A major cause of coronal tooth discoloration may be attributed to remnants of obturation materials left in the pulp chamber following root canal therapy. Endodontic materials that contain certain compounds such as eugenol, phenol, and silver additives may lead to colour changes in coronal tooth structure when they come in contact with dentine. The degree of staining in such cases varies according to the material used and is usually challenging to manage. Several studies evaluated the discoloration potential of sealers and the changes over a period of time. Most of the previous studies used digital imaging as a method of colour measurement, and focused on limited products only.The objective of this study was to assess coronal discoloration due to four commonly used endodontic sealers with gutta- percha, using spectrophotometric analysis. Это и многое другое вы найдете в книге ANALYSIS OF CORONAL DISCOLORATION FROM COMMON OBTURATION MATERIALS (Mohamed Elkhazin)