prosthodontics Flashcards
what is a margin
a margin is a prepped area of the tooth that the crown will be seated in at the cervical area of the too
what are three types of margin for a prepped tooth
bevel - angle within a tooth prep for better retention
chamfer - tapered finish line of the margin at the cervical area of tooth prep
shoulder - margins of a tooth prep for a cast restoration
what type of tooth can a post and core procedure be performed on
if a tooth has been treated endodontically and is nonvital
what scenario would require more than on retraction cord and how many cords would be used
if the sulcus is too deep for just one sized cord
- as many cord needed to fill sulcus would be used
what is the importance of a temporary provisional crown coverage
- protects the pulp
- maintains periodontal health
- provides occlusal stability
- maintains tooths position
- protects margins and preparation from fracture
- help patient chew
when selecting shade for a prosthesis, which type of lighting is best to use
natural light
if a dentist wanted to add strength to a core buildup on a nonvital tooth, what could they use
pin retention
what type of impregnated retraction cord is indicated for a patient with heart disease
a cord impregnated with aluminum chloride
how long should retraction cord be left in the sulcus
no longer than 5-7 minutes
if a patient has a hypertrophied gingiva, what type of gingival retraction would be used
surgical retraction would be used by removing electrosurgically or with a surgical knife
what type of try is used when taking reversible hydrocolloid impression
metal water coolant tray
which type of elastomeric impression material has a strong odor
polysulfide
which type of elastomeric materials are used for final impression for a crown or bridge
polysulfide
polyether
silicone
polysiloxane
what are indications for a partial denture
- replaces several teeth in same quadrant in same arch
- temp replacement for missing teeth
- avoids additional reduction in tooth structure
- replaces missing teeth for patients that cannot tolerate long appointments
- allows patient to maintain good oral hygiene
- serves as splint for periodontally compromised teeth
contraindications for partial dentures
- lack of suitable teeth in arch
- rampant carries or severe periodontal conditions
- lack of patient acceptance
- chronic poor oral hygien
why is it necessary to reline a denture
- a denture becomes loose over time
- loss in vertical dimension can occur
- inflammatory hyperplasia is present
overall it can create a more proper, comfortable fit for patient
what are the steps to disinfect a case before sending it to the lab
- remove wax setup from lab packaging, disinfect, rinse
- seat patient
- assist in placing wax setup for fit in denture
- assist with verifying appearance
- assist with evaluation of retention
6.prepare lab prescription
- disinfect case, return to articulator, pack, return to lab
- document
why are custom trays used? and steps involved in fabricating a custom tray
it is constructed to fit the mouth to take accurate impressions
- knead resin to form a flat patty
- place material on cast
- trim away excess tray material
- use excess material to shape handle
- hold handle until it is firm
what are the different elastomeric impression materials? and what is it used for
light bodied
- less viscous; used for its ability to flow into and around the details of prepared teeth
regular and heavy bodied
- thicker; used to fill trays, and helps light bodied material into close contact with prepared teeth
what are preliminary impressions and what material is used
used to create an accurate reproduction of teeth and surrounding tissues
- alginate is most commonly used
how would you instruct a patient to look after their bridge after cementation
- fixed prosthesis and supporting tissues must be brushed and carefully flossed each day
- bridge threader is used to thread dental floss under the pontic and down the sulcus and abutments of bridge
what are the care instructions for a denture
- with denture removed, thoroughly rinse oral tissues at least once a day
- clean all surfaces of denture
- during cleaning, hold dentures over a sink half-filled with cold water
- do not soak denture in hot water or strong solution
- when not in mouth, store dentures in moist, airtight container
- do not wear dentures at night
list the 3 classifications of impressions and why they are taken
preliminary impressions
- creates accurate reproduction of the teeth and surrounding tissues (diagnostic cast/models, custom trays, provisional coverage, ortho appliances)
final impressions
- used to produce exact detail of the teeth and surrounding tissues needed to make indirect cast restos
bite registrations
- used to produce a reproduction of the occlusal relationship of the max and mand teeth when mouth is occluded
what is an indirect restoration and examples
restorations that is fabricated outside the mouth by dental lab tech
- crowns
- dentures
- bridges
- veneers
- inlay
- onlay
what is the most common method for gingival retraction
mechanical and chemical retraction
at what point during prep does gingival retraction take place
to manage bleeding and saliva and widen sulcus before taking final impressions
