Dental Hypotheses

: 2014  |  Volume : 5  |  Issue : 1  |  Page : 28--32

A case of embedded staple pin in the root canal: Management and microbiological analysis

Brinda S Godhi1, Naveen S Yadav2, Shruti S Kumar1, Raghavendra Shanbhog1, MN Sumana3, S Rashmi1,  
1 Department of Pedodontics and Preventive Dentistry, JSS Dental College, Mysore, Karnataka, India
2 Department of Prosthodontics, Peoples Dental Academy, Bhopal, Madhya Pradesh, India
3 Department of Microbiology, JSS Medical College, Mysore, Karnataka, India

Correspondence Address:
Brinda S Godhi
No 768 E & F Block, Kuvempunagar, Mysore - 570 023, Karnataka


The presence of foreign object in the root canal is one of the challenging occurrences in endodontic therapy. The possibility of these foreign objects getting impacted into the tooth is more when pulp chamber is open either due to trauma or due to large carious lesion. We herewith report a case of a 12-year-old boy who presented with staple pin lodged in the root canal of maxillary right permanent central incisor. We also describe the management of the case and microbiological analysis of the foreign body.

How to cite this article:
Godhi BS, Yadav NS, Kumar SS, Shanbhog R, Sumana M N, Rashmi S. A case of embedded staple pin in the root canal: Management and microbiological analysis.Dent Hypotheses 2014;5:28-32

How to cite this URL:
Godhi BS, Yadav NS, Kumar SS, Shanbhog R, Sumana M N, Rashmi S. A case of embedded staple pin in the root canal: Management and microbiological analysis. Dent Hypotheses [serial online] 2014 [cited 2022 Jan 29 ];5:28-32
Available from:

Full Text


The discovery of a foreign object embedded in a tooth is relatively uncommon. Children have the habit of placing foreign objects in the oral cavity. The chance of these foreign objects getting impacted into the tooth is more when pulp chamber is open either because of traumatic injury or large carious exposure. There are several reports describing the placement of foreign objects by the patients into the exposed pulp chambers and canals. The objects are varied from pencil lead, [1] darning needles, [2] metal screws, [3] beads, [4] paper clips, [5] staple pins, [6],[7],[8],[9] minute hand of the watch, [10] a tooth pick, [11] etc. These object once lodged may become a source of pain and infection causing the patient to present to the dentist.

It is always necessary to take a proper case history and detailed clinical examination. Diagnostic X-rays are very important and help us to ascertain the size, position, and type of the object. This helps in establishing the technique for retrieval.

There have been several cases describing the placements of foreign body in the root canals. Hall [1] reported the introduction of a wooden object into the canal. Nernst [2] described the insertion of various metallic objects like needles and pins in the canal.

This report describes the case of a foreign object impacted in the middle one-third of the immature maxillary central incisor which was retrieved and treated successfully. Additionally, microbiological analysis of the retrieved foreign object was carried out.

 Case Report

A 12-year-old boy reported to a private clinic with a complaint of broken upper front tooth associated with history of pain for the past 1 month. History of presenting illness revealed that the patient met with trauma 2 years ago during play. The pain was spontaneous in nature as the patient also had a swelling with draining sinus. The crown of the tooth was horizontally fractured at middle third. The pulp chamber was open to the oral cavity [Figure 1]a. Patient reported that he did not receive any treatment for the same.{Figure 1}

Intraoral examination revealed fractured tooth involving enamel dentin with opening into pulp chamber of tooth number 21 (Federation Dentaire Internationale). On examination, following clinical features were observed in tooth number 21.

Tooth was discolored and intraoral swelling with draining sinus on the labial mucosa was present. Due to this fact a vitality test was not performed. Intraoral periapical radiograph revealed a radiopaque object at the middle third of the root with periapical radiolucency involving tooth number 21 and tooth number 22. Apex was open in relation to tooth number 21 [Figure 1]b. On questioning patient admitted that he had used staple pin to clean the tooth when there was food lodgement. Vitality test was carried out to the adjacent tooth which revealed tooth number 11 and tooth number 22 were vital. Based on clinical and radiological examination, diagnosis of chronic periapical abscess was established with relation to tooth number 21. Considering the clinical and radiographic findings, it was decided to do root canal therapy, with an attempt to retrieve the foreign object and thereafter complete the root canal treatment.

