RPD - Mouth Preparations (Quiz 4)

1. Periodontally hopeless teeth

2. Residual roots

3. Detrimental to design or RPD

4. Impacted teeth

When considering surgical preparations before a RPD, what are all of the INDICATIONS for extractions?

- Extraction

- Orthodontic correction

- Dentoalvoeolar segment osteotomy

What are 3 treatment options for severely malposed or extruded teeth?

- Enlarged tuberosities

- Bony exostoses or tori

- Displaceable soft tissue

- Muscle attachment and freni

- Bony spindles and knife-edge ridges

- Ridge augmentation

- Implants

Besides teeth, what might also need surgical preparations? (7)

1mm

In designing a maxillary removable partial denture framework for a patient with an enlarged tuberosity, what is the minimum recommended thickness of the metal base to ensure adequate strength and rigidity?

Bony exostoses or tori

What has the following characteristics:

- Thin and friable mucosa

- Interference with path of insertion

- Can compromise the extension of denture components

Displaceable soft tissues

What has the following characteristics:

- Soft flabby ridges

- Folds of redundant tissue

- Surgical stent

- Rounded

- Vestibular deepening

During surgical preparation for a removable prosthesis, what is the recommended management for bony spines and knife-edge ridges?

Overdenture abutments

In surgical preparation for prosthetic treatment, implants are often placed to support what?

Periodontal preparation

All of the following is all apart of ____________ for RPD:

- Periodontal disease and plaque control (home care instructions, recall, perio tx)

- Insufficient attached gingiva (resistance of periodontium)

- Suprabony gingival pockets (exposure of more of the clinical crown, inadequate crown:root ratio)

Occlusal plane modification

What procedure is used to correct minor occlusal discrepancies before removable partial denture fabrication?

- Enameloplasty

- Survey crown

What are two treatment options for the corrections of malposed teeth or teeth with unacceptable contour?

true

T/F: Splinting of natural teeth is indicated when abutment tooth's bony support is not significantly compromised

- Fixed splinting with surveyed crowns

- Cast restorations

- Swing lock RPD or multiple rests

What are three methods of splinting natural teeth for RPD support?

Exposure of dentin and therefore increase...

- Sensitivity

- Caries susceptibility

what things should you be cautious of when preparing teeth for abutment?

- Acceptable path of insertion

- Esthetics

- Comfort

- Retention

- Stability

- Support

What are the six objectives of abutment preparation?

1. Guiding plane

2. Height of contour adjustments

3. Retentive grooves or depressions

4. Rest seats

What is the sequence for the types of abutment preparations?

Guiding planes

Define the following:

Tooth surfaces where minor connectors or guide plates will be placed

- w/ cylindrical diamond bur

- rounded smooth edges (in harmony with existing tooth contour)

- no undercuts

- faciolingually: proximal surface

How should guiding planes be prepared?

- Occlusal 1/3-2/3 (Height: 2-4mm)

- Flat

What are the occlusogingival guiding plane preparation height measurements?

middle 1/3 of the clinical crown

Where should the guiding planes be placed on the lingual surface of the tooth?

2-4mm

For the guiding planes on the lingual surfaces for reciprocating arms, the occlusogingival height should be ____-____mm

anterior

Purpose of establishing guiding planes on ______ teeth:

- To establish normal width

- To reduce unsightly spaces between tipped tooth and RPD

tapered diamonds burs

HOC adjustments permits circumferential clasp location above the HOC. What burs do we use for this?

To allow better adaptation and path of insertion for the prosthesis

During height of contour adjustment, what is the main purpose of eliminating sharp facioproximal and linguoproximal line angles?

- Mesiobuccal of upper molars

- Distobuccal of premolars

- Mesiolingual of lower molars

What are 3 very common locations that receive adjustments of height of contour?

0.03"

when adjusting the height of contour, you are limited by the thickness of the enamel and should NOT make more than a ______ reduction

retentive groove or depression

ID the abutment preparation:

- Increase depth of undercut

- Proportional to retention required

- Tapered diamonds

3mm

What is the occlusogingival height of a retentive groove preparation?

