Delivery and Cementation of Metal-Ceramic and All-Ceramic Restorations Flashcards
1
Q
What are the basic steps to check a bridge/framework before seeing the patient?
A
- Evaluate the framework/final prosthesis
— Any need for remake or alteration
— Any adjustments needed prior to patient appointment - Check the prosthesis for:
—Proximal Contacts
—Internal Surface
—Marginal Adaptation
—Inter-Abutment Stability
—Occlusal Contacts
—Occlusal Anatomy and Finish
—Axial Contours
—Overall design - Clean the prosthetic for patient try in
2
Q
With a Metal Ceramic framework, or a Zirconia-based framework, often, trying in the framework is necessary to ensure the fit prior to…
A
porcelain veneering
3
Q
When evaluating how the framework/bridge looks before delivery what should you look for?
A
- Metal-ceramic finish lines
- Framework design to support porcelain
- Pontic contours
- Connector location; dimension; contour
- Adequate cut-back for porcelain
- Adequate metal thickness in areas to be veneered
4
Q
What is the first step in the delivery process?
A
remove the temporary
5
Q
If you did a lot of adjusting to the temporary at the previous appointment, causing it to be more than slightly different than the previous matrix what should you do before removing the temporary?
A
a new matrix of the temp can and should be made of the temporary, to save you time in case you need to remake the temp due to breakage in the process of removing it
6
Q
How do you remove a temporary?
A
- Using Curved Hemostat, gently rock the
temporary back and forth to break the
cement seal - Care should be taken to grasp the temporary in a manner in which the temporary is not likely to break
- Clean out the inside of the temporary, disinfect it, and set it aside
- ALWAYS make sure you have either the
temporary matrix or take a new one - If the temp does not come off, you may need to gently section off the temp in order to
remove it
7
Q
Special care should be taken when removing a temporary on teeth with…
A
an RCT, or Post, or Build Up
8
Q
IF the temporary does not come off easily, or you are concerned at all about the materials and their stability under the temp, what should you do?
A
SECTION off the temp
9
Q
How can you section off a temporary?
A
Use a very thin tapered diamond to section Mesial-Distal and Buccal-Lingual and then gently remove the sections by applied lateral force in between the criss-crossed lines you just made
10
Q
How should you clean the tooth once the temporary is removed?
A
- Clean off any excess cement chunks
- Clean the tooth preparations with pumice slurry
11
Q
What should you NOT use to clean a tooth after removal of a temporary?
A
prophy paste
12
Q
What are the first steps when trying the prosthesis in the mouth?
A
- Check marginal fit first. If margin adapts well
with no open gaps, proceed to next steps - If marginal gap exists, assess why. Check contacts with floss to see of they are too tight, and therefore may be keeping bridge from seating all the way
-If contacts are acceptable, next proceed to checking internal fit.
13
Q
If margins feel sealed, contacts are adequate, go ahead and…
A
take a radiograph to confirm margin seating
14
Q
When a crown does not appear to seat all the way, and contacts appear adequate, using a material like _________ can help assess of the internal of the crown or if the preparation needs any adjustment
A
Fit Checker
15
Q
What would you do about this situation?
A
send it back to the lab
16
Q
How should the tissue look when the crown is contacting it?
A
Look for passive contact with tissue. Slight blanching of tissue acceptable. More than this, adjust pontic/tissue contact. If adjustment is made, this tissue portion needs to be HIGHLY polished.
17
Q
When bridge fully seats, has floss contact, and pontic fit is acceptable, next is _________
A
occlusion
18
Q
Check occlusion in what types of movements?
A
MI, lateral, and protrusive movements
19
Q
Anterior bridges need to have appropriate length in protrusive to protect against…
A
porcelain chipping
20
Q
What should you evaluate with esthetics during the delivery process?
A
- Look at the angulation of the facial
- Step back and view the patient from several
feet away - If you as the dentist are happy with the fit and esthetics, THEN show the patient.
21
Q
What should you do for polishing and finishing during the delivery process?
A
- Metal adjustments can be polished like Gold. Brown and Green polishers work very well. Brown is Course and Green is fine. Two step polishing
- Try to stay away from polishing at the ceramic metal junction with these burrs. The colors can stay in the porcelain and contamination the porcelain porosities. It’ll look ugly!!
22
Q
If it is necessary to smooth or polish at the Metal-Ceramic
junction…
A
the burr/stone should be held perpendicular to the junction otherwise, the metal particles contaminate the porcelain decreasing the esthetics
23
Q
How should you polish porcelain?
