Secondary caries formation by Streptococcus mutans in restorations with bioactive materials

• Grant number: 19/14729-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): February 01, 2020
• Effective date (End): January 31, 2021
• Field of knowledge: Health Sciences - Dentistry - Dental Clinics
• Principal Investigator: Taciana Marco Ferraz Caneppele
• Grantee: Juliana Benace Fernandes
• Host Institution: Instituto de Ciência e Tecnologia (ICT). Universidade Estadual Paulista (UNESP). Campus de São José dos Campos. São José dos Campos , SP, Brazil

Abstract

The study aims to evaluate the formation of Streptococcus mutans-induced secondary caries at the margin of restorations located on dentin and enamel using bioactive materials of the alkasite category with and without adhesive, glass ionomer cement in comparison to resin composite. One hundred samples (blocks of 7x7x3 mm) of bovine incisor tooth will be used. Fifty standardized cavities with 2mm deep will be performed in enamel and fifty in dentin. All prepared samples will be randomly divided into five groups (n=20), according to the restoration material that will be used: Alkasite without adhesive (Cention N-Ivoclar Vivadent), Alkasite with adhesive (Cention N-Ivoclar Vivadent + Tetric N Bond Universal Adhesive -Ivoclar Vivadent), glass ionomer cement (Equia Forte - GC); resin composite (Tetric N-Ceram - Ivoclar Vivadent), and 20 prepared samples with no restoration (control group - 10 enamel/10 dentin). All the groups will be divided into two subgroups, half of the samples will be restored in enamel and the other half in dentin. The samples will be exposed to thermocycle aging (5.000 thermal cycles). The samples will be sterilized and exposed to a cariogenic challenge using a bacterial system using Streptococcus mutans. Then the analysis will proceed to examine the samples under a stereomicroscope observation (50x). The development of artificial carious lesions will be quantified by surface and subsurface knoop microhardness and by the analysis with polarized light microscopy. The data collected will be evaluated to normality, and the appropriate statistical tests will be applied. (AU)