A case of unusual anatomy: a mandibular second premolar with four canals.

AIM: The aim of this case report is to describe conventional root canal treatment on a mandibular second premolar with four canals.
SUMMARY: The pulp of a mandibular second premolar had become irreversibly inflamed, probably as a result of bacterial microleakage from a carious lesion. The general dental practitioner had initiated root canal treatment, but due to procedural difficulties referred the case. Conventional root canal treatment was then performed with magnification. Preparation was undertaken in a crown-down manner using balanced force hand instrumentation with flexible K-type files and files of Greater Taper. The root canals were obturated with vertically condensed gutta-percha technique. KEY LEARNING POINTS: Good illumination and magnification are vital during root canal treatment. Crown-down preparation using the balanced force technique with flexible files makes instrumentation easier and prevents many of the procedural errors that can occur with filing techniques. Greater Taper instruments made of nickel-titanium are sufficiently flexible to be used in complex curved canals and obviate the need for step-back flaring of the apical preparation. Vertical compaction of warm gutta-percha may simplify the obturation of complex root canal systems. When the technical difficulty of a procedure exceeds the expertise of the practitioner, specialist referral may be required.