11. adapted from quizlet: ryanef123 FP 20 - Try-in and Cementation (Dr. Filokyprou)

What are the five procedures after you get your case back?

1) Pre-op evaluation of crown on die before pt's appt

2) Try-in and adjustment

3) Pre-cementation polishing

4) Cementation

5) Post-cementation finishing

During pre-operative evaluation of the restoration, what should you evaluate for the internal surface of the restoration? (3)

• Allow complete seating of crown

• Provide space for film of cement

• Allow crown margins to be in intimate contact with finish line of prepared tooth

If there are small metal nodules in the internal surface of the restoration, how do you get rid of it?

Small round carbide bur in low speed (in armamentarium numbers ½ and 2)

During pre-operative evaluation of the restoration, what should you evaluate for the external surface of the restoration? (4)

• Proximal contacts

• Ideal contour

• Highly polished/glazed

• Occlusion on articulator

What type of occlusion on a restoration would you consider sending it back to the lab?

Hypo-occluded -- to add more restoration material onto it

If you see a red mark on the opposing arch, what does that mean?

The lab may have had to do some adjustments to the occlusion on the opposing arch to achieve enough occlusal clearance

If you see a red mark on the opposing arch, what should you do?

You want to bring the pt back and recontour the prep, and make a final impression so that the crown restoration can be adjusted properly with enough occlusal clearance

YOU DO NOT WANT TO RECONTOUR THE NEIGHBORING TEETH

What is the try-in procedure and sequence for a crown?

1. Removal of the interim restoration

2. Proximal contacts - use floss and finger

3. Pontic-ridge contact in case of FPD

4. Marginal adaptation

5. Stability

6. Occlusion

7. Contour

8. Esthetics

When you're removing the interim restoration, why might the patient report hypersensitivity of the interim restoration?

• Hyperocclusion

• Open margin

• Overcontoured below finish line → gum inflammation and difficulty cementing

(Recement the interim for several days to let the sensitivity resolve)

Is anesthesia required for removal of interim restoration?

No - usually not required, patient can give better feedback with occlusion if not anesthetized

What tool can you use to remove the interim restoration?

Hemostat

What can you use to remove residual temporary cement?

Cotton pellet and explorer, maybe scaler

T/F: Gingival overgrowth should be monitored when trying in a crown-- consider postponing cementation of fixed restoration

True

Ideal proximal contact is achieved when you can _________

• Floss teeth (should be tight but not too tight - compare with adjacent teeth, waxed floss)

• A strip of articulating paper (Accufilm II, 20μ) held by hemostat can be pulled with some resistance

The following are signs of (tight/loose) contact

• Prevent correct seating

• Discomfort to patient

• Difficult to floss

Tight

The following are signs of (tight/loose) contact

• Cause food impaction

• Possible tooth migration

• Gingival overgrowth

Loose aka light

How do you adjust proximal contacts that are too tight?

• Lightly roughen the surface with ultrafine diamond or matte surface

• Piece of articulating paper between crown and the adjacent tooth

• Fine football diamond in low speed handpiece

• Adjust tighter contact first

• Contour the proximal surface, if necessary

T/F: Adjust the tighter contact first, and contour proximal surface if necessary when trying in a crown

True

How do you adjust proximal contacts on a full cast gold crown that are too light?

Solder

How do you adjust proximal contacts on a metal ceramic crown that are too light?

Add porcelain before cementation

T/F: The pontic-ridge contact should produce no blanching, and should be easily cleansible

True

What can you use to assess the pontic-ridge contact during the try-in for a crown?

Fit Checker

What burs can you use to adjust the pontic-ridge contact during the try-in for a crown?

• Fine football diamond

• Coarse rubber point

describe T contact of modified ridge lap temp crown

buccal has T shaped contact

What material is a fit checker?

silicone 1:1 paste

which color fit checker is used for PFM vs ceramic zirconia crown?

• hite for PFM and blue for zirconia for better contrast

• each fit checker system comes w two tubes, and use equal amounts of silicone and paste

If you can see the defective margin visually, it usually ranges from ____-____µ

5-90µ

if you can feel the defective margin with the tip of the explorer, that means the margin is prob around ____-____µ, because that's the diameter of the explorer

70-80µ

defective margins under ______µ is clinically acceptable

<120µ

What is the ISO specification for a marginal gap?

