Effectiveness of water activated by dielectric barrier discharge (DBD) plasma as an irrigating agent in endodontics

• Grant number: 23/12059-1
• Support Opportunities: Scholarships in Brazil - Master
• Start date: February 01, 2024
• End date: August 06, 2025
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal Investigator: Cristiane Yumi Koga Ito
• Grantee: Victória Kelly Fonseca Tavares
• Host Institution: Instituto de Ciência e Tecnologia (ICT). Universidade Estadual Paulista (UNESP). Campus de São José dos Campos. São José dos Campos , SP, Brazil
• Associated research grant: 19/05856-7 - Use of low temperature atmospheric pressure plasma in dentistry: from laboratory bench to clinics, AP.TEM
• Associated scholarship(s): 24/06821-0 - Physical-chemical and antimicrobial properties of water activated by a dielectric barrier discharge (DBD) plasma produced under different levels of humidity, BE.EP.MS

Abstract

Traditional irrigation methods in Endodontics may have limitations because it is a complex and clinically challenging process since it is difficult to completely remove the biofilm because it does not reach certain regions of the root canal system due to anatomical issues. Studies report that conventional endodontic irrigants, despite demonstrating antimicrobial action, have toxic potential to involved and surrounding tissues. In this context, water activated with plasma appears, which demonstrates effective antimicrobial activity, associated with anti-inflammatory effects and inducers of tissue repair. Low toxicity is an advantage reported in the literature. Thus, the aim of the present study is to evaluate the effectiveness of plasma-activated water as an irrigating solution in Endodontics. Therefore, the best condition for activation of deionized water that presents antimicrobial activity against indicator microorganisms Enterococcus faecalis and Candida albicans will be determined. Different activation protocols will be evaluated using different gases and activation time, using a Dielectric Barrier Discharge Plasma activation system (DBD), recently patented by our group. The chemical characterization of the generated plasma will be performed by molecular beam mass spectroscopy and optical emission spectroscopy. The physicochemical properties of plasma-activated water will be monitored through the parameters of pH, electrical conductivity, and concentrations of NO3-, NO2-, H2O2, HNO2 and O3. Afterwards, microorganisms in planktonic form or biofilms will be exposed to activated water for different times and the viability of the remaining cells will be evaluated by cultivation and by confocal laser microscopy. The study of the effects of activated water on the structures of microbial cells will be carried out by transmission electron microscopy. Activated water with better antimicrobial activity will be evaluated for cytotoxicity to mammalian cells, according to ISO 10993-5:2009. For proof of concept, activated water with antimicrobial effect and low toxicity will be evaluated using an ex vivo endodontic infection model.