A
- Margin adjustment should be made perpendicular to the margin and rotation of polisher should be toward bulk of material
- Easiest to polish prior to cementation
24
Q
How should you adjust/polish ceramic?
A
- Use gentle forces when inserting and testing the fit of Bridge
- Do not overheat/create excess vibration. This leads to microcracks and tends toward fracture
- Use fine diamonds
- Use separate instruments for metal and
porcelain - Polish porcelain with diamond rubber points and then a fine diamond impregnated polishing paste
25
What should you check for the framework?
- Does the framework wobble or rock on the preparations?
- Check the Proximal contacts.
- Check internal surface
- Check the margin adaptation of the framework
26
If there is a postive margin defect what does that mean?
there is too much framework material, and this can be polished away with a stone or rubber wheel to see if this allows the rock to disappear
27
If there is a negative margin defect what does that mean?
an open margin and a new impression will need to be taken
28
If the framework still rocks after adjustments what may be true?
Then the Framework may be distorted
- Section the framework through a connector
- Evaluate each retainer separately
- If individually, each retainer fits, move forward with solder technique
- If individually, either retainer still wobbles or rocks, take a new impression
29
How do you section a framework?
- Cut should be:
--- At least 0.2mm wide
--- Flat
--- Have parallel sides
- Making sure individual retainers are solidly placed and stationary, make Duralay relation.
- Once Duralay has set, evaluate framework to make sure rocking or wobble has been removed
30
Once framework returns from soldering at the laboratory after sending it for adjustments:
- Evaluate all aspects of the framework again
- Take a Pre-Veneering Radiograph to confirm Margins
- Take a shade and send back to the lab for porcelain veneering
31
If ceramic bridge does not fit in the patient mouth, what do you do?
You will need to take a new impression
32
What are the conventional cements?
- Zinc Phosphate
- Zinc-Oxide Eugenol
- Polycarboxylate
- Glass Ionomer
33
What are the resin-based cements?
- Resin
- Resin-Modified Glass Ionomer
34
What are the features of zinc phosphate?
- Gold standard which all other cements are compared to
- Oldest cement we have known in dentistry
35
What are the advantages of zinc phosphate?
- high rigidity
- no shinkage or expansion
- acceptable strength
- historical long-term success
- excellent restoration retention
36
What are the disadvantages of zinc phosphate?
- significant post-op tooth sensitivty
- technique sensitive
- dissolution
- no cariostaic properties
37
What are the features of zinc-oxide eugenol?
- Used primarily as a temporary cement
- Created to reduce post op sensitivity
- Does have low strength and is soluble
38
What are the features of polycarboxylate?
- Reduced pulpal irriation
- primarily used as a temporary cement
- Not a strong cement
39
What are the advantages of polycarboxylate?
no post-op sensitivity
40
What are the disadvantages of polycarboxylate?
- significant dissolution
- short-term success
41
What are the features of glass ionomer?
- Low solubility
- Fluoride releasing
- Coming back into service now due to lack of caries found on crown margins 10-20 years after initial crown seating
42
What are the advantages of glass ionomer?
- high rigidity
- no shrinkage or expansion
- acceptable strength
- chelation to tooth (chemical bond)
- high caariostatic properties
- historical long-term success
- excellent restoration retention
43
What are the disadvantages of glass ionomer?
- significatn but infrequent post-op tooth sensitivity
- somewhat technique sensitive
- mild dissolution
44
What are the features of resin cement?
- Requires a bonding agent and an etchant
- Sometimes these are separate, but now many cements have the etch and bonding agent included in the cement making it a one-step process
45
What are the advantages of resin cement?
- acceptable strength
- no dissolution
- fast set
- high strength
46
What are the disadvantages of resin cement?
- flexibility, resilience (little impact resistance)
- mild to moderate post-op sensitivity
- no cariostatic properties
- significant shrinkage on set
- significant restorations coming off
47
What are the features of resin-modified glass ionomer?
- Strong cement
- Fluoride releasing
- Most popular cement used today
48
What are the advantages of resin-modified glass ionomer?
- no or slight post-op sensitivity
- moderate cariostatic properties
- provides "tack" set reducing water/saliva contamination
- acceptable strength
- historical long-term success
- good restoration retention
49
What are the disadvantages of resin-modified glass ionomer?
- mild dissolution
- mild shrinkage
50
Why does dentistry keep making new cements?
- Dentistry is constantly in flux working to make our procedures easier, faster, and longer lasting
- This creates confusion sometimes, as reclassifications are needed as new breakthroughs are made
51
What is luting?
implies the use of a moldable substance to seal a space or to cement two components together
52
What is the function of luting cements?
