Gutta-Percha

The cones are made mostly of zinc oxide and gutta-percha, with plasticizers and radiopacifiers added.

Gutta-percha is easy to manipulate, radiopaque, plastic and relatively inexpensive. Radiopacity lets the filling be seen on a radiograph.

The core material occupies almost all of the prepared canal. A small amount of sealer fills the gap between dentin and the cone, including lateral canals and tubules the cone cannot enter.

Cold lateral condensation and thermoplasticized techniques are both used to obturate canals. In micro-CT studies, both left voids, while thermoplasticized techniques generally produced fewer voids.

Standardized cones have a 0.02 taper. When a canal is prepared to a given standardized file size, a cone of the same size can be inserted and adapted to it.

Gutta-percha does not bond to dentin and shrinks as it cools. A complete, fluid-tight canal fill therefore relies on both the sealer and the obturation technique.