Banca de QUALIFICAÇÃO: SARAH EMILLE GOMES DA SILVA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : SARAH EMILLE GOMES DA SILVA
DATE: 19/12/2024
TIME: 14:00
LOCAL: Online
TITLE:

CHARACTERIZATION OF NEW GENERATIONS OF MULTILAYERED DENTAL ZIRCONIA CERAMIC: IN SILICO AND IN VITRO STUDY

KEY WORDS:

Zirconia; CAD/CAM; Pigments; Ceramic

PAGES: 30
BIG AREA: Ciências da Saúde
AREA: Odontologia
SUBÁREA: Materiais Odontológicos
SUMMARY:

Microstructural advancements have revolutionized dental zirconia, making it suitable for a wide range of clinical applications. The latest innovation, multilayer yttria-stabilized zirconia (MYL), combine a strong opaque layer at the gingival third with a highly translucent layer at the incisal edge. Various factors affect the mechanical and optical properties of dental ceramics, including the application of stains for restoration characterization. This study aims to evaluate how different pigment application protocols affect the mechanical, optical, and surface properties, toothbrushing wear, masking ability, and the fatigue life of multilayer zirconia, considering connector size in 3-unit posterior fixed partial dentures (FPDs) through both in silico and in vitro analysis. For the first stage of the project, three hundred and sixty (N=360) ceramic discs (Ø:12mm; 1.5mm-ISO 6872) will be made, 120 of ultra-translucent zirconia (UT-NexxZr+, Sagemax Bioceramics), 120 of a multilayered zirconia ceramic 3Y-TZP and 5Y-PSZ (ML-NexxZ T multi, Sagemax Bioceramics) and 120 of a multilayered zirconia ceramic 4Y-PSZ and 5Y-PSZ (MLT-NexxZr+ multi, Sagemax Bioceramics). After sintering, each ceramic discs from each ceramic type will be divided into 8 groups (n=15), according to the factors “Stain application (C-Control; Pe-Pre-sintering; Po-Post-sintering; PP-Pre and post-sintering)” and “Toothbrushing wear” (T-With simulated toothbrushing or without). The discs will receive the stain application according to the studied factor. Three cylindrical substrates with different shades (A1, C4D and metal substrate) will be fabricated to perform the masking ability evaluation of the discs with digital spectrophotometer for color measurements. Complementary analyzes of X-ray Diffraction (XRD), roughness and fractography analysis will be also carried out. All specimens will be subjected to biaxial flexural strength (σ) test (with a static load cell of 10kN). The results will be statistically evaluated using 2-way ANOVA, Tukey test (5%) and Weibull analysis. For the second stage of the project, an in-silico analysis of will be conducted to evaluate the fatigue behavior of the same zirconia systems simulating 3-unit posterior fixed partial dentures (FPDs) with different connector sizes (4 x 2.5 mm and 3 x 3 mm), multilayered zirconia with gradient technology shows varying strength and resistance in connector areas, depending on the connector size. A 3-unit FPDs (replacing the second upper premolar) will be constructed using a computer aided design and computer-aided manufacturing (CAD-CAM) system. Finite element analysis (FEA) will be executed. A hemispherical indenter will be used to simulate occlusal load. The occlusal load phase of the chewing cycle will be applied at the premolar pontic. The in vitro simulation of the FEA model with fatigue strength test will be also performed.

COMMITTEE MEMBERS:
Presidente - 1640419 - RODRIGO OTHAVIO DE ASSUNCAO E SOUZA
Interna - 1678126 - PATRICIA DOS SANTOS CALDERON
Externa à Instituição - RENATA MARQUES DE MELO - UNESP