Fixed....this Really Sucks

Front 1

The presence of these results in no path of insertion or draw

Back 1

undercut

Front 2

What is the proper taper

Back 2

6 degrees between opposing walls. Angle of convergence. total over all taper is 12 degrees

Front 3

List the 10 steps involved in fabricating all metal crown

Back 3

1. prep tooth
2. fabricate provisional restoration
3. impression
4. cast
5. die
6. wax up
7. invest
8. cast
9. clean
10. mount

Front 4

What is the number of times the tooth is duplicated in the process of fabricating a crown

Back 4

5 times
6 times if you inclded the provisional
1. impression
2. cast
3. wax up
4. invest
5. cast final

Front 5

This is an cemented extra coronal restoration covering all of the clinical crown

Back 5

full crown or complete veeer crown

Front 6

This is a restoration where portions of the clinical crown are veneered

Back 6

partial veneer

Front 7

THis restoration fits with in the anatomic contours of the clinical crown of the tooth.

Back 7

Intracoronal cast restorations

Front 8

This is a thin layer of dental porcelain or cast ceramic bonded to facal surface with an appropriate resin

Back 8

laminate or facial veneer

Front 9

This is a prosthetic appliance that is permanently attached to remaining teeth replacing missing teeth

Back 9

fixed partial denture

Front 10

This is the tooth serving as attachment for FPD

Back 10

abutment

Front 11

This attaches to the pontic and is an extracoronal restoration cemented to the prepared abutment teeth

Back 11

retainer

Front 12

What are the different types of rigid connector

Back 12

solder joints and cast conectors

Front 13

What are the different types of non rigid connectors

Back 13

precision attachments stress breakers

Front 14

What are the 5 components of a complete diagnosis

Back 14

1. Med/dental history
2. TMJ/occlusal evaluation
3. intraoral exam
4. diagnostic casts
5. full mouth radiographs

Front 15

What are 6 health findings that affect dental treatment

Back 15

1. Serum hep/HIV: must provide protection for yourself, patients, and staff
2. previous reaction to drug
3. Reaction to dental material: impression materials and nickel containing alloys are bad
4. Cardiovascular problems: hypertension
5. Epilepsy: keep anxiety low
6. Diabetic patients: beware of perio, healing delays
7. Hypoglycemic: may need to eat sugar, make sure pt eats meal
8. Xerostomia: increase in caries; caused by 375 drugs

Front 16

If you evaluate the occlusion of a patient and determine that it is normal

Back 16

maintain the occlusion

Front 17

If the occlusion is abnormal determine

Back 17

if it can be improved prioro to restorations or if restorations can improve it

Front 18

During a TMJ evaluation which muscles need to be palpated

Back 18

massater
temporalis
medial and lateral pterygoid, trapezius, sternomastoid

Front 19

What are the steps for an intraoral exam

Back 19

1. oral hygiene
2. attached gingiva: if lacking poor candidate for crown
3. inflammation, pockets, mobility
4. caries, gingival lesions, decalcfied areas
5. examine previous restorations and prostheses
6. evaluate occlusion- facets, interferences, slide

Front 20

What are the reasons and uses of diagnostic casts

Back 20

allows view of edentulous spaces/ curvature of arch
length of abutment teeth can be gauged for max retention and resistance
further analysis of occlusion
occlusal plane discrepancies and super erupted teeth
diagnostic wax up

Front 21

What are the reasons and uses of full mouth radiographs

Back 21

1. correlate all facts collected prior
2. examine for caries
3. examine for periapical lesions
4. bone levels
5. crown to root ratios
6. widening of the PDL
7. presence of retained root tips

Front 22

Uncontrolled hypertension is defined as

Back 22

systolic above 160 and diastolic above 95

Front 23

What are the indications and advantages of a complete veneer crown

Back 23

1. most retentive of the veneer preparations and resistant
2. Used when less extensive and less destructive designs have been considered and lack in retention, resistance, coverage, or esthetics.
3. When all axial surfaces of posterior teeth are attacked by decay or caries, full metal crowns can strengthen and support a tooth

Front 24

What are the 5 principles that govern the preparation for a CVC

Back 24

1. preservation of tooth structure
2. retention and resistance
3. structural durability
4. marginal integrity
5. preservation of peridontium

Front 25

Preservation of tooth structure requires

Back 25

limited amount of sound tooth structure removed

Front 26

Structural durability must contain..

