An experimental model for the investigation of the tooth support mechanism

A model was constructed from clear plastic in which a cone to represent a tooth was supported by a rubber membrane as the periodontal ligament. The periodontal spaces in the model contained water and the side tubes were used as manometers to measure pressure changes under varying loads. Displacement of the water in the main chambers occurred with lateral movement but variations in pressure were not observed. Axial forces caused an upward bulging of the rubber and pressure difference between the chambers, that at the apex being approximately 20 per cent greater than at the base. It is suggested that, under either lateral or axial load, the periodontal ligament is in tension. During mastication, the ligament in toto appears to act as a hydro-elastic damper.