Class III, IV, and V preps Flashcards
Do you need to clean the tooth before a class III prep?
Yes
What is used to clean the tooth?
Pumice
Should you take shade before or after dam placement?
Before
When should you check occlusion?
Before placing dam
When can you leave unsupported enamel in a composite prep?
Class 3 facial wall
Should liner be placed before or after the etch?
Before etching
SHould glumma be placed before or after the etch?
After
Which of the following is a location you would NOT place a bevel?
subgingival margin
axiopulpal line angle
gingival margin
always bevel margins in composite preparations
Subgingival margin
Which of the following types of burs will create the most surface area?
coarse diamond
fluted carbide
polishing point
Coarse Diamond
Which ingredient in desensitizing toothpastes is primarily responsible for its desensitizing ability?
Potassium nitrate
Hydrogen peroxide
Gluma
Sodium laurel sulfate
Potassium nitrate
In ideal Class III composite preparations, facial contact should what?
be broken in the gingival portion only
remain intact for optimal esthetics
be broken by 0.5mm for placement of matrix band
be broken by 0.5mm for optimal esthetics
be broken in the gingival portion only
When using an enamel hatchet to trim the buccal and lingual walls of a Class II amalgam box, the broad, flat side of its blade should be held:
At a 90° angle to axial surface of tooth
At a 45° angle to axial surface of tooth
At any angle, depending on what surface you need to cut
At a 45° angle to the occlusal surface of tooth
At a 90° angle to axial surface of tooth
Is it acceptable for a class III to leave sound undermined enamel to preserve incisal contact?
Yes
What should the inciso-gingival length of a class III prep be on a max lateral?
1.5 mm
What should the inciso-gingival length of a class III prep be on a max central?
2 mm
What should the mesial distal width of a class III prep be on a max lateral?
1 mm
What should the mesial distal width of a class III prep be on a max central?
1.5 mm
Should the class 3 prep be done parallel or perpendicular to long axis of tooth?
Perpendicular
The purpose of the bevel is to ____ the bond to the tooth
Increase
Can you bevel dentin and cementum?
No
Same principles as Class III BUT the incisal angle is missing
◦Increase in restorability difficulty level!
Class IV Prep
Increase the bevel and extend beyond the bevel with the resin for more ______ and a better ______ appearance.
retention; esthetic
Should you use tofflemires or clear matrices for class 3 and 4 composite restorations?
Clear matrices
______
- Increases retention
- Reduces microleakage
- Sides of enamel rods don’t bond well
Bevels
What 2 portions of the tooth can’t be bevelled?
Cementum
Dentin
Bond strength to natural sclerotic dentin is __-__% lower than to sound cervical dentin-REMOVE with bur
25-40%
◦Flexure and fatigue of enamel and dentin
◦Caused by occlusal forces
◦Stress is concentrated at cervical area of tooth, causing fractures
Abfraction
What are the 5 instances when a non-carious cervical lesion needs to be treated?
◦Lesion is deep enough to compromise tooth
◦Sensitivity
◦Involved in partial denture design
◦Defect is approaching pulp
◦Defect contributes to a periodontal problem
What type of composite is best for abrasion?
Flowable composite
◦Pain caused by dentinal fluid movement ◦From mechanical or chemical stimuli ◦Temperature changes ◦Air drying ◦Osmotic pressure
Hydrodynamic Theory of dentin sensitivity
Causes of _______
Caries or leaky restorationVoid-fluid flows into void
◦Ex. From CaOH liner having washed away
Premature occlusion
Exposed dentin
◦Recession or incomplete formation of CEJ
Exposed cementum
Post-periosurgery
Abrasion and erosion
◦Includes iatrogenic from polishing instruments
Tooth Sensitivity
What is the component of sensitivity toothpaste that helps sensitivity?
Potassium Nitrate
_____ is a desensitizing agent placed by dentist when prepping tooth
-Place after etching
Gluma
How do treatments help sensitivity?
Block fluid movement in dentinal tubules
