9/27 Recorded Lecture: Tissue Management & Recording Impressions Flashcards
TF? Elastomeric material that has set remains elastic.
T
What to include in crown impression
Adjacent teeth and tissue surrounding those teeth
All elastomeric material are hydrophobic except:
polyethers
Means to increase sulcus size to take impressions:
mech, chem, or surgical
These can lead to permanent soft tissue damage, ie recession:
improper manipulation of impression material, poor tissue displacement technique
3 prerequisites to successful impression taking:
healthy tissue, saliva control, …
Ways to maintain tissue health:
control pd, careful prep, interim resto
Methods of saliva control:
cotton rolls placed by ducts, moisture absorbing cards, flange-type evacuator, e.g., Svedopter (speejector), retractors), la, anti-sialagogic meds
Antisialogogic meds:
ABCH: atropine, bromide, clonidine, hypochloride
How does la effect saliva control?
blockage of impulses from the pdl, considerable reduction
Sulcus will remain open this long after cord removal/ mechanical retraction:
30s
how to surgically remove small amts of tissue:
scalpel, electrosurgery or laser
What is being stretched cord placement?
periodontal circumferential fibers
Means of tissue displacement w impregnated cord:
mechanico-chemical retraction
Cord placement is easier using:
braided or knitted cord
How long to leave cord in and when to take out:
5 min, directly before taking the impression
3 types of cords
BTK: braided twisted, and kneaded
Cord types for mech displacement:
twisted, knitted
Cord is impregnated with:
epi or aluminum potassium sulfate
Alternative to cord packing:
paste system, contains aluminum chloride
2 names for cord without chemical:
plain, non-impregnated
One cord remains in sulcus when using this technique:
double cord technique
List the 5 cord thicknesses:
000, 00, 0, 1, 2
What determine the size cord to use?
sulcus depth, tooth location
Benefit of twisted cord:
can customize cord, ind strands can be removed
Issue w using braided cord:
can double up and bc too thick & cause gingival trauma
compressible cord type:
knitted
Cord types we use in clinic:
braided and knitted
Classifications of chemicals used to displace gingiva:
astringents, vasoconstrictors
Ex’s of astringents;
aluminum chloride (AlCl3), ferric sulfate (Fe2(SO4)3
vasoconstrictors:
sympathomimetic (effects similar to sym system) amine-containing eye wash/ epi
2 ways vasocs restrict blood flow:
decreases cap size, tissue fluid seepage
Issue epi cord can cause:
tachycardia
Don’t use epi cord for these pts:
high BP, diabetes, cv disease, and hyperthyroidism
Moa of astringent:
transient ischemia shrinking gingiva, tissue fluid leakage
Are astringents acidic or basic?
acidic
What to be aware of when using astringent:
if adhesive cement is used for restoration, minimize contact with tooth, affect smear layer
Hemodent pH:
1.2
Astrigident pH
0.7
Least acidic astringent we use at SDM
Viscostat:
packing cord:
cord should not overlap
Which cord is impregnated w astringent in the double cord tech?
2nd, larger
1st cord is called __, 2nd cord is called __:
preparation cord, impression cord
Where to start cord placement:
interproximal area, deeper sulcus
Ex of paste for tissue displacement:
expasyl, made of aluminum chloride and kaolin
Is expasyl mech, chem, or both?
both
Function of aluminum chloride:
hemostasis
Function of kaolin:
tissue retraction, very viscous
What is removed with electrosurgery?
inner epi lining of gingival sulcus (sulcular lining)
What might be an issue if the tissues are inflamed?
more bleeding
Potential harm of electrosurgery:
gingival recession
Disadvantages of electrosurgery:
Can’t use on pts w electronic mx devices or thin attached gingiva, or w metal instruments bc it could shock, deep soft tissue anesthesia req
Pts w these mx devices can not get electrosurgery:
pacemaker, transcutaneous electrical nerve stimulation (TENS) unit, insulin pump
Attached gingiva, where you can not do electrosurgery:
labial tissue of max canines
Biologic width:
CT + je, formed next to tooth, sup to crestal bone
There is a proportional relationship bw:
alveolar crest, ct attchament AND epi attachment and sulcus depth
biological width is about:
2.04mm
Invasion of the biological width may cause:
gingival irritation, enlargement, gingival and bone recession
If the margin of a restoration is very close to alveolar bone, this can happen:
inflammation, recession
How to prevent invasion of biologic width with lesions that approach the alveolar bone:
crown lengthening, also inc’s ferrel
Retention of impression material to prefabricated tray is provided by:
perforations, rim locks, adhesives
What influences the type of tray you will use for a impression?
material type
Property that prefabricated trays must have to red distortions of impression:
rigidity, design that will control material thickness
What type of impression material do we use to take impressions for crown fabrication?
elastomeric
Effect of moisture contamination while taking impression:
voids
improper fitting interim can lead to:
gingival enlargment
Cord packing technique we use at SDM:
double
Why isn’t electrosurgery used more often?
potential for gingival recession
If the margin of a resto is w/in __mm of the alveolar bone it may lead to issues:
2mm
When to use prefabricated trays:
uncomplicated fixed prosth
