Banca de DEFESA: ARETHA HEITOR VERISSIMO
Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.DISCENTE : ARETHA HEITOR VERISSIMO
DATA : 20/03/2018
HORA: 09:00
LOCAL: DEPARTAMENTO DE ODONTOLOGIA
TÍTULO:
EFFECT OF DIFFERENT REPAIR STRATEGIES ON THE BOND STRENGTH TO COMPOSITE RESIN AND CELL VIABILITY OF NEW CAD/CAM BLOCKS: IN SITU STUDY
PALAVRAS-CHAVES:
CAD / CAM, nanoceramic resin, surface treatment, bond strength, shear strength, glassy ceramics, microbiology, hardness.
PÁGINAS: 87
GRANDE ÁREA: Ciências da Saúde
ÁREA: Odontologia
SUBÁREA: Materiais Odontológicos
RESUMO:
Introduction: New CAD/CAM blocks of resin, hybrid and ceramic restorative materials have been recently developed. However, the literature does not yet have a repair protocol for these materials against a cohesive fracture of the restorative material. Purpose: To determine the influence of surface treatment (diamond burs, abrasive jet Al2O3, COJET, and hydrofluoric acid) and in situ aging on CAD/CAM shear bond strength (Lava Ultimate / 3M, Vita Enamic / VITA and VITA Suprinity / VITA) to the composite resin. Methodology: 300 blocks (6 x 5 x 2.5mm) were made, with 100 of each restorative material. Fifty samples of each restorative material were embedded in total dentures in use, and after a period of 60 days (aging in situ), the 150 aged and 150 no aged samples were randomly divided (N = 30 / n = 10) according to treatment done: Diamond burs + Single Bond Universal (SUB), Diamond burs + silane + conventional adhesive; Hydrofluoric acid 10% + silane + conventional adhesive; COJET + silane + conventional adhesive; abrasive jet aluminum oxide Al2O2 + silane + conventional adhesive. Then, Z350 (3M ESPE) composite resin cylinders (Æ: 2.37mm, height: 2mm) were built on the cementation surface of the blocks. Subsequently, the 300 specimens were then thermocycled (10,000 cycles, 50 / 550C) and then the shear test (50KgF, 0.5mm/min). After fracture, the failure analysis was performed in stereomicroscope (20X). Additional samples were made from each restorative material for further analysis: Vickers microhardness (10 units each); analysis of cell viability (10 units each); scanning electron microscopy (SEM) analysis of surface treatments (10 units each). And in two samples of each block by surface treatment were carried out the analyzes of EDS and XRD for characterization of the materials. The data of shear strength (MPa), cell viability (UFC/mL) and microhardness (HV) were analyzed statistically by ANOVA (2 factors) for the first two (1 factor) for the latter and Tukey's test (5%). Results: For the LU, the highest bond strength was observed in the group Diamond burs + Universal Single Bond (SUB) aged (14.67Mpa), for the VE the aged HF group (17.10Mpa) had higher union strength, for VS the HF group without aging (14.27Mpa) presented higher bond strength. Adhesive failure presented a higher prevalence in all types of CAD / CAM block. The Vita Suprinity (734.31HV) exhibited the highest hardness of Vikers and the Lava Ultimate (137.34HV) the lowest statistically relevant. Cell viability demonstrated no difference between fungal adhesion between the three materials. Regarding the analysis of the treated surfaces (SEM), it was observed that the blasting showed a greater change in the surfaces of the materials; the EDS analysis showed that surface sandblasting with Al2O3 and COJET showed the deposition of aluminum in the composition of all materials. Conclusion: The bond strength of the materials was altered by in situ aging. The zirconium-reinforced glass ceramic has a higher hardness, surface treatments promote surface changes of topography as composition in the materials tested.
MEMBROS DA BANCA:
Presidente - 1640419 - RODRIGO OTHAVIO DE ASSUNCAO E SOUZA
Interno - 1678126 - PATRICIA DOS SANTOS CALDERON
Externo à Instituição - RENATA MARQUES DE MELO - UNESP