RPD Holy Grail Flashcards by Annabella Moody

Which of the following are done last?

a. Framework try in
b. create rests
c. CR record
d. altered cast

d. altered cast (assures support for RPD)

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List the correct order of the following:

-CR record
-altered casts
-Framework try in
-creates rests

Framework try in
create rests
CR record
altered cast

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If an RPD is part of the treatment plan, plan the RPD before beginning:

any other treatment

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These are the clinical steps for an RPD fabrication:

diagnosis, treatment plan, hygeine
diagnostic casts
draw design & list abutment modifications on the prosthesis design page
instructor approval
complete phase 1 treatment
abutment modifications
preliminary impression to check abutment modifications
fabricate & cement crowns or fixed partial dentures
final framework impression
make two casts
draw design on 2nd cast
instructor approval/corrections of drawing/design on casts
complete RPD framework prescription (instructor signature required)
2nd poured cast with design sent to lab with 1st pour
inspect wax up
framework adjustments (create rests)
altered cast impressions (if needed)
jaw relation records (CR record)
select & set denture teeth
try-in with teeth & wax
process, adjustment, deliver to patient (altered cast)

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How far distally should the denture base extend in a class I distal extension case?

2/3 of the retromolar pad

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Bilateral edentulous area posterior to remaining teeth describes:

Kennedy Class I

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Maxillary framework extends: (in Kennedy Class I)

2/3 distance to hamular notch (resin engages further)

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How far distally should the retention extend for a distal extension case?

Extends to 2/3 from the guide plate to 2/3 of the retromolar pad

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Which of the following is the hardest to obtain with a distal extension case?

VDO record (possibly also establishing plane of occlusion)

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Essential to prevent displacement or deformation of the metal framework during resin-packing procedures:

Cast stop

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Cast stops project from the tissue surface of the ____ to contact the _____

minor connector; dental cast

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A ____ should be used to join acrylic resin and metal components at the internal surface of an RPD

Butt joint

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A butt joint should be used to join ____ & ____ components at the ____ surface of an RPD

acrylic resin; metal components; internal

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Each internal finish line of a butt joint should display an angle of:

90 degrees

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The internal angles of external finish lines should be:

slightly less than 90 degrees

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The internal angles of external finish lines should be slightly less than 90 degrees, what does this result in?

This results in improved mechanical retention for acrylic resin components

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In a butt joint:

internal=_____
external= ____

internal= 90
external=acute

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Base plate wax on cast for relief in edentulous areas:

Wax patterns

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Wax patterns are made on the:

Refractory casts

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The cast that is used for fabricating the framework:

Refractory cast

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What does “support” mean for direct retainers?

Resists vertical movement toward the soft tissues

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Resistance to removal from the tissues or teeth:

Retention

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Resistance to movement in a horizontal direction (anterior-posteriorly or medio-laterally):

Stability

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Resistance to movement towards the tissues or teeth:

Support

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A tooth that supports a partial denture:

abutment

A component of a partial denture that provides both retention and support for the partial denture:

Retainer

What three components are required for clasp assembly:

support, resistance & retention

T/F: The completed RPD must be passive

True

T/F: The RPD should exert forces on the teeth & soft tissue

False- the RPD should NOT exert forces on the teeth or soft tissue

T/F: The toe of each retentive claps should lie passively in a measured undercut

False- the TIP of each retentive clasp should lie passively in a measured undercut

Where should the tip of each retentive clasp lie?

Passively in a measured undercut

Clasps should be ____ when fully seated, meaning:

Passive; not directing force on the tooth

The reciprocal arm of the clasp should contact the tooth:

before the retentive tip passes the height of contour

The reciprocal arm of the clasp should contact the tooth before the retentive tip passes the height of contour so it can:

hold the tooth in place as the retentive tip puts off-axis pressure on it

The reciprocal arm of the clasp should contact the tooth before the retentive tip passes the height of contour so it can hold the tooth in place as the retentive clasp puts off-axis pressure on it. This:

neutralizes stress from the retentive tip

T/F: Class I lever is ideal. RPI is a example of a class I lever

False; False Class I lever= most detrimental Class II lever= ideal RPI is an example of a class II lever

RPI is an example of what type of lever?

