Restorative glass ionomer cements modified with cellulose nanocrystals: evaluation of fluoride release

• Grant number: 14/23924-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: January 01, 2015
• End date: December 31, 2015
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Maria Fidela de Lima Navarro
• Grantee: Lívia Yukari Shimohara
• Host Institution: Faculdade de Odontologia de Bauru (FOB). Universidade de São Paulo (USP). Bauru , SP, Brazil

Abstract

The modified glass ionomer cements with cellulose nanocrystals (CIVNCC) significantly increased mechanical resistance of conventional glass ionomer cement restorative (CIV), routinely used in dental clinic. The ability of mechanical resistance is an important requirement for a material, however it is important to note that the F-ions released gradually by the CIV, give the material property anticariogênica, preventing the installation of new carious lesions. So, our goal is to modify various trademarks of restorative glass ionomer cement of low, medium and high viscosity with nanocrystals obtained from eucalyptus pulp, assess the release of F-of composites developed and characterize them by means of scanning electron microscopy (SEM), energy dispersive spectroscopy x-ray (EDS), x-ray diffraction and infrared spectroscopy (FTIR) Fourier transform. Bodies of evidence (cps) with different concentrations of NCC in total mass will be made, thus obtaining the experimental groups of different restorative cements tested. Seventy proof bodies (cps) of each of the test groups, as well as the respective controls, shall be made using a metal matrix of 11.0 mm in diameter and 3 mm thick. After the prey of cements, the cps will be heavy and distributed randomly in experimental groups Test group (n10) and the control group (n10), according to predetermined times (1, 6, 12, 24, 72, 168 and 336 hours) for analysing the release of F-. The cps will be immersed in 10 ml of deionized water, suspended by means of nylon cord in falcon tubes sealed and identified, the 37° C. F-concentration will be measured through specific ion electrode coupled to pot. The results obtained will be converted into µg and submitted to the appropriate statistical test (parametric or non-parametric) (p<0.05).