Characterization of aesthetic restorative materials and influence of its thickness on the mechanical behavior of posterior monolithic crowns

• Grant number: 14/15637-7
• Support Opportunities: Regular Research Grants
• Duration: April 01, 2015 - March 31, 2017
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Renata Garcia Fonseca
• Grantee: Renata Garcia Fonseca
• Host Institution: Faculdade de Odontologia (FOAr). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil
• Associated researchers: Flávia Zardo Trindade ; Gelson Luis Adabo ; Paulo Francisco Cesar

Abstract

Currently, there is a great demand for use and supply of esthetic restorative materials, often with similar indications. A recent proposal to restore posterior teeth is the monolithic crowns. There are three restorative aesthetic materials, very competitive to each other, currently available for the fabrication of monolithic crowns to posterior teeth, which are: lithium disilicate (IPS e.max CAD), yttria stabilized zirconia (LAVA Plus Crown) and a new nanoceramic material (Lava Ultimate CAD/CAM). However, there is a question which remains for researchers and clinicians, that is: Which one of these new and "innovative" materials present better performance in a long term? Therefore, to answer questions like that and prove which one present the best biomechanical performance and why, factors such as composition, microstructure, and some physical and mechanical properties should be investigated. Thus, this study aims to investigate the effect of composition, microstructure, hardness, elastic modulus, toughness and flexural strength of those materials as well as the influence of the thickness of monolithic crowns on its flexural strength during compressive and fatigue test. For this purpose, bar-shaped specimens will be fabricated according to the ISO 6872:2008 standard to test the toughness and four-point flexural strength test. After the flexural strength test, part of specimens will be used for the microhardness test and the other part will be used for microstructural analysis in a scanning electron microscope (SEM) coupled to an energy dispersive spectrometer (EDS) whereby the chemical composition will be determined. For the compressive and fatigue test, prepared tooth shaped samples will be produced in resin (G10) to receive monolithic crowns made by those three aesthetic materials in different thicknesses (0.5, 1.0, 1.5 mm). The internal fit of the crowns will be also assessed by the replica technique, using an impression material, prior the cementation step. After the compressive test in a universal testing machine, the fatigue test will be performed to determine the Weibull and slow crack growth parameters and the lifetime of those three materials. Fractographic analyses will be performed by scanning electron microscopy (SEM). The data will be statistically analyzed according to their distribution. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

LUDOVICHETTI, FRANCESCO SAVERIO; TRINDADE, FLAVIA ZARDO; WERNER, ARIE; KLEVERLAAN, CORNELIS JOHANNES; FONSECA, RENATA GARCIA. Wear resistance and abrasiveness of CAD-CAM monolithic materials. JOURNAL OF PROSTHETIC DENTISTRY, v. 120, n. 2, AUG 2018. (14/15637-7)