Antimicrobial activity of N-acetylcysteine against bacteria associated with peri-implantitis: an in vitro study

• Grant number: 25/19314-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2025
• End date: July 31, 2026
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal Investigator: André Pitondo da Silva
• Grantee: Leandro Moreira de Alvarenga
• Host Institution: Universidade de Ribeirão Preto (UNAERP). Campus Ribeirão Preto. Ribeirão Preto , SP, Brazil

Abstract

Peri-implantitis is a frequent complication in implant dentistry, mainly associated with polymicrobial biofilm formation that is highly resistant to conventional treatments. Chlorhexidine is widely used as the standard antimicrobial agent; however, it presents important limitations, including cytotoxicity and reduced efficacy against mature biofilms. In this context, N-acetylcysteine (NAC), a cysteine derivative with antioxidant, mucolytic, and antimicrobial properties, emerges as a promising alternative capable of disrupting the extracellular biofilm matrix and reducing microbial viability. This study aims to evaluate the in vitro antimicrobial activity of NAC against Staphylococcus aureus, Porphyromonas gingivalis, and Prevotella intermedia, comparing its efficacy to 2% chlorhexidine. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) will be determined, as well as the effect of NAC on biofilms of S. aureus grown on titanium discs, using quantitative (CFU counts) and qualitative (SEM) analyses. The expected results will contribute to validating NAC as a potential therapeutic strategy for implant surface decontamination, providing safer and more effective perspectives for peri-implantitis management.