Banca de QUALIFICAÇÃO: ARIANE SALGADO GONZAGA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : ARIANE SALGADO GONZAGA
DATE: 15/09/2021
TIME: 14:00
LOCAL: Plataforma ZOOM
TITLE:

MECHANICAL, THERMODYNAMIC AND CHEMICAL CHARACTERIZATION OF COMMERCIAL CuNiTi WIRES – A CLINICAL AND LABORATORIAL LONGITUDINAL COMPARATIVE  STUDY

KEY WORDS:

Orthodontics. Orthodontic wires. Differential Scanning Calorimetry. Smart Materials. Fluorescent X-Ray Spectrometry.

PAGES: 722
BIG AREA: Ciências da Saúde
AREA: Odontologia
SUBÁREA: Ortodontia
SUMMARY:

Introduction: Copper Ni-Ti wires (CuNiTi) have specific indications for clinical use, remaining in the oral environment for a long period. For this reason, their mechanical, thermodynamic and structural characteristics must be preserved throughout the period of use of these materials. Objectives: To investigate whether there are changes in the mechanical, thermodynamic, structure and surface chemical composition of CuNiTi 35°C wires subjected to in vivo aging (clinical use) and in vitro (thermocycling), highlighting the possible differences between the aging methods for each parameter studied. Materials and Methods: The total sample will consist of 85 (eighty-five) pre-contoured 0.016” thermodynamic archwires, with copper addition, and austenitic final temperature (Af) of 35°C, 25 (twenty-five) of which are Ormco® (ORM), 15 (fifteen) Eurodonto® (EUR), 15 (fifteen) Morelli® (MOR), 15 (fifteen) American Orthodontics® (AO) and 15 (fifteen) Orthometric® (ORT). The analyzes of these archwires will result in three articles. Article 1 consists of a clinical experiment, in which 10 (ten) units of ORM wires will be installed in 05 (five) patients, and will remain in the oral environment for 30 (thirty), 60 (sixty) and 90 (ninety) days. At each period, a complete hemiarch plus 1/3 of the lower right hemiarch will be removed for analysis. For article 2, the remaining 75 archwires will be subjected to thermocycling for in vitro simulation of aging on intraoral environment for 30 (600 cycles), 60 (1200 cycles) and 90 days (1800 cycles) with temperature variation of 5°C and 55°C, with 90 (ninety) second baths at each temperature and 15 (fifteen) second transition between baths. After each period of aging, the wires of article 1 and 2 will be subjected to a standardization test of their dimensions, Scanning Electron Microscopy (SEM), Fluorescent X-Ray Spectrometry (FXR), uniaxial tensile tests and Differential Scanning Calorimetry (DSC) tests. Finally, the article 3 will compare the results of laboratory analyzes of the thermodynamic characteristics of in vivo and in vitro aged archwires, highlighting possible differences and similarities between the methods. 

BANKING MEMBERS:
Presidente - 1009536 - SERGEI GODEIRO FERNANDES RABELO CALDAS
Externo à Instituição - FÁBIO LOURENÇO ROMANO - USP
Externo à Instituição - ROGÉRIO LACERDA DOS SANTOS - UFJF