Final Exam Flashcards
the wearing away of a surface
abrasion
removing material by a shearing off process
cutting
involves the abrasion of a surface by an abrasive agent where cleaning is not abrasive and will not alter the surface characteristics of enamel or a restorative material
polishing
the process of producing the final shape and contour of a restoration
finishing
most common abrasive in prophy paste, natural glass, rich in silica
pumice
very fine abrasive
tin oxide
very common abrasive in dentistry
aluminum oxide
what are the types of abrasives
chalk, pumice, sand, tin oxide, and aluminum oxide
what are the factors affecting abrasion
hardness, size, shape, pressure, speed, and lubrication
abrasive must be harder than the surface
abrasive hardness
grit (fine/course), larger is more abrasive
abrasive size
spherically shaped particles are less abrasive than irregularly shaped particles
abrasive shape
more pressure =
more abrasion
rate at which device is rotating
abrasion speed
reduces abrasion, but cuts down on heat; mixing water and pumice to create a slurry
abrasion lubrication
what are the reasons for polishing
- reduce adhesion or corrosion
- make surface smooth
- increase esthetics
when choosing an abrasiveness, should you start with fine or course
start with course and move to fine
what can’t you use sodium bicarbonate air polishing on
sealants, composites, and glass ionomers
what type of air polishing should you use if sodium bicarbonate air polishing is contraindicated
aluminum trihydroxide
is aluminum trihydroxide harder or softer than sodium bicarbonate
harder
the contraindications for air polishing are ___________ restriction, _____________ disease, conditions that limit ___________ or ___________ like COPD, patient with _______________ infections, _________________ patients, and patients taking ___________, ______________, and ______________
sodium
respiratory
swallowing or breathing
communicable
immunocompromised
potassium, antidiuretics, and steroids
what are the steps for debonding ortho resin
- identify resin
- removal of bulk resin
- final finish
- evaluation
identifying the resin is necessary to avoid what
removing enamel
to identify a resin you should do what
dry the tooth with air
what is required to remove the bulk resin
handpiece and a carbide finishing bur
to remove bulk resein, what should you do frequently
rinse and dry
when doing the final finish of debonding ortho resin, you use _________ _________ __________ finishing cups and points at low speed over the surface where the resin had been
aluminum oxide composite
once the resin is fully removed, you need to polish each tooth with what
fine pumice slurry and prophy cup
a metal alloy of which one of the elements is mercury
amalgam
metals that are a combination of several elements
alloy
made by mixing approx. equal parts of powdered metal with liquid mercury
dental amalgam
the process of mixing the alloy and liquid mercury through use of an amalgamator/triturator
trituration
what are the properties of metal
highly thermal and electrical conductivity
ductility
opaque
luster
dissolves to some extent in H2O
bends without breaking
ductility
does not transmit light/appears white on x-rays
opaque
strongly reflects light and appears bright and shiny
luster
amalgams are held in place by mechanical retention achieved via _________ and grooves that are placed in the cavity prep with a bur
undercuts
causes setting expansion and increases strength and corrosion resistance
silver (Ag)
causes setting contraction and decreases strength and corrosion resistance
tin (Sn)
increases hardness and strength, increases setting expansion, reduces corrosion, decreases creep
copper (Cu)
reduces oxidation of the other metals in the alloy
zinc (Zn)
zinc containing alloy
> 0.01% zinc
zinc free alloy
< 0.01% zinc
rough, irregular particles don’t slide past each other easily; manufactured by milling an ingot of alloy; requires more mercury leading to inferior properties
lathe cut alloy
lathe cut alloys can resist what
condensation pressure
particles are spherical and are manufactured by atomization of molten alloy: the silver tin alloy is melted and sprayed through a nozzle to form a mist of small droplets that are quickly cooked
spherical alloy
spherical alloy needs __________ mercery which gives it better properties
less
spherical alloy can take ________ condensation pressure compared to lathe cut alloy