Luting cements act as an adhesive, bonding the restoration to the tooth surface. They achieve this through a combination of chemical bonding and mechanical interlocking, where the cement fills tiny voids between the tooth and restoration, creating a physical lock
53
What are the advantages of luting cements?
- Adhesion to tooth substance and alloys
- Easy manipulation
- Strength
- Solubility
- Film Thickness properties comparable to Zinc Phosphate
- Fluoride release
54
What are the disadvantages of luting cements?
- Needs accurate proportioning
- Critical manipulation
- Lower Compressive strength
- Greater viscoelasticity than Zinc Phosphate
- Short working time
- Clean surfaces needed for best adhesion
55
What are resin based cements aka adhesive cements?
Adhesive Resin Cement with Dentin Bonding Agent and included an etchant
56
What is a self-etch resin based cement?
- cement contains an etching primer in the cement to prepare the tooth for bonding
- Requires dentin bonding agent
57
What is a self-adhesive resin based cement?
- contains etchant and dentin bonding agent in the cement
- SpeedCem Plus is Self-Adhesive and used in clinic
58
Dental cement primers enhance the bond between the...
dental cement and the tooth surface or the restorative material, like a crown or veneer.
59
What are the advantages of resin based cements?
- High Strength
- Low oral solubility
- high micromechanical bonding to dentin, alloys and ceramic surfaces
60
What are the disadvantages of resin based cements?
- Need for meticulous and critical technique
- More difficult sealing
- Higher film thickness
- Possible leakage
- Pulpal Sensitivity
- Difficulty in removal of excess cement
61
What are the special considerations for cementing all ceramic restorations?
- Resin Cements
--- require a moisture free environment
--- A Resin Cement is required for low-strength glass ceramics (veneers)
- Resin Modified Glass Ionomer cements are contra-indicated with low strength glass ceramics
--- expand as they set which could cause fracture
- Resin Cements are recommended for eMax crowns to offset the brittle nature of glass ceramic
62
What are the steps to determine which type of cement to use?
- consider type of material
--- Metal, PFM, Zirconia, Ceramic
- consider design of material
--- Veneer, Crown, Inlay/Onlay, Bridge
- tooth preperation and location
--- Retentive prep, Non-Retentive prep
- additional factors
--- High Caries prone patient?
--- Wacky Occlusion?
--- Moisture Isolation a problem?
--- Clencher or Grinder
63
What types of cements for PFM cementation?
With adequate preparation retentive features Zinc Phosphate, Glass Ionomer, or Resin Modified Glass Ionomer cement can be used
- RMGI is most commonly use
64
For a PFM, without totally adequate preparation retentive features, wonky occlusion, or bruxer, _______ cement should be considered due to its increased strength
Resin Cement
65
Due to strength of Glass Ceramics, ________ is the cement of choice.
Resin Cement
| -Prefer Dual Cure or Self Cure
66
What needs to be done to the internal surface when cementing glass ceramic crowns?
- Hydrofluoric Acid Etch to roughen for
micromechanical retention for e.Max or Feldspathic porcelain
- Typically this is done by the lab.
67
_______ treatment in internal surface to enhance the chemical bond between glass/ceramic/Resin Cement
Silane
68
What cements can you use with zirconia crowns with adequate preps?
With adequate preparation retentive features Zinc Phosphate, Glass Ionomer, or Resin Modified Glass Ionomer cement can be used
- RMGI is most commonly used
69
What cements can you use with zirconia crowns with wonky occlusion, bruxer, etc?
Resin Cement should be considered due to its increased strength
70
What is need on the internal surface of a zirconia crown before cementation?
- Abrasion needed. Lab leaves internal too smooth
- Air abrasion or diamond Bur leaving horizontal roughened lines on internal walls
71
Patient should close down on _________________ to help with seating of crown
soft cotton roll
| DO NOT USE ANYTHING HARD FOR THIS STEP – Leads to fracturing
71
________ from some temporary cements will prohibit polymerization of any composite Resin
Eugenol
| removed by acid etchant
72
Provisional cement residue occludes tubules and decreases...
effective bonding
73
If occlusion does not permit solid pressure for crown seating, firm pressure from...
finger is used to fully seat crown until cement has cured on its own, or it has been light cured
74
If you cure fully with too much excess...
it will be very challenging to be able to remove all the cement. You’ll need high speed handpieces and a whole lot of luck.
75
What do you need to check after the prosthesis is cemented?
- Recheck occlusion
--- Adjust if necessary
--- Use a fine Diamond with water to avoid excess heat
- Polish with diamond impregnated discs or points
- take a post-cementation radiograph
- discuss OH with patient
