Retrieval of separated instrument from the root canal using ultrasonics: A report of two cases

Saurabh Ramtekkar; Sonia Baghla; Manjusha Warhadpande; Darshan Dakshindas

doi:10.4103/ijohr.ijohr_1_21

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CASE REPORT

Year : 2021 | Volume : 7 | Issue : 1 | Page : 45-48

Retrieval of separated instrument from the root canal using ultrasonics: A report of two cases

Saurabh Ramtekkar, Sonia Baghla, Manjusha Warhadpande, Darshan Dakshindas
Department of Conservative Dentistry and Endodontics, Government Dental College and Hospital, Nagpur, Maharashtra, India

Date of Submission	05-Jan-2021
Date of Acceptance	24-Feb-2021
Date of Web Publication	12-Jul-2021

Correspondence Address:
Dr. Saurabh Ramtekkar
Department of Conservative Dentistry and Endodontics, Government Dental College and Hospital, Medical Campus, Medical Square, Nagpur - 440 003, Maharashtra
India

Source of Support: None, Conflict of Interest: None

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DOI: 10.4103/ijohr.ijohr_1_21

Abstract

Every dental clinician may have encountered instrument separation during root canal treatment. Separation of endodontic instrument in the root canal affects accessibility to the apical foramen of root thus compromising cleaning and shaping, which ultimately affects success of treatment. The traditional methods to recover separated instruments often require removal of large amount of tooth structure, potentially leading to perforation and even root fracture. Today, these dangers can be minimized with innovations in technology such as dental operating microscope and ultrasonics. The present two cases highlight on the successful retrieval of separated instruments from the coronal and middle third of the root canals using ultrasonics under dental operating microscope.

Keywords: Instrument, microscope, retrieval, separation, ultrasonics

How to cite this article:
Ramtekkar S, Baghla S, Warhadpande M, Dakshindas D. Retrieval of separated instrument from the root canal using ultrasonics: A report of two cases. Indian J Oral Health Res 2021;7:45-8

How to cite this URL:
Ramtekkar S, Baghla S, Warhadpande M, Dakshindas D. Retrieval of separated instrument from the root canal using ultrasonics: A report of two cases. Indian J Oral Health Res [serial online] 2021 [cited 2023 Jun 3];7:45-8. Available from: https://www.ijohr.org/text.asp?2021/7/1/45/321114

Introduction

In endodontic practice, clinicians may come across with different procedural errors during any phase of endodontic treatment. Among these endodontic mishaps, separation of endodontic instruments within root canal is one of the most frustrating incidents.^[1] Fractured root canal instruments may include endodontic files, silver points, lentulo spirals, Gates-Glidden drills, tips of carrier-based obturators and spreaders.^[2] The prognosis of such cases depends on many factors, such as root canal anatomy, the type of instrument fractured, its location inside the canal, root canal curvature, length and thickness of the separated instrument. The possible strategies to manage such type of cases include retrieval of the separated instrument fragment, bypassing the separated instrument fragment or leaving the fragment as true blockage.^[3]

Today, the use of both nickel–titanium (NiTi) hand files and rotary instruments has become very much popular because of their great flexibility as compared to their stainless steel counterparts.^[4],[5],[6] However, there is a potential risk of unexpected fracture with NiTi instruments. With the increased use of NiTi instruments, the incidence of instrument separation inside root canals has increased.^[7] Such events during root canal treatment lead to obvious anxiety and frustration to the clinician.^[8] The removal of separated instruments from root canals is very difficult with a reported success rate ranging from 55% to 79%.^[7],[8] A few techniques for retrieval have been described in the literature with most successful method being the use of ultrasonics along with magnification.^[9],[10]

In this case report, retrieval of separated instruments from root canals has been demonstrated with the help of ultrasonics under dental operating microscope.

Case Reports

Case 1

A 45 year female patient reported to the Department of Conservative Dentistry and Endodontics, Government Dental College and Hospital, Nagpur, with chief complaint of pain in lower right back region of jaw since 10 days. She had a history of incomplete root canal treatment 7 days back. The patient had noncontributory medical history with no history of swelling or pus discharge. Intraoral examination revealed access cavity preparation with tooth 44. Pain on percussion was positive. Intraoral periapical radiograph suggested a separated instrument in the coronal third of the root canal [Figure 1a]. A diagnosis of incomplete root canal treatment with apical periodontitis in relation to tooth 44 was made and retrieval of the separated instrument fragment was planned. The patient was explained about the procedure in detail and a written consent form was obtained prior to commencement of the procedure.

Figure 1: (a) Intraoral periapical radiograph showing separated instrument in coronal third of root canal. (b) Retrieved instrument with extractor tube of Masserann kit. (c) Intraoral periapical radiograph after instrument retrieval. (d) Working length determination. (e) Master cone radiograph. (f) Immediate post obturation radiograph. (g) 6 months' follow-up radiograph

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In the first appointment, under local anesthesia and rubber dam isolation, access cavity was modified and canal orifice was located using DG16 explorer. When k file No. 15 (Mani, Japan) was introduced into the canal, obstruction was felt. With the help of dental operating microscope (Opto DM PRO model, Opto Electronics, Sao Paulo, SP, Brazil), coronal end of the separated instrument could be appreciated. Ultrasonic tips (Pro Ultra ENDO Tips, DENTSPLY Tulsa Dental, Tulsa, Oklahoma) were used around the fragment to expose it and a staging platform was made around the instrument. The extractor tube of Masserann kit with a diameter of 1.2 mm was slid into the staging platform to sleeve the fragment and the plunger rod was manually turned inside the extractor tube in clockwise direction to hold the fragment. The entire assembly was now rotated slowly in anticlockwise direction to unscrew and withdraw the fragment from the canal [Figure 1]b. Radiograph was taken to confirm the complete retrieval of instrument fragment [Figure 1]c. Working length was determined using electronic apex locator (Root ZX mini, J. Morita Corp., Kyoto, Japan) and confirmed radiographically [Figure 1]d. Biomechanical preparation was done using rotary files along with irrigation using 3% sodium hypochlorite solution (Prime Dental Products Pvt., Ltd., Pune, Maharashtra, India). Calcium hydroxide paste (RC Cal, Prime Dental products, Mumbai, Maharashtra, India) was used as an intra-canal medicament and the patient was recalled after 1 week.

