Effect of Different Sealers on Adhesion and Sealability of Gutta-Percha in Root Canals⁠⁠

Abstract

Although gutta-percha has long been proven as a gold standard obturation material, its non-adhesive nature to the dentin requires the use of sealers to seal the voids, conform to canal anomalies, and increase the long-term sealability. The ability of adhesion to both dentin and gutta-percha, and the ability to resist microleakage with time, are the key characteristics of performance of a root canal sealer. Many types of sealers have been developed with varying degrees of ease such as the conventional zinc oxide-eugenol mixtures to resin based sealers and, most recently, calcium silicate-based bioceramics. The physicochemical and biological properties are different in each of the classes and consequently affect adhesion and sealing behavior. Comparative research has indicated that resin based sealers are better in bonding dentin by micromechanical interlocking, but bio ceramic sealers are better in terms of chemical bonding, bioactivity and long term dimensional stability. Conversely, zinc oxide-eugenol sealers offer lower adhesion and they have the tendency to dissolve casting doubt on their effectiveness in the long term. This review critically analyses the existing evidence touching on the adhesive and sealing properties of various sealers with recent developments and clinical implications. A particular focus is made on laboratory models which are applied to test adhesion and microleakage and their applicability to clinical performance. There is collective evidence that there is a trend towards the use of calcium silicate-based sealers due to their better sealing and biological properties, even though additional clinical trials would be justified to be able to prove their effectiveness in the long term.