L2a: Planning and preparing for prosthetic dentistry

Question 1

Which are the considerations for treatment planning for the replacement of missing teeth?

Answer 1

• All restorations must be able to withstand the constant occlusal forces to which they are subjected.
• The supporting tissues surrounding the abutment teeth must be healthy and free from inflammation before any prothesis can be contemplated.
• Normally abutment teeth should not exhibit mobility, since they will be carrying extra load.

Question 2

Which are the evaluating factors?

Answer 2

• Crown-root ratio.
• Root configuration.
• Periodontal ligament area.

Question 3

What is crown-root ration?

Answer 3

The ratio of the length of the tooth occlusal to the alveolar crest of the bone compared with the length of the root embedded in the bone.

Question 4

Which is the ideal crown-root ration?

Answer 4

Ideal crown-root ration is 1:2

Question 5

Which is the minimum crown-root ratio?

Answer 5

Minimum crown-root ratio is 1:1

Question 6

Which is the acceptable crown-root ratio?

Answer 6

Acceptable crown-root ratio is 1:1.5

Question 7

Which root configuration is more preferable?

Answer 7

Roots that are broader labiolingual than they are mesiodistally are preferable to roots that are around in cross section.

Question 8

Which roots offer better periodontal support?

Answer 8

Multirooted posterior teeth with widely separated roots will offer better periodontal support than roots that converge, fuse or present a conical configuration.

Question 9

Which is the benefit of larger teeth?

Answer 9

Larger teeth have a greater surface area and are better able to bear added stress.

Question 10

What is the length of the pontic span that can be successfully restored limited by?

Answer 10

The length of the pontic span that can be successfully restored is limited by the abutment teeth and their ability to accept the additional load.

Question 11

What does Ante’s Law say?

Answer 11

The root surface area of the abutment teeth had to equal or surpass that of the teeth being replaced with pontics.

Question 12

What must abutment teeth be free from?

Answer 12

Abutment teeth must be free from:

• periodontal diseases
• periodontal pockets
• osseous defects
• gingival inflammation
• must have an adequate zone of attached gingival