Minimum amount of Taper

# What is minimum of amount of taper that should be maintained for an ideal tooth preparation?
a) 4 Degree
b) 5 Degree
c) 6 Degree
d) 12 Degree

The correct answer is D. 12 degrees.

Some important points on tapers:
• The relationship of one wall of preparation to the long axis of that preparation is the inclination of that wall. • Sum of the inclination of two opposing walls gives the taper of the preparation.
• Recommended taper is 3-12 degree. According to Schillinberg 6 degree is recommended.
• Minimum taper that is necessary to insure the absence of undercuts -12 degree.
• A taper or total convergence of 16 degrees has been proposed as being achievable clinically while still affording adequate retention. This probably an acceptable overall target. It can be as low as 10 degree on preparations of anterior teeth and as high as 22 degrees on molars.

CLICK HERE TO PRACTICE MORE MCQs.

CPC Line

# Transverse line extending from or between the middle of upper canine and incisive fossa is called:
a) Horizontal line
b) Orientation line
c) Transverse line
d) CPC line

The correct answer is D. CPC line.

Canine-papillary-canine line (CPC line) is used as a guide to orient the upper canine teeth in complete dentures. The incisive papilla is a stable landmark for arranging labial surfaces of central incisors 10mm anterior to the incisive papilla. The tips of canines should be set on a horizontal line which pass through the posterior border of incisive papilla.

Palatopharyngeal Incompetence

# Palatopharyngeal incompetence is treated by?
a) Palatal lift prosthesis
b) Obturator prosthesis
c) Pharyngeal speech prosthesis
d) Pharyngeal bulb prosthesis

The correct answer is A. Palatal lift prosthesis.

Palatal lift prosthesis is useful for patients with velopharyngeal incompetence who exhibit compromised motor control of the soft palate & related musculature. The objective of palatal lift prosthesis is to displace the soft palate to the level of normal palatal elevation, enabling closure by pharyngeal action.

Over Dentures in Prosthodontics

# The use of selected initial roots in over denture therapy is called :
a) Overlaying denture therapy
b) Biologic denture therapy
c) Submucosal vital root retention
d) Submerged denture therapy

The correct answer is C. Submucosal vital root retention.

In over dentures, anterior abutments are preferred over posterior abutments since the anterior ridge is more vulnerable to resorption than the posterior ridge.