Comparison of two methods to measure permeability of dentin

Dentin permeability was measured alternatively with two methods: a 10-microl capillary method with visual evaluation (PC) and a motorized automatic measuring device (Flodec, FD), both interposed in a simulated perfusion system. Eight human third molar coronal fragments were connected to systems, and their permeability to distilled water measured at 0, 5, 10, 15, 20, 25, and 29 cm H(2)O pressure. Resultant permeabilities (in microl/s) for both techniques were interrelated with the use of the Passing and Bablok nonparametric method, which gives information about the range of constant and proportional errors and their 95% confidence intervals (95CI). The relationship between the methods is described by the regression formula: FD = -0.0003 + 0.945.PC, with 95CI for constant (-0.0015-0.0009) and for slope (0.738-1.168), indicating that both methods are interchangeable, although not identical.