25µ

What four errors can occur with marginal adaptation?

• Overextended/overhanging

• Overextended/overcontoured

• Underextended/undercontoured

• Open (over 50µ)

How do you know that it's a open defective margin rather than overextension/undercontouring?

Use explorer to check

How can you adjust a small overextended margin?

Adjust and finish on the die: metal collar may be exposed, small carbide bur and mark w red pencil

How can you adjust an underextended margin?

May be acceptable, may not need to adjust

How can you adjust an open margin?

• Correct excessive proximal contact

• Remove residual temporary cement

T/F: After adjustment of a crown, if not too tight but still open, there may be minute undercut, unseen defect or distortion

True

What can all of the following be used for?

- Materials: disclosing waxes, a suspension of rouge in acetaic acid, air abrasion, powered spray (Occlude®), water soluble marking agents (Accufilm IV), and elastomeric detection paste (pressure indicator paste - Fit Checker™; white and blue)

Checking the internal surface of a crown

(High spot shown through the material)

what are we looking for in fit checkers?

Even layer of thickness for cement

How do you adjust the intaglio surface of the final restoration to have the proper fit?

1) Fit checker

2) Mark areas of heavy contact with red pencil

3) Go in with round bur to remove metal on those spots

What type of radiograph would we use to assess the marginal adaptation (verifies the seat of the restoration after adjustments that were previously made, especially proximal margins)?

Bitewing BUT not fully reliable; should be combined with the other means

parallel to tooth and shows interproximals

T/F: After radiographic inspection, further adjustment may be required; repeat the previous means (proximal contacts, pontic-ridge contact, marginal adaptation)

True

What do you do after checking fit?

Assess rocking and if it's loose

How do you asses rocking in a single crown?

Press buccolingually

How do you asses rocking on an FPD?

Press mesiodistally

T/F: You should differentiate rocking from flipping due to a short prep, overtaper, or lack of retention

True

What happens when you feel a bit of rocking on the FPD?

It might mean that there is heavy tissue contact from the pontic to the ridge

When checking stability, if it is too loose or rotating...

May need to remake after reprep

When checking stability, if it is not too loose...

Consider improving retention by roughening the inside or resin cement

All of the following can be used for what?

• Articulating paper

• Occlusal spray

• Occlusal indicator wax

• Shim stock/ Mylar strip

• Foils

• Transparent acetate sheets

• T scan

• Pressure sensitive films

• Photo occlusion

• Occlusal sonography

• Alginate impression material

• Polyether rubber impression bites

• Black silicone

Occlusal contact marking indicators or occlusal indicators

(hydrophobic/hydrophilic) mixture on plastic film of articulating paper

hydrophobic

On articulating paper, the harder the bite, the ________ the mark

Darker

T/F: A light occlusal mark is not necessarily an occlusal contact

True

T/F: A dark occlusal mark is an occlusal contact or premature contact (high spot)

True

All of the following are true about using articulating paper for occlusion, EXCEPT:

A) Articulating paper is affected by saliva, thickness, film material, operator experience, biting force, and time: 40 µ less influenced by experience, strength, duration of biting

B) Can be used multiple times

C) Teeth must be kept dry

D) The thicker the strip, the darker the mark: Accufilm II (20 µ) - 0.5 mm

E) When 40 µ thick strip used, marking material was dispersed around the actual contact in halo-like fashion

B) Should only be used ONCE

What is the sequence of occlusion check?

1) Centric contacts

2) Eccentric or lateral contacts

3) Protrusive contacts

If the patient can hold shim stock on adjacent teeth without but not with the crown, what is wrong with the crown?

It is too high

A premature contact (small arrow) on the buccal incline of the maxillary palatal cusp produces a _________ shift (large arrow) of the mandible.

Buccal

A premature contact (small arrow) on the palatal slope of the maxillary buccal cusp produces a _______ shift (large arrow) of the mandible

Lingual

A premature contact (small arrow) on the palatal incline of the maxillary palatal cusp produces a ________ shift (large arrow) of the mandible

Lingual

With centric contacts, how can you adjust a high spot or premature contact only; no overcorrection?