Class II

RPI stands for:

Rest (mesial) Proximal plate I-bar

What type of support allows for an RPI?

Tooth-tissue support (Class I, II, & long Class IV)

Does an RPI satisfy the principle of encirclement?

RPI= class II lever= _____

stress release

Wrought wire needs an elongation factor of:

more than 6%

It is important that a wrought wire clasp have an elongation percentage of more than 6% (PTQ), allowing _______ without microstructure hangers that could compromise its physical properties (like creating a fracture)

Allowing the clasp to bend

Cheek biting is caused by:

a) lack of horizontal overlap b) mandibular teeth too far buccal

Moving the buccal cusps lingually increases:

horizontal overlap

Caused by insufficient horizontal overlap between maxillary & mandibular teeth:

Cheek biting

If artificial teeth are correctly positioned and cheek biting occurs:

round the buccal cusps of the mandibular posterior teeth to move the buccal cusps slightly lingually (thereby creating a greater horizontal overlap)

If cheek biting occurs artificial teeth are incorrectly positioned or rounding does not help:

remove artificial teeth & reset them

Caused by the artificial teeth being positioned too far lingually, resulting in a decrease in tongue space:

Tongue biting

Tongue biting is caused by the artificial teeth being positioned too far _____, resulting in a ____ of tongue space

lingually; decrease

How do you fix tongue biting?

By rounding lingual cusps/recontour the lingual surfaces of mandibular teeth

What would the following alterations help? -gentle "rounding or rolling" of the lingual cusps and recontouring of the lingual surfaces of the mandibular teeth

tongue biting

What do you do if you have tried to correct tongue biting with rounding of the lingual cusps and recontouring of the lingual surfaces of mandibular teeth, yet the patient is still tongue biting?

Remove & reset artificial teeth

which of the following foes not call for a rebase?

dentition or moveable

A laboratory technique in which the bulk of the denture base is removed and replace using new resin:

Rebasing

The rebasing approach results in a ________, but is technically complicated by the fact that the retentive meshwork is buried within the denture base- often without sufficient relief beneath the mesh to allow for adequate bulk of new resin

base of uniform quality

Rebasing is indicated when: (3)

1. denture bases do not extend to cover all of the denture-bearing tissues 2. denture base has been fractured 3. denture base has become irreparably discolored

1. denture bases do not extend to cover all of the denture-bearing tissues 2. denture base has been fractured 3. denture base has become irreparably discolored What would you do for the following situations?

Rebase

_____ when both denture base and denture teeth need work _____ when at least 2mm is present under denture base OR indirect retainer lifts 2mm+

Remake Reline

When should you reline the denture base?

1. when at least 2mm is present under denture base 2. when indirect retainer lifts 2mm+

The anterior teeth disclude the posterior teeth when the mandible moves in protrusion:

anterior guidance

anterior guidance describes the anterior teeth disclude the posterior teeth when:

the mandible moves in protrusion

With anterior guidance, the _____, _____, and ______ disclude the posterior teeth when the mandible moves in protrusion

canines, central incisors, lateral incisors

With anterior guidance, the canines, central incisors, & lateral incisors, disclude the posterior teeth when the mandible moves in:

protrusion

Contacts between posterior teeth during excursive movements are considered _____ that can create damaging effects the teeth & periodontium

interferences

With anterior guidance, describe what should occur with the posterior teeth:

The posterior teeth should NOT touch (in excursive movements)

These create off-axis forces in posterior teeth, where you're close to the TMJ, meaning high load in off-axis direction, leading to damaged teeth:

interferences (posterior teeth)

Which of the following are involved in support? a) rest b) major connector c) denture base d) all of the above

d) all of the above

What material is most commonly used to make denture bases?

PMMA

What denture base material is being described? -difficult to adjust -poor esthetics -part of cast framework -good thermal conductivity -can be kept thin

Metal

What denture base material is being described? -acrylic resin -most common -easily adjusted & relined -good esthetics -attachment to framework by lattice or mesh

Polymethyl methacrylate (PMMA)

_____ is the most common material to sue for the denture base

PMMA

What type of material would you use in distal extension cases?

