Comparison of pulpal blood flow in dog canine teeth determined by the laser Doppler and the 133xenon washout methods.

Pulpal blood flow measurements by laser Doppler flowmetry were compared with those made simultaneously and on the same teeth by the 133Xe washout method. Pulpal method flow in the resting state was 82.4 ml/min per 100 g as calculated from the fast component of the 133Xe washout, whereas laser Doppler flowmetry recorded 263 mV. The close intra-arterial (i.a.) injection of the vasoconstrictor norepinephrine (10(-2)-10(-1) micrograms/kg) caused a reduction of pulpal blood flow by 20.2% with the 133Xe washout and by 9.7% with the laser Doppler flowmetry in 6 observations in 4 dogs. The laser Doppler flowmetry measurements of these norepinephrine-induced changes correlated significantly with changes measured by the 133Xe washout method as analysed by linear regression (p = 0.004).