less
what are the advantages of amalgam
long lasting, cost effective, least technique sensitive
(y) designated the ___________ alloy or gamma phase and is composed of the unreacted alloy particles
Ag-Sn (silver-tin)
(y1) or gamma one designated the __________ phase
Ag-Hg (silver-mercury)
(y2) gamma two designated ____________
Sn-Hg (tin-mercury)
contains tin/mercury which easily corrodes and is not often used because of this
low copper amalgam
less mercury = stronger
high copper amalgam
what percent silver, tin, and copper is present in high copper amalgam
40-60% silver, 27% tin, and 1-30% copper
what is the most common type of amalgam used today
high copper amalgam
high copper amalgam has high strength and low _________
corrosion
admix high copper amalgam is also known as what
dispersion alloys
admix high copper amalgam contains what type of particles
lathe cut and spherical particles
what are the factors affecting amalgam handling/performance
mercury concentration, trituration, moisture, and anatomy
if zinc is present in amalgam, expansion occurs with _____________
moisture
what anatomy affects handling amalgam
open contacts or overhangs
minimal ____________ is avoided by following the manufacturer’s instructions
dimensional change
low tensile strength and high compressive strength
strength of amalgam
slow change in shape of amalgam caused by compression
creep
self sealing; margins remained sealed as corrosion occurs= microleakage is reduced
oxidizes
what are the working and setting times of amalgam
regular set and fast set
what is the order of coarsest to finest of polishing burs
brownies, then greenies, then super greenies
polishing amalgams under wet conditions will slow ___________ but cut down on __________
abrasion
heat
process of removing excess ortho cement
debonding
what are ortho related issues
poor homecare, food retention, and white spot lesions
what are root canals filled with
gutta percha
removes 1-3 mm of root apex
apicoectomy
what are the indications for endodontics
infection, cracked tooth, decay into pulp
protects sites after perio surgery
COE-pak (perio packs)
what should you do when removing surgical sutures
grab the knot, pull it to one side, and snip it near the tissue
approved as a desensitizing agent
SDF
what percent silver and fluoride is in SDF
24-27% silver and 5-6% fluoride
kills cariogenic bacteria
silver in SDF
what are the indications for SDF use
dentinal hypersensitivity and active root caries
SDF causes ___________ on soft tissues and arrests _______________
staining
carious lesions
what are contraindications for SDF
allergy to silver or silver containing compounds
ulcerative gingivitis or stomatitis
irreversible pulpitis
what is the application process for applying SDF
- polish
- isolate
- dry
- place drop of SDF into dampen dish
- apply SDF with micro brush
sensitivity due to exposure of dentin
dentinal hypersensitivity
exposure of dentin is caused from what two things
gingival recession and loss of enamel
what are the at home treatment options for dentinal hypersensitivity
sensitivity toothpaste, prescription toothpaste, fluoride rinse, and sensitivity strips
what are the in office treatment options for dentinal hypersensitivity
topical treatments, resin light cured adhesives, and glass ionomer light cured adhesives
restorations that are constructed outside of the mouth
indirect restorations
restorations that are fabricated inside of the mouth
direct restorations
cannot be removed from the oral cavity
fixed restorations
how can fixed restorations be classified
- by how much tooth structure they replace
- by which material they are made from
intracoronal, restore pits/fissures but NO cusps
inlays
replace more tooth structure, may cover entire occlusal surface, and replace cusps
onlays
restorations that are placed on the facial surfaces of anterior teeth
veneers
use bonded composites and require minimal structure removal
direct veneer
requires preparation of the tooth and placement of a porcelain
indirect veneer
used when a significant amount of structure is lost, covers entire crown of tooth, and can be all ceramic, porcelain, gold, or porcelain fused to metal
crowns
replaces missing tooth or teeth
bridge
replacement tooth part of a bridge
pontic
crowned teeth holding Pontic in place
abutment
fragile ceramic material but has great esthetics
porcelain
