Open Questions Flashcards
What are the advantages of Alginate? (3)
cheap setting time can be controlled hydrophilic easy non-toxic good surface detail
What are the disadvantages of Alginate? (3)
unstable
setting time depends on operator
poor R tear
What are the advantages of Polyethers?
hydrophilic
accurate
thixotropic behavior
easy
What are the disadvantages of Polyethers?
allergies
fast setting
poor R tear
What are the advantages of Polysulphides?
accurate
cheap
long expiration
What are the disadvantages of Polysulphides?
hydrophobic
smell unpleasant
non esthetic
What are the advantages of Silicon C?
cheap
easy
good tear strength
What are the disadvantages of Silicon C?
hydrophobic
low dimensional stability
less accurate
What are the advantages of Silicon A?
acceptable taste fast easy to use accurate thixotropic behavior
What are the disadvantages of Silicon A?
difficult to mix hydrophobic hydrogen release expensive difficult to take out of the mouth latex gloves use only
How are additional silicones commonly reffered as?
polyvinyl siloxane
How are irreversible hydrocolloids commonly reffered as?
alginates
4 types of elastic materials you know?
hydrocolloids (irreversible, reversible)
silicones
polysulphides
polyethers
Which crowns can you use if the tooth is vital?
ceramic, zirconia, pfm
Which crowns can you use if the tooth is non-vital?
similar but will need opaque layer addition to cover any possible discolouration or post if ceramic not used
Types of removable prosthodontics for replacing a missing tooth:
acrylic
cocr
Types of fixed prosthodontics for replacing a missing tooth:
implants
conventional bridge (cantilever or fixed)
resin bonded bridge (maryland)
What are the advantages of implants?
adjacent teeth not involved at all
aesthetics
good term prognosis
What are the disadvantages of implants?
contraindicated wthen OH is poor and to heavy smokers
surgery involved
expensive
What are the disadvantages of conventional bridge?
most destructive option
can lead to devitalisation
What are the advantages of conventional bridge?
long term prognosis
aesthetics
What are the advantages of resin bonded bridge?
quick
predictable
least invasive
aesthetic
What are the disadvantages of resin bonded bridge?
can debond easier
metal may be visible - aesthetics
What kind of info do you need when a patient comes to your office?
- complain, dental history, medical history, social history, history of presenting complain
- clinical examination
- extraoral examination
- intra-oral examination: soft and hard tissues
- special tests
Indications for least invasive method:
good OH
neighboring teeth are non-restored
single posterior tooth replacement
Contraindications for least invasive method:
teeth periodontally involved
bruxism
abutment teeth are heavily restored
Which elastic material do you use for a crown/bridge?
additional silicones
Which elastic material do you use for a removable prosthesis?
alginates
What are the techniques for mandible manipulation in centric relation?
chin point guidance
chin point guidance with anterior jig
bimanual manipulation
using a spint
Maximum Intercuspal Position definition:
=max contact of all teeth together for that individual’s occlusion
Centric Relation definition:
=bilateral, unstrained mandible position in which the condylar disc is in the most sup ANT position in the glenoid fossa and the initial 20mm of incisal opening is pure hinge axis
Which position do we use when we want to make large changes to the occlusion?
RCP
What kind of approach is RCP?
re-organised approach
Which position do we use when we want to conform the patient’s occlusion?
ICP
What kind of approach is ICP?
conformative approach
What type of defective margins do you know?
over contour
over extended
under extened
open margin
What type of cements do you know?
Hard Cements - ex: GIC, Resin Cements
Soft Cements - ex: Zinc Oxide w/ or w/o Eugenol
Indications of Soft cements:
- temporaty crowns
- definitive restorations if: symptomatic tooth or trial assessment is required
Indications of Hard cements:
- definitive cementation
- acid base rxn
- polymerisation rxn
- combination of above rxns
Indications of Glass Ionomer Cement:
single metal or pfm crowns
fixed-partial and metal-ceramic dentures
patients w/ high risk caries
Advantages of Glass Ionomer Cement:
high compression strength
reasonable working time
Fluoride release
Disadvantages of Glass Ionomer Cement:
low tensile strength
not resistant to acid dissolution
sensitivity to early moisture contamination
Indications of Resin Cement:
porcelain veneers
ceramic, Zr2O3 and composite onlays
resin bonded bridges
ceramic, Zr2O3 or fixed-partial dentures
Advantages of Resin Cement:
high compressive and tensile strength
R to water dissolution
R to acid dissolution
Disadvantages of Resin Cement:
high technique sensitive
marginal leakage due to polymerization shrinkage
variable film thickness
What type of ceramics do you know?
- Glass matrix ceramics - ex: feldspatic, synthetic: lithium disilicate, glass infiltrated
- Polycrystallined ceramics - ex: alumina, stabilized zirconia
- Resin Matrix ceramics
Definition of a crown:
=artificial replacement to restore missing tooth structure using materials such as ceramics, metal, combination of them
Types of crowns:
zirconia, all metal, all ceramic, pfm, partial coverage crown(onlay, inlay)
most conservative crown to most destructive crown:
zirconia, all metal, all ceramic, pfm, porcelain fused to zirconia
Indications for a dental crown:
protection of remaining tooth structure
aesthetics
abutments for rpd
to alter the occulsal plane
Measuring and monitoring tooth surface loss:
study casts, wear indices, photographs, direct measurements
Basic Erosive Wear Examination (BEWE):
0 no tooth surface loss
1 initial loss of tooth surface
2 distinct defect, hard tissue loss <50% than tooth surface area
3 hard tissue loss >50% of the surface area
How can you check the fit of the crown?
visual: margins, direct or w/ mirror, magnification
instruments: explorer, correct size tip and angle approach
3 reasons for intervention in tooth wear cases:
altered appearance
sensitivity / pain
loss of function
Different types of tooth surface loss?
attrition, abfraction, abrasion, caries, trauma, iatrogenic damage, acid dissolution
Attrition description and sings:
=horizontal wear and flattening of incisal edges or cuspal tips of teeth from tooth to tooth contact
Acid Dissolution description and sings:
=loss of tooth surface due to chemical processes in facial and cervical areas
Extrinsic factors: dietary and environmental
-upper ant: B
-post: O + P
Intrinsic factors: pathological - caries, vomiting
-upper ant: P
-post: O
cupping of incisal edges and cusps tips
perimolysis (small enamel rim around lesions)
smooth, shiny and rounded lesions
All Ceramic advantages:
aesthetics, no allergies, biocompatible
All Ceramic disadvantages:
destructive method, low repair potential, wear on opposing dentition, translucent, abbrasive to opposing teeth
Monolithic Zirconia disadvantages:
expensive, wear on opposing teeth, translucent
Monolithic Zirconia advantages:
aesthetics, no allergies, biocompatible, durable
Monolithic Zirconia VS All Ceramic crowns
monolithic zirconia: more expensive and its durable
all ceramic: repair potential lower and destructive method
