Removing fractured endodontic instruments with a modified tube technique using a light-curing composite

Area of Science:

• Endodontics
• Dental Materials Science
• Biomaterials

Background:

• Fractured endodontic instruments pose a clinical challenge.
• Current removal methods have limitations.
• An alternative tube technique using light-curing composite was investigated.

Purpose of the Study:

• To evaluate the efficacy of a light-curing composite in a tube technique for removing fractured endodontic instruments.
• To compare the removal strength of light-curing composite against cyanoacrylate and dual-curing composite.

Main Methods:

• Stainless steel endodontic instrument fragments (Hedstrom and K-files) were prepared.
• Fragments were secured, and cyanoacrylate, dual-curing, or light-curing composite was applied using a microtube.
• Pull-out tests were conducted to measure the failure load.

Main Results:

• Light-curing composite (SDR) exhibited significantly higher median failure loads (up to 62.5 N) compared to cyanoacrylate (14.7 N) and dual-curing composite (35.8 N).
• Hedstrom files showed higher removal forces than K-files when using SDR.
• SDR demonstrated a median force of 79.7 N for Hedstrom files and 53.3 N for K-files.

Conclusions:

• Light-curing composite in a microtube technique is a superior alternative for removing fractured endodontic instruments.
• This method offers greater bond strength than cyanoacrylate or chemically cured composites.
• The findings support the clinical application of light-curing composites for instrument retrieval.