•Purpose: To perform measurements of the width of the roots and the root canals of human anterior teeth between 1 and 5 mm from their apices.
•N= 100 human extracted teeth (20 max. central incisors, 20 max. lateral incisors, 20 man. incisors, 20 max. canines, and 20 mand. canines).
•5 cross-sectional cuts were made through the roots of the teeth 1, 2, 3, 4, and 5 mm from the apex.
•sections of the roots were mounted on object glasses with clear glue and examined in the light microscope.
•The largest and smallest diameters of the roots and of the root canals at 1, 2, 3, 4, and 5 mm from the apex were measured by a light microscope equipped with a measuring eyepiece.
•Most highlighted Results:
–Maxillary Central Incisors:
– All teeth had one root with one root canal -20%) the canal ended at a level between 1 and 2 mm coronal to the anatomic apex.
– At 1 mm from the apex the largest diameter of the root canals varied between 0.3 and 0.45 mm.
-The size of the canal increased in a coronal direction (at the 5-mm level the largest diameter 0.45 – 0.9 mm).
Maxillary Lateral Incisors:
– All teeth had one root with one root canal.
-(10%) the canal ended between 1 and 2 mm coronal to the anatomic apex.
-At the 1mm level the largest diameter was between 0.2 and 0.6 mm.
-5 mm from the apex the diameter varied between 0.3 and 1.0 mm.
– All teeth had one root (16 one root canal, 4 two canals).
-(10%) had root canals that ended between 1 and 3 mm coronal to the anatomic apex.
-The largest diameter of the root canals at the 1-mm level varied between 0.15 and 0.7 mm.
-At 5-mm level the largest width was 1.3 mm.
-one root with one root canal.
-(30%) the canal ended at a level between 1 and 3 mm coronal to the anatomic apex.
-At 1 mm from the apex the largest diameter of the root canals varied between 0.2 and 0.45 mm.
-At 3 and 5 mm from the apex: width of the canals between 0.3 and 0.7 mm.
-one root. (18 had one root canal 2 had two canals).
-The largest diameter of the root canals at the 1-, 2-, an d 3-mm levels: between 0.1 and 0.8 mm.
– At the 5-mm level, wider canals were observed (1.3 mm).
-Circular-shaped preparations might be made with acceptable frequency in the apical 5 mm of maxillary central incisors and canines, and in the apical 3 mm of mandibular canines.
-A circular canal might be prepared in maxillary lateral incisors and mandibular incisors only at the 1mm level from the apex.