RDP's Flashcards
What must a Kennedy Class IV Prosthesis provide for>
- Must be regarded as a Class I denture in reverse (especially if long edentulous span)
- Forces of rotation around anterior abutment teeth
- Indirect retention must be obtained posterior to the fulcrum line
What are some Advantages/Indications of Implant Assistance in RDPs?
- Distal extension support
- Reduced bone resorption
- Elimination of unesthetic retentive elements
- Decreased stress on abutments
- Improved comfort and patient satisfaction
What increases the effectiveness of Indirect Retainers?
- Needs definitive rest seat
- Distance from fulcrum line
- Major and minor connector rigidity
For an RPI, the superior edge of the proximal plate contacts _____ mm of the inferior portion of the guiding plane (junction of occlusal and middle 1/3)
1 mm
What mandibular major connectors are these?
- Labial bar
- Lingual bar
Where are forces applied to a Mucosa borne RDP?
Forces are applied to tissue only
Describe a Kennedy Class I…
Bilateral Edentulous areas located posterior to the remaining natural teeth
What are some Disadvantages of a Rotational Path RDP?
- Adjustment of rigid retentive component difficult
- Less tolerance for error
- Requires well prepared rest seats
What is the minimum space required for a lingual bar?
- 8 (7) mm from the gingival margin to the floor of the mouth
- 3 mm from free gingival margin to superior border of the bar
- The bar should at least 5 (4) mm in height
What are the 3 Biomechanical Classications for RDPs?
- Tooth borne
- Tooth-mucosa borne
- Mucosa borne
Describe the McDermott Classification…
- A modification of the Kennedy Classification
- Indicates arch configuration, and natural tooth abutment location
What do implants help do in regards to stress on abutments?
Decreases Stress on Abutments
What are some Advantages of a Swing Lock RDP?
- Relatively inexpensive method of utilizing remaining dentition
- Simple
Where surface is the Modified T-Bar placed undercut wise?
Distofacial Undercut
What is this called?
Krol
What are 4 indications for a Swing Lock RDP?
- Too few teeth for conventional RDP design
- Remaining tooth mobility
- Position not favorable for conventional design
- Maxillofacial applications
What Kennedy Classification is the altered cast technique used for?
Class I and II RDPs
Define Minor Connector…
“The connecting link between the maor connector or base of a RDP and the other units of the prosthesis, such as the clasp assembly, indirect retainers, occlusal ressts, or cingulum rests.”
What are 3 RDP Design Philosophy’s?
- Stress Equalization
- Physiologic Basing
- Broad Stress Distribution
What 2 functions must a Minor Connector provide?
- Must be rigid
- Transfer functional stress to teeth and ridge
What are some uses of a Surveyor?
- Survey of diagnostic and master casts (locate and measure undercuts for fixed and removable prostheses)
- Create measurable contours in wax patterns for fixed prostheses
- Aid in placement of precision attachments for fixed and removable prostheses
What Kennedy Classes are Twin Flex designs indicated for?
Kennedy Class 3 and 4
Describe the prep for an Occlusal Rest…
- Triangular and concave
- Rounded apex
- Shold follow the fossa outline
- Inclined towards the center of the tooth
- Should allow for minimum 1.0 mm metal thickness
What are the third 3 Indications for RDPs?
- Patient desires removable prosthesis
- High caries index
- Obturation of palatal defect
Where are mesial torqueing and axial forces directed on a RPI:Krol setup?
What is the abutment tooth braced by?
- Mesial torqueing and axial forces directed through mesial rest
- Abutment tooth is braced by the mesial adjacent tooth
What is this a picture of?
Distal Extension Support
What are 5 Advangages of using an I-Bar?
- Exact placement of retention contact
- Minimal interference with natural tooth contour
- Maximum natural cleansing action
- Passive functional movement of an extension prosthesis
- Reduced metal display, better esthetics
Pictures for Review…
Describe Kennedy Class III Edentulism…
Unilateral edentuous area with natural teeth located both anterior and posterior to it
Schneid and Mattie Classifications…
What must a Kennedy Class II Prosthesis provide for?
- Must embody features of both Class I and Class III designs
- The dentulous side (if modification space is present) must be designed as a Class III denture
- The distal extension side must be designed as a Class I denture
What is the undercut measurement for a T-Bar?
.01 inch distal undercut
What kind of clasp is this?
Y Clasp
What are some advantages of a Twin Flex Clasp?
- Esthetic
- Adjustable
- 19 gauge wrought wire
- Soldered in 0.01 undercut
- Encirclement
What are the 3 Pillars for Design Considerations for RDPs?
- Support
- Retention
- Stability
What is a material you could use to help decide the space available for RDP Design Considerations?
Multiple Putty Matrices
Define Major Connector…
“The part of a removable partial denture that joins the components on one side of the arch to those on the opposite side”
What mandibular major connectors are these?
- Lingual plate
- Double lingual bar
Describe a Class II lever system as it relates to RDPs…
What are 5 Advantages of a Rotational Path RDP?
- Minimal # of clasps
- Anterior clasp often eliminated
- Better esthetics
- Less tooth preparation compared to a precision attachment
- May be used in absence of F/L undercut
What are first 3 indications for an RDP?
- Youth or advanced age of patient
- Great length of the edentulous span for FDP
- Excessive alveolar bone loss
Describe a Category 2 Rotational Path RDP…
- Rotational centers are located at the gingival extensions of the rigid retainers
- AP rotation replacing anterior teeth
- Lateral paths of rotation utilizing proximo-facial undercut
What are 4 different types of rests?
- Occlusal rest (proximal, channel)
- Cingulum rest
- Incisal rest
- Lingual rest (resin bonded “Ivanhoe”, dimple
Describe the shape of an Incisal Rest…
- Rounded “V” shaped notch, extends onto facial surface of tooth
What is the recomended impressions material for your RDP master impression?
Irreversible Hydrocolloid
Describe a Cingulum Rest…what shape is it?
Where is it only indicated?
- Chevron (“V”) shaped
- Must be gingival to occlusal contacts
- Only indicated on maxillary cuspids
- Bonded rests
What alternative solution can you do if for any reason you can not do the altered cast technique?
- Complete a reline
- Functional reline (Lynal)
- Selective pressure reline impressions
What are some restorative space considerations when tx planning implants/removable?
Describe Height of Contour…
“A line encircling a toth and designating its greatest circumference at a selected axial position determined by a dental surveyor”
This contour will change position as the cast is tilted on the surveying table
What is the path of insertion governed by?
Minor Connector
What is the Flexibility of Clasp affected by:
- Length
- Taper
- Diameter
- Cross-sectional form
- Material
What are some Circumferential Clasp Design Features?
- Clasp should originate from framework above the heigh of contour
- Retentive tip directed occlusally
- Terminate at line angles
- Retentive arm positioned as far apical as possible
What is an implant design consideration for a Kennedy Class IV design?
- Possible to remove the retentive arm
- Bilateral
- Anterior
When the altered cast procedure is used, the clasp design/tooth mobility…
doesn’t matter
What kind of bar clasp is this?
Modified T-Bar Clasp