Surgical Removal of Apically Extruded Fractured H-File

Abstract

One of the most frequent endodontic mishaps is the separation of the endodontic instrument in the root canal. It often results from incorrect use or overuse. A fractured instrument inside a root canal can affect the outcome of endodontic treatment as it interferes with proper debridement and shaping procedures as well as with irrigation of the canal portion apical to the level of obstruction.

The purpose of this article is to present a case report of the surgical removal of a broken Hedstrom file from the periapical region of the root of a maxillary canine.

INTRODUCTION

Separation of endodontic instruments in a root canal is an unfortunate occurrence that may hinder the root canal procedure and negatively impact the outcome. It is reported that the prevalence of broken instruments ranges from 0.5% to 5%1. Fractured instrument itself may not cause treatment failure. The fractured segment, always accompanied with bacteria and dentine debris, is a foreign object and might cause inflammation. Above all, fragments present in the root canal can hinder proper preparation and filling of root canal space, and hence prognosis might be adversely affected. Many a times, this leads to failure of root canal therapy and burdens the patients with anxiety2.

Strindberg found a statistically significant 19% higher failure frequency for cases in which there was instrument breakage compared with cases without breakage. Therefore, the best option in the management of root canal instrument fracture is removal. Several techniques and devices have been used for the removal of broken instruments. Difficult cases are occasionally encountered in which the separated file cannot be retrieved from the canal1.

Intentionally leaving a fragment in the root canal might be considered when non-surgical removal has been attempted without success3. In addition, vigorous reduction of the dentinal walls of the root canal space might cause perforation of the canal wall1.

Endodontic instruments rarely separate beyond the apical foramen.

Therefore, an attempt to remove the segment from such cases with a surgical approach is often necessary. Before surgery, the precise position and size of the fractured instrument should be understood as well as its relation to the root apex and surrounding anatomic structures1.

The aim of this article is to present a case where we have used radiographic means to locate and successfully remove a fractured endodontic instrument partially beyond the apical foramen using a surgical approach.

CASE REPORT

A 32-year-old female patient came to the Department of Conservative Dentistry and Endodontics, Seema Dental College and Hospital, Rishikesh. On taking a brief history, it was found that she had undergone endodontic therapy with respect to the upper right canine, from a private clinician 10 days back, after which she complained of persisting pain. For a second opinion, she visited this college. On clinical and radiographical examination, it was seen that a 5 mm segment of Hedstrom file was separated at least 3 mm beyond the periapex in relation to right maxillary canine.

The patient was informed regarding the mishap and a treatment plan was made to surgically remove the fragment.

No other relevant medical history was reported.

Pre-operative preparations

An IOPA was taken to measure: (1) The exact size of the fractured instrument, (2) the distance from the reference point (cusp) to the apex of the tooth.

Figure 1	Figure 2

PROCEDURE

The surgical procedure was performed under local anesthesia using 2% lignocaine with 1:2,00,000 adrenaline. A crevicular incision was given from the mesial aspect of the maxillary right lateral incisor till the distal aspect of the maxillary right first premolar and two vertical releasing incisions extending into the vestibule were made to raise a trapezoidal flap.

Subperiosteal reflection was done to expose the buccal cortical plate. A 5 mm bony window was prepared using a no. 4 round bur at stall out speed and meticulous irrigation through the buccal cortex corresponding to the root apex of the canine at the previously calculated length.

The instrument was carefully visualized and then removed with a mosquito forceps.Figure 2.

A post-operative radiograph was taken to confirm complete removal of the fractured segment. Figure 3

Figure 3	Figure 4

Next, the canal was obturated using 6% gutta-percha and 2% accessory cones and MTA fillapex sealer. Figure 4

The gutta-percha was burnished at the apical end of the canal with a hot burnisher. The wound was then curetted, and irrigation was done with normal saline. Platelet rich fibrin was used to graft the surgical site and closure was done with 3-0 silk suture. Figure 5

Patient was prescribed amoxicillin 500 mg/8 h for 7 days, ibuprofen 600 mg/8 h for 3 days, and 0.12% chlorhexidine gluconate mouthwash thrice a day for 7 days. After 7 days, the patient was recalled for suture removal. At the 6 month recall examination, the maxillary canine was asymptomatic with progressive regeneration of the periapical bone. Figure 6

Figure 5	Figure 6

DISCUSSION

Endodontic procedural errors, such as under-filling, overfilling, fractured instruments, and root perforations and ledges, increase the risk of post-treatment diseases largely as a result of the inability to eliminate intra-radicular microorganisms from the infected root canal.

The instrument separation is an unfortunate sequelae of endodontic instrumentation. Reasons for separation include overuse of the instrument, improper use of the instrument, microcracks inherent in the new instrument, and calcified or curved canals4.

The fractured root canal instruments may include endodontic files, lateral or finger spreaders, spiral fillers, or Gates-Glidden burs, and can be nickel titanium, stainless steel or carbon steel; in our case it was a stainless steel H-file. A fractured endodontic instrument can lie either within the root canal or within the soft tissue beyond the apical foramen as in the present case. When an instrument fractures during root canal preparation and is present within the canal, there are three basic approaches to deal with the problem: (i) Remove it; (ii) bypass and seal it within the root canal; or (iii) block the root canal with it.

And for a successful surgical removal of a fractured endodontic instrument present beyond the apical foramen, the following are necessary; (i) knowledge of the cause of fracture and how to plan the treatment; (ii) determining the precise location of the fractured segment; and (iii) skilful operation under scrupulous infection control.

A thorough history, clinical examination, and good quality periapical radiographs are essential for pre-operative diagnosis of the teeth scheduled to undergo apical surgery.

Periapical radiography is limited by the fact that the information is rendered in only two dimensions. Interpretation is more difficult when the background pattern is complex. The use of computed tomography (CT) scans has enabled evaluation of the true extent of periapical lesions and their spatial relationship to important anatomical landmarks. The introduction of cone-beam CT represented an important new development in dentomaxillofacial radiology and precipitated a shift from 2 to 3 dimensional data acquisition, image reconstruction, and visualization5.

Being a rich source of growth factors, platelet rich fibrin (PRF) posses many advantages in bone regeneration and was thus used to fill in the bony defect. PRF contains and releases different growth factors that stimulate bone and soft tissue healing.5 Growth factors are actively participating in tissue repair mechanism such as angiogenesis, chemotaxis, cell proliferation, extracellular matrix deposition, and remodelling. Currently available clinical evidence suggests that healing rate of surgical sites enhanced with PRF is upto two to three times higher than normal surgical sites6.

CONCLUSION

Prevention of instrument separation is the best strategy. In case of separation and presence of instrument beyond the apical foramen; precise location of the fractured segment should be predicted and the segment must be removed with the aid of modern gadgets as done in the present case, followed by successful treatment of the tooth without any complications.

REFERENCES