Caracterização da composição, estrutura, morfologia e propriedades térmicas de cones de guta-percha.

Abstract

The success of endodontic treatment is specially determined by a complete and hermetic sealing of the root canal. Cold or thermoplastisized gutta-percha points are frequently used for canal filling. However, there may be chemical undesirable variations of available commercial trades, leading to an incomplete filling of the canal and to a bad result of the treatment. Our objective was to study the crystaline structure, chemical composition and thermal properties of three standardized and unstandardized gutta-percha points available in Brazil (Dentsply, Tanari and Endopoints), by using DRX, FTIR, FRX and MEV/EDX. Thermal analyses was studied by DSC and TG. DRX showed the presence of two compounds, zinc oxide and barium sulfate. FTIR revealed typical bands and peaks of ZnO and BaS04 and unsaturated areas. These were probably related to polymer, waxes/resins. FRX and EDX analysis revealed that ZnO predominated in all the marks and BaS04was only found in DNE, TE and TNE TG determined that gutta-percha points were irreversibly decomposition when the temperature was 132°C and DSC showed thermal behaviour typical of Bgutta-percha, with two endothermic peaks. We conclude that gutta-percha points have both inorganic (80%) and organic phases (20%) and that thermal manipulation may lead to irreversible changes in chemical structure which permanently alter its physical properties.