A Single-File Endodontic Case by Dr David Bretton

by Dr David Bretton

This case demonstrates how a GDP can achieve satisfactory endodontic outcomes using a single-file system

Introduction
Endodontics is an area of dentistry that has historically provided the general dental practitioner (GDP) with challenges. The introduction of nickel titanium (NiTi) files has transformed the shaping process and endodontic experience.

NiTi files have unique characteristics that make them useful in endodontics: shape memory and superelasticity. NiTi files have continually evolved, e.g., M-wire, R-phase wire, electropolishing and electrical discharge machining (EDM).

These developments have now allowed us to be able to complete endodontic shaping using just one file.

Case report:
History and assessment
A 47-year-old patient presented complaining about a small swelling he’d recently noticed in the upper left quadrant. He reported slight discomfort and tenderness in that region but no pain from the tooth. The patient was a regular attender and had no relevant medical history.

There were no significant extraoral findings and no lymphadenopathy; intraorally there was a small buccal sinus present adjacent to tooth 26. There was some minor inflammation periodontally, but no significant probing depths.

Tooth 26 had a large amalgam restoration present and teeth #25 and #27 were both unrestored (Fig. 1). Tooth #26 was tender to percussion and unresponsive to sensibility testing with dichlorodifluoromethane (DDM) spray from Roeko Endofrost.

A preoperative periapical radiograph (Fig.?2) revealed that #26 had a large restoration with periapical pathology.

Diagnosis, treatment options and treatment plan
A diagnosis was made of #26 pulp necrosis with chronic periapical periodontitis. Treatment options discussed included doing nothing (not advised), endodontic treatment or extraction (± replacement). The patient elected for endodontic treatment, after which the tooth would receive a cuspal-coverage restoration.

Treatment
Treatment was carried out with the assistance of 4.3x magnification loupes from Orascoptic XV1, with the tooth isolated by rubber dam (Fig. 3).

Treatment was completed over two visits (resolution of signs and symptoms can be reassuring before obturation). Current evidence suggests, however, that there is little difference in outcome between single and multiple visits (Figini et al., 2007).

Tooth #26 was accessed through the existing restoration and four canals were located. It is often beneficial to remove all of an old restoration before endodontic treatment to accurately assess restorability and prognosis (Abbott, 2004). A second mesiobuccal canal (MB2) was located due to a good knowledge of the anatomy of the pulp chamber floor (Krasner & Rankow, 2004). An MB2 has been identified in approximately 90 percent of upper first molars (Schwarze et al., 2002). With the assistance of ultrasonic instrumentation, I was able to gain access to MB2 with a Size?10 K-file (Fig.?4). Frequent irrigation was carried out with 3 percent sodium hypochlorite (NaOCl) delivered using a 27-gauge irrigating needle. A 10?file was used to explore all the canals. I was then able to progress to size 15 and 20 files before coronal shaping with a WaveOne Gold Primary File. An electronic apex locator (Dentsply ProPex Pixi) was used with a 10?file and zero readings were found.

I reduced back 0.5mm to estimate the position of the apical constriction and provide me with working lengths (Table?1). Tooth?#26 was dressed with UltraCal XS nonsetting calcium hydroxide from Optident, PTFE tape and a temporary GIC restoration.

At the second visit, two weeks later, the sinus had resolved. The tooth was reaccessed under rubber dam and the four canals quickly located. The canals were prepared using a Primary (25. 07) file. Frequent recapitulations with a 10 K-file were carried out to prevent risk of blockage of the canal system.

Khademi et al. (2006) reported that an apical preparation of #30 is the minimum instrumentation size needed for penetration of irrigants to the apical third of the root canal. Earlier studies, however, reported that a #25 file was as efficient as a #40 file for reducing residual microorganisms (Yared & Dagher, 1994) and that no excessive apical enlargement was necessary for intracanal bacterial reduction (Coldero et al., 2002).

After the canals were shaped, they were cleaned with a final EDTA rinse to remove the smear layer and dried using paper points, ready for obturation (Fig. 5).

All four canals were obturated with gutta-percha and AH Plus Root Canal sealer from Dentsply, and the tooth was restored with an amalgam core in preparation for a cuspal-coverage restoration. A periapical radiograph was taken to assess the outcome (Fig.?6). The root canal treatment appeared well obturated (2D) and within 2mm of the radiographic apex.

The patient was then happy to proceed with the cuspal coverage restoration as planned to improve the long-term prognosis (Aquilino & Caplan, 2002; Nagasiri & Chitmongkolsuk, 2005; Ng et al., 2011). Despite the periapical lesion and preoperative sinus tract, a good prognosis was predicted.

Conclusion
In conclusion, I believe that the GDP is now able to efficiently take on more complex and challenging endodontic cases. This is made possible with knowledge of the literature and by taking advantage of some of the newer file systems and technology that are available.

 

Fig. 1

 

Fig. 2

 

Fig. 3

 

Fig. 4

 

Fig. 5

 

Fig 6

Table 1

References

Click here for references