ROOT CANAL CURVATURE - CLASSIFICATION

I.Zidell's classification of root canal systems
Class 2- complicated canals with constricted foramina
a. Severe curve
b.Dilacerated curve
c. Bayonet curve
d. Apical bifurcation
e. Apical curve
f. Additional canals
g. Lateral or accessory canals

II. Ingle and Taintor
1. Apical curve
2. Gradual curve
3. Sickle-shape curve
4. Dilaceration
5. Bayonet

III. Pucci and Reig - similar classification


IV. Schneider's classification on the basis of degree of
curvature
1. Straight (5 ° or less)
2. Moderate (10-20 ° )
3. Severe (25-70 ° )

V. Dobo Nagy et al. .
This is based on Schneider's angle and the radius of the circle that could be
superimposed on the curved part of the root canal.

VI. Backman et al. classified root canals on the basis of
"radius quotient," which was obtained by dividing a given
angle by its radius measurement

VII. Southard et al. - similar classification


Reference...JOE..1995

MECHANISM OF ULTRASONICS - ACOUSTIC STREAMING

¢ Acoustic streaming is the rapid movement of particles of fluid in vortex(circular)-like motion about a vibrating object.

¢ When a vibrating file is immersed in a fluid, the file is observed to generate a streaming fluid comprising two components:

¢ Primary field consisting of rapidly moving eddies in which the fluid element oscillates about a mean position, and a superimposed secondary field consisting a patterns of relatively slow, time independent flow. Characteristically the fluid is transported from the apical end to the coronal end.

¢ In a endosonic file the greatest shear stresses will be generated around points of maximum displacement, such as the tip of the file and the antinodes along its length

¢ it is probable that will also be important in moving the associated irrigant around the canal so that maximum benefit is achieved from the chemical irrigant.

Martin H. the ultrasonic synergistic system. Int Dent J 1984;34:198 –203.

Martin H. the ultrasonic synergistic system of endodontics. Endod Dent Traumatol 1985;1:201– 6.

Ahmad M. Ultrasonic debridement of root canals: acoustic cavitation and its relevance. J Endod 1988;14:486 –93.