pressure could be responsible for all the drug effects.