• Round bur

• Football diamond

when using shim stock should you use more or the same amount of resistance as between adjacent teeth?

Same amount of resistance

With centric contacts, how can you adjust hypooclusion?

Adding or remake

(New interocclusal record and pick up impression with the restoration)

T/F: Ask the pt to bite down hard to make sure high contacts show

FALSE

(You may end up fracturing the porcelain)

When checking occlusion what color is for centric contacts?

Red

When checking occlusion what color is for eccentric contacts?

Blue

What type of occlusal schemes are acceptable when checking eccentric or lateral contacts?

• Canine guidance

• Group function

• (avoid working and nonworking interferences)

In general for posterior teeth, the occlusal adjustments will tend to be the ________ inclines on the balancing side, and _________ inclines on the working side

• BULL (buccal upper, lingual lower) on balancing side (nonworking side)

• LUBL (lingual upper, buccal lower) on working side

Where will protrusive contacts generally be? (3: anterior, vs upper posterior, vs lower posterior)

• Upper lingual of anterior teeth

• Distal incline of upper posterior

• Mesial incline of lower posterior

You do not want an overcontoured crown and the concavity occlusal to the furcation extends on the _______ wall all the way

Axial

What does a change of shade requires?

Remake (easier to stain darker than lighten, essentially not possible)

What bur do you use to recarve the anatomy?

Tapered diamond

After all the adjustments were made, the restoration must be polished to what?

A high shine

Always use polishing burs from _______ to _______

Coarse to fine (fine > ultrafine diamond)

What polishing bur is for metal crowns?

Brownie > greenie

What polishing bur is for porcelain crowns or glazing?

Blue > pink > gray

what is this?

intraoral polishing kit

Before you continue with cementation, what must you do?

Show the patient the restoration in the mouth

How do you prepare the tooth after it is verified and before cementation?

• The tooth preparation is cleaned with a rubber cup and pumice

• The tooth preparation should be rinsed thoroughly with a water syringe.

• The preparation is dried with an air syringe

(tie floss under connector ro clean under pontic)

What is the dynamic load procedure for cementation of restoration?

1) Insert bite stick and have pt bite down after placing restoration in

2) Move bite stick up and down to move restoration down as it is seated

What is the static load procedure for cementation of restoration?

Stick a cotton roll or bite stick and have patient bite down hard

describe steps of cementation lab project

The cement we have in clinic is a dual-curing cement. How long do you light cure the cement for to remove excess?

5 seconds to gel up the excess cement and then you can easily clean it up

- Can be very difficult to remove excess cement once it has fully set

What do you do post-cementation?

Re-evaluation margins, proximal contacts, and centric/lateral/protrusive occlusion

T/F: YOU SHOULD ALWAYS CONFIRM OVERALL RESTORATION FIT WITH BW OR PA X-RAY

True

T/F: Adhesive cementation is the strongest cement you will find, and should use this for veneers

True

T/F: Convention cement is used for PFM or posterior teeth

True

T/F: Variolink is dual-cure and has several shades

True

What is the self-adhesive cement that we use in clinic?

relyX unicem

What type of cement?

- Dual-cure two paste resin cement

- Adhesive and self-adhesive indications

3M RelyX Universal

What type of cement?

- Self-etch, selective-etch and total-etch adhesive

- MDP primer for zirconia and metal

- Silane primer for glass ceramics, composites, fiber reinforced posts

3M Scotchbond Universal Plus

What is self-adhesive recommended for?

- Post

- Crown

- Bridge

What is selective etch adhesive recommended for?

- Inlay

- Onlay

What is total etch adhesive recommended for?

- Table Top

- Veneer

- Adhesive Bridge

T/F: relyX unicem is not recommended for veneers

True

T/F: relyX unicem does not need etching or bonding

True

T/F: relyX unicem is a dual cure cement and is moisture tolerant

True

T/F: e.max is radiotranslucent

True

T/F: Zirconia is radiopaque

True

ID the margin adaptation:

- Corrected by adjusting and finishing on the die

- Metal collar may be exposed

small overextended margin