Back 26

bulk of material that can withstand forces of occlusion
must consider the occlusal reduction
functional bevel and axial reduction

Front 27

Margins that are smooth and fully exposed of cleansing action ensure

Back 27

preservation of periodontium

Front 28

are subgingival margins recommended

Back 28

no

Front 29

This prevents the removal of the restoration along the path of insertion

Back 29

retention

Front 30

This prevents dislodgment of the restoration by forces directed in apical and oblique direction and prevents movement of the resotration under occlusal forces

Back 30

resistance

Front 31

What is the essential element of retention?

Back 31

two opposing vertical surfaces on the same prep

Front 32

limiting the freedom of displacement from torquing or twiting forces in a horizontal plane _____ the resistance of the restoration

Back 32

increases

Front 33

Longer preps have more ____ and _____.

Back 33

surface area and retnetion

Front 34

If a prep has shorter walls, they should have ____ taper to increase resistance

Back 34

less taper

Front 35

What can be placed on a short walled prep on a large tooth

Back 35

grooves to decrease rotational radius

Front 36

What can be substitued for internal forces

Back 36

groove, box form, or pinhole can be substititued for a destroyed wall

Front 37

This is the path the restoration will be placed onto or removed. It is considered faciolingually and mesioditally.

Back 37

path of insertion

Front 38

The MD must _____ the contact area for path of insertion or

Back 38

else it will be locked out

Front 39

Define margin

Back 39

end prep

Front 40

Define finish line

Back 40

margin of prep, you want an acute angle with nearby pulp)

Front 41

define axial wall

Back 41

vertical walls of the prep that provide retnetion

Front 42

Define functional bevel

Back 42

prevents thin or overcontoured crown, provides sufficient bulk and is part of the occlusal reduction

Front 43

These are both used to limit the paths of insertion and freedom of displacement. They increase resistance and retention

Back 43

box and groove

Front 44

Tipping displacement is decreased by _____

Back 44

longer walls

Front 45

This describes the relationship between two opposing axial walls of a CVC prep

Back 45

angle of convergence/divergence

Front 46

True or false: the more nearly parallel the less the retention

Back 46

false, the greater!

Front 47

The average taper surveyed from labs is _____ degrees

Back 47

20, this is the maximum tper that can be accepted

Front 48

The maximum degree of taper which can be achieved clincially and still afford adequate retention

Back 48

16

Front 49

As surface area increases, retention ____
As length increases, retention _____
As diameter decreases, retention___

Back 49

increases
increases
increases

Front 50

What are the 4 design features of a proper CVC prep

Back 50

1. occlusal reduciton
2. funcitonal cusp bevel
3. axial reduction
4. chamfered margin

Front 51

What are the auxiliary retention devices and their indications

Back 51

grooves, boxes, pinholes, steps, occlusal shoulder

these increase retention and resistance along with prevent dislodgment

Front 52

An offset ties ____ together while an isthmus ties ___ together

Back 52

grooves
boxes

Front 53

the optimum bevel angle is ____degrees

Back 53

45

Front 54

How much occlusal reduction for the functional cusps and non functional cusps of a CVC

Back 54

1.5- functional
1 mm - non funcitonal

Front 55

Crowns must end on ______

Back 55

natural tooth structure

Front 56

This is optimum condylar position; the condyle is in the most superoanterior position along the articular eminence of the glenoid fossa.

Back 56

Centric relation

Front 57

This is a physio unstrained position and it often used as a repeatable reference point for mounting on articulators

Back 57

centric relaiton

Front 58

centered contact position of occlusal surface of maxillary and mandibular teeth

Back 58

centric occlusion

Front 59

The mandible travels along a path that is guided by anterior teeth contacting and which disoccludes the posterior teeth

Back 59

anterior guidance

Front 60

condylar inclination linked to anterior guidance is 5-10 degrees _____ because anterior guidance guides the mandible ____

Back 60

steeper
down

Front 61

True or false: anterior guidance is linked to vertical and horizontal overlap of anterior and occlusal morphology of posterior teeth

Back 61

true

Front 62

Anterior teeth, such as the canines guide what movement of teeth?

