Classification Standards

Question 1

Predominantly Base Alloys

Answer 1

Noble Metal Content <25%

gold + platinum group

Question 2

Noble Alloys

Answer 2

Noble Metal Content >=25% (gold + platinum)

Question 3

Titanium/Ti Alloys

Answer 3

Titanium >= 85%

Question 4

High Noble Alloys

Answer 4

Noble Metal Content >= 60% and gold >= 40%

Noble metal content means gold + platinum

Question 5

Noble Metal Content group is what elements?

What about the subgroup?

Answer 5

Gold + Platinum group

Platinum, palladium, rhodium, indium, osmium, ruthenium

Question 6

Swenson’s Formula (for tooth selection)

Answer 6

Cusp Angle = Incisal Guidance + 1/2 (Condylar Guidance - Incisal Guidance)

Question 7

Theilman’s Formula

Balanced Occlusion (C) =…

Answer 7

C = Condylar Inclination x Incisal Guidance / Occlusal plane x cusps inclination x Comp curve

Question 8

If you adjust the condylar guidance, what impact can this have on occlusal form of restorations?

Answer 8

Cusps may be taller or shorter (Vertical)

Question 9

Adjusting inter condylar distance will have what impact on occlusal form?

Answer 9

The greater the distance, the smaller the cusp grooves and fossa will have to be.

Question 10

Adjusting anterior guidance will have what impact on occlusal form?

Answer 10

Posterior cusps may be taller or shorter (vertical)

Question 11

Adjusting the plane of occlusion will have what impact on occlusal form?

Answer 11

The flatter the plane of occlusion, the shorter the posterior cusps will be (vertical)

Question 12

Adjusting the curve of spee will have what effect on occlusal form?

Answer 12

Vertical (the greater the curve, the taller the cusps can be)

Question 13

Lateral translation adjustment will have what effect on occlusal form?

Answer 13

The greater the translation, the wider the cusp grooves and fossa will have to be

Question 14

Horizontal determinants of occlusion (4)? How does adjusting each affect occlusal form?

Answer 14

1. Distance from rotating condyle
2. Distance from midsagital plane
3. Lateral translation movement
4. Intercondylar distance

Question 15

Vertical determinants of occlusion (5)? How does adjusting each affect occlusal form?

Answer 15

1. Condylar guidance
2. Incisal guidance
3. Occlusal plane
4. Curve of spee
5. Lateral translation movement

Question 16

What is the third point of reference for articulators?

Answer 16

It is used to complete the plane of condylar position and determine the occlusal plane on the articulator

Question 17

Frankfort Horizontal plane - what landmarks?

Answer 17

1. Orbitale

2. Porion

Question 18

Ala-tragus line (camper’s plane)

Answer 18

1. Inferior border of ala

2. Superior border of tragus

Question 19

Centric Relation

Answer 19

Maxillomandibular position in which the condyles articulate with the thinnest avascular portion of their respective disks with the complex in the most anterior-superior position against the shapes of the articular eminence.

Question 20

MIP

Answer 20

Complete intercuspation of all teeth independent of condylar position

Question 21

When do you restore in MI or CO?

Answer 21

Restore in MI when patient is satisfied with bite and no occlusal dysfunction. Restoration is only a one or a few teeth
CO - Redesign to ideal occlusion - an increase in OVD planned

Question 22

Alginate impression reaction

Answer 22

H2O + Potassium alginate + Calcium sulfate + (Sodium phosphate) -> Calcium alginate + calcium phosphate

Question 23

Gypsum reaction

Answer 23

Calcium sulfate dehydrate _ heat -> calcium sulfate hemihydrate (from 2 H2O down to 1/2)

Question 24

How thick is die spacer? What is it’s role?

Answer 24

20-40 microns

Provides space for cement and improves seating.

Question 25

Fixed - Retention form factors (5)

Answer 25

1. Total occlusal convergence 2. Base/height ratio 3. Surface area 4. Effect of grooves/boxes 5. Cement

Question 26

Fixed - Resistance form factors (5)

Answer 26

1. Total occlusal convergence 2. Base/height ratio 3. Tooth location 4. Grooves/boxes 5. Cement

Question 27

Fixed - Goodacre prep recommendations - How much TOC? - Prep height for anteriors - Prep height for posteriors - Height/base ratio - What about line angles? - What about surface roughness?

Answer 27

1. 10-20 TOC 2. 4 mm anteriors 3. 3 mm posteriors 4. 0.4 ratio 5. Facial/lingual - proximal line angles need to be preserved 6. Smooth tooth surfaces enhance fit

Question 28

Irreversible hydrocolloid - 5 components

Answer 28

1. Potassium alginate 2. Calcium sulfate dehydrate 3. Diatomaceous earth 4. Potassium sulfate 5. Trisodium phosphate

Question 29

What is the retarder in irreversible hydrocolloid?

Answer 29

Trisodium phosphate

Question 30

What does Diatomaceous earth do in irreversible hydrocolloid reaction?

Answer 30

Improves consistency and flexibility

Question 31

Polyether - Composition (5)

Answer 31

1. Base (polyether, silica filler, plasticizer) | 2. Accelerators (sulfonate and thickening agent)

Question 32

Polyether - Adv/Disadv - Dimensional stability - Water tolerance - Tear strength - Rigidity - Single or multiple pours? - Uses?

Answer 32

1. Good dimensional stability 2. Hydrophilic 3. Poor tear strength 4. Rigid 5. Multiple pours 6. Implants, fixed

Question 33

Polysulfide - Composition

Answer 33

Polysulfide, lead dioxide (accelerator), titanium dioxide (filler), dibuthyl phthalate (plasticizer for viscosity), oleic acid (retarder)

Question 34

Polysulfide - Reaction theory

Answer 34

In the presence of accelerator (lead dioxide), the polysulfide polymers undergo chain linking at the thiol group

Question 35

The three elastomeric materials we use in dentistry?

Answer 35

Polyether, polyvinylsiloxane, polysulfide

Question 36

Condensation Silicone or Addition produces ethyl alcohol? Which produces hydrogen gas?

Answer 36

Condensation produces ethyl alcohol. This accounts for the shrinkage. Addition silicone (PVS) produces hydrogen gas)

Question 37

How do manufacturers account for hydrogen gas production in addition silicone?

Answer 37

Palladium as a scavenger