In second appointment, calcium hydroxide paste was removed using normal saline and canals were then irrigated with 17% aqueous ethylenediaminetetraacetic acid solution (Prevest DenPro Ltd., Jammu, Jammu and Kashmir, India) as a final flush. Master cone was selected and checked radio graphically [Figure 1]e. Root canals were obturated with gutta-percha (Diadent Group International, Korea) and AH Plus sealer using warm vertical compaction technique [Figure 1]f. Six months' clinical and radiographic follow-up was taken and the tooth is asymptomatic [Figure 1]g.

Case 2

A 38 year female patient reported to the Department of Conservative Dentistry and Endodontics, Government Dental College and Hospital, Nagpur, with chief complaint of pain in lower right back region of jaw since 7 days. The patient had started root canal treatment 2 weeks before at a local dentist. Medical history was noncontributory. Intraoral examination revealed access cavity preparation with tooth 46 and the tooth was tender on percussion. Intraoral periapical radiograph was taken which suggested separated instrument in the middle third of the root canal in mesial root [Figure 2]a. The case was diagnosed as incomplete root canal treatment with apical periodontitis in relation to tooth 46. The patient was explained about the procedure in detail and a written consent form was obtained prior to commencement of the procedure.

Figure 2: (a) Instrument separation in middle third of mesial root. (b) Retrieved instrument fragment. (c) Radiograph after instrument retrieval. (d) Working length determination. (e) Master cone radiograph. (f) Immediate postobturation. (g) Six months' follow-up radiograph

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In the first appointment, local anesthesia (Lignox 2% A, Indoco Remedies Ltd., India) was administered, tooth was isolated using rubber dam and access cavity was modified. Canal orifices were located using DG16 explorer under dental operating microscope (Opto DM PRO model, Opto Electronics, Sao Paulo. SP, Brazil) and a straight line access was made using Gates Glidden drills. Obstruction to canal was felt when k file No. 15 (Mani, Japan) was introduced into the mesiolingual canal.

The separated instrument was located in the middle third of mesiolingual canal. Mesiolingual canal orifice was enlarged using Gates Glidden drills (Dentsply International). Circumferential staging platform to expose 2–3 mm of the coronal most part of the broken instrument was created by using Gates-Glidden drills. After this, ultrasonic tips (Pro Ultra ENDO Tips, DENTSPLY Tulsa Dental, Tulsa, Oklahoma) were used around the fragment into the mesiolingual canal between the exposed end of the file and the prepared staging platform and activated to loosen the fractured instrument. The instrument fragment floated out from the canal following the ultrasonic activation. Fractured instrument was found to be approximately 4 mm in length [Figure 2]b. [Figure 2]c shows radiograph after removal of fractured instrument. Working length was determined using electronic apex locator (Root ZX mini, J. Morita Corp., Kyoto, Japan) and confirmed radiographically [Figure 2]d.

Biomechanical preparation was completed by rotary files along with irrigation with 3% sodium hypochlorite (Prime Dental Products Pvt. Ltd., Pune, Maharashtra, India). The canals were filled with Calcium hydroxide paste (RC Cal, Prime Dental products, Mumbai, Maharashtra, India) and the patient was recalled for obturation after 1 week. Master cone was selected and checked radio graphically [Figure 2]e. The root canals were obturated by warm vertical compaction of Gutta percha (Diadent Group International, Korea) and AH Plus root canal sealer [Figure 2]f. Six months' clinical and radiographic follow-up was taken and the tooth is asymptomatic [Figure 2]g.

Discussion

Instrument separation is one of the most challenging and troublesome incidents in endodontics. For successful retrieval of separated instrument from root canal, a straight-line access is always mandatory.^[11] Final prognosis of treatment after instrument separation depends on many factors such as stage of root canal preparation, level of infection, and intracanal site of separated instrument. An attempt to retrieve the separated instrument is considered as a more favorable option but it should not weaken the existing radicular tooth structure as it may lead to removal of excessive radicular dentin. Excessive destruction of root dentin may lead to root perforation and postoperative fracture, thereby reducing the long-term prognosis of the tooth.^[12]

To date, no standardized procedure for the safe retrieval of fractured instruments exists, although various techniques and devices have been suggested. Ultrasonic technique for retrieval is simpler and less invasive. The contra-angled design and availability in different lengths and sizes enable the use of ultrasonic tips in deeper parts of root canal.^[13] Ultrasonics combined with dental operating microscope improves visibility and accessibility allowing easy retrieval of the separated instrument.

Conclusion

The use of ultrasonic along with magnification is one of the most effective methods for retrieval of separated instruments. Adhering to the basic concepts and utilizing safe techniques during root canal treatment will eliminate the incidence of instrument separation.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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