Back 62

lateral excursion and protrusive movement of the mandible

Front 63

distance from the fulcrum (condyles) reduces load, thus which teeth have the highest load?

Back 63

the molars

Front 64

The force load can be reduced by ______

Back 64

prprioceptive threshold and reflexes

Front 65

If a steep protrusive path exist, then the posterior cusps are

Back 65

longer

Front 66

A lot of horizontal overlap equals ____ cusps

Back 66

shorter

Front 67

List the 4 potential interferences in occlusion

Back 67

1. centric
2. working
3.non working
4. protrusive

Front 68

this is a premature contact when the mandible close while condyles are in optimum position in the glenoid fossa. The mandible deflects post, ant, and or laterally

Back 68

centric

Front 69

This is a unwanted contact of maxillary and mandibular posterior teethon the side of movement.

Back 69

working

Front 70

this is unwanted contact on side opposite of directed movement. It is destructive to masticatory apparatus.

Back 70

nonworking

Front 71

Why are nonworking side interferences destructive

Back 71

mandibular leverage changes
force is outside of the long axis of tooth
normal muscular function is disrupted

Front 72

This is premature contact as the mandible moves forward

Back 72

protrusive

Front 73

why are protrusive interferences destructive

Back 73

teeth proximity to muscles
oblique vector force

Front 74

What are examples and indications of pathological occlusion

Back 74

trauma
occlusal wear
fractured cusps occlusal disharmony
local factors

Front 75

List the 5 criteria of a healthy occlusion

Back 75

1. condyles superoanteriorly against disc and along the eminence of the glenoid fossa; posterior teeth solidly and evenly contacted/ant teeth with slighter contact
2. occlusal force in long axis of the tooth
3. Working Contacts esp on canines disocclude NW instantly with lateral movement
4. ant teeth contact and disocclude posterior teeth during protrusive excursion
5. post teet contact heavier than anterior when upright in osture

Front 76

Maximum number of teeth contact in all excursive movements . This reduces load on individual teeth by many teeth sharing stress.

Back 76

bilateral occlusion
-good for dentures

Front 77

This is group function and eliminates all contact on the non working side.

Back 77

unilateral occlusion
-occurs in cases with ant bone loss and absent canines

Front 78

This is canine protected; anterior overlap prevents nonworking and working posterior contact during excursion

Back 78

mutually protected occlusion

Front 79

The farther anterior a tooth is located, the _____ influence of the TMJ joint, and the ____ of anterior guidance

Back 79

less
greater

Front 80

Why is PFM indicated over an all ceramic crown

Back 80

PFM is indicated because it is more resistant to fracture

Front 81

Why is PFM indicated over a metal FPD

Back 81

A pfm provides an esthetic fixed FPD

Front 82

What is another name for a PFM

Back 82

metal ceramic restoration

Front 83

Describe how a PFM is layered

Back 83

it consists of a ceramic layer bonded to a thin cast metal coping that fits over the tooth preparation.

Front 84

In areas where there will be ceramic coverage, reduction should be

Back 84

1.5-2.0 mm occlusally

Front 85

when prepping a tooth for a PFM, how far should the radial shoulder extend?

Back 85

1.0 mm pst the proximal contact

Front 86

What are the three layers of porcelain that are present on a PFM

Back 86

Opaque
dentin
enamel

Front 87

This type of porcelain conceals the metal underneath. It initiates the development of the shade and plays an important orle in the development of the bond between the ceramic and the metal

Back 87

opaque

Front 88

This porcelain makes up the bulk of a PFM restoration, providing most of the shade or color

Back 88

Dentin or body

Front 89

This porcelain imparts translucency to the restoration

Back 89

enamel or incisal

Front 90

If a PFM is to be prepped on an anterior tooth that has 4 mm of recession what must you consider?

Back 90

The optimum location for gingival finish line of a crown prep is on enamel. However in this type of situation the margin must be extended apically. A shoulder is a poor choice and would end in an axial reduction dangerously close to the pulp. You must create a chamfer finish line and the PFM will have a wide metal gingival collar

Front 91

Should the contacts of a PFM be in porcelain or metal

Back 91

metal if possible, porcelain is abrasive on enamel and gold restorations.

