Authors: Kuttler Y.
Title: Microscopic investigation of root apexes.
Journal: J Am Dent Assoc
Date: May 1955
Citation: 50(5):544-52
Category: Anatomical Considerations
Evidence-based Ranking: 5
Purpose/Objectives: To observe, measure, diagram and draw conclusions concerning the properties of root canal apices with the aid of magnification.

Materials & Methods: 268 extracted teeth were gathered and separated into group 1 ( age 18-25) and group 2 (age greater than 55). The apical foramens were located with the aid of dye and then sectioned along the plane that would include any curvature of the canal. These sections were measured and diagramed and the average measurements recorded.

Results: Group 1 Group 2 Distance from center of apex to center of foramen 495 microns 607 microns Foramen diameter at surface 502 microns 681 microns Deviation from center of Canal 255 microns 287 microns

Author’s Conclusion: 1) Center of foramen deviates more with age 2) Diameter of foramen increases with age 3) Last .5mm of canal cannot be sealed hermetically 4) Cemento-dentinal junction can be even or unequal 5) The apical constricture gets tighter with age 6) The apical cementum gets thicker with age