PMMA

What type of joint is used with PMMA? Describe:

Butt joint (90 degrees) with major & minor connector

Can you reline a PMMA base?

yes

Advantages of acrylic resin bases (PMMA) include: (3)

1. ability to reline the base as the supporting tissues change 2. esthetically superior to metal bases 3. ease of repair

Disadvantages of acrylic resin bases (PMMA) include: (4)

1. dimensional stability less than metal base- warpage 2. lower strength than metal- long spans 3. porous- hygiene 4. low thermal conductivity

What occurs if instead of a butt joint (90 degrees) for acrylic resin bases, a feathered edge is used?

distortion, breakage, or separation from the framework causing injury to the underlying soft tissue

Which of the following is true about PIP? a) PIP means pink indicating paste b) Should be put on camio surfaces c) Should be put in great amounts d) Should be in brush strokes

True: d) Should be in brush strokes Corrections: a) PIP means PRESSURE indicating paste b) Should be put on INTAGLIO surfaces c) Should be put in SMALL amounts

Checks soft tissue impingement during framework adjustment step:

PIP

PIP is placed on ____ surfaces to check for ____ areas

intaglio; pressure

If clasps are tight on a class III with circumferential clasp you use what to adjust? a) 139 b) hemostat c) 200 d) remake

a) 139

A class III is _____ supported

tooth

Indications for a circlet:

undercut OPPOSITE of edentulous side

An undercut adjacent to the edentulous side means no:

circlet

For adjusting retentive clasps as a general rule, at the tine of insertion _______ retention should be used

slightly less than maximum

Only the _____ should be used when adjusting a half round cast circumferential clasp

139 plier

Only the 139 plier should be used when adjusting:

half round cast circumferential clasp

Clasps should be adjusted in:

small increments

Excessive bending of a clasp in one direction only will lead to:

accelerated fatigue and failure of the clasp

The surveyor is used for: a) undercuts b) interferences c) path of draw d) all of the above

d) all of the above

If there isn't alot of inter arch space, what material should be used for the denture base?

metal

Metal bases can not be relined so they are generally not used for:

tooth-tissue borne RPDs or in areas where teeth have been removed in 12 months

Why are metal bases not used for teeth have been removed within twelve months?

resorption will still be occurring at an increased rate, and relining will usually ve required

T/F: All distal extension cases require clinical remount. All class III might require clinical remount

First true; second false

All ______ cases require a clinical remount

distal extension

All _____ supported RPDs will require clinical remounting

tooth-tissue

Which of the following will require a remount: a) Class III tooth supported b) Class I tissue supported c) Class II tissue supported

b & c

Chromium-cobalt shrinks:

2.2-2.4%

What metal is used at UMKC?

Co-Cr

Why is Co-Cr used more than Ni-Cr:

Due to nickel allergy

Possibly causes of failure of chromium-cobalt alloys include:

1. cold-working 2. shrinkage-porosity 3. low percent elongation 4. excessive carbon in the alloy

Cause of a chromium cobalt failure that reduces the percentage of elongation that causes a decrease in hardness:

cold-working

Cause of a chromium cobalt failure due to the alloys shrinking approximately 2.3% resulting in porosity:

Shrinkage porosity

Cause of a chromium cobalt failure directly related to greater brittleness:

Low percentage elongation

Cause of chromium cobalt failure that involves reactions with other constituents to form carbides:

Excessive carbon in the alloy

Which occurs last? a) altered cast technique b) CR record c) framework made d) rest created

a) altered cast technique

Put the following in order: -create rests -framework try-in -altered cast -CR record

1. Framework try-in 2. Create rests 3. CR record 4. Altered cast

What is the purpose of an altered cast impression?

To capture an accurate relation between the teeth, framework & residual ridge (in distal extension cases)

What do you need for a clinical remount?

