Identification of Apical and Cervical Curvature Radius of Human Molars

Abstract

<p>To determine the frequency of apical and cervical curvatures in human molars using the radius method and cone-beam computed tomography (CBCT) images. Four hundred images of mandibular and maxillary first and second molars were selected from a database of CBCT exams. The radius of curvature of curved root canals was measured using a circumcenter based on three mathematical points. Radii were classified according to the following scores: 0 - straight line; 1 - large radius (r>8 mm, mild curvature); 2 - intermediate radius (r>4 and r<8 mm, moderate curvature); and 3 - small radius (r≤4 mm, severe curvature). The frequency of curved root canals was analyzed according to root canal, root thirds, and coronal and sagittal planes, and assessed using the chi-square test (significance at α=0.05). Of the 1,200 evaluated root canals, 92.75% presented curved root canals in the apical third and 73.25% in the cervical third on coronal plane images; sagittal plane analysis yielded 89.75% of curved canals in the apical third and 77% in the cervical third. Root canals with a large radius were significantly more frequent when compared with the other categories, regardless of root third or plane. Most root canals of maxillary and mandibular first and second molars showed some degree of curvature in the apical and cervical thirds, regardless of the analyzed plane (coronal or sagittal).</p>

Fracture of nickel titanium rotary instrument during root canal treatment and re‐treatment: a 5‐year retrospective study

“…, Estrela et al . ). Moreover, previous studies have shown that small instruments are prone to distortion in clinical or simulated use as a result of stresses on the relatively small cross section leading to torsional failure (Sattapan et al .…”

Common Operative Procedural Errors and Clinical Factors Associated with Root Canal Treatment

“…Prior identification of the radius of curvature of a root canal constitutes a functional conduct (97). The most root canals of maxillary and mandibular first and second molars have some degree of curvature in the apical and cervical thirds, regardless the analyzed plane (98).…”

Study of Root Canal Anatomy in Human Permanent Teeth in A Subpopulation of Brazil's Center Region Using Cone-Beam Computed Tomography - Part 1

“…The anatomic structures of human teeth (number of roots, root canals, apical foramina, root canal isthmuses, root ramifications, root curvatures, developmental disturbances), which constitute its micromorphology have been evaluated by destructive and non-destructive methodologies (1-7). Among the methods described in the literature include decalcification, radiography, vertical and cross-sectional cutting, histological evaluation, stereomicroscopy analysis, surgical microscopy, plastic casts, scanning electronic microscopy, cone beam computed tomography (CBCT) and micro-computed tomography (MCT) (2)(3)(4)(5)(6)(7)(8)(9)(10)(11).…”