examples of cad/cam systems
veneers
inlay
onlays
crowns
bridges
dentures
what are the benefits of using cad/cam
- one visit
- no impressions
- no provisional
- reduced tooth sensitivity
- no lab costs
what type of bur does the dentist used when preparing a tooth for crowns or bridges
diamond burs
how does a CLD receive its retention
depends on the support of the remaining alveolar ridge and the suction achieved between prosthesis and tissues covering the ridge
what type of material is used when taking an impression for a denture reline? and what type of impression tray is used
a mix of zinc oxide eugenol impression paste or an elastomeric impression material
- tray used is the existing denture
when would pre0formed polycarbonate crowns be used for provisional coverage
- provisional coverage is esthetically acceptable
- contours are similar to those of natural teeth
- cervical margin is smooth and fits snug with no more than 0.5mm of space
- does not extend below the margin of prep
- occlusal surfaace is aligned with the occlusal plane of adjacent teeth
what type of restorative materials are acceptable to use for core build ups
reinforced glass ionomer cement
what are some complications of alveolar resorption
uneven distribution of pressure on prosthesis, which keeps it from fitting properly
how would abrasion of natural teeth against porcelain be avoided
placement of acrylic teeth with natural
what type of bur is used to trim a custom provisional crown
acrylic lab burs
what is the difference between light body and heavy body impressions materials
light-bodied is less viscious, heavy bodied is more
what details are included when writing a lab prescription
- dentists name, license number, address, phone number and signature
- identification of patient
- type of prosthesis requested
- types of materials used
- exact shade of restoration
- anatomical characterization
- date when case is expected back
how long can a provisional crown be worn
1-2 weeks
when is a template impression that is to be used to fabricate custom provisional crowns taken
before dentist prepares the teeth for final impressions
what is the order of appointment sequence for dentures
1: records
2. prep
3. try in
4. delivery
5. post delivery
what are indications and contra-indications of a fixed bridge
indications
- supportive tissues are healthy
- suitable abutment teeth present
- patient in good health and wants prosthesis
- patient has skills and motivation to maintain good oral hygiene
contra-indication
- necessary supportive tissues are diseased or missing
- suitable abutment teeth are not present
- patient is in poor health
- patient has poor oral hygiene
- patient cannot afford treatment
retraction cord is only avaliable in one size
false
It is necessary to always anesthetize a patient before crown cementation procedures.
false
partial denture clasps help stabilize the denture in the mouth
true
mobile teeth can be used as abutment teeth
false
gold or metal crowns can be fabricated using the cad/cam system
true
a partial denture is supported and stabilized primarily by the abutment teeth
true
when denture repairs are sent to the lab, the patient may be without their denture for up to 6 days
false?
low saliva flow is a contraindication for removable denture
true
the most common type of material used to temp cement a provisional crown is lass ionomer cement
true
provisional coverage is only necessary for vital teeth
true
chamfer
a tapered finish line of the margin at the cervical area of tooth prep
what is a maryland bridge
consists of a pontic with winglike extensions
what is an articulator
a dental lab device that stimulates the movement of the mandible and tmj when the cast is attached to it
reversible hydrocolloid
a type of material that changes its physical state form a sol to a gel and back to sol
irreversible hydrocolloid
materials that cannot return to the sol state after they become gel
fixed prosthesis
restoration that is permanently cemented or bonded into place
removeable prosthesis
prosthesis that the patient can place in and take out of the mouth
direct veneer
composite resin is bonded directly to the facial tooth surface
pontic
artificial tooth that replaces a missing natural tooth in a fixed bridge
abutment
a tooth, root or implant used for support and retention of prosthesis
pfm
porcelain fused to metal
pbm
porcelain bonded to metal
immdediate denture
full or partial denture placed immediately after extraction of teeth
over denture
full denture supported by one or more remaining natural teeth or implant
cud
complete upper denture
cld
complete lower denture
pud
partial upper denture
pld
partial lower denture
inlay
cast restoration designed to replace a conservative class II cavity
onlay
cast restoration designed to replace a class II prep
cad/cam
computer aided design / computer aided manufacturing that designs anatomical features, size and shapes of a tooth resto on computer
retrusion
position of the mandible posterior from the centric position related to the maxilla
bevel
an angle within a tooth prep for better retention
shoulder
margina of a tooth prep for a cast resto
components of a partial denture
- framework
- connectors
- retainer
- rest
- artificial teeth
