Compounds derived from cinnamic acid as biomodifiers in dentin pretreatment: antimicrobial, antibiofilm and effect on dentin bond strength

• Grant number: 22/02591-5
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Effective date (Start): July 01, 2022
• Effective date (End): December 31, 2022
• Field of knowledge: Health Sciences - Dentistry - Dental Materials
• Principal Investigator: Aimée Maria Guiotti
• Grantee: Larissa de Souza Oliveira
• Host Institution: Faculdade de Odontologia (FOA). Universidade Estadual Paulista (UNESP). Campus de Araçatuba. Araçatuba , SP, Brazil

Abstract

Long-term stabilization of the composite-adhesive-dentin interface represents a major challenge in restorative dentistry. In this context, the use of collagen biomodifying phenolic compounds was proposed to avoid the degradation of the hybrid layer. Cinnamic acid and its derivatives are phenolic compounds that stand out for their multiple medical applications. Among them, its potent antioxidant and antimicrobial activities. In this context, this study aims to evaluate: 1) The antimicrobial/antibiofilm activity of compounds synthetically derived from cinnamic acid; 2) To analyze the bond strength of the composite-adhesive-dentin interface after dentin treatment with the test solution formulated with a cinnamic acid-derived compound with the best biological action. The antimicrobial activity of four cinnamic acid derivatives will be evaluated by determining the minimum inhibitory concentration (MIC) and minimum bactericidal/fungicide concentration (CMB/CFM) on Streptococcus mutans and Candida albicans. Then, the compounds that show bactericidal/fungicidal activity will be evaluated for dual-species antibiofilm action (S. mutans + C. albicans) by counting Colony Forming Units (CFUs). To analyze the bond strength of the composite-adhesive-dentin interface, the dentin substrate will be previously treated with the test solution with the best performing compound in the microbiological tests. 24 natural human teeth will be used. The Universal Single Bond adhesive will be applied and light cured, followed by the application of two layers of 2 mm thick composite resin (Z250 XT), which will be placed on the substrate and light cured for 20 s each. The teeth will be sectioned in half, along the long axis of the tooth, and one of the halves will be used to evaluate the bond strength to microtensile 24 hours after the adhesive process, while the other half will be subjected to thermal cycling (6000 cycles, 5 and 55° Ç). After the microtensile bond strength tests, the samples will be sent for analysis of the fracture pattern. The data obtained with the execution of this study will be analyzed statistically, considering p<0.05.(AU)