Polymeric Sustained-Release Chlorhexidine Coating on Gutta-Percha Points for Prolonged Intracanal Antimicrobial...

Area of Science:

• Endodontics and Microbiology
• Drug Delivery Systems
• Antimicrobial Efficacy

Background:

• Persistent endodontic infections by Enterococcus faecalis and Candida albicans are primary causes of root canal treatment failure.
• Conventional irrigants like chlorhexidine (CHX) have limited effectiveness due to microbial survival and challenges in complex root canal anatomy.
• Existing antibacterial dressing techniques are unsatisfactory due to component depletion and uneven distribution.

Purpose of the Study:

• To develop and evaluate a novel sustained-release device (SRD) for delivering CHX using coated gutta-percha points.
• To assess the antimicrobial efficacy and release characteristics of the CHX-eluting gutta-percha points against E. faecalis and C. albicans.

Main Methods:

• Gutta-percha points were coated with sustained-release CHX varnishes (CHX1, CHX2) or placebo.
• In vitro antimicrobial activity was tested using agar diffusion assays.
• Release kinetics were analyzed in a 3D-printed tooth model using fluorescence microscopy.
• Biofilm-infected models were treated with placebo, single CHX irrigation, or SRD-coated points, with microbial viability quantified by CFU/mL analysis.

Main Results:

• SRD-coated points showed sustained antimicrobial activity for up to 21 days against E. faecalis and 19 days against C. albicans.
• Fluorescence analysis confirmed continuous CHX release for up to 15 days, with diffusion into complex canal areas.
• SRD treatment significantly reduced microbial load (2-3 log10 CFU/mL) and prevented regrowth, outperforming single CHX irrigation.

Conclusions:

• Sustained-release CHX via polymer-coated gutta-percha points offers prolonged antimicrobial activity against biofilms, superior to conventional CHX application.
• Coated gutta-percha points show potential as a removable intracanal drug delivery platform before final obturation.
• Further research, including direct-release quantification and in vivo studies, is needed for clinical translation.