Bacterial reduction with nickel-titanium rotary instrumentation

Area of Science:

• Endodontics
• Microbiology
• Dental Materials Science

Background:

• Apical periodontitis is often associated with intracanal bacterial infection.
• Effective bacterial reduction during root canal instrumentation is crucial for treatment success.
• Nickel-titanium (NiTi) rotary and traditional stainless-steel hand files are common instrumentation techniques.

Purpose of the Study:

• To compare the efficacy of 0.04 tapered NiTi rotary instrumentation versus stainless-steel K-file step-back instrumentation in reducing intracanal bacteria.
• To evaluate bacterial reduction in teeth with apical periodontitis using sterile saline irrigation.

Main Methods:

• Forty-eight patients with apical periodontitis were randomized to receive either NiTi rotary or K-file instrumentation.
• Intracanal bacterial samples were collected before, during, and after instrumentation.
• Samples were incubated anaerobically, and colony-forming units (CFUs) were calculated and log-transformed.

Main Results:

• Both instrumentation techniques resulted in a significant and uniform reduction in intracanal bacteria (p < 0.0001).
• No statistically significant difference in CFU counts was observed between NiTi rotary and stainless-steel hand instrumentation (p = 0.42).
• Neither technique was able to render the root canals completely bacteria-free.

Conclusions:

• NiTi rotary and stainless-steel hand K-file instrumentation techniques demonstrate comparable efficacy in reducing intracanal bacteria.
• Complete bacterial elimination from infected root canals remains a challenge with current instrumentation methods.
• Further research may be needed to explore adjunctive methods for enhanced intracanal disinfection.