Front 92

What are the disadvantages of porcelain occlusal surfaces compared to metal

Back 92

abrasve on enamel
fracture more and weaker in strength
need a more destructive, deeper crown prep to provide adequate space for porcelain

Front 93

What are the advantages of porcelain over metal

Back 93

esthetics

Front 94

How far should the porcelain/metal junction be away from contacts

Back 94

1 mm

Front 95

On a mandibular anterior PFM will the contact be in metal or porcelain

Back 95

porcelain no way to avoid it

Front 96

True or false: relatively thin porcelain of uniform thickness and supported by rigid metal is strongest for a PFM.

Back 96

True

Front 97

What should be the minimum thickness of porcelain

Back 97

.7 mm, the desirable thickness is 1-1.5 mm

Front 98

For adequate strength and rigidity a noble metal coping for a PFM should be at least ___ to ____ thick

Back 98

.3 to .5 mm thick

Front 99

What are the 4 mechanisms of bonding between ceramic veneer and the metal substructure

Back 99

1. mechanical entrapment
2. compressive forces
3. van der waals forces
4. chemical bonding

Front 100

This type of bond between ceramic veneer and the metal substructure is created by interlocking the ceramic with microabrasions in the surface of the metal coping, which are produced by finishing the metal with noncontaminating stones or disks and air abrasion

Back 100

mechanical entrapment

Front 101

When the coefficient of thermal expansion of a properly designed metal coping is slightly higher than that of porcelain veneered over it this type of bonding mechanism occurs

Back 101

compressive forces

Front 102

This bonding mechanism is formed by a mutual attraction of charged molecules

Back 102

van der waals

Front 103

This type of bonding is indicated by the formation of an oxide layer on the metal and by bond strength that is increased by firing in an oxidiing atmosphere.

Back 103

chemical bonding

Front 104

Why must the facial surface of maxillary anterior tooth prepared for a PFM crown be prepared in 2 planes

Back 104

If only one plane is reduced- opaque porcelain may show through, the labial surface may be overcontoured, and the pulp may be encroached upon.

Front 105

What is the difference between PFM and all ceramic

Back 105

All cereamic crowns contain no metal or gold

Front 106

True or false: All ceramic crowns produce the best esthetic effect of all dental restorations but are also the most susceptible to fracture

Back 106

true

Front 107

What are 3 common errors made in labial reduction

Back 107

1. reducing in one plane: the opaque porcelain may show through and the restoration will not be esthetic
2. extension of gingival plane; the labial surface may be over contoured and bulky
3. extension of the incisal plane: the pulp may be encroached upon and the facial surface will be over tapered

Front 108

Name 7 advantages of All ceramic crowns

Back 108

1. optical properties (translucency and opaque if you wish to block color)
2. No metal
3. thermal conductivity
4. biocompatibility
5. can be bonded to tooth
6. in office fabrication, no provisional
7. cost

Front 109

Should a patient with bruxism have ceramic crowns

Back 109

No

Front 110

If you are going to do all ceramic on a molar what type of material should be used

Back 110

Zirconia

Front 111

What type of material should be used for a all ceramic on a pre molar or an anterior

Back 111

E max
(can use z sethetic for anteriors as well)

Front 112

Describe an articulator

Back 112

An articulator is a mechanical device used to hold casts of the patients teeth and stimulate the mandibular movements by replication of the paths of movement of the posterior determinants, the TMJ

Front 113

What are the two basic types of articulators

Back 113

arcon and non arcon

Front 114

An arictulator that is anatomically accurate, condylar elements are attached to the lower member and the mechanical fossae are on the upper. accurate and easy to disassemble

Back 114

arcon

Front 115

An articulator that has condylar elements on the upper member and the paths simulating the glenoid fossa are on the lower, more popular for dentures

Back 115

non arcon

Front 116

The facebow is used with any ______ articulator. It transfers the position of the _____ cast in relation to the condyles of the articulator.

Back 116

adjustable
maxillary

Front 117

What information does the face bow transfer

Back 117

1. maxillary teeth
2. transverse horizontal axis
3. third reference point from the patients skull

Front 118

What is the limitation of the arbitrary caliper style ear axis facebow

Back 118

It does not capture the exact location of the hinge axis, but 75% of the time the arbitrary hinge axis is within 6 mm of the pt's true hinge axis so it usually sitll works pretty wel unless doing a full mouth reconstruction

Front 119

What is the accuracy of the kinematic face bow

Back 119

It pinpoints the exact location of a persons hinge axis,
These are good for full mouth reconstruction

Front 120

An articulator that closely duplicates mandibular movement will allow you to

Back 120

fabricate a more accurate restorations and reduce chair time needed to make adjustments

Front 121

Does the size of the articulator have an effect on the restorations accuracy?

Back 121

Yes, as the mandible moves up and down the cusp tips move along a sagittal plane with with the cent of rotation at the transverse hinge axis which passes through the condyles. If the location of that axis relative to the cusp tips differes markedly from pt to articulator the radius of the arc of closure may be different and produce errors

Front 122

What are the advantages of a semi adjustable articulator

Back 122

larger size allows close approximation of distance between axis of rotation and teeth, reproduces the direction and end point of condylar track, and good for most single units and FPDs

Front 123

What is the disadvantages of a semi adjustable articulator

Back 123

It does not reproduce intermediate track of some condylar movements, intercondylar distances can only be adjusted to s, m l if at all. restorations will require some intraoral adjustment

Front 124

What are the capabilities of a fully adjustable articulator

Back 124

Reproduces all border movements, intercondylar distance is fully adjustable, highly accurate reproduction of mandibular movements

Front 125

Describe centric relation record

Back 125

A record used to replicate on the articulator the relationship between the maxillary and mandibular arches that exists when the condyles are in their most anteriosuperior position in the glenoid fossa (no teeth should be contacting); used for diagnostic casts or restoration of significant portion of the occlusion

Front 126

Describe intercuspation record

Back 126

used for casts that are to be used for the fabrication of restorations for a small part of the occlusion; done with the bite registration material in a triple tray.

Front 127

what influence does anterior guidance have on natural dentition

Back 127

anterior guidance permits the separtion of posterior teeth during lateral excursive and protrusive movements.

Front 128

Describe the amount of force on anterior teeth compared to posterior teeth

Back 128

The anterior teeth are farther away from the fulcrum, so the load is less for them than th eposterior teeth. Without anterior guidance, all functional forces will be on the posterior teeth, resulting in excessive forces and potential damge

Front 129

Why should anterior guidance be recorded on an articulator

Back 129

To take into account the influence of the incisors and canines on the occlusion during excursive movements. Anterior guidance is linked to the combination of vertical and horizontal overlap of the anterior teeth, which affects the morphology of the posterior teeth

Front 130

What are the implications of not properly registering anterior guidance on an articulator

Back 130

If crowns involving the lingual contours of anterior teeth are to be placed and AG is not registered properly restorations may be made with lingual contours or length that will not provide AG

Front 131

If changes in occlusion are anticipate or teeth are going to be lengthened, it is important to make what?

Back 131

a custom incisal guide table

Front 132

How do you make a custom incisal guide table

Back 132

1. incisal guide pin is raised at least 1 mm off the incisal guide block
2. moisten guide block, round end of pin, and anterior teeth with vaseline
3. apply resin to the guide block
4. move articulator through all excursive movements repeatedly keeping the anterior teeth touching at all times
5. light cure

Front 133

This is a negative likeness and is made by placing some soft, semi fluid material in the pt's mouth and allowing the material to set.

Back 133

Impression

Front 134

What is the indirect technique of making a restoration

Back 134

fabricating a restoration that is not directly fabricated on the pt's tooth. aka using an impression to produce a cast and then make a crown

Front 135

Define hydrophilic impression material

Back 135

readily wettable by gypsum

Front 136

what are examples of hydrophilic impression material

Back 136

alginate and polyether

Front 137

Define hydrophobic impression

Back 137

resistant to wetting

Front 138

What are examples of hydrophobic impression materials

Back 138

polyvinyl siloxane, condensation-reaction silicones

Front 139

A material that exhibits the property of becoming more fluid when the shear rate is increased by deforming or distrubing it (shaking, injecting through a syringe) is said to be

Back 139

thixotropic

Front 140

Hydrophillic materials have surfaces that are ____ wettable therefore have _______ contact angles, and thus ____ the probablility of entrapping bubbles during pouring up of the impression.

