JVD 2015 #4 - Evaluation of the Natural Crown Convergence Angle of Dog Carnassial Teeth

Question 1

According to “Evaluation of the natural crown convergence angle of dog carnassial teeth” by Zimmerman, Soukup,

what is the ideal CA (convergence angle) published for humans?

what factors in crown prep design are important for appropriate resistance and retention forms?

Answer 1

<12deg;

height, diameter, H/D ratio, surface area and CA all influence resistance and retention form

Question 2

According to “Evaluation of the natural crown convergence angle of dog carnassial teeth” by Zimmerman, Soukup,

were there any significant associations between 108CA and weight, age, or skull type? 409?

Answer 2

No sig difference

Question 3

According to “Evaluation of the natural crown convergence angle of dog carnassial teeth” by Zimmerman, Soukup,

what is the definition of convergence ange?

what are the primary vectors during mastication for the carnassial teeth?

Answer 3

angle between two opposing axial walls of a tooth crown;

shearing force in a palatobuccal oblique direction for 08, and opposite for mandibular 9’s

Question 4

According to “Evaluation of the natural crown convergence angle of dog carnassial teeth” by Zimmerman, Soukup,

what was the mean convergence angle of 08 and 09’s in this study?

How does this compare to the previously reported “ideal” CA?

Answer 4

08: 42 deg
09: 36 deg

3-4x greater than previously reported 12deg. ideal angle

Question 5

According to “Evaluation of the natural crown convergence angle of dog carnassial teeth” by Zimmerman, Soukup,

what was the previously reported CA of canine teeth?

what was the retention rate in that study and what was the majority CA?

Answer 5

35. deg for canines;

clinical retention rate was 90%,

75% of teeth in the study possessed a CA >25deg

Question 6

According to “Evaluation of the natural crown convergence angle of dog carnassial teeth” by Zimmerman, Soukup, based on the authors previous studies,

what is the best luting cement for resistance and retention?

Answer 6

resin-based cement

Question 7

According to “Evaluation of the natural crown convergence angle of dog carnassial teeth” by Zimmerman, Soukup,

what do the authors suggest for creating a natural convergence angle that has resistance and retention w/o taking down too much of the axial walls?

Answer 7

parallel axial wall reduction only in the cervical 1-2mm of prep while maintaining the natural convergence angle for the remainder of the preparation…

P.S. Don’t do this in phase II (hahaha)