Gutta-percha points

Gutta-percha has been used in endodontics for over 100 years. The material is hand- or machine-rolled into tapering points of standardized sizes.

The classical standard series has a taper of 0.02 with tips measuring from 0.15 mm (ISO 015) in diamtere increasing by 0.05-mm-intervals to 0.60, then by 0.10-mm intervals to 1.40 mm (ISO 140). Points for lateral condensation an ancillary purposes are less rigorously standardized and are usually labelled fine, extra fine, coarse or similarly.

Gutta-percha points actually contain only some 20 per cent gutta-percha. Current materials have mainly zinc oxide to make up the difference, with food coloring additives to give the (red) color. In the past, additional metal salts of varying chemistry were added, primarily for improved X-ray contrast.

Gutta-percha may be softened by heat or organic solvents, typically chloroform. Both mechanisms of softening cause some swelling of the material, with the subsequent toughening accompanied by shrinkage. Softening of the gutta-percha makes it more adaptable and facilitates the obturation of recesses and accessory canals in the root canal system. But the shrinkage must be counteracted by mechanical pressure during hardening, which may not be easy to control.

Gutta-percha is meant for bulk filling. By itself, it does not provide a bacteria-tight seal, and one has to apply a sealer to secure that function of the root filling.

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