MOUTH PREP FOR RPD PART 1 - ABUTMENT TOOTH MODS

What are the 6 steps of RPD treatment in clinic?

1. Collection of diagnostic data and development of treatment plan

2. Disease control (stage 1): includes endo, extractions, caries removal, perio, tx.

3. Correction of disrupted occlusal condition, occlusal equilibrium, and plane

4. Pre prosthetic surgery (hard and soft tissue)

5. Fixed posthodontic restoration

6. Starting RPD construction

What is the best option to establish occlusal plane?

Orthotodontics

How to establish occlusal plane when tooth is supraerupted less than 2mm?

Enameloplasty - diamond/finishing carbide burs

How to establish occlusal plane when tooth is supraerupted greater than 2mm? (3)

Reduce Dentin + Restoration

Reduce Dentin + Crown

Reduce Dentin + Endo + Post + Crown

How to establish occlusal plane when there is dental and bone extrusion/dentoalveolar compensation? (2)

Bone block lifting / Crown Lengthening + reduction + endo + crown

Tooth extraction

What must be established before fixed procedures start?

Why?

RPD design

Crowns can be used at abutment with the correct location of the survey line and rest seats

What must be completed before RPD construction?

All fixed procedures

What are the 8 clinical steps for RPD Fabrication?

1. Inital exam and diagnostic impressions

2. Diagnostic MMRR —> Design

3. Teeth modification and master impression

4. Framework try in

5. Definitive MMRR

6. Teeth setup and wax tryin

7. RPD delivery

8. Post Insertion care

Abutment tooth mods aim to create what?

How?

ideal abutment teeth contour for an RPD components

through Enameloplasty

Clasp Assembly:

___ directs forces to long axis

Retentive arm - what part must be cervical to survey line?

Reciprocal arm is where?

Proximal plate is where?

Rests

Terminus

Occlusal to survey line

Occlusal to survey line

What are the four types of tooth mods and how?

Proximal plate - guide planes

Retentive arm - change survey line location

Reciprocal arm - change survey line location

Rest - Prep rest seat

Indications for Tooth Modifications:

Inadequate tooth _________ for RPD ______

Adequate _______ thickness to complete modification in ______

Tooth does not have ______ ______ present

Contour - retainer

enamel - enamel

extensive restoration

What can be considered for a tooth with extensive restorations that needs a tooth modification?

Surveyed crown

Step by Step Sequence of tooth mods? (3)

1. Survey Cast and select the optimal path of insertion.

2. Make teeth modification chart list.

3. With diagnostic cast as a guide, complete teeth modifications

What are the 3 steps of complete teeth modifications?

1. Prepare guide planes on proximal and lingual surfaces

2. Change the survey line.

3. Rest seat preperation

Guide planes are prepped on what surfaces?

Proximal and lingual

Guide planes are on ___ or _____ surfaces of teeth that are parallel to _____ and to the ______ of ______ and ______

Proximal or lingual

Eachother - path of insertion and removal

What is the flat rigid component of the RPD and what does it ensure?

Proximal plate and bracing element

one path of insertion.

Guiding planes ensure what?

That the RPD seats along a single path of insertion

T or F:

It is mandatory to use guiding plates on as many teeth as possible?

Guiding plates are most effective when used on many teeth?

F

T

Guide planes are more effective when:

They are ______

More than one common _____ surface

Directly opposed by what?

Placed on _____ teeth

Cover a _____ surface area

Parallel

Axial (proximal and lingual)

Another guide plane

Many

large (more effective but not always applied due to biomechanics)

Sometimes guide planes are prepared for eliminating what?

interferences

What should be brought chairside when prepping tooth mods?

surveyed tripoded cast + surveyor

When prepping guide planes, the bur should be placed at the same angle as what?

Analyzing rod -> parallel to path of insertion

T or F: Guide planes should follow the curvature of the tooth BL when viewed from the top?

T

T or F: Guide planes should follow the curvature of the tooth in the occlusal-gingival dimension?

F -> they are flat in this dimension

Proximal BL guiding planes in the posterior should not cross what?

Line angles to facial and lingual surfaces

Proximal BL guiding planes in the anterior:

Should be ______ guide plate

Minimal to no modifications to the _________

______ with natural tooth structure

Wraps to where?

Short

Proximal contact

Blends

Lingual surface

Proximal Guide plate mods should be how big in the OG dimension for distal extension cases?

Where?

1.5-2 mm (<2mm) - occlusal third

In distal extension cases, reduced height results in _______ contact with the _______ and permits greater freedom of ________ for the removable partial denture. Hence, potentially damaging forces are ______.

decreased

minor connector

movement

minimized

Proximal guide planes can be ______ bounded or ______ _____ area

tooth bounded or tooth supported area

Proximal Guide plate mods should be how big in the OG dimension for tooth bounded/supported?

Why?

2-4mm

Provides more retention and a single path of insertion

Lingual guiding plates dimension?

Where?

2-4mm

Middle third

The retentive tip of the direct retainer is located in the undercut and is ______ (______ to the survery line)

Where are the rigid portions of the clasp?

flexible (cervical)

Above the undercut (occlusal to survery line)

Lowering the Survey Line is useful when what? (2)

High survey line

Suprabulge clasps needed

Lowering the survey line can be used to eliminate ______ in areas where rigid elements are placed

Interference (occlusion)

How can lowering the survey line improve esthetics?

Allows the retentive arm to be placed more gingival to reduce clasp display

Maxillary teeth are often tipped which way?

Mandibular?

Facially

Lingually

Raising the survey line does what?

When do we do it? (2)

Creates an undercut

When there is no retentive undercut or undercut is too far gingival

Raising the survey line is only feasible when what?

Axial surface is parallel to path of insertion

How to raise the survey line:

prep _____ undercut

___mm from where?

What bur?

Ovoid

1 - gingival margin

Round bur