Assessment of an experimental chelating agent regarding effects on dentin, chlorhexidine adsorption, and biofilm formation prevention capability

• Grant number: 24/05290-1
• Support Opportunities: Scholarships in Brazil - Master
• Start date: January 01, 2025
• End date: March 31, 2026
• Field of knowledge: Health Sciences - Dentistry - Endodontics
• Principal Investigator: Talita Tartari
• Grantee: Rafaela Caires Santos
• Host Institution: Faculdade de Odontologia de Piracicaba (FOP). Universidade Estadual de Campinas (UNICAMP). Piracicaba , SP, Brazil

Abstract

Due to the great anatomical complexity, the physical and chemical effects of irrigants are crucial to assist in reaching surfaces not touched by instruments and to reduce the microbial load in endodontic treatments. Thus, there is a growing interest in new irrigation solutions aimed at enhancing the cleaning and disinfection of the root canal system (RCS). Among these, etidronic acid (HEDP) has stood out as an alternative to EDTA. Its alkaline pH allows for its use mixed with sodium hypochlorite (NaOCl) throughout the entire biomechanical preparation, providing continuous chelation of the smear layer without compromising the dissolution of organic matter by NaOCl and enhancing the antimicrobial action of this irrigant. The chelating agent sodium gluconate (SG) also shows potential for this same type of use, as it demonstrates the ability to remove calcium ions and stability in an alkaline pH. Moreover, irrigating solutions with residual antimicrobial activity, such as chlorhexidine (CHX), when used as the final irrigant, can hinder the recolonization by surviving microorganisms from the instrumentation and the adhesion of others that could cause secondary infections. Therefore, enhancing the substantivity of CHX is desirable to help avoid therapy failures. In light of these considerations, this project aims to compare the mixture of SG with NaOCl to other irrigation protocols, associated or not with PUI, regarding: 1) changes in dentin composition and microhardness and the removal of calcium from dentin; 2) the amount of CHX adsorbed to dentin immediately after irrigation and over time; and 3) the ability to prevent biofilm formation by Enterococcus faecalis.