EXAM Flashcards
what are the two pastes called in dycal (calcium hydroxide)?
catalyst, base
when mixing IRM (zinc oxide eugenol) how much powder should you initially add to the liquid?
1/2
when mixing zinc polycarboxylate (durelon) how much powder should you incorporate initially?
all
to use the powder/liquid resin modified glass inonomer (relyx) what is the powder:liquid ratio?
1:1 (3:3)
when mixing liners, bases and cements the ppe required is?
gown, protective eyewear, mask, exam gloves
cavity ___ acts as a protective barrier between the tooth preparation and the restoration?
varnish
___ is used as a low strength base/liner in cavity preparation in which dentin no longer covers the pulp?
calcium hydroxide
___ provide thermal insulation and support for restorations?
high strength base/liners
for use as a provisional and intermediate restoration, dental cements are mixed to a ____ consistency?
secondary
as a ___ cements are used to provide protection and support for the surgical site, to provide patient comfort and to help in the control of bleeding?
surgical dressing
no cement is ideal for every ___ situation?
clinical
____ is the measure of the cements ability to flow under pressure?
viscosity
the cement’s resistance to deformation/fracture under an applied force is a measure of it’s ______ properties?
mechanical
_____ is based on the interlocking of one material with another like velcro?
mechanical adhesion
______ occurs at the molecular level when atoms of the two materials swap electrons or share outer electrons?
chemical adhesion
dental cement that has been used for many years is available in a powder/liquid and paste/paste system, can be used for temporary cementation temporary and intermediate restorations, high and low strength bases, root canal sealers and periodontal dressings?
zinc oxide eugenol (zoe)
two dental cements that set through an acid base reaction?
zinc polycarboxylate, zinc oxide eugenol (zoe)
dental cement that is used as a permanent luting agent, luting of orthodontic bands and brackets, restorative materials, low and high strength bases and core build ups?
glass ionomer cements
dental cements that are modified composite resins with lower viscosity used for bonding of cermic indirect restorations, conventional crowns, and bridges and for direct or indirect bonding of orthodontic brackets?
resin based cements
dental amalgam is still widely used because no other direct restorative material has?
ease of manipulation, durability, low cost
amalgam has been studied and tested more than nay other direct restorative material?
true
lathe-cut alloy?
irregularly shaped particles formed by shaving fine particles from an alloy ingot
spherical alloy
small spheres of alloy particles produced by spraying a fine mist of liquid alloy into an inert gas environment
admixed alloy
mixture of lathe-cut and spherical alloys
how long does it take for a newly placed amalgam restoration to gain its maximum strength?
24 hours
amalgam is among the strongest directly placed restorative material?
true
what could be done to help prevent could sensitivity in a tooth with a deep amalgam restoration?
place a base
a patient with a recently place amalgam filling calls the office and states that occassionally they get a little electric shock in the tooth followed by a metallic taste. what type of reaction is occuring?
galvanic
amalgam safety?
safety of the patient, safety of the dental staff, safety of the environment
while trying to load the triturator you have accidently opened the cap and spilled mercury onto the floor. the best way to clean and dispose of the contents is?
use and follow the directions of a mercury spill kit
what item is needed to contain the amalgam when preparing a class 2 amalgam?
matrix band
fluoride helps to protect the teeth from decay by?
making the enamel more resistant to bacterial acids
when tooth enamel first begins to demineralize, what is one of the corrective measures that can be taken to stimulate remineralizeation?
use a daily rinse containing fluoride
when enamel is remineralized with fluoride?
the resultant remineralized crystal is more resistant to acids
fluorosis is always considered to be?
a sign that the person has ingested more than the optimal amount of fluoride
nightly home fluoride treatment with 1.1% sodium fluoride as a brush on gel or in custom trays is indicated for?
elderly patients taking medications that cause dry mouth
sealant materials
an unfilled or lightly filled resin
when a dental sealant is placed, the technique?
requires the field to be kept dry
best candidate for a sealant?
a newly erupted tooth with numerous deep fissures
if caries in a fissure is undetected and is inadvertently covered by a well placed dental sealant what will happen?
caries will stop progressing
very small filler particles are added to sealant material for which purpose?
to decrease wear of the sealant
how is the surface of the tooth prepared before acid etching for sealant placement?
the surfaces are cleaned with pumice
the acid most commonly used to etch the enamel for sealant application is which one?
