Principles of Tooth Preparations Flashcards
A crown preparation is an ___ surgical procedure
irreversible
What are the 7 principles of tooth design and restoration design?
- preservation of tooth structure
- retention form
- resistance form
- added preparation features
- marginal integrity
- structural durability of the restoration
- preservation of the periodontium
In consideration of preservation of tooth structure are biological factors such as:
(what are other things you must consider in addition to the structure you are working on)
- dental pulp
- gingival tissues
- adjacent teeth
When considering preservation of tooth structure, if not careful, injury can occur such as:
- mechanical damage
- temperature damage
- chemical damage
- bacterial damage
Pulpal integrity: Any time a bur touches a tooth, the pulp is:
stimulated to respond
Pulpal integrity: A crown preparation _____ the pulp
“traumatizes”
Pulpal integrity: most pulps respond with:
a healthy healing response
Pulpal integrity: some pulps respond by:
dying (pulpal necrosis)
Pulpal integrity: some pulps remain ___ with lingering pulpal inflammation
hypersensitive
Why can the pulp become/remain hypersensitive or necrotic?
- decreased thickness of dentin remaining between prepared walls & pulp
- heat transferred to tooth during prep
When considering pulpal integrity, what is “vital core”?
leave at minimum 1mm of dentin surrounding pulp
How much MINIMUM of dentin should be surrounding the pulp?
1mm
If there are risks like killing the pulp, why do we prepare teeth for crowns?
Crowns are placed for many reasons such as:
- Esthetics
- Prevention of catastrophic fracturing
- Protection of Root Canal Teeth
- Make tooth stronger
What must be in balance when considering preservation of tooth structure?
(1&2 vs. 1&2)
- unnecessary destruction of sound tooth structure
- preservation of structural integrity of the remaining tooth structure
VERSUS
- mechanical requirements the patient needs
- esthetic requirements the patient desires
When considering preservation of tooth structure:
When preparing a tooth for a crown in a conservative manner, the operator allows for a:
morphological reduction
Preservation of the basic primary tooth anatomy within the preparation (axial wall and occlusal anatomy):
morphological reduction
Morphological reduction leaves the ____ of residual tooth structure surrounding the pulp
maximal thickness
What type of features does morphological reduction leave in the tooth preparations?
- anti-rotational features
- retentive features
- resistive features
As we create our crown preparation, we need to form the tooth utilizing geometric form criteria we call:
- retention
- resistance
A seating groove in a crown preparation allows for:
retention & resistance
Axial reduction in a crown preparation allows for:
retention & resistance
Prevention of removal along the path of insertion:
retention
Retention usually occurs:
in patients chewing sticky foods
Created by two opposing vertical surfaces with converging surfaces held to within certain parameters:
retention