File breakage is not so common complication in dental treatments. It is also known as file separation which can happen while treating a tooth in root canal procedure.
Several types of sizes and lengths are used to clean and file the canals. This procedure is crucial as all the debris and the dead nerve is removed from the canals for proper debridement. The fine technique of root canal debridement uses varied file such as hand files and rotary files. These files are passed into the canals till the apex for complete cleaning and shaping of the walls. copious transport agents such as normal saline or diluted hydrogen peroxide are used to ease the cleaning procedure. EDTA is also used as a mediator.
There are several reasons for a file breakage in a canal such as
- Severely curved canals – here the file engages as there is no straight line of access.
- Cyclic fatigue- the rotating file flexes until fracture occurs.
- Frequent use of a single file- this leads to flat files where in the flutes are missing. The wear and tear increases, such files when used multiple times would separate in the canals.
- Torsional stress- occurs in separation of file when one of the file portion gets locked in the canal while the shaft of the file is in rotation
- Undue pressure – vigorous pressure applied by the dentist while working in the canals. The stress and fatigue directed on the file makes I separate in the canal.
Thorough debridement with normal saline and diluted hydrogen peroxide leads to easy passage of files for smooth and efficient working and lessen file breakage.
Even if with all measures a file still breaks in the canal, one should not panic. The dentist would inform of the same. X-rays are taken to visualise the depth of the file or its exact location .
Once the file is located there are several ways one can deal with it .
- File breakage in apical third in canal: such files are left untouched as a complete seal is acquired. Care should be taken that no nerve is still intact.
- File breakage in middle third: this file can be retrieved by using small numbered file to the one separated. Retrieving of files requires proper knowledge of the root structure and ultra sonic devices
- File breakage in coronal portion of the root : these files can be easily retrieved as they are separated at the orifice region. Bypassing another file in anti clock wise direction eases the separated file out of the canal.
The first line of treatment of a broken file should be its retrieval with basic hand file and then with ultrasonic devices . under any circumstances if the file1 is not retrived the patient is informed not to panic as the file is made up of non corrosion metal and can cause no harm to the tooth or it’s surrounding structures. To leave the broken file into the canal the dentist should explain the patient the various reasons such as the curved root structure, and the position of the fragments. In subsequent follow up the dentist should also note the pulp status and periapical infection . If periapical infection is seen under the root tip and apicosectomy is performed where access is made from the apex of the root and complete debridement is done . retrograde gutta percha are placed and sealed with adequate apical seal.