RELATIONSHIP BETWEEN ENDODONTIC PREPARATIONS AND HUMAN DENTIN PERMEABILITY MEASURED IN-SITU

Endodontic preparations may induce changes in the permeability of radi cular dentin, The aim of this study was to analyze the variation of hy draulic conductance measured in situ after three endodontic preparatio ns (manual K+H files, ultrasonic preparation, and manual with NaOCl an d EDTA), Scanning electron microscopic analysis of the canal walls was made to permit correlations between variations of permeability and th e amount of surface covered with smear layer or organic debris, There was an inverse relationship between the variations in dentin permeabil ity and the presence of smear layer. The significance of this correlat ion was variable according to the techniques used, Dentin thickness wa s as significant a factor in influencing radicular permeability as was the smear layer, The use of EDTA induced a considerable increase in r adicular permeability, The use of ultrasonics produced a similar but w eaker effect.