Interocclusal record (jaw relation)

Clinical remounting procedure:

1. facebow preservation 2. pickup impression 3. block out undercuts 4. remount cast and interocclusal record 5. articulate

Describe a pickup impression (used in clinical remount)

when you insert an RPD in the mouth and take an impression, so that the impression picks up the RPD and shows where the teeth are

Which of the following is NOT an advantage of chromium-cobalt alloys? a) low density (weight) b) high modulus of elasticity (stiffness) c) low material cost d) resistance to tarnish e) increased flexibility

e) increased flexibility - we want rigid not flexible

Necessary to ensure that the partial denture functions as one unit:

Rigidity

If the denture flexes, _____ & ____ can be compromised

cross arch stabilization & stress distribution

A major connector can be made more rigid by:

using a more rigid alloy (chromium-cobalt = most rigid)

Chromium-cobalt alloys are _____ in comparison to gold or palladium alloys

more rigid

Chromium-cobalt alloys stiffness can be overcome by including:

wrought-wire retentive elements in their framework

____ alloys are approximately twice as flexible as _____ alloys

gold alloys; chromium-cobalt alloys (PTQ)

Kellys combination syndrome would present as:

Lack of osseous tissue in the anterior maxilla

What does NOT describe Kelly Combination syndrome? -lack of osseous tissue in the anterior maxilla -loose tissue in the posterior maxilla -intrusion of the mandibular anteriors -cystic palatine nerve

Loose tissue in the posterior maxilla

T/F: Guide plane should be 1/2 distance between cusp tips. Guide plane is as wide as rest

True; True

How wide should the guide plane be?

-as wide as the widest portion of the occlusal rest -1/3 the BL width of the tootg -1/2 distance between the cusp tips

With a guide plane, the normal tooth contour should be maintained:

T/F: Gingival margin to superior border of lingual bar is 3-4mm. Measure the distance on the cast, not on the mouth.

First statement true; second false- measure the gingival margin to superior border of lingual bar in the mouth

Beaded border depth:

1mm deep; 1.5mm wide

a prepared groove on the master cast along the designated borders of maxillary major connectors:

bead

What is the purpose of a bead?

1. increased rigidity 2. guide for finishing 3. compensates for casting inaccuracies 4. displaces soft tissue, preventing food/air/fluid collection

What is the PRIMARY action of a bead?

displaces soft tissue, preventing food/air/fluid collection

Describe the dimensions of a beaded border:

using 1/2 round bur- 1mm deep and 1.5 mm wide; feathers out to noting 6mm from the free gingival margin; shallower over the mid-palatal suture

If you have a large inoperable torus, you need to use:

horseshoe

If you have a very high palatal vault, you need to use:

horseshoe

I-bar with distal extension does not use:

DF undercut (it does use MF and mid-F)

Papillary hyperplasia is all except:

destructive bone disease

Papillary hyperplasia is a form of:

denture stomatitis

Where is papillary hyperplasia found at?

Palatal vault

Causes of papillary hyperplasia include:

1. local irritation 2. poor fitting denture 3. poor oral hygeine 4. leaving dentures in 24 hours a day

Treatment of papillary hyperplasia includes:

1. educate patient on oral hygeine 2. advise patient to leave denture out at night 3. soak denture for 30 min in 1% sodium hypochlorite & rinse thoroughly 4. use tissue conditioner 5. patient should brush irritated area lightly with a soft brush

T/F: A cingulum rest is placed between the incisal & middle 1/3 of incisors

False- near cervical end for maxillary anterior teeth

Indications for lingual rest seats include:

1. primarily maxillary canines- not incisors 2. canines with gradual lingual slope

____ transmits the forces along the long-axis of the tooth; prevents migration

Positive rest seat

A positive rest for a cingulum rest is used because:

it prevents lateral movement

A positive rest for a cingulum rest directs forces:

toward long axis of tooth

A surveyed crown is indicated when: a) the survey line is in the gingival 1/3 b) no undercuts exist on abutment teeth c) with the help of enameloplasty, one cannot have the changes necessary for the abutment teeth without cutting into the dentin d) all of the above are true

d) all of the above are true

Indirect retainers have all of the following characteristics except:

Its a DO rest on a posterior abutment (we want as far forward as possible so use an MO)

Hyperplastic tissue should be removed prior to construction of your RPD to:

provide a firm, stable base for the denture

Before construction of a CD or RPD, it is very important to:

surgically remove the hyperplastic tissue

The best impression technique for a patient with loose hyperplastic tissue is to: