Quiz 2/9 Restoration of the Endodontically Treated Tooth Flashcards
Leads to higher occurence of fractures in endo teeth compard to vital:
loss of structural integrity asoc with access prep, ie caries, existing restos
When to consider retreatment?
root canal space is grossly contaminated
Factors involved in longevity of resto after endo:
coronal leakage, recurrent caris, fractures, cuspal coverage, post type
Types of posts:
direct, indirect, tapered, parallel, textured, smooth, threaded, unthreaded
Factors to think about before restoration:
good apical seal, no sensitivity to pressure, no exudates, no apical sensitivity, no active inflammation
3 causes of loss of tooth structure:
caries, endo, previous restos
Foundation materials:
composite, amalgam
Cast post and core materials:
metal, ceramic
Prefab p/C materials:
metal, carbon files, glass fiber, ceramic post
4 foundation resto materials:
composite restoration, cast post, prefab post and malgam in distal canal, prefab post and amalgam in palatal canal
TF? Cemented posts are ideal for anteriors:
F. weaken, not reinforce
Do all endo treated anteriors require full coverage restos?
no
Posts not recommeded for anterior:
cemented, metal if itsnot ful coverage
A crown is needed after anterior endo when:
extensive loos of structure, serves as an FDP and RDP abutment
TF? Better prognosis for endo treated anteriors restored with a post.
F
Endo treated anteriors not crowned after obturation are lost __ times more freq than thoes crowned.
6
Endo treated posteriors req:
cuspal coverage (except maybe man premolars)
Posterior tooth that may not req cuspal coverage after endo:
man premolar
complete coverage crowns are recommended on these posterior teeth:
teeth w high risk of fracture (Max premolars)
Recommendation for posterior teeth w sig coronal tooth loss:
cast P/C or prefab post along with resin/amalgam foundation resto
posterior tooth w high risk of fracture:
max premolar
Function of post:
retain core in tooth w extensive loss of coronal tooth structure
Compicatons related to p/c
perforation root fracture,. placement beyond apex
Principles of canal prep:
apical seal, min enlargement, adequate post length, pos hor stop, vert antirotational slot, extension of final resto margin onto sound tooth
What to think about in regards to coronal tooth structure for p/c crown:
maximal coronal structure, enough ferrul (ortho, crown lengthening)
More likely to result in root fracture, short or long posts?
short
Post best for retentio:
parallel is better than tapered
Post should be this long:
L of clinical crown, 3/4 L of root, 1/2 L of canal, 1/2 L of root in bone
Keep this much GP in apex of canal:
3-5mm
TF? The larger the post diameter, the better the retention.
F
Post diameter should not exceed:
1/3 of xs diameter of root
Goal of post diameter:
retain as much dentin as possible
Ideal post surface texture:
serrated or roughened > smoth
Luting agents most to least effective:
adhesive resin cement > ZOP/ GI cement > poly carboxylate
Post is not necessary if:
there is more than 3-4mm of coronal tooth structure w reasnable wall thickness (Is this molars only?)
When to use an amalgam post:
mostly pos, enough remaining coronal tooth structure w a circumferential cervical tooth structure
Which root to use for cemented post (only this type) multirooted teeth:
widest canal
Place post in this canal for man molars:
distal
Place post in this canal for max molars:
palatal
Where is the greatest stress distribution found in the post?
the shoulder, esp interproximaly and at the apex
Are stresses red as the post shortens or lengthens?
lengthened
Which distribute stress more evenly, parallel or tapered?
parallel
Type of post that generateds the highest amt of stress at apex:
parallel
Posts that distribute stress well:
threaded
Issue w threaded posts:
can produce high stress conc during insertion and loading
Function of cement:
more even stress distribution to root w less stress conc
Where to place antirotational groove:
bulkiest root
Don’t use this type of instrument to remove GP:
end cutting
Instruments to use to remove GP
hot ndo plugger (system B), GG drill (rotary)
System B is:
hot endo plugger
How large to maket he canal when using a prefab post:
1-2 sizes larger than MAF
Be aware of this when using a custom post:
UC’s, peroration (non-circular xs)
Coronal walls should be this wide:
at least 1mm
Create these in your coronal prep:
pos vertical stop and intirotational groove
Remove this from crown:
internal and external UC’s, unsupported tooth structure
Post type easiest to treat:
Fiber
Stronger, ceramic and zirconia OR metal?
metal
Which should be thicker, ceramic and zirconia OR metal?
ceramic and zirconia
Metal posts:
high modulus of elasticity, rigid alloy, electrolytic action of dissimilar metals
Fiber posts:
easier to retreat, less strength, stiffness, lower fracture threshold
When to use custom made posts:
misaligned teeth, mandibular incisors
Direct procedure for custom post:
acrylic or thermoplastic resin, no binding pattern
Indirect procedure for custom post:
impression/ cast
Resto materials that can be used for prefab post:
amalgam, GI, resin
Adv’s of prefab post:
max conservation of tooth bc UC’s don’t need to be removed, Tx rew 1 fewer pt visit, fewere lab procedures, good resistance to fatigue test and good strength characterisitcs
Disadv’s to prefabricated posts:
amalgam corrosion, microleakage of composite, hard to place rubber dam and matrix if min tooth remains
When are custom cast P/C preferred?
wnen most tooth structure is lost
Procedures for core fabrication w custom P/C:
direct and indirect pattern
TF? The reline material must extend all the way down the post space.
F
how does the wire enhance resistance of the provisional?
by engaging the apical portion oft he post sapce
Part of interim resto for apical to cornonal:
reinforcing wire, autoploymerizing resin, preformed crown
Do we etch the canal before placing resin when making a provisional after an endo tx?
ask/ check ?
How to fill post space canals completely w cement:
lentulo rotary paste fillers or a cement tube
Steps to cementing post:
coat post, inject into canal, gently seat
Why don’t we care if there is a small cement line?
bc dissolution is prevent by the presence of the definitive resto
How to remove existing post:
forceps, ultrasonic, post puller, trephines
When woudl you need to remove a post?
to retreat, incompletely seated post
