With the aid of laser-Doppler-flowmetry we are able to determine changes in the microcirculation of the tooth pulp. This method can also be used for testing the histocompatibility of dental materials. The zinkoxiphosphate cement Tenet and the glass ionomer cement Ketac-Cem are examined for tissue tolerance. This is done by determining the incisal and apical changes in pulpal microcirculation. Tenet has almost no discernible effect on pulpal microcirculation. Ketac-Cem causes a longlasting hyperaemia in half of the cases which seems to depend on the depth of cavity preparation.