While other materials are available for obturating root canals, gutta percha is still the most widely used and accepted material. Gutta perch is biocompatible, inert material which does not irritate tissues. Composed of zinc oxide, barium sulfate and transpolyisoprene, gutta percha has the ability to adapt to root canal walls.
Resilon, a thermoplastic polymer which contains bioactive glass, has become increasingly popular as a filling material recently. This technique involves the creation of a chemical bond between the sealer and filling material.
Other paraformaldehyde-containing pastes have been proposed but, due to antigenic and cytotoxic effects on tissue, these have not been approved for use. They are also known to cause chronic inflammation, necrosis and sequestration of bone.
Source: Dental Secrets, Elsevier, 2015