Back 140

more
lower
decrease

Front 141

Materials that are hydrophobic are ___ wettable, have ____ contact angles, and _____ the probability of air entrapment during pouring up of the impression

Back 141

less
higher
increase

Front 142

Materials have _____ viscosity when the shear rate is increased, More thixotropic materials have this property and are therefore used during impression taking

Back 142

lower

Front 143

What is the difference between accuracy and precision

Back 143

An accurate, undistorted impresion must be provided to the lab. It must be as nearly an exact duplicate of the prepared tooth. Thus when the crown is made it will precisely fit onto the tooth

Front 144

List the characteristics of an acceptable impression

Back 144

1. Should be an accurate or exact duplication of the prepared tooth, including all of the preparation and enough uncut tooth surface beyond the preparation to allow the dentist and technician to e certain of the ocation and configuration of the finish line.
2. Other teeth and tissue adjacent to the prepared toth must be accurately reproduced to permit proper articulation of the cast and contouring of the restoration
3. It must be free of bubbles, especially in the area of the finish line an docclusion surfaces of the other teeth in the arch

Front 145

Define contact angle

Back 145

ange at which a liquid meets a solid surface. The greater the contact angle the increased likelihood of air entrapment during pouring of an impression

Front 146

Define wettability

Back 146

ability of a liquid to maintain contact with a solid surface, resulting from intermolecular interation between the two Surface with better wettability are hydrophilic, surfaces wiht poor wettability are hydrophobic

Front 147

Define tear strength

Back 147

A test that provides a measure of resistance to tearing

Front 148

Why is tear strength important to impression material

Back 148

It is better to have an impression material that has a strong tear strength. This allows it to be removed from the mouth while still getting an accurate impression of the tooth and surrounding tissues instead of small pieces of the impression material tearing off It also allows a more accurate cast to be made.

Front 149

What type of tear strength does alginate and polysulfide rubber base have?

Back 149

alignate has a weak tear strength and polysulfide rubber base has a good tear strength

Front 150

What is dimensional stability

Back 150

ability of a substance to retain its shape when subjected to varying degrees of temperature, moisture, pressure, or other stress.

Front 151

Which impression material has the worst dimensional stability

Back 151

Alginate (irreversible hydrocoloid) has the worst dimensional stability because it deforms readily which is why it has to be poured up almost immediately after the impression is taken.

Front 152

Which impression material has the best dimensional stability

Back 152

polyvinyl siloxane
it can withstand multiple cast pours and be transported from one location to another

Front 153

What impression material has intermediate dimensional stability

Back 153

Polysulfide, but it contracts as it cures, thus to minimize inaccuracy from this an impression should be poured within one hour

Front 154

What are the least viscous materials used in impressions

Back 154

Light bodied polysulfide and condensation silicone

Front 155

What is the most viscous materials used for impressions

Back 155

heavy bodied polysulfide

Front 156

What type of viscosity do polyvinyl siloxane and polyether have

Back 156

intermediate

Front 157

What is the cheapest impression material

Back 157

Alginate, because it is easily bought and stored in bulk and can be rationed out in exact amounts as needed

Front 158

Of the elastomeric materials, which are the most and least expensive?

Back 158

polyvinyl siloxane is the most expensive, it must be dispensed through a cartridge which makes it difficult to ration the amount of material being used.

Polysulfide impressions are the least expensive

Front 159

What are common problems that require remaking of impressions

Back 159

Presence of blood, saliva, debris, calculus, plaque, soft tissue, tongue and lips can hind getting a good, accurate impression. the impression material is not able to displace these elements and they will be recorded in the impression rendering it inaccurate

Front 160

How is an irreversible hydrocolloid mixed, its working time, and setting time?

Back 160

water and powder are combined and hand mixed. working time is less tahn 1 minute. the material takes 2-4 minutes to set depending on the exact type of alginate

Front 161

How is polysulfide mixed, its working time, and setting time

Back 161

Acid and base components are mixed on a mixing pad for 30 sec, cannot exceed 1 minute. Syringe is loaded and the material takes 8-10 minutes to set

Front 162

How is Condensation silicone mixed, its working time, and its setting time?

