B

Gutta-percha cones soften at temperatures used in autoclaves or dry-heat units, so heat methods are unsuitable; brief immersion in chemical disinfectants (e.g., 1–5 % sodium hypochlorite) provides rapid, effective sterilization without deforming the material [Cardoso, 1999, PMID 10687516; Ozalp, 2006, PMID 17174684].