phosphoric acid
the tip of the light wand of the curing light should be held how close to the sealant?
very close about 1mm away from the surface
reasons why pits and fissures are so susceptible to caries?
the enamel lining them is always very thin
after placement of a sealant what should be checked?
the occlusion, the contact areas with adjacent teeth, the sealant surface for voids or porosities
the most common reason for loss of a sealant shortly after placement is which of the following?
saliva contamination after acid etching
how should the surface of the enamel appear after acid etching?
frosty white
what does acid etching do to the surface of the enamel?
it creates a roughened, irregular surface
the most important requirement for sucessfully bonding sealants to enamel is?
good isolation to prevent saliva contamination
studies show caries to occur in pits and fissures most often in which group of teeth?
permanent molars
how does a sealant adhere to the etched enamel surface?
micromechanical retention
the main purpose of desensitizing agents?
is to plug the openings of the exposed dentinal tubules
what ingredient in silver diamine fluoride stains the decayed portion of the tooth and anything it comes in contact with?
silver
application to silver diamine fluoride ___ times per year has shown to arrest caries at 90%?
2
fluoride varnish can remain on the tooth for ____ days with light brushing?
1 to 3
a ___ is used to provide a stronger bond between the fillers and the matrix?
saline coupling agent
____ add a variety of colors to composite?
pigments
the ___ shrinkage of a composite can be minimized by placing and curing the composite in small increments?
polymerization
____ in the composite are composed of quartz, silica and glass?
fillers
flowable composites exhibit ___viscosity?
low
pit and fissure sealants are ____ viscosity composite resins?
low
____ refers to the shrinkage that occurs when the composite is cured?
polymerizationco
composites wear ____ amalgams?
faster than
one advantage of glass ionomer compared to composite is?
that it has been shown to release fluoride
which one of the following types of composites generally will shrink the most when polymerized?
flowable composite
the completed impression forms a ____ reproduction of the teeth and tissues?
negative
____ ___ commonly called study models are made to further study the patient who is no longer present in the dental office?
diagnostic casts
____ is by far the most widely used impression material because it is inexpensive, easy to manipulate and reasonably accurate for many dental procedures?
alginate
with the growing use of CAD/CAM technology ____ ___ are being used more and more as an alternative to impression materials?
digital impressions
impression material that is reversible?
agar
bite registration, diagnostic casts and final impressions are the three basic categories of impression materials?
true
oldest impression material not commonly used anymore?
polysulfide
which impression material produces a by product of water, gas or alcohol?
condensation silicone
what is true of polysulfide?
it has the smell of rotten eggs (sulfer)
what is an inelastic impression material?
impression plaster
elastic impression materials?
polyether, polyvinyl siloxane, alginate
when taking final impressions there is only on type of viscosity available?
false
true
polyvinylsiloxane: a very accurate addition silicone elastomer impression material. it is used extensively for crown and bridge procedures because of its accuracy, dimensional stability, and ease of manipulation?
final impressions are made as a precursor to other treatment?
false
when you are ready to remove the tray, use a finger at the side of the tray to apply pressure to break the seal while pulling the tray quickly away from the teeth with a snap, protect the teeth in the opposing arc with fingers placed on top of the tray?
true
it is better to choose a smaller tray when taking alginate impressions so that the patient doesn’t gag?
false
___ _____ are impressions that are more accurate in the replication of the oral structures?
final impressions
_____ _____ are used to help mount diagnostic casts in their proper relationship on an articulator and also help the lab make the final restoration so that it functions as similarly to the original tooth as possible?
bite registrations
gypsum is a man made product that is rarely used today in dentistry?
false
____ products are the most frequently used to make replicas of the patients mouth?
gypsum
the mixing of plaster and stone in a flexible rubber bowl with a broad metal spatual is called_____ ?
spatulation
diagnostic and working casts have two parts the _______ portion which replicates the hard and soft structures and the ____ portion which aids in handling and articulation the casts?
anatomic, art
a study model is a _____ reproduction
positive
an impression is a ______ reproduction
negative
double pour method?
involves two seperate mixes and two seperate setting times
single step method?
involves one mix which is used to pour both portions of the cast
boxing method?
wax is used to form a wall in which the gypsum base will be poured
the amount of water to the amount of powder (the ratio) can greatly affect the consistency of gypsum and how it reacts?
true
amount of powder for mandibular impression?
two scoops
amount of water for maxillary impressions?
three measures
