RPD Test1 Flashcards
3 types of RPD’s:
Tooth borne
Tooth-mucosa borne
Implant-assisted
Clasp-Retained RPD’s: Resistance to vertical dislodging forces:
Resistance to lateral, torsional, horizontal forces:
Resistance to vertical seating forces:
Retention
Stability (Bracing)
Support
A tooth, a portion of a tooth, or that portion of a tooth or of a dental implant that serves to STABILIZE or retain a prosthesis:
Abutment
Any type of device used for the stabilization or retention of a prosthesis:
Retainer
6 advantages of RPD vs FPD:
Abutment teeth may not require restoration (more conservative)
Better OH
Cross-arch stabilization
Reduced Fees
More esthetic (sometimes - if clasps not visible )
Replace bony & soft tissue contours
Implants can be used for Distal Support by placing as posteriorly as possible - this refers to _____ forces
Downward
Support is gained by the most ______ placement possible
Retention is gained by the most ______ placement possible
posterior
anterior
Treatment sequence (4 part):
Examination
Diagnosis
Treatment Plan
Treatment
Hypersensitivity, mobility, and soft tissues are all part of what in the Treatment sequence?
Examination
T/F
Examination phase includes radiographs
True
4 things looking for in Radiographic Examination:
Pathology
Caries
Quantity of bone
Quality of bone
In the Diagnosis/Tx planning phases, what 7 things can you do with Mounted Diagnostic Casts:
Preliminary Design
Tx Sequence
Path of Placement
Unfavorable tooth position, contours, inclinations
Embrasure clearance
Occlusion/articulation
Interarch distance
The component of a RPD used to retain and prevent dislodgment - consists of clasp assembly or precision attachment
Direct Retainer
What partially encompasses or contacts the abutment tooth - acts as a direct retainer?
Clasp Assembly
What portion of the Clasp Assembly in stabilizing and retaining the RPD
Clasp
What are the 3 parts of a Clasp Assembly?
Rest
Retention
Reciprocation
(latter 2 are the Clasp)
Plates or Bars - connects one side to the other
Smaller portion connects to clasps or rests:
Major Connector
Minor Connector
RPD component functioning through a lever action:
Indirect Retainer
What area of an RPD connects the resin base and can be open lattice or mesh:
Plastic retention (Denture base) area
Most posterior portion of an open lattice w/ no posterior teeth in an RPD
Tissue stop
The location of the Fulcrum Line is criteria for selection of the Maxillary Major Connector
True
Maxillary Major Connector has to be ___mm from gingival margins
If less, use what type of design?
6mm
Plate type design
The Maxillary Major connector’s anterior borders must follow what?
The posterior borders end where?
Valleys of Rugae
Hard palate - do NOT extend onto soft palate
What type of Maxillary Major connector is used with questionable teeth?
Plate type design
5 types of Maxillary Major Connectors:
Anterior palatal strap
Posterior palatal strap
Ateroposterior palatal strap
Modified palatal plate
Complete palatal plate
Location of edentulous area, functional depth of lingual vestibule, anticipated loss of natural teeth, inclination of remaining teeth - all are criteria selection for what?
Mandibular Major Connector
How deep does the Lingual Vestibule need to be for a Mandibular Major Connector?
7mm
3mm from tooth, 4mm of connector
If 3mm from gingival margins cannot be obtained for a Mandibular Major Connector (for total of 7mm), what type of designs should be used?
Plate type designs
Metal of the surface of ______ is highly polished
on _____ isn’ t highly polished
Mandibular Major Connector
Maxillary
The portion of a dental prosthesis (RPD) that is reduced to eliminate excessive pressure:
Relief Area
Name 2 types of RPD:
Tooth borne
Tooth-mucosa borne
4 types of Mandibular Major Connectors:
Lingual bar
Sublingual bar
Lingual plate
Labial bar
2 requirements for a Minor Connector:
Rigid
Max exposure (must not impinge on marginal gingival tissues)
How thick should the Minor Connector-Rest Junction be?