Back 162

mix acid and base for 30 sec then roll into a cigar shape and place in tray. Place in patients mouth for 2 minutes

Front 163

How is Polyvinyl siloxane mixed, its mixing time, and setting time

Back 163

If tube dispensed mix material with spatula for 45 sec until streaks are eliminated then load into syringe. IF using the cartridge system load the cartridge and place a new tip on the gun dispensing the material mixes the acid and base components. It takes 7 minutes for it to set

Front 164

How is polyether mixed, its mixing time, and setting time

Back 164

mix with spatula for about 1 minute. Load material into a syringe and dispense into the tray. The material will set in 4 minutes

Front 165

What is the effect of the water/powder ratio on die stone properties

Back 165

the proper ratio is key to getting a good stone pour. Improper ratio can alter properties of the set of the stone such as setting time, porosity, expansion, and strength of the stone Excess water should be removed from impressions before pouring them up

Front 166

Are die stone models trimmed on a wet or dry model trimmer

Back 166

Dry to ensure excess water does not get into the stone and hinder its ablity to fully set correctly

Front 167

Discuss how die stone differs from other gypsum products

Back 167

Die stone has a lower water:powder (22-25 per 100 g) and has 2x hardness of gypsum products. Dried dies are 2x strong than wet dies, even with all the extra strength and hardness, the best die stones still abrade with repeated insertion and removal of restorations

Front 168

List characteristics of an acceptable cast

Back 168

1. bubble free, especially along the finish lines of the preparation
2. All portions of the cast must be distortion free with good reproduction of all necessary oral structures
3. The casts must be trimmed to ensure access for carving wax pattern margins

Front 169

What is the proper technique for making a pindex master cast

Back 169

1. master cast poured using a vacuum mixed die stone
2. the cast is trimmed and marked for the drilling of pin holes
3. holes are drilled and notched
4. pindex pins are glued into position
5. separator is applied
6. pindex sleeves are positioned over pins
7. the base is poured and the cast is seated into the base
8. dies are separated with a saw
9. the cast is mounted

Front 170

What are the requirements of a provisional restoration

Back 170

1. pulpal protection
2. positional stability
3. occlusal function
4. easily cleaned
5. non impinging margins
6. strength and retention
7. esthetics

Front 171

How does a provisional provide pulpal protection?

Back 171

the restoration must be fabricated of a material that will prevent the conduction of temperature extremes and the margins should be well adapted well enough to prevent leakage of saliva

Front 172

How does a provisional restoration give positional stability

Back 172

It prevents the tooth from extruding or drifting away. Any such movement will require adjustments or remake of the final restoration

Front 173

Why must a provisional provide occlusal function

Back 173

Being able to funciton occlusally on the provisional restoration will aid patient comfort, ward off tooth migraiton, and possibly prevent joint or neuromuscular imbalance

Front 174

Provisionals are classified by whether they are ____ or _____

Back 174

prefabricate or custom made

Front 175

What are examples of prefabricated provisionsals

Back 175

stock aluminum, anatomic metal crown forms, celluloid shells, polycarbonate crown forms

Front 176

What are examples of custom made crowns

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fabricated of several different kinds of resins by a variety of methods direct or indirect such as polymethyl meth acrylate ,
poly ethyl methacrylate, poly vinylethyl methacrylate
bisacryl composite
vlc uerthane dimethacrylate.

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What type of resin is alike

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poly methyl methacrylate

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What is the difference between making a provisional direct or indirect

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Direct is done on actual prepared teeth in the mouth, it is good for novices

Indirect is done outside of the mouth on a cast made of quick set plaster, preferred over direct for accuarcy

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What are the basic principles of making a provisional

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The outer surface is made a variety of ways that capture the shape of the anatomy of a tooth

The inside of the provisional is made by the prepped tooth

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What is the overimpession technique?

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Make an alginate overimpression befor eprepping the tooth and fill and smooth defects on the diagnostic cast if there are issueues with anatomy

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When custom provisionals are not possible or desirable, a quick and easy way to produce esthetic provisionals to protect the tooth and keep the patient comfortable is to use

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a prefabricated provisional

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What cements are commonly used for provisional restorations

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zinc oxide with eugenol-temp bond base and accelerator can be mixed with vaseline for weaker temporary bond

zinc oxide w/o eugenol- eugenol inhibits polymerization of resins like methacrylate, allows for the future addition of methacrylate to cured methacrylate