finishing and polishing Flashcards
what is the purpose of finishing and polishing
they are meant to remove excess material and smooth roughened surfaces
what is the purpose of cleansing
cleansing techniques are meant to remove food and other debris from a surface without damaging it
what are dentifrices
pastes or powder used to clean the teeth
what is abrasion
a wearing process
are the materials used for finishing and polishing abrasive
yes they primarily are
what dose abrasion result from
it results whena hard rough surface such as sandpaper disk plows grooves into a softer material and cause material from such grooves to be removed from the surface
what are the 3 factors that primarily affect the rate of abrasion
speed at which the abrasive material travels across the surface being abraded
size
pressure
what is the surface roughness and what is its symbol
the measure of the irregularity of the finished and polished surface and is measured in micrometers,Ra
what is the Ra of a SMOOTH surface
the surface roughness is less than 0.2 micrometers and is desirable to reduce retention of bacteria and to have a shiny appearance
what is gloss
the measure of the reflection of light from a surface
how many GU (gloss units) does a totally non-reflective surface have
and glass
- 0 GU
2. glass has 1000 GU
when is it low-gloss,semi-gloss-and high-gloss respectively
less than 10,10-70,greater than 70 is considered high gloss
what are the 3 types of abrasives
finishing,polishing,and cleansing abrasives
classify dental abrasives from most to least rough
finishing, polishing, cleansing
what abrasives are used in AIR-ABRASION units commonly used for finishing
aluminum oxide
name 7 types of abrasives
- aluminum oxide
- quartz(sio2)
- sand( a form of quartz)
- garnet
- DIAMOND
- SILICON CARBIDE(SIC)
- pumice
how is an amalgam restoration polished
polishing is perflrmed with a creamy paste of extra fine silex abd water applied gently in an unwebbed rubber cup with a slowspeed hanpiece for 30 sec per surface
why is the roughness of finished and polished Gic higher than that of composites and hybrid inomers
because of the larger particle sizes of the filler
what does MTA stand for and what is its purpose
mineral trioxide aggregate, used in a single step procedure as an apical barrier, allowing obturation-sealing- in the same appointment
what is mta used for
MTA is used for creating apical plugs during apexification, repairing root perforations during root canal therapy, and treating internal root resorption.
what is apexification
it is a procedure a dentist or endodontist performs to close the end of an open tooth root. It’s often required for treating permanent teeth with incompletely formed roots that require root canal therapy
what is the best material to use when it comes to restoration that are in proximity to the gingiva
GIC
not composite
how can we measure smoothness by color,give ab example
closer to white-> smooth
closer to black->rough
so yellow is smoother than orange
black is more coarse than brown
when is the process of finishing and polishing done for
- amalgam
- composite
- compomer
- GIC
- Hybrid inomer
- the next day
- directly after application
- directly after application
- after 24 hrs
- after 24hrs
what can and cannot be used as a prophylaxis if amalgam restoration is present
what can be used are products containing pumice or khaffan but zirconium silicate cannot be used for its large rough particles.
what ingredient in grey MTA is responsible for tooth discoloration
ferrous oxide, the replacement of it by magnesium oxide in white MTA
why does MTA have antibacterial properties
because of it high PH level, very basic