1.5mm
The Minor Connector should be located __mm from other vertical components
5mm
4 components of a Clasp Assembly:
Clasp
Reciprocal Clasp
Cingulum
Rest
Minor connector
3 types of Rests:
Cingulum
Incisal
Occlusal
2 components of a Clasp:
Retentive component
Bracing (stabilizing) component
What side of the Clasp engages the Undercut?
What side doesn’t?
Retentive
Bracing
T/F
Encirclement (180 at least) and Passivity are requirements of Clasps
True
3 Clasp Categories:
Suprabulge - cast circumferential
Infrabulge - cast bar
Combo
3 types of Suprabulge (circumferential) Clasps:
Cast circlet (Akers)
Embrasure
RPC (RPA)
2 types of Bar (Infrabulge) clasps:
RII
RPI
T/F
Rests are a type of Indirect Retainer
True
3 types of Indirect Retainers:
Rests
Minor connectors/proximal plates
Lingual plate major connector
If you have a Clasp, you need a _____
Rest
T/F
RPD clasp needs a rest otherwise would move in a cervical direction and cause trauma
True
A Rest directs forces where?
Long axis of tooth
Rest dimension should be ____ faciolingual width of tooth
Marginal ridge reduced ___ mm
(__mm if using Gold)
1/3
- 5 mm
- 0 mm
The angle of the minor connector and the rest should be ____
less than 90 degrees
2 adjacent occlusal rest seats form what?
Embrasure clasps
What type of Rest Seat is saddle shaped, has a potentially objectionable metal display, and has greater mechanical advantage than lingual rest seats?
Incisal rest seats
Type of rest seat w/ inverted U/V that may require use of restoration to establish
Cingulum
What Rest seat is placed in the mesial or distal half o fthe tooth at the junction of the middle and gingival one third?
Ball
Rest Seat prep sequence:
Guiding plane
Rest seat
smooth/polish
2 types of denture bases that contact mucosa:
Resin on metal
metal
What type of RPD has an internal finish line of the metal component?
Maxillary (tooth or tooth-mucosa borne)
If Internal/External finish line, External should be ____
Internal should be ____
less than 90 degrees
90 degrees
T/F
Use a metal denture base for max strength and when relining is not anticipated
True
T/F
A surveyor can be used to evaluate esthetics
True
T/F
The height of contour and the survey line are the same
False
*different if tilt
T/F
RPD should help to eliminate oral disease, preserve what remains, restore function and esthetics and not interfere with patients speech
True
What teeth are lost first?
Which tend to be last?
Posteriors
Mandibular anteriors
Resistance to removal from the tissues or teeth
Retention
Resistance to movement in a horizontal direction
Stability
Resistance to movement towards the tissues or teeth
Support
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
Angle viewed between a vertical rod contacting an abutment tooth and the axial surface of the abutment cervical to the height of contour
Angle of Cervical Convergence
A Palatal Major Connector is greater than ____mm in width
Palatal Bar is less than __mm in width
8mm
8mm
Vertically parallel surfaces of abutment teeth shaped to direct a prosthesis during placement/removal
Guiding Planes
Functional Impression vs. Static Form
Harder vs softer matl.
*records in function vs. not supporting a functional load
Simultaneous contact of both maxillary and mandibular teeth
Balanced Occlusion
Dynamic registration of opposing dentition
Functional Occlusal Registration
More than relining - replacement of the entire denture base w/o changing occlusion
Rebasing
Resurfacing of denture base with new matl to make it fit the underlying tissue more accurately
Relining
RPD component used to retain or prevent dislodgment (consists of clasp assembly or precision attachment)
Direct Retainer
RPD part that assists in preventing vertical displacement of distal extension via lever over fulcrum
Indirect Retainer
Clasp Assemblies partially encompass of contact the ______
Abutment
2 types of clasp arms that terminate in the undercut
Bar Clasp (comes off denture framework)
Circumferential
Clasp arms operate by friction
False
Resists movement away from tissue:
Resists lateral movement:
Resists movement toward tissue:
Retention
Stability
Support
4 Tx objectives for RPD’s
Eliminate disease
Preserve remaining teeth and supporting structures
Restore/improve mastication esthetics and phonetics
Restore health, comfort, quality of life
5 phases of the Problem List
Urgent
Control
Re-evaluation
Definitive
Maintenance
Major connectors must be ______
Rigid
3 Functions of the Major Connector:
Unification
Stress Distribution
Cross-Arch Stabilization (Counterleverage)
T/F
Major connectors should be placed as far from the FGM as possible and practical
True
What 2 soft tissue areas are of utmost concern when designing a Major Connector
Moveable part of Mx Soft Palate
Mb lingual frenum
Major connectors in the upper arch should terminate ___mm or more from the gingival crest tissues
6mm
What Maxillary design is circular and especially useful in cases with a torus
Anterior-Posterior Palatal Strap
*If less than 8mm, Palatal Bar
3 cases to use a Full Palatal Plate:
Long distal extension
6 or less Ant. teeth
Primary abutments periodontically involved
When to use a Palatal Bar?