aka porcelain bonded to metal, strong, and look ok but not as nice as all ceramic
cermometal
metals that are a combination of several elements
alloys
a measure of the ability of a material to be stretched before it breaks
elongation
process that pushed metal against the tooth to close gaps between the tooth and the casting metal
burnishing
noble metals are classified based on what
lack of chemical reactivity
what are the noble metals
gold, platinum, and palladium
precious metals are classified based on what
cost
what are the precious metals
gold, platinum, palladium, and silver
when talking about metals, you should know that % is related to what
fineness
what is the most biocompatible metal
titanium
what are the non precious alloys
nickel and chromium
can be molded under heat
thermoplastic material
acrylic resins are activated how
light cure
what is the base of a denture made of
pink acrylic resin
what are the teeth of a denture made of
acrylic (most common) or porcelain or composite
mandibular dentures tend to lack what
retention
how do you reline a denture
adding base material to compensate for loss of ridge
what is the proper cleaning technique for a denture
soaked in denture tablets and brushed with soap and water, no toothpaste
aka bonding; joining together of two objects using a glue or cement
adhesion
a material that can stick to a flat surface or bond two flat surfaces together
adhesive
bonding using surface irregularities smaller than can be seen with the eye or felt with an explorer; material flows
micro mechanical bonding
mechanism by which two things are fused together by the hardening of a glue or adhesive
macro mechanical bonding
why are adhesive necessary
retention, reduction of micro leakage = less recurrent decay
when teeth are heated and cooled by the ingestion of hot and cold foods, expansion and contraction occur
percolation
repeated expansion and contraction at different rates results in what
fluids being sucked in and pushed out at the margins of a restoration
what are the surface factors affecting adhesion
cleanliness and biofilms
creates a microscopically rough enamel surface
acid etching
acid etch is made of _________% phosphoric acid
35-37%
how long do you leave acid etch on the tooth for
15-30 seconds
what will the tooth look like after acid etching
white chalky
what are the two resin systems
low viscosity and composite material
low viscosity resin systems set by what
addition polymerization with light or chemical reaction
after the bonding resin is set, a composite restorative material is placed
composite material resin system
layer of debris that produces when dentin is cut
smear layer
the smear layer extended into the what
dentinal tubules
micro/macro mechanical adhesion is good for what
less recurrent decay, less sensitivity, less staining, and less damage from temperature changes
what are dental cements used for
luting agent glue, pulp protection, endo sealer, perio packs, and cavity varnish
rarely used: seals tubules under amalgams
cavity varnish
the consistency of a luting agent should be what
1 inch string
thicker, replace dentin, protects pulp
bases
thin, secondary dentin formation, reduces dentinal sensitivity, protects pulp
liners
liners are ___________ and bases are ___________
chemical
thermal
what does ZOE stand for
zinc oxide eugenol
IRM is the same thing as ZOE because they both contain what
eugenol
does IRM or ZOE have more material
IRM
are IRM and ZOE temporary or permanent
temporary
what are the powders in cements
zinc oxide and powdered glass
what are the liquids in cements
eugenol, phosphoric acid, and poly acrylic acid
what are the properties of phosphoric acid
irritating and acidic
strongest and least soluble luting cement
glass ionomer
glass ionomers are known for having what two good things
adhesion and biocompatibility
what do glass ionomers release
fluoride
what is the composition of sealant material
polymer resin called bisphenol A-glycidylmethacralate
when should sealants be placed
deep fissures, high risk for decay, and when 6 and 12 year molars erupt
what are the steps for applying a sealant
polish, rinse, dry, etch, rinse, dry, apply, cure, examine
sealants must be placed in what type of environment
dry
what is the most common reason for sealant failure
saliva contamination
should/can you place sealants after applying fluoride
no
should you place sealants over decay
no