# Evaluation of the Antibacterial and Antifungal Efficacy of Chitosan Nanoparticles in Irreversible Hydrocolloid Impression Materials: A Cross-Sectional Study

## TL;DR

This study shows that adding chitosan nanoparticles to dental impression materials significantly reduces bacteria and fungi, offering a self-disinfecting solution.

## Contribution

The novel contribution is demonstrating the efficacy of chitosan nanoparticles as a self-disinfecting agent in irreversible hydrocolloid dental impression materials.

## Key findings

- Incorporating 1% chitosan nanoparticles significantly reduced bacterial and fungal counts in dental impressions.
- The antibacterial and antifungal effects increased over time, with significant reductions observed at the 10-minute interval.
- The modified material offers an eco-friendly alternative for reducing cross-contamination risks in dental practice.

## Abstract

Introduction: Irreversible hydrocolloid (IHC) impression materials are widely used in dentistry for diagnostic impressions; however, they pose a risk of cross-contamination. Current cleaning methods such as rinsing with water may not be sufficient for effective disinfection. Incorporation of antimicrobial agents into IHC materials can reduce this risk. Chitosan, a biopolymer with proven antibacterial and antifungal properties, has potential as a self-disinfecting agent for IHC materials. This study aimed to evaluate the antibacterial and antifungal efficacy of chitosan nanoparticles (CHN) incorporated into IHC (alginate) impression materials.

Materials and methods: This cross-sectional study was conducted in the Department of Prosthodontics, at the Surendera Dental College and Research Institute, Sri Ganganagar, Rajasthan, India, with 20 dentulous patients. A 1% CHN was incorporated into the IHC impression material to serve as Group 1, while conventional alginate mixed with distilled water with a one-week interval between each impression served as Group 2. Impressions were made on patients' maxillary arches, with bacterial and fungal samples collected at 0- and 10-minute intervals after rinsing the impressions. The samples were cultured on nutrient agar and Sabouraud dextrose agar for bacteria and fungi, respectively. Colony counts were assessed and statistically analyzed.

Results: The study found a significant reduction in both bacterial and fungal counts in impressions made with Group 1 compared with Group 2 at both 0- and 10-minute intervals (p<0.001). At 10 minutes, bacterial counts decreased significantly in Group 1 (from 75.50±34.56 to 26.00±16.03), and fungal counts were also reduced (from 2.70±1.22 to 0.55±0.69). The antibacterial and antifungal efficacy was increased at the 10-minute interval, compared to the 0-minute interval.

Conclusion: Incorporating 1% CHN into the IHC impression material significantly enhanced its antibacterial and antifungal properties, making it an effective self-disinfecting agent. This modification reduces the need for additional disinfection steps and offers a practical solution for improving cross-infection control in dental practice. CHN's biocompatibility and biodegradability further support its potential as an eco-friendly and sustainable alternative for dental materials.