When no other option viable
*usually too much bulk
What type of connector is poor from a biomechanical standpoint and shouldn’t be used unless absolutely necessary?
*Tori prevents use of other connectors
Palatal Horseshoe Plate
Maxillary Major connectors should be how far away from the FGM?
Mandibular Major connectors should be how far away from the FGM?
If this distance isn’t possible in either arch, where should the border of the connector be?
6 mm
3 mm
On teeth
The most commonly used Mandibular Major Connector:
Lingual bar
A Lingual Bar (Mandibular) requires a vestibule how deep?
Flat on the tissue side, ____ on the tongue
Occluso-gingival width of ____to____ mm
Thickness of ____to_____mm
7-8 mm or more
convex
4 - 6 mm
1.5 - 2 mm
A Lingual Bar with extension over the cingula of Anterior Teeth:
- most often used when there is less than 3mm from the FGM
- can be contraindicated by mobile teeth (perio)
Lingual Plate
Lingual bar + secondary bar on cingula (mandibular):
*not recommended
Continuous Bar Retainer (Kennedy Bar, Double Lingual Bar)
T/F
Indications for a Mandibular Labial Bar are extremely rare and may include severe lingual inclination of the teeth
True
2 Types of gridwork minor connectors connecting denture base and teeth to the major connectors:
Open Lattice - can interfere if too thick
Mesh - less retention of acrylic
Relief under the Gridwork should start how far away from the tooth?
*metal wears less, better hygiene next to tooth
1.5 - 2 mm
Junction of Gridwork to major connector is a Butt joint with relief so must be at what angle?
Acute
Mandibular Gridwork should extend ____ the way from abutment to the retromolar pad
It should NOT extend where?
2/3
Ascending portion of the pad
Maxillary gridwork extension to Hamular notch:
2/3
Major connector should be at least __mm away from imaginary line of teeth
2mm
T/F
A tissue stop is an extension of metal through the framework contacting the ridge
True
What contacts guide planes (a type of minor connector)?
Proximal Plates
T/F
Guide plates can’t be in undercut so wax is used to create zero degree blockout
True
4 parts, extra-coronal direct retainer:
retentive arm
reciprocal (bracing) arm
rest
minor connector
T/F
Retention should be uniform (undercuts should be the same measurement e.g. 0.1)
True
T/F
The clasp arm engaging the undercut should be flexible
True f
What type of clasp is used for Kennedy Class III’s?
Cast Circumferential (Circlet/Akers)
Wha is the clasp of choice in tooth-borne cases?
Cast Circumferential (Circlet/Akers)
Cast Circumferential has a ______-bulge bracing (reciprocal) arm that is thicker and located in the _____ 1/3 of the tooth
the _____-bulge retentive arm is in the ____ 1/3 of the tooth
Suprabulge, Middle 1/3
Infrabulge, Gingival 1/3
A double Akers Clasp, aka…
Embrasure Clasp
3 Stress-Releasing clasp assemblies for Class I and II RPD’s
RPI (bar clasp w/ mesial rest)
RPA
Combo
Rests should be in contact with the adjacent teeth
False
The proximal plate in an I-bar construction should be ___mm thick
(the I-bar itself comes off of the gridwork)
1 mm
A combination clasp has what shape wire?
Round (flexible)
Cast Circumferential clasps are used for every class except?
Indirect Retainers are used for every Class except?
Class I
Class III
Indirect Retainers should be placed where?
