Introduction
The success of root canal therapies requires factors such as proper
irrigation and instrumentation, dense obturation, and good coronal
sealing. For this purpose, knowledge about the morphology of the root
canal system and its variations is essential (1). Most permanent
mandibular first molars typically have 2 roots- mesial and distal with 3
root canal systems. Still, variations concerning the number of roots and
canal morphology are also not occasional. Radix Paramolaris
(mesiobuccally) and Radix Entomolaris (distolingually) are variations
determined according to the position of the third additional root (2).
In the literature review, the prevalence of RE according to race and
ethnic group includes a wide range from 0.6 to 29.7% (3).
Radix entomolaris (RE) is often not diagnosable because of overlapping
by the distal root with orthograde radiographs and it can only be
discovered by a careful correlation between clinical and radiographical
examination(1).
Roots that have a double curvature are called S-shaped roots(4).
S-shaped canals, also known as bayonet root canals(5), are found in
approximately 10% of clinical cases(4). Due to the complexity of these
canals, the root treatment process in these teeth is very challenging
(5, 6).
complex root canal curvatures or S-shaped canals in radix entomolaris
create rare circumstances. Accordingly, the current study aimed at
presenting three cases of management of radix entomolaris of the
mandibular first molar with complex root curvature or (s-shaped canal).