D R L AY L A A B U - NA B A’A . P H D, B D S , M F D RC S I

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Introduction to Removable Prosthodontics II

OBJECTIVES2

At the end of this lecture you will be able to:

1. Define the Key Terms.

2. Explain the indications and contra indications for removable prostheses.

3. List treatment options for partially edentulous patients

4. List types of removable partial dentures.

5. List basic components of a partial dentures.

6. Overview clinical steps.

Dr Abu-Naba'a 2010

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Defining Prosthodontics

Dr Abu-Naba'a 2010

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Prosthodontics

pros·tho·don·tics \pro s´tha-do n´ti ks\ n, pl but sing or pl in constr (1947):

dental specialty pertaining to the diagnosis,

treatment planning,

rehabilitation and

maintenance of the oral function,

comfort,

appearance and

health of patients

GPT

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Prosthodontics

with clinical conditions associated with

missing or

deficient teeth and/or

maxillofacial tissues

using biocompatible substitutes

GPT

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Prosthesis

pros·the·sis \pro s-th ´si s\ n, pl–ses (1900)

1: an artificial replacement of an absent part of the human body

2: a therapeutic device to improve or alter function

3: a device used to aid in accomplishing a desired surgical result

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Dr Abu-Naba'a 2010

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Sub Divisions of the specialty

Prosthodontics

IMPLANTMAXILLOFACIALFIXEDREMOVABLE

Removable