4mm

What is the mesiodistal length of a retentive groove preparation?

0.01" (or 0.25mm)

What is the depth of a retentive groove preparation?

gingival margin

Additional retentive groove preparations should be parallel to the ____________ & gently sloping contoured depression (no sharply defined dimple or pit

#4 round bur

What bur is used to make a retentive groove preparation for the dimple of the I-bar?

Gentle depression on the facial surface with smooth contour (retentive clasps cannot flex into and out of deep indentations)

When preparing a retentive groove on an abutment tooth for an RPD clasp, what should the ideal contour be?

A. Line angle area

In abutment preparation, retentive grooves are typically placed in which area of the tooth?

A. Line angle area

B. Gingival margin

C. Center of the buccal surface

D. Occlusal fossa

1.5mm

For an occlusal rest seat, it should be ___mm deep at the marginal ridge

0.5mm

For an occlusal rest seat, it should be ___mm deeper at the deepest portion than initial 1.5mm

A. Less than

For an occlusal rest seat, the preparation should be ________ 90 degrees:

A. Less than

B. Equal to

C. More than

- #4 or #6 round carbide

- Tapered diamond bur

What bur should we use to prepare an occlusal rest seat?

Round line angle

What type of line angle do rest seats have?

With wax

How do you check the depth and inclination of an abutment preparation?

With fine diamond or green stone and rubber point

How can you finish and polish an abutment preparation?

1.5-2mm

For an embrasure occlusal rest seat, it should be ____-____ mm deep

3-3.5mm

For an embrasure occlusal rest seat, it should be ____-____mm wide

true

T/F: For an embrasure occlusal rest seat, all contours must be gently rounded & NO undercuts

#37 inverted cone bur

What bur can you use to prep the crescent or inverted V-shaped cingulum rest seat?

Round internal line angle

What type of line angle do cingulum rest seats have?

From one marginal ridge to the opposite marginal ridge

In preparing a cingulum rest seat for a maxillary canine, the rest should extend from where to where?

2.5-3mm

for a cingulum rest seat that is crescent or inverted V-shaped, the mesiodistal width should be ____-____mm

1.5mm (should be closer to 1mm)

for a cingulum rest seat that is crescent or inverted V-shaped, the faciolingual width should be ____mm

1.5mm

for a cingulum rest seat that is crescent or inverted V-shaped, the incisogingival depth should be ____mm

path of insertion

for a cingulum rest seat that is Ledge Shaped, the axial wall should be parallel to the ______

1-1.5mm

for a cingulum rest seat that is Ledge Shaped, the gingival floor should be ____-____mm wide

B. Equal to

for a cingulum rest seat that is Ledge Shaped, the prep should be made _____ 90 degrees

A. Less than

B. Equal to

C. More than

Flat end diamond bur or tapered fissure bur

What type of bur should you use for a ledge shaped cingulum rest seat?

junction of middle and gingival 1/3

Where should the small occlusal rest seat preparation for a ball or lug rest seat be made?

#4 or 6 round bur

What type of bur should you use for a ball or lug shaped cingulum rest seat?

Ball or lug rest seat

What type of cingulum rest seat is like a small occlusal rest seat and is a marginal ridge reduction?

- Crescent/V-shaped

- Ledge

- Ball or lug rest seat

What are the 3 kinds of cingulum rest seats discussed in lecture?

survey crown

Define the following:

Crowns that are used as abutments for RPD

survey crown

What has the following characteristics:

- More ideal retentive contour

- Definite guiding plane

- Optimum occlusal rest

- Effective reciprocation

true

t/f: if a rest seat or guiding plane is placed IN the metal survey crown, additional reduction must be made in the preparation

crown ledge or shoulder

In surveryed crowns, ___________ restores the lingual contour and makes a more effective reciprocation

Ledge

What is the arrow pointing to?

- Tripoded path of insertion

- Guiding planes

- Undercut

- Rest seat

Before trying in a surveyed crown, what features must be verified on the master cast to ensure proper RPD design?

- Recontouring

- Polishing

- Ensure 0.01" undercut

What are three modifications for surveyed crowns?