What Is the Purpose of a BTR Pen in Dentistry? A Complete Guide

What Is the Purpose of a BTR Pen in Dentistry?

Few situations in modern endodontics are as frustrating as an instrument separating inside a root canal. A rotary file, a hand file, or even a lentulo spiral can fracture mid-procedure, leaving a metal fragment lodged deep in the canal. That fragment blocks proper cleaning, shaping, and disinfection — and if it stays there, it can compromise the long-term prognosis of the tooth. The BTR Pen (Broken Tool Remover) was created to solve exactly this problem. A BTR Pen is a specialized endodontic instrument that uses a fine nitinol loop to lasso and extract fractured file fragments from root canals while preserving surrounding dentin.

What Is a BTR Pen?

The BTR Pen (Broken Tool Remover) is a specialized endodontic instrument developed by the Polish manufacturer Cerkamed. Its sole purpose is the retrieval of fractured instrument fragments from root canals. The concept is elegantly simple: a slim, pen-shaped stainless steel handle drives an ultra-thin working tip fitted with a microscopic nitinol loop. The clinician slides the loop over the exposed end of the broken fragment, tightens it, and withdraws the fragment from the canal in a controlled way.

Because the working tip is thin and flexible, it can follow narrow and curved canal anatomy without requiring aggressive enlargement of the canal — one of the main drawbacks of older retrieval techniques such as trephine burs or extractor tubes, which often sacrifice healthy dentin and weaken the root.

The Main Purpose: Safe Removal of Separated Instruments

The core purpose of the BTR Pen can be summed up in three points:

1. Retrieving broken files and instruments — NiTi rotary files, stainless steel hand files, lentulo spirals, and even thermafil carriers can be grasped and pulled out using the loop technique.
2. Preserving tooth structure — the flexible nitinol loop reaches the fragment through minimally prepared access, so far less dentin is removed compared with ultrasonic troughing alone or tube-based extractors. A 2022 study published in Materials (Dulundu & Helvacioglu-Yigit) evaluated the efficiency of the BTR Pen system on different types of separated instruments and its effect on the fracture resistance of the treated roots.
3. Making retreatment predictable — a removed fragment means the canal can be fully negotiated, disinfected, and obturated, which restores a predictable path to successful endodontic treatment instead of bypassing the fragment or referring the case to surgery.

How the Loop Technique Works

The BTR Pen loop technique, typically performed under a dental operating microscope, involves four steps:

1. Expose the fragment. The coronal portion of the separated instrument is uncovered, usually with ultrasonic tips, so a small part of it protrudes into the canal space.
2. Calibrate the loop. A dedicated calibrator is used to size the nitinol loop so that it matches the fragment’s diameter.
3. Lasso the fragment. The loop is guided over the exposed end of the broken instrument.
4. Tighten and retrieve. Turning the mechanism of the pen closes the loop around the fragment with considerable gripping force — roughly 1.5 kg for the 0.3 mm tip, 2 kg for the 0.4 mm tip, and 2.3 kg for the 0.5 mm tip — allowing the fragment to be extracted along the canal’s path.

The entire tool is designed for one-handed operation, which is a genuine advantage when the other hand is occupied with a mirror or microscope adjustments.

What’s in the Set?

A complete BTR pen set includes the stainless steel handle, a calibrator, single-use nitinol loop tips (available in 0.3, 0.4, and 0.5 mm diameters), spare springs of different hardness, and silicone O-rings. The handle itself is autoclavable and designed for repeated use — it disassembles into individual components for thorough cleaning and sterilization — while each nitinol loop tip is intended for a single patient only.

Why It Matters for Everyday Practice

Before loop-based systems, removing a separated file often meant extensive ultrasonic troughing, expensive tube-and-adhesive kits, or referral for apical surgery — each option carrying a real cost in dentin, chair time, or patient stress. The BTR Pen brings instrument retrieval within reach of general practices and endodontic offices alike:

• Minimally invasive — canal enlargement is kept to what is needed to expose the fragment.
• Versatile — three tip sizes cover fragments of different diameters and depths.
• Ergonomic — pen-grip design and one-handed operation suit work under magnification.
• Economical — the reusable handle carries a lifetime warranty; only the loop tips are consumable.

Final Thoughts

The purpose of the BTR Pen in dentistry is straightforward: to give clinicians a reliable, conservative, and repeatable way to remove broken endodontic instruments from root canals. By combining a flexible nitinol loop with a precise, one-handed tightening mechanism, it turns one of endodontics’ most dreaded complications into a manageable clinical step — saving teeth that might otherwise face compromised treatment or extraction.

Sources: Cerkamed product documentation (cerkamed.com), the official BTR Pen website (btr-pen.com), and Dulundu M., Helvacioglu-Yigit D., “The Efficiency of the BTR-Pen System in Removing Different Types of Broken Instruments from Root Canals and Its Effect on the Fracture Resistance of Roots,” Materials, 2022.