Polishing Materials and abrasion Flashcards
What is cutting?
Removal of material by shearing off process like drilling and milling
What is abrasion?
The wearing away of substance or structure through a mechanical process such as grinding, rubbing, or scraping.
What are the two types of abrasion?
Two-body abrasion- abrasive praticles fixed to substrate
Three-body abrasion- abrasive particles move in a space between the surface being polished and an application device.
What are the different types of classifications?
Finishing abrasives-hard for contour and remove irreg
Polishing abrasive -fine- for smoothing
cleansing abrasives- soft to remove soft debris
What are the types of abrasives?
- Chalk
- Pumice
- sand
- Cuttle
- Garnet
- Emery
- Silex
- Tin Oxide
- Aluminum Oxide
What are some bonded and coated abrasives?
Diamond burs
Stones
Rubber wheels or points
Rubber Cups
Discs and strips
polsihing powders
What are some characterisitics of abrasives?
Should be irregular shape with sharp edges
Should have high impact strength
Should be attrition resistant, so it does not wear
Factors Affecting Rate of Abrasion are ?
Hardness
Size
Shape
Pressure
Speed
Lubrication
What are some polishing process or why doe we polish?
Reduce adhesion
make surface feel smooth
increases esthetics
reduces corrosion
What is the selective polishing theory?
that only teeth are require are stained ones
What is the essential selective polishing ?
- pastes or cleaning agents chosen specifically becasue of estetic restorations in the patients mouth
- goal of polsihing is to create a smooth surface on teeth and restorations with the least abrasive agent needed.
What is air polishing?
utilizes air and water and polsihing powder to remove stains and polsih teeth
What are the different types of polishing powder?
- Sodium bicarbonate
- Aluminum trihydroxide
- Glycine Powder
- Calcium Carbonate
Alumium trihydroxide cannot be used on?
Dentin
cementum amalgam
gold
composites
glass ionomers and implants
can disrupt and damage luting agents and restorative margins
If you are going to polish a tooth with composite restorations it is best to use?
Glycine based powders
