Provisional restorations Flashcards
A prosthesis designed to enhance esthetics, stabilization and/or function for a limited period of time after which it is to be replaced by a definitive prosthesis:
Provisional
A provisional is used to assist in the determination of the ___________ of a specific treatment plan or the form and function of the planned definitive prosthesis
therapeutic effectiveness
What allows for patients to not need a provisional, as the patient leaves the office with the definitive cemented restoration?
Digital dentistry
Functions of provisional restorations include: (6)
- prevent sensitivity
- prevent drifting
- allow tissues to heal
- return function to the dentition
- esthetics
- diagnostic evaluations
Requirement of provisional restorations include: (7)
- pulpal protection
- positional stability
- occlusal function
- ability to clean
- marginal integrity
- strength & retention
- esthetics & phonetics
What do provisional restorations protect against? (3)
- plaque & saliva
- irritating & painful stimuli (temp changes, chemicals, fluids)
- abrasion or breakage of prepped tooth
Provisional restoration positional stability requires: (3)
- proximal contacts
- occlusal contacts
- inter-abutment stability with a bridge
The proximal contacts of a provisional restoration prevent:
lateral drifting of the prepared and/or adjacent teeth
What should you expect when a patient comes to a crown seat appointment and tells you the temporary fell off a week and a half ago:
Expect that adjustments will be needed to counter the tooth movements that likely occur
When your provisional lacks ______ this can lead to extrusion (collapsing the vertical space between prep and opposing dentition)
occlusal contacts
What would cause your definitive to seat high resulting in the need for more adjustments than desired?
Extrusion caused by lack of appropriate occlusal contacts in the provisional
The patient comes in and since the provisional you gave them lacked occlusal contact, the definitive crown sat high and needed lots of adjustment, what it at risk?
Material thinning and therefore destruction of anatomy compromising the unction of the crown
If the patient complains of their temporary causing them pain and you notice that it is broken or cracked this could be due to:
temporary too high (occlusal contacts too high)
List the occlusal contact requirements for a provisional restoration:
- ideal centric occlusion contacts
- lateral & protrusion guidance where appropriate (anterior teeth)
- no contact in lateral or protrusive on posterior teeth
Describe the type of margins that should be seen with a provisional restoration:
Non-impinging margins
Physiologic contours, emergence profiles, embrasures & proximal contacts allow for a good:
provisional/periodontal interaction
In regards to provisional marginal integrity. the fit of the provisional should be:
as close to the finish line of the tooth as possible
What type of surface finish should the margin of a provisonal display, how would you check this?
smooth surface finish- make sure its undetectable with explorer
In regards to provisional marginal integrity. seal the margin to prevent:
pain, sensitivity or dislodgement
Your patient comes in 3 days after provisional placement with pain and sensitivity of the gingiva and states that the provisional has dislodged from the tooth, what is the likely cause?
You did not accurately seal the provisional at the margin & the gingiva is now irritated
Describe the emergence profile of a provisional margin:
Emergence profile is flat or slightly concave- NOT convexed or bulging
T/F: the provisional margin emergence profile should be convexed
False- should be flat or slightly concave NOT convex or bulging
What does a rough margin on a provisional lead to?
Leads to plaque accumulation & gingival inflammation
What can lead to very challenging impressions or crown seating?
Bleeding gums
What is needed in the provisional for strength?
Adequate thickness of material
Because the temporary requires adequate thickness of material to withstand breaking or dislodgment, this requires:
adequate tooth reduction
What temporary restoration material is being described below?
-easy to use & polish & trim and polish
-used in lab
-brittle material which can fracture if occlusal load is too strong & if material is too thin
Bisacryl
What allows the maintenance of phonetics with a provisional?
Proper tooth length, position & contours
What factors contribute to provisional esthetics & phonetics?
- proper tooth length, position & contours
- facial lip support
- proper tooth form & appearance
- compatible tooth shade
T/F: Most interim materials shrink as they solidify
true
The _____ forms the external portions of the interim while the _____ forms the internal of the interim
Matrix; preparation
What materials may be used for temporary pre-fabricated crowns?
- aluminum or tin-silver
- stainless steel
- polycarbonate shells
- cellulose acetate shells
- VLC moldable crowns
Pre-fabricated crown forms are limited to:
single units
Pre-fabricated crown forms must be lined with:
auto-polymerizing resin
Your patient comes in on a Friday at 4:00, they are in a wedding the next day and their crown fell off their front tooth and is broken beyond repair, what is the best option?
Pre-fabricated crown form (such as polycarbonate shell)
What is being described below:
-less time consuming
-can be used for singles but required for multiple units
-improved contours & esthetics
-simnulated planned restorations when used with diagnostic wax-up
Custom-molded interims
Currently used materials for provisional restorations include:
- acrylic resins
-Poly methyl methacrylate (PMMA) jet acrylic
-Powder/liquid formulations - Bis-acryl composite resins
-Bis-GMA containing mateirals
-Chemically activated
-Lighted activated
What are the advantages of PMMA as a provisional restoration material?
What are the disadvantages of PMMA as a provisional restoration material?
- good marginal fit
- good strength
- good polishability
- durability
- high exothermic heat increase
- low abrasion resistance
- free monomer toxic to pulp
- high volumetric shrinkage
What are the advantages of Bis-Acryl as a provisional restoration material?
What are the disadvantages of Bis-Acryl as a provisional restoration material?
- good marginal fit
- low exothermic heat increase
- good strength
- low shrinkage
- surface hardness
- less stain resistance
- limited shade selection
- limited polishability
- brittle
What provisional material involves a chemical conversion of monomer to biologically inert polymer through a chain reaction?
PMMA (Jet acrylic) temporary material
What component of PMMA may be toxic to the pulp?
Unreacted free monomer
Inadequate polymerization of PMMA results in:
poor mechanical properties
Describe the polymerization of PMMA:
Polymerization is EXOTHERMIC & there is SHRINKAGE upon polymerization & cooling
What are the properties associated with the monomer of PMMA?
Chemical or allergic irritation
What are the properties of the “set material” of PMMA?
- Exothermic reaction
- volumetric shrinkage
- increased strength due to polymerization
Properties of polymer (powder)
- with proper amount we have:
- too little powder=
- too much powder=
- adequate strength & handling
- loss of strength
- poor handling & adaptation
What components of PMMA are the “liquid”?
Monomer & activator
What components of PMMA are the “powder”?
Filler & initiator
Monomer & activator describe the _____ components of PMMA, while filler & initiator describe the ____ components of PMMA
liquid; powder
You must continually put on and take off the temporary as you trim and polish it so that it will still fit the tooth because of:
The shrinkage that occurs during polymerization
What provisional material is being described?
-good marginal fit
-good strength
-polishes well
-good durability
PMMA
What provisional material is being described?
-toxic monomer
-high exothermia
-high shrinkage
-low abrasion resistance
PMMA
What provisional material is being described?
-good marginal fit
-low exothermia
-low shrinkage
-good surface hardness
-good biocompatibility
-good color stability & patient acceptance
-can light cure
Bis-Acryl resin
What provisional material is being described?
-limited polishability
-no rubbery stage
-high cost
-brittleness
Bis-acryl resin
The most commonly used materials for provisionals
Bis-acryl resin
Problems with interim restorations include:
- time to fabricate
- length of time temp is required in the mouth
- materials are good not great
- managing deficiencies (relining & repairing)
How should you treat a fractured surface of a provisional?
- grind to expose a fresh surface
- roughen the surface
- use composite flowable resin to compare
What are the two types of cements for cementation of provisional/
- Eugenol
- Non-Eugenol
What is an example of a Eugenol cement?
ZOE (Temp bond)
What is an example of a non-Eugenol cement?
- polycarboxylate cement (Ultratemp)
- glass ionomer cement (Smart Temp)
- resin cement (Telio)
- ultratemp=
- smart temp=
- resin cement=
- polycarboxylate cement
- glass-ionomer cement
- resin cement
Describe the properties of ZOE (temp bond):
- low strength
- Eugenol is a sedative for the tooth
- Eugenol can inhibit resin polymerization
Describe the properties of polycarboxylate cement (ultratemp):
Low strength cement (non-eugenol)
Describe the properties of glass-ionomer based cement (temp smart):
longer term temporary use (non-eugenol)
Describe the properties of resin cement (Telio):
Translucent (non-eugenol)
With cementation, you should mix equal parts of ___ and ___ on mixing pad with spatula
base; catalyst
What should you do AFTER cementation of a provisional?
Re-check occlusion (as the cement thickness sometimes inhibits full seating of the provisional)
T/F: you should have a thick layer of cement on axial walls of the provisional
False - thin layer !
