Resin-modified glass ionomer cements for restoration (RMGIC): flexural strength

• Grant number: 17/19951-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: January 01, 2018
• End date: December 31, 2018
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Ana Flávia Sanches Borges
• Grantee: Laura Terumy Onodera Saito
• Host Institution: Faculdade de Odontologia de Bauru (FOB). Universidade de São Paulo (USP). Bauru , SP, Brazil

Abstract

This project aims to evaluate the flexural strength of resin-modified glass ionomer restorative cements (RMGIC) of different brands, national and international, and to compare with the findings in the literature and with the results obtained by the Brazilian Centar for Glass Ionomer Cement Education - GIC BraCE (CNPq) with chemically activated restorative glass ionomer cements (GIC). Specimens (sp) (n = 5) of each trade mark [Resiglass R (RR); GC Gold Label 2 LC (F2); IonoLux (I); Vitremer (V); Riva Light Cure (R); Vitro Fil LC (VF)] will be prepared using a polymethyl methacrylate (PMMA) mold of 25x2x2mm for the three-point flexural strength test, according to the ISO 9917-2: 2007. The sp will be prepared according to each manufacturer recommendations. After mixing, the cement will be inserted into the mold and compressed using two steel plates and a screw clamp. The whole set will be stored at 37 o C and one relative humidity of at least 90% for 1 h. Then, the sp will be carefully removed from the molds and stored in distilled water at 37 o C for 23h. Then, sps from each group will be submitted to the flexural strength test in a universal test machine (Kratos equipment, K5000, Cotia, Brazil) with a load cell of 200 kgf in the velocity of 0.75 ± 0.25 mm / min. The results obtained will be transformed in MPa. The results will be analyzed using SPSS software (Statistical Package for Social Sciences, IBM Inc., New York, NY, USA), version 20.0, through descriptive statistical analysis. Data collected will be submitted to ANOVA and Tukey Tests, if they present normal distribution, or to Kruskal-Wallis and MannWhitney Test, if they do not present a normal distribution, adopting a significance of 5% (p <0.050). The importance of carrying out this project comes from the lack of standardization of the materials available on the market today. This situation makes it harder to determine their clinical applications, since they present many different properties, characteristics and costs, even when indicated for the same purpose. (AU)