Complex Amalgam Flashcards
Retention form decreases if cavity walls are
shortened or removed
How is primary retention derived?
From opposing walls
What is a foundation restoration?
COmplex restoration prepared in such a manner that the restorative material will serve in lieu of tooth structure in subsequent procedures for developing the final restoration (crown prep)
Foundation restoration must be independently retentive of
tooth structure that may be removed during subsequent preperation
Crown prep requires uniform removal of
1.0-1.5 of tooth structure
Describe a temporary/caries control restoration
Used to restore a tooth temporarily for caries control (partial decay excavation and placement of temporary/sedative restoration)
Temporary restoration can be dependent on
remaining tooth structure (unsupported) for support
Capping weakened cusps increases their
resistance form
Cusp capping is necessary for adequate ___________ form when decay severely undermines enamel
resistance
What are the rules for capping a cusp?
- Required when facial (lingual) extension is 2/3 from primary groove toward cusp tip
- Evaluate clinical factors fo esthetics and occlusion (interferences), parafunctional habits (bruxism), opposing dentition (removable or fixed appliances) and arch location
Required reduction for supporting cusps
2mm
Required reduction for non-supporting cusp
1.5mm
What do you do if you suspect an incomplete cusp fracture?
Identify offending cusp using tooth slooth. If clinical symptoms are alleviated with capping, then full coverage crown may be indicated. Rule out possible pulp involvement
What cusps are frequently affected for incomplete cusp fractures?
Non-supporting- Max Buccal and Mand Lingual
Are undercuts needed for a direct restoration?
Yes
Are undercuts needed for an indirect restoration?
No-not allowed
Describe clinical order of operations (Max 1st molar example)
- Prepare ideal Class I outline
- Extend outline to sound structure depending on extent of decay
- Drop required proximal box
- Cross oblique ridge if necessary
- Decide on cusp capping
What is minimum shoulder dimension for molars?
1.5mm
What is the minimum shoulder width for premolars?
1mm
What are possible secondary retention features if primary is compormised?
- Slots
- Grooves
- Boxes
What plane is slot located in?
Transverse or horizontal
Where are slots located?
in dentin, 1mm from external surface, 0.5mm from DEJ
What bur do you use to prepare slots?
331/2 inverted cone
What plane are grooves/locks in?
Longitudinal plane
