Cementatailn of indirect restoration

Question 1

When should the crown be checked on the die?

Answer 1

Prior to patient attendance

Question 2

What to do when checking crown on the die?

Answer 2

Assess die for defects

Assess internal crown surface for defects, assess fit on die, compare to prescription.

Question 3

How can the airway be protected when trying the crown in the mouth?

Answer 3

Gauze

Question 4

What to do if crown fails to seat in mouth?

Answer 4

Ensure no temp material at embrasures

Check proximal contacts and adjust if needed, recheck for lab errors.

Question 5

What is the cause of tight proximal contacts?

Answer 5

Imprecise die location

Abrasion adj stone contacts, insufficient temporary -> tooth movement.

Question 6

How to remedy tight proximal contacts?

Answer 6

Grind down

Question 7

Cause of casting blebs on fit surface?

Answer 7

Air bubbles trapped during investment

Question 8

How to remedy blebs on fit surface?

Answer 8

Remove carefully

Question 9

Cause of overextended crown margins?

Answer 9

Poor imp

Poor die trimming, surplus untrimmed.

Question 10

How to remedy overextended crown margins?

Answer 10

Trim from axial surface and polish

Question 11

Cause of underextended crown margins?

Answer 11

Poor imo

Poor die trimming, difficulty identifying finish line.

Question 12

How to remedy underextended crown margins?

Answer 12

Remake

Question 13

Cause of damaged dies?

Answer 13

Finish line or internal overextension

Question 14

How to remedy damaged dies?

Answer 14

Remove additional material or remake

Question 15

How to remedy if no die spacer has been used?

Answer 15

Remake

Question 16

How to assess proximal contacts?

Answer 16

Floss

Question 17

What to do if proximal contacts are open?

Answer 17

Return to lab

Question 18

What are the 3 different types of cementation?

Answer 18

Non adhesive luting, micro-mechanical retention, molecular adhesion

Question 19

What does non adhesive luting cement require?

Answer 19

Retentive prep

Question 20

When is micro-mechanical retention required?

Answer 20

When inadequate retention and resistance form

Question 21

When is molecular adhesion good?

Answer 21

When insufficient retention and resistance form

Question 22

What are the ideal properties of luting cements?

Answer 22

Biocompatible and biomimetic

Inert, neutral pH, non-dissolving, ability to flow, adequate working and setting time, aesthetics minimize natural tooth, radiopaque.

Question 23

What is iwanson thickness gauge used for?

Answer 23

Checking the thickness of the surface of the crown

Question 24

What are the two broad categories of luting cements?

Answer 24

Permanent, temporary

Question 25

What are the two types of permanent luting cements?

Answer 25

Water based, resin based

Question 26

What are the two types of temporary luting cements?

Answer 26

Oil based, oil-free

Question 27

What type of luting cement is ZOE?

Answer 27

Temporary

Question 28

Advantage of ZOE?

Answer 28

Eugenol has obtundant effect on pulp ## Footnote Antimicrobial, cheap.

Question 29

Disadvantages of ZOE?

Answer 29

Low tensile strength, variable setting time

Question 30

What kind of luting cement is zinc polycarboxylate?

Answer 30

Permanent

Question 31

Advantages of zinc polycarboxylate cement?

Answer 31

No adverse effects on pulp ## Footnote Adheres to enamel and dentine, fluoride release, good compressive strength.

Question 32

Disadvantages of zinc polycarboxylate cement?

Answer 32

Low adhesion

Question 33

What kind of luting cement is zinc phosphate?

Answer 33

Permanent

Question 34

Which cement can be used in areas of high masticatory load or long span prosthesis?

Answer 34

Zinc phosphate

Question 35

Disadvantage of zinc phosphate?

Answer 35

No adhesion to tooth ## Footnote No antibacterial properties.

Question 36

Indications for zinc phosphate cement?

Answer 36

Metal supported restorations with retentive preps

Question 37

Contraindications of zinc phosphate cement?

Answer 37

Composite or all ceramic crowns due to lack of adhesion ## Footnote Non-retentive preps.

Question 38

Advantages of GI cement?

Answer 38

Fluoride release, adhesion to tooth and metal, easy to use

Question 39

Disadvantages of GI cement?

Answer 39

Slow initial set, sensitive to early moisture contamination ## Footnote Protect with fluoride varnish, superceded by RMGIC.

Question 40

Indications for GI cements?

Answer 40

Metal supported restorations with retentive preps ## Footnote Adequate moisture control.

Question 41

Advantages of RMGICs?

Answer 41

Superior strength to GIC, fluoride release, easy to use, high bond to dentine

Question 42

Disadvantages of RMGICs?

Answer 42

Polymerisation shrinkage, difficult to remove excess cement

Question 43

Example of commercially available resin cement?

Answer 43

RelyX

Question 44

Advantages of resin cements?

Answer 44

Adhesive, bonds to tooth

Question 45

Disadvantages of resin cements?

Answer 45

Requires excellent moisture control ## Footnote Technique sensitive, expensive, requires careful removal of excess.

Question 46

What is the bonding mechanism for methacryloyloxydecyl phosphate (MDP)?

Answer 46

Phosphate ester group chemically bonds to metal and oxide ceramic ## Footnote Methacryl group on other side bonds to resin.

Question 47

Bonding mechanism of silane?

Answer 47

Silane methacrylate chemically bonds to etched silicate ceramic ## Footnote Chemical bond to polymers of adhesive or resin cement.

Question 48

What is immediate dentine sealing?

Answer 48

Application of dentine bonding agent immediately following crown preparation

Question 49

Which product is used for immediate dentine sealing?

Answer 49

Optibond FL

Question 50

Advantages of immediate dentine sealing?

Answer 50

Improved bond strength, reduced post-op sensitivity, reduced bacterial leakage, improved restoration adaption, reinforcement of remaining tooth structure

Question 51

Disadvantages of immediate dentine sealing?

Answer 51

Technique sensitive, additional clinical time, not much evidence