Following rubber dam application, a conventional access cavity was prepared and the pulp chamber was cleared of debris by copious irrigation with saline solution. The object was retrieved using H-file, remaining food particles were flushed out using normal saline and sodium hypochlorite irrigating solution. The technique used was simple syringe technique. Retrieved staple pin appeared black in color and was sent for microbiological evaluation [Figure 2].{Figure 2}

The foreign body was subjected to microbiological evaluation. It was flushed with 200 ml of sterile saline which was then inoculated onto blood agar plate and incubated at 37°C, anaerobically for 48 h. The plate showed dry opaque whitish colony. A smear was made from the colony and stained with gram stain. On microscopic examination, it showed gram positive, branching, filamentous bacteria [Figure 3]. One more smear was prepared from the colony on blood agar and stained with modified Zeihl-Neelsen stain and examined under microscope and showed non-acid fast, branching, and filamentous bacteria. The organism isolated was identified as 'Actinomyces' species.{Figure 3}

Smear layer was removed using 17% ethylenediaminetetraacetic acid (EDTA). [12]

Non-setting calcium hydroxide was used as intracanal medicament and Intermediate Restorative Material (IRM) was placed. After 1 week when tooth was asymptomatic, it was obturated using roll cone technique. Composite build up was done followed by cementation of acrylic temporary crown [Figure 4]a and b.{Figure 4}

The procedure was carried out without the aid of any visual enhancements as it was pretty much a very straight forward case.


There have been a myriad number of reports in dental literature describing varied and unusual foreign objects in the pulp chambers and canals of the tooth. The most common being pins, ornaments, metal screws, nails, sewing needles, beads, etc. [2],[3],[4],[5] A foreign body can act as foci for infections in any part of the living organism. If left untreated it can lead to various complications. Therefore, it is very important that an attempt is made to retrieve the foreign object immediately to prevent any untoward consequences. [13] Foreign objects are usually seen in wide open canals that have been exposed either due to caries or trauma or iatrogenically kept open for draining. During emergency root canal treatment, some practitioners choose leaving the pulp chamber open where pus continues to discharge through the canal and cannot be dried within a reasonable period of time. Cohen and Brown, [14] 2002 suggested that such a procedure may place the patient at risk for foreign body lodgement. Dislodged restorations is another common cause for the foreign body lodgement.

In this case, the patient had experienced dentoalveolar trauma in relation to tooth number 21, which resulted in the open pulp chamber. Patient admitted to using staple pin to relieve food lodgement in the tooth with open chamber. There was no history of any other endodontic treatment.

These foreign bodies are usually detected by radiographs when the patient presents to the dentist either with pain or swelling in the region of the foreign body lodgement. Radiographs also aids in assessing the level of difficulty involved in retrieving the foreign object. There are various radiographic methods amongst which the most preferred method is the parallax view. The other diagnostic techniques are vertex occlusal view, triangulation technique, sterioradiography, and tomography. [7] In our case, the object was easily located using a simple intraoral periapical radiograph which revealed the presence of a foreign object in the middle third of the root.

There are numerous methods carried out for the removal of foreign object from the root canal, though there is no particular standard method discussed in the literature. [15] The dentist should consider few factors before treating a case of foreign object removal. The root canal anatomy, radicular thickness as well as the location and size of the foreign object play a critical role in treatment planning. Other factors like clinical skill of the operator and availability of equipment also influence the treatment outcomes. [16],[17],[18]

The commonly followed techniques are using operating microscope with ultrasonic files, Masserann kit, modified Castroviejo needle holder, and Steiglitz forceps all of which have been described in the literature. The use of an operating microscope is advantageous as it provides illumination and visualization of the root canal. Another technique described by Glick [19] consists of inserting multiple H-files and twisting them around the foreign body especially used in cases where the radicular structures are weak. The braided multiple H-files would exert a grip and removes the foreign body. Contemporary endodontic instruments can also be used along with other instruments like ultrasonic equipments, fine forceps, endodontic files, etc.