As far as possible from distal extension base
BUT, incisors often not strong enough, so furthest Canine/Premolar
T/F
Indirect retainers are auxiliary cingulum rests or occlusal rests, not bar retainers or lingual plates
True
The struts of an Open Lattice in the Mb and Mx are _____ wide (the struts themselves)
The distance between struts is 5-7 mm for premolars and ____ for molars (Mb and Mx)
1.5-2.0 mm
7-10 mm
T/F
The Flange should generally be shortened rather than extended to adapt mucosa
True
T/F
Denture bases should have internal/external finish lines that do not coincide and are acute
The external metal finish line should end 2mm lingual to replacement teeth
True
True
Occlusal rests for molars and Mx premolars are ____ the facio-lingual tooth width or ___ the inter-cusp width.
____ the mesio-distal tooth length
1/3
1/2
1/4-1/3
The marginal ridge must be lowered ___to ____ mm to allow sufficient bulk of metal
1 to 1.5 mm
Deepest occlusal portion of a rest should be ____ mm and angle of rest should be ACUTE
1.5 mm
A positive rest seat is _____
If not positive work is done by ______
Acute
Incline Plane
If a rest is prepared next to an existing tooth the seat is flared which direction?
Lingually
*don’t want to impinge marginal ridge
Embrasure occlusal rests have additional marginal ridge reduction to ______
1.5 mm
Lingual rest seats (cingulum) are used for what 2 situations?
No posterior teeth available
Indirect retention
Cingulum rests are an inverted V or U and broadest in the middle, measuring ____ mm F/L in a Positive Rest Seat
M/D length is ____
1 mm
2.5 - 3 mm
A guide plane in Tooth Supported Segments should be ___ to ___ mm in height
in Distal Extension should be __ to ___ mm in height
2 to 4 mm
1.5 to 2.0 mm
What RPD is tooth borne with little, if any, soft tissue support?
Class III
T/F
Class III RPD’s generally do not rotate and no compensation for rotational forces is needed
True
T/F
Class III RPD’s preferred base is acrylic b/c relining an issue
False
*metal preferred, lining not an issue b/c tooth-borne
T/F
Three is a Fulcrum Line in Class III RPD’s
False
T/F
The indirect retention in a Class IV is posterior
True
T/F
Use a cutting tool to construct guide planes on proximal surfaces using Surveyor
True
3 planes of rotation:
Sagittal
Horizontal
Frontal
What Classes are partially tooth and partially tissue supported?
I, II, and IV
T/F
Soft tissue is 250x more depressable than hard tissue
True
1st class Lever like a:
2nd class:
3rd class:
teeter totter
wheel barrow (fulcrum at wheel)
fishing rod (fulcrum at hand)
Distal extension RPD has distal rest on distal abutment, what Class Lever is created?
Class I (Pry bar effect extracts tooth)
Retainer at junction of middle/cervical 1/3’s
What 6 Methods can decrease the effect of Class I Lever acting on a distal extension RPD?
Retention/Retainer
RPI/RPA retainer
Wire clasps
Extended Soft Tissue Bases
Indirect Retainers
Make sure occlusal forces directed in long axis
Maxillary Major connector provides ______ and is Polished
Mandibular Major connector doesn’t provide _____ and is NOT polished
Support
Support
In Hernandez review, anything beyond ___mm is more of a Plate than a Strap
12 mm
*but actually 8, no?
Polish what surface of a Mandibular Bar?
Intaglio
What is the ideal undercut for a Rigid Component?
.010
180 circumference, Retention, Bracing, Support, Reciprocation, Encirclement, Passivity are all requirements of what?
Clasp
A complete circle flexes in what direction?
Wrought wire semi circle flexes in how many directions?
all
2
3 types of Suprabulge clasps:
Cast circlet (Akers)
Embrasure
RPC (RPA)
Rest seat prep sequence:
3 steps
Guide planes
Rest seats
polish
A Mesial rest disengages ____ and _____
apically
mesially
An I-bar should be placed where buccally?
mid to mesial
When would you NOT use a positive rest?
Wrought wire clasp
*Flat pulpal floor, circumferential wire around tooth
A cingulum rest should be positive
True
4 types of rests:
Occlusal
Incisal
Cingulum
Ball
