9/4: Principles of Tooth Preparations Flashcards
- What are the 7 principles of tooth design and restoration design?
a. Preservation of tooth structure
b. Retention form resistance form
c. Added preparation features
d. Marginal integrity
e. Structural durability of the restoration
f. Preservation of the periodontium
- What biologic factors are in consideration with a crown prep?
a. Dental pulp
b. Gingival tissues
c. Adjacent teeth
- This is known as “vital core”
a. Leaving a minimum of 1 mm of dentin surrounding pulp
- What problems can you have with pulpal integrity?
a. Decreases thickness of dentin
b. Heat transfer during preparation
- When preparing a tooth for a crown in a conservative manner, the operator allows for a
a. Morphological reduction
- This is preservation of the basic primary tooth anatomy within the preparation
a. Morphological reduction
- As we create our crown preparation, we need to form the tooth utilizing geometric form criteria we call”
a. Retention
b. Resistance
- Making grooves on the prep were designed for what?
a. Resistance and retention
- The functional cusp bevel is made for
a. Structural durability
- The planar occlusal reduction is made for
a. Structural durability
- The axial reduction was designed for what?
a. Resistance and retention
- This is prevention of removal along the path of insertion
a. Retention
- How is retention created?
a. 2 opposing vertical surfaces with converging surfaces
b. Cements offering frictional resistance
c. Mechanical factors such as dental cements
- This is the prevention of restoration being dislodged by apical or oblique forces
a. Resistance
- Resistance is typically through what forces?
a. Occlusal forces
- Can resistance be through lateral forces that are not along the POI?
Yes
- What is the greatest determining factor in a crown’s dislodgement?
a. Resistance
- Resistance is built into a preparation by forming walls to block anticipated movement due to
a. Leverage
b. Rotation
- What factors can affect the resistance form of a tooth preparation?
a. Total occlusal convergence
b. Preparation wall length
c. Tooth width after preparation
d. Geometric form
e. Surface area of tooth preparation
- These limit the paths of insertion, grooves, boxes vertical planes, pins
a. Geometric forms
- This is defined as the angle of convergence of taper between 2 opposing walls of a tooth preparation
a. Total occlusal convergence
- This is defined as the angle of convergence of taper of one wall of a preparation in relationship to the long axis of the preparation
a. Inclination
- What is the ideal TOC?
a. 6 degrees
- How much convergence do you want on both sides of the prep?
a. 3 degrees = 6 total