title: Brazilian gutta-percha points. Part II: thermal properties.
abstract: This study was undertaken to explore the effect of heating on gutta-percha, analyzing the occurrence of endothermic peaks corresponding to the transformation that occurs in the crystalline structure of the polymer during thermal manipulation. This study also sought to determine the temperature at which these peaks occur, causing a transformation from the beta- to the alpha-form, and from the alpha- to the amorphous phase. Eight nonstandardized gutta-percha points commercially available in Brazil (Konne, Tanari, Endopoint, Odous, Dentsply 0.04, Dentsply 0.06, Dentsply TP, Dentsply FM) and pure gutta-percha (control) were analysed using differential scanning calorimetry (DSC) and thermogravimetry analysis (TGA). The transition temperatures were determined and analysed. With the exception of Dentsply 0.04 and Dentsply 0.06, the majority of the products showed thermal behaviour typical of beta-gutta-percha, with two endothermic peaks, exhibiting two crystalline transformations upon heating from ambient temperature to 130 degrees. Upon cooling and reheating, few samples presented two endothermic peaks. It was concluded that heating dental gutta-percha to 130 degrees C causes changes to its chemical structure which permanently alter its physical properties.
authors: Department of Endodontics, University of Fortaleza, Rua Bento Albuquerque 685, Papicu, Fortaleza, CE, Brazil, CEP 60190-080. manigliaf@secrel.com.br
authors: Cláudio
authors: C
authors: Maniglia-Ferreira
authors: Eduardo Diogo
authors: ED
authors: Gurgel-Filho
authors: João Batista Araújo
authors: JB
authors: Silva
authors: Regina Célia Monteiro de
authors: RC
authors: Paula
authors: Judith Pessoa Andrade
authors: JP
authors: Feitosa
authors: Brenda Paula Figueiredo de Almeida
authors: BP
authors: Gomes
authors: Francisco José de
authors: FJ
authors: Souza-Filho
mesh_terms: D001938:Brazil; D002152:Calorimetry, Differential Scanning; D004055:Differential Thermal Analysis; D006171:Gutta-Percha / Q000737:chemistry*; D008422:Materials Testing; D012390:Root Canal Therapy; D018709:Statistics, Nonparametric; D013499:Surface Properties; D013696:Temperature; D013816:Thermodynamics; D013818:Thermogravimetry
chemical_list: D006171:Gutta-Percha