Instrument retrieval forcep (IRF) for removal of broken instrument fragment from the root canal of tooth.

Abstract

Abstract - The separation of an endodontic instrument during a root canal procedure is one of the most common endodontic mishaps. During routine therapy, at any stage, an endodontic instrument can fracture due to flexural fatigue, torsion or manufacturing defects. A separated instrument (SI)poses major challenges, including the possibility of intracanal corrosion and limited or no accessibility for chemo-mechanical preparation of the canal apical to the SI. Hence, removal of separated instrument or bypassing is necessary to gain access to the entire length of the canal. The removal of SI depends upon the canal configuration, type of instrument, and its location in the canal. Generally, mechanical methods for instrument retrieval can be classified into two groups, namely those involving trephine burs to trough the fractured instrument periphery in the preparation step followed by removal attempts using devices and those involving ultrasonics or special files to create a tiny space only on the side of the fractured instrument in the preparation step followed by removal attempts using devices or ultrasonics. These devices include special files and loops to remove the fractured instruments. Mechanical devices involving trephine burs include the Masserann Kit (Micro-mega), Cancellier Extractor Kit (SybronEndo), Endo Extractor (Brasseler Inc.), Endo Rescue (Komet/Brasseler), Micro Retrieve & Repair System (Superline NIC Dental) and iRS (Dentsply Tulsa Dental). Also, recently, XP Endo shaper and XP Endo Finisher file systems are available for removal of the nonvisible fractured instrument. However, all these devices and methods requires creation of a a thin space between the canal wall and the fractured instrument apart from extensive dentin removal along the inner canal wall for loosening of the fractured file. This results in the decrease in fracture resistance of radicular dentin which ultimately leads to a poor prognosis of the particular tooth. Hence, a new and effective method or device is needed which should overcome the above shortcomings and increase the long-term survival of the affected tooth. The IRF forcep is planned to work in such a way that there will be minimum requirement for removal of radicular dentin for removing fractured instrument and this will result in the preservation of sufficient dentin thickness.

Specification

Description:Components
1. Working part (jaw) - This will be the working part of the IRF forcep. It will be a
hollow tube consisting slit of length more than half of tube's length.
2. Sliding tube - Hollow metallic tube of dimensions more than working part which will
ensure the proper sliding mechanism.
Detailed Description
This IRF forcep will be constructed using sliding tube mechanism, where two hollow tubes
will be used which will slide on each other. The lower tube will have two lateral slits which
will help in gripping the fractured instrument. Lower tube will be the working part whereas the
upper tube will slide over this tube and it will close the slits which will helps us in holding the
broken fragment. Diameter of the upper tube will be greater than closing diameter of working
part but length of working part must be greater than upper tube. Because of greater length, the
slits will be properly closed and this will help in grasping the instrument. Slit will be
approximately 17-18mm in length and length of working part will of 20-21mm. While upper
tube will be of length 10-11mm and diameter 1mm. Closing diameter of working part will be
of 0.5-0.8mm. These will be the approximate dimensions of the instrument. We can also give
handle on the upper end of the IRF forcep which will help in proper working of the instrument.
Broken fragment will be positioned centrally between the tips, by sliding upper tube on lower
which will close the slit helping us in gripping the broken fragment. Since dimensions are very
small it can easily enter in root canal without any loss of tooth structure.
Mechanism of action - Firstly, the IRF forcep will be inserted into the root canal, then the
instrument will be engaged inside the jaws of the IRF forcep and confirmation will be done
regarding proper holding of broken fragment. This will be ensured with the help of
radiovisiography (RVG). The IRF forcep will be activated by sliding the upper tube on working
part, which will close the lateral slit and the instrument will be grasped. Then it will be pulled
out from the root canal. , Claims:1. RIF Forcep for removing broken fragment of instrument from root canal comprising,
two working tips or jaws; movable jaws are made between these lateral slits are present.
2. Non-working part tube is made of larger diameter than closing diameter of working
part, this tube will slide over the working part which helps in grip the instrument.
3. Dimensions of the instrument.
4. Easy retrieval of broken fragment from the root canal without loss of radicular dentin.

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