Physicochemical and mechanical characterization of dentin substrates produced by different in vitro dentin caries induction protocols

• Grant number: 24/19923-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2025
• End date: January 31, 2026
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Josimeri Hebling Costa
• Grantee: Giulia Burlim de Souza
• Host Institution: Faculdade de Odontologia (FOAr). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil

Abstract

Adhesive interfaces are frequently produced on modified dentin substrates, like caries-affected dentin (CAD). This substrate is less mineralized, more porous, contains more exposed collagen, has greater water content, and has increased proteolytic activity compared to sound dentin. Thus, producing a strong and stable adhesion between resin materials and this substrate is challenging. The use of naturally formed in vivo CAD, although viable, incorporates important variables that are difficult to control, such as the degree of dentin involvement, the depth of the lesion, and the area available for adhesion. The development of dentin caries through laboratory models has been investigated, such as the use of acid gels (static method), pH cycling (dynamic method), and microbiological methods with monospecies and multispecies biofilms, with the aim of more realistic studies. Therefore, the overall aim of the present project is to compare in vitro dentin caries induction protocols by physical, chemical, and mechanical characterization of the substrates produced before and after the selective removal of carious tissue. Naturally (in vivo) produced dentin caries lesions will be the control. The following analyses will be performed to answer the project's objectives: attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy (ATR-FTIR) to calculate mineral:matrix ratio (MMR), mineral quality (MQ) and collagen maturity (CM); transversal nanohardness and elastic modules; and scanning electron microscopy. Data will be submitted to appropriate statistical tests based on the type of distribution (Shapiro-Wilk) and homogeneity of variances (Levene). Statistical inferences will be made at the 5% level of significance.