title: Composition and mechanical properties of gutta-percha endodontic points.
abstract: Gutta-percha endodontic filling points were found to contain approximately 20% gutta-percha (matrix), 66% zinc oxide (filler), 11% heavy metal sulfates (radiopacifier), and 3% waxes and/or resins (plasticizer). The mechanical properties were indicative of a partially crystalline viscoelastic polymeric material. They were found to obey Hooke's law and displayed a prominent upper and lower yield point when stressed beyond the proportional limit. The essential differences in mechanical properties of individual brands were found to be a function of the gutta-percha and zinc oxide concentration.
mesh_terms: D004548:Elasticity; D006171:Gutta-Percha / Q000032:analysis; D013314:Stress, Mechanical; D014783:Viscosity; D015032:Zinc / Q000032:analysis
chemical_list: D006171:Gutta-Percha; D015032:Zinc