EDTA has been the most suggested aid in lubricating the canal along with saline and sodium hypochlorite. [12],[20]

Literature usually suggests the use of calcium hydroxide as the choice for intracanal medicament. However, if the infection fails to heal, a triple antibiotic paste can be employed consisting of ciprofloxacin, metronidazole, and minocycline which successfully eliminate the endodontic infection. [21] The paste is packed into the canal and sealed with zinc oxide eugenol cement. Once the tooth in question is asymptomatic after routine follow-ups of the patient, the canal is obturated and subsequent esthetic rehabilitation of the tooth is done. [22],[23],[24],[25]

However, the retrieval of the foreign object can prove to be challenging if the object is lodged at the periapical region. In such cases, periapical surgery is the treatment of choice as suggested by Zillich and Pickens. [26] Srivastava and Vineeta [27] have also recommended intentional reimplantation to remove the foreign objects in some cases.

In the present case, the foreign object was located at the middle one-third of the root canal, which enabled us in retrieving the object successfully by using H-file after conventional access cavity preparation. Irrigation was done using normal saline and sodium hypochlorite solution.

The prognosis is good when treated immediately with the successful retrieval of the foreign object. [1] If the focus of the infection is not eliminated, complications may follow.

The microbiological evaluation of the staple pin indicated the presence of Actinomyces species. Actinomyces is a genus of the actinobacteria class of bacteria. They are gram positive, facultative anaerobes. They are present as normal commensal flora of the oral cavity. [13] In rare cases, these bacteria, mainly Actinomycosis israelii, can lead to Actinomycosis, characterized by abscesses in oral cavity, lungs, or gastrointestinal tract. [13]

Goldstein et al., [13] discussed the development of Actinomyces infection at the apex of the tooth with the radiopaque foreign body in the root canal. It was their inference that foreign object aided in establishment of anaerobic conditions necessary for development of infection. Antinomycosis species can penetrate deeply into the dentinal tubules. [13] For this reason, infectious microbial agents can be eliminated only after the induction of appropriate intracanal irrigants. Growth of Actinomyces is known to be inhibited by low concentrations of antibiotics. Sodium hypochlorite solution, calcium hydroxide, EDTA, and chlorhexidine were also found to be highly effective in killing Actinomyces. Newer root canal irrigants in the horizon are a mixture of tetracycline isomer, an acid and a detergent (MTAD), tetraclean, electrochemically activated solutions, ozonated water, photon-activated disinfection, and herbal irrigants. [24],[25],[28],[29]

Therefore, we employed calcium hydroxide [30] as intracanal medicament and sodium hypochlorite as an irrigant which proved to be successful in eliminating the infection in subsequent visits. Once the endodontic therapy was completed, composite build up was done followed by acrylic temporary crown to esthetically restore the tooth.

The patient was satisfied with the esthetic rehabilitation of the tooth. He was recalled for routine follow-ups, that is, once in 10 days to observe for any failures. The tooth in question was asymptomatic, hence, proving the endodontic procedure to be successful.


Discovery of any foreign object in the root canal calls for immediate retrieval and subsequent therapies to eliminate the infection. Failure to do so may lead to several complications. This paper reports the diagnosis, treatment, and microbiological evaluation of a case regarding foreign body inclusion in the root canal of the tooth. The article also reviews briefly, various techniques of retrieval, and emphasizes the judicious use of intracanal antibiotics to ward off the microbial infection. Knowledge about these techniques and management of infection can aid the clinician to skillfully treat the patient and restore the tooth to its form and function.


1Hall JB. Endontics-patient performed. ASDC J Dent Child 1969;36:213-6.
2Nernst H. Foreign body in the root canal. Quintessence Int (Berl) 1972;3:33-4.
3Prabhakar AR, Basappa N, Raju OS. Foriegn body in a mandibular permanent molar - a case report. J Indian Soc Pedod Prev Dent 1998;16:120-1.
4Subbareddy VV, Mehta DS. Beads. Oral Surg Oral med Oral Pathol 1990;69:769-70.
5Cataldo E. Unusual foreign object in pulp canal. Oral Surg Oral Med Oral Pathol 1976;42:851.
6Rao A, Sudha P. A case of stapler pin in the root canal-extending beyond the apex. Indian J Dent Res 1999;10:104-7.
7McAuliffe N, Drage NA, Hunter B. Staple diet: A foreign body in a tooth. Int J Pediatr Dent 2005;15:468-71.
8Aduri R, Reddy RE, Kiran K. Foreign object in teeth: Retrival and management. J Indian Soc Pedod Prev Dent 2009;27:179-83.
9Holla G, Baliga S, Yeluri R, Munshi AK. Unusual object in the root canal of deciduous teeth: A case report of 2 cases. Contemp Clinic Dent 2010;1:246-8.
10Ozsezer E, Ozden B, Kulacaoolu N, Ozden FO. The treatment of unusual foreign objects in a root canal: A case report. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2006;102:e45-7.
11Grossman LI. Endodontic case reports. Dent Clin North Am 1974;18:509-27.
12O'Connell MS, Morgan LA, Beeler WJ, Baumgartner JC. A comparative study of smear layer removal using different salts of EDTA. J Endod 2000;26:739-43.
13Goldstein BH, Sciubba JJ, Laskin DM. Actinomycosis of the maxilla: Review of literature and report of case. J Oral Surg 1972;30:362-6.
14Cohen AS, Brown DC. Orofacial dental pain emergencies: Endodontic diagnosis and management. In: Cohen S, Burns RC, editors. Pathways of the Pulp, 8th ed. St. Louis: Mosby. p. 31-75.
15Hulsmann M. Methods for removing metal obstructions from the root canal. Endod Dent Traumatol 1993;9:223-37.
16Hulsmann M, Schinkel I. Influence of several factors on the success and failure of removal of fractured instruments from the root canal. Endod Dent Traumatol 1999;15:252-8.
17Suter B, Lussi A, Sequeira P. Probability of removing fractured instruments from root canal. Int Endod J 2005;38:112-23.
18Ruddle CJ. Broken instrument removal. The endodontic challenge. Dent Today 2002;21:70-6.
19GutmanJL, Dumsha TL, Lovdahl PE. Problem solving challenges in the revision of previous root canal procedures, 4th ed. St Louis: Elsevier Mosby; 2006. p. 239-79.
20Baumgartner JC, Mader CL. A scanning electron microscopicevaluation of four root canal irrigation regimens. J Endod 1987;13:147-57.
21Sato T, Hoshino E, Uematsu H, Kota K, Iwaku M, Noda T. Bactericidal efficacy of a mixture of ciprofloxacin, metronodazole, minocycline and rifampicin against bacteria of carious and endodontic lesions of human deciduous teeth. Microb Ecol Health Dis 1992;5:171-7.
22Lumley PJ, Walmsley AD. The removal of foreign objects from root canals. Dent Update 1990;17:420-3.
23Schulz J, Gutterman JR. In: Cohen S, Burns RC, editors. Pathways of the Pulp. St. Louis: CV Mosby; 1976. p. 79-81.
24Williams VD, Bjorndal AM. The Masseann technique for removal of fracture post in endodontically treated teeth. J Prosthet Dent 1983;49:46-8.
25Takushige T, Cruz EV, Asgor Moral A, Hoshino E. Endodontic treatment of primary teet using combination of antibacterial drugs. Int Endod J 2004;37:132-8.
26Zillich & Pickens TN. Patient included blockage of the root canal. Report of a case. Oral surg Oral Med Oral Pathol 1982:54:689-90.
27Srivastava N, Vineeta N. Foreign body in the periradicular area. J Endod 2001;27:593-4.
28Barnard D, Davies J, Figdor D. Susceptibility of actinomyces israelii to antibiotics, sodium hypochlorite and calcium hydroxide. Int Endod J 1996;29:320-6.
29Sushma J, Prashant J. Newer root canal irrigants in horizon: A review. Int J Dent 2011;2011:8513259.
30Sathorn C, Parashos P, Messer H. Antimicrobial efficacy of calcium hydroxide intracanal dressing: A systemic review and metaanalysis. Int Endod J 2007;40:2-10.