Restorations of extensively damaged vital teeth Flashcards
Pulp and ____ mm thick surrounding layer of dentin
should be preserved if possible
1 mm
Central Core (Pulp Chamber) ______ as we age
shrinks and recedes
Which anterior tooth has less shrinkage of pulp chamber ?
Canine
If there is extensive peripheral destruction in a tooth, what is the best restoration?
Full Crown
If Isthmus destruction greater than ½
intercuspal width, what restoration should you select?
– Crown or Onlay
If More that 50% of tooth structure is gone
and loss of cuspal support, what restoration?
– Crown (and
likely a core build up too)
If Combined Central and Peripheral destruction, what restoration?
-Core Build up and Crown
Increased axial reduction in the _____ of the preparation wall will
reduce taper and create more retention and greater resistance form.
cervical 1/2
Sloping surfaces left after cusp fracture or caries
removal need retention, what should you do for crown prep?
Break slope into vertical and horizontal
components
Grooves placed ____ to the long
axis of the tooth
parallel
Grooves used in short preparation walls with minimal occlusal clearance: -\_\_\_\_ grooves shorten the radius of the arc of rotation –
Proximal
Walls of a groove or a box are
best placed ______ to the
displacing force
perpendicular
When two boxes are needed, less than 180 degrees of tooth
circumference remains.
-This poses a great risk for cuspal fracture
What do you do?
-Use a Build Up and full crown to protect against fracture
What are the 4 ways to increase wall height?
Place margin more apically
Add materials to build up tooth
Crown lengthening
Orthodontic extrusion
Replaces lost tooth structure to improve
retention of a crown
A core must be anchored firmly to the tooth
and not just placed to fill the void
Retention for a core is often with the use of
pins
Core Build up
A Build Up is needed when more than
______ of the tooth structure is lost
50%
Use of pins recommended if ____ or more of the
clinical crown has been destroyed.
½
Mechanical properties Compressive strength Dimensional stability Isolation less technique sensitive Matrix placement can be difficult if tooth is severely broken down. Often used in RCT teeth into canal for strength Limitations: Matrix placement can be difficult if tooth is severely broken down Slow setting material (10-15 minutes before band removal) No bonding or natural retention Requires at least 2mm thickness Color shows through some ceramic crowns Final crown prep occurs another day Not used to a great extent any longer.
Amalgam core buildup
Mechanical properties Bonds to tooth structure Still needs help with pins Quick setting Tooth prep at same visit Ease of manipulation Can be thinner than 2mm Color of material aids in crown matching Limitations Technique sensitive Microleakage possible as material shrinks when cured Isolation can be challenging
Composite core build up
____ are helpful to support the Build
Up material when residual tooth
structure does not provide adequate
retention itself.
Pins
T/F: Pins shouldnt be placed parallel
True
\_\_\_\_\_are used only to protect pulp in teeth that are have excavations that are deep and near the pulp. - can be used to fill in undercuts when an entire Build up is not needed. - are weaker materials that do not provide strength like a Build up. Bases are not strong enough to support grooves, boxes or other retentive features.
Bases
What are the 5 steps for applying bases?
- Gluma (Gluteraldehyde)
- 2x60 second coats - Dycal / Calcium Hydroxide
- Vitrebond
- Glass Ionomer?
- Routine restoration steps
