Objectives of tooth preparation (which one is the most important?)
- REMOVE ALL CARIES AND PROTECT THE PULP (important!!)
- . Extend the prep outlines as conservatively as possible
- Determine the form of the preparation that can withstand msticatory forces and prevent fracture of the restoration and/or tooth
- to allow the placement of the final restorative material that is both esthetic and functional
Purpose of restorative dentistry
- removal of defective or diseased tooth structure
- establishment of a form to meet biochemical purposes
- maintain vitality of pulp (minimize trauma)
7 G. V. Blacks steps!!!
- Outline form
- Resistance form
- Retention form
- Convenience form
- Removal of carious dentin
- Finishing the enamel walls and dentin
- Performing a toilet of the cavity/cleaning, inspecting and desensitization
2 important characteristics of outline form
- removal of all undermined and unsupported enamel and carious dentin/enamel
- Proper placement of cavity margins (cavosurface margins) for placement and finishing of restoration
“extension for prevention” primarily applies to ___, while “conservative cavity preparation” primarily applies to ___
“extension for prevention” primarily applies to AMALGAM, while “conservative cavity preparation” primarily applies to COMPOSITE
What is resistance form?
-It is the shape and placement of cavity walls in order to resist fracture of RESTORATION and REMAINING TOOTH from masticatory forces.
Which is more favorable for resistance form, flat or rounded floors? why?
FLAT FLOORS. Because they help prevent movement of restoration as the masticatory force is directed on the resto. Rounded pulpal floors create rocking action which produces a wedging force and can result in shearing of a cusp
Slight rounding of internal angles allows for reduction of ___ ___
internal stress. ie. lowers risk of potential fracture of remaining tooth and restoration
what is retention form?
mechanical shape of preparation that resists displacement of restoration through tipping, lifting, or pulling forces
What do we mean by convenience form?
Margins and shape of the cavity prep must allow the operator to have proper:
- visibility
- access (instruments)
- placement (final restorative material)
- finishing (eg. allow hand pieces and burs to fit)
during the step of finishing enamel walls and cavosurface margins, what needs to be removed?
- unsupported enamel
- weak enamel
- fragile enamel
What does it mean to perform a toilet of the cavity?
- removal of loose debris using air/water syringe
- cleanse and dry preparation without desiccation of the dentin
