EFFECTS OF PULSATILE VERSUS NON-PULSATILE PULPAL PRESSURE SIMULATIONSON DIFFUSIONAL TRANSPORT ACROSS HUMAN DENTIN IN-VITRO

The influence of a simulated pulsatile pulpal pressure on the diffusio n of NaCl through slices of human dentine (n = 12) was evaluated in vi tro. The average hydraulic conductance of the slices of dentine was 0. 0131 +/- 0.0031 mu l/cm(2) per min per cmH(2)O(x +/- SD). A 1 mol/l Na Cl solution was placed on one side of the slices of dentine and deioni zed water on the other side. The time needed to reach a steady state a nd the quantity of NaCl that diffused through the slice were successiv ely measured on the same slice of dentine, under three conditions: wit hout pressure simulation, with a static pressure of 1.5 kPa, and with a pulsatile pressure varying from 1.2 to 1.8 kPa. The pressure was app lied to the deionized water. When a static pressure was applied, the t ime required to reach a steady state increased from 24 to 30 h. When a pulsatile pressure was applied the time required to reach a steady st ate decreased from 24 to 12 h. No statistically significant difference was found between the quantity of NaCl that had diffused when the ste ady state was reached. Copyright (C) 1996 Elsevier Science Ltd.