Influence of increment thickness in physical and photoelastic properties of dental composites with different organic compositions

• Grant number: 14/02707-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: May 01, 2014
• End date: December 31, 2014
• Field of knowledge: Health Sciences - Dentistry
• Principal Investigator: Flávio Henrique Baggio Aguiar
• Grantee: Renata Pereira
• Host Institution: Faculdade de Odontologia de Piracicaba (FOP). Universidade Estadual de Campinas (UNICAMP). Piracicaba , SP, Brazil

Abstract

This study aims to evaluate the Knoop microhardness, the degree of conversion and photoelasticity of three dental composites: Two microhybrids and one nanohybrid , subjected to different increment thicknesses. 45 specimens will be prepared and submitted to microhardness and degree of conversion tests. The specimens will be divided in 9 groups (n = 5 each) according to the composite (microhybrid Filtek Z - 250 - 3M Espe; Surefil SDR Flow - Dentsply; nanohybrid N'Durance - Septodont) and increment thickness (1; 1.5; 3 mm). The samples will be prepared and submitted immediately to the Knoop microhardness test to evaluate the microhardness on the top and bottom surfaces. After, degree of conversion will be measured by Fourier Transformed Infrared Spectroscopy on the top and bottom surfaces. For photoelasticity testing, photoelastic models will be manufactured from a second upper premolar with a Class I cavity. The composites will be inserted into the cavity of the photoelastic model and photoactivated. The samples will be divided in 9 groups (n = 5 each) according to the type of composite (microhybrid Filtek Z - 250 - 3M Espe; Surefil SDR Flow - Dentsply; nanohybrid N'Durance - Septodont) and restorative technique (bulk filling increment (3mm); two increments of 1.5 mm; three increments of 1mm). The specimens will be prepared and submitted immediately and 24 hours after photoactivation to photoelasticity test for evaluation of stress generated by polymerization shrinkage of the composite. Data will be analyzed statistically.

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)

PEREIRA, RENATA; CALDAS GIORGI, MARIA CECILIA; ESTEVES LINS, RODRIGO BARROS; THEOBALDO, ESSICA DIAS; NUNES LEITE LIMA, DEBORA ALVES; MARCHI, GISELLE MARIA; BAGGIO AGUIAR, FLAVIO HENRIQUE. Physical and photoelastic properties of bulk-fill and conventional composites. CLINICAL COSMETIC AND INVESTIGATIONAL DENTISTRY, v. 10, p. 287-296, 2018. (14/02707-7)