Quantitative Evaluation of Debris Removal from NiTi Rotary Endodontic Instruments After Different Cleaning Procedures

Area of Science:

• Dental instruments
• Sterilization and decontamination
• Endodontics

Background:

• Endodontic instruments require effective decontamination and sterilization for patient safety.
• Current protocols for cleaning nickel-titanium (NiTi) rotary files lack standardization.
• Assessing debris removal is crucial for ensuring instrument safety and treatment success.

Purpose of the Study:

• To quantitatively evaluate the efficacy of different cleaning protocols in removing debris from used NiTi rotary endodontic files.
• To compare the effectiveness of steam sterilization alone, ultrasonic cleaning plus steam sterilization, and manual cleaning plus ultrasonic cleaning plus steam sterilization.
• To identify optimal cleaning strategies for endodontic instruments.

Main Methods:

• Forty-eight Mtwo NiTi rotary instruments were used and divided into four groups.
• Protocols included: negative control (new sterile), steam sterilization only, ultrasonic cleaning + steam sterilization, and manual cleaning + ultrasonic cleaning + steam sterilization.
• Scanning electron microscopy (SEM) and Fiji software were used to quantify debris on file surfaces.

Main Results:

• The negative control group (new instruments) had the least debris, while steam sterilization alone showed the most debris.
• No significant debris differences were found between manual + ultrasonic + steam sterilization and ultrasonic + steam sterilization groups.
• Higher debris accumulation was observed from coronal to apical sections in control and steam sterilization only groups.

Conclusions:

• A comprehensive cleaning approach combining mechanical, chemical, and ultrasonic methods is superior for debris removal from endodontic instruments.
• Existing cleaning protocols are insufficient for complete debris removal.
• Further research is needed to standardize protocols, or consider single-use instruments.