Dental root treatment commonly comprises removal of the necrotic pulp or its remnants, cleaning, widening, and sterilization of the root canal, and filling of the prepared canal with core and sealing materials. Popular core materials are silver, gutta-percha, and silicon rubber points, and these are sealed in place by a cement sealer.
The filling materials are in direct contact with the dentin of the canal walls and in a more indirect contact with the soft connective tissue in the apical area. Accordingly, various features of biocompatibility are a prime requirement of the endodontic sealant cements. These cements must also display acceptably low levels of solubility in aqueous media in addition to providing a good seal along the entire contact area for prevention of ingress of bacteria. Setting characteristics must be such that placement in the moist and warm endodontic environment can be accomplished without premature hardening; hence moisture activation, as observed with certain luting cements of the ZOE type, cannot be tolerated. Radiopaqueness is a property frequently called for whenever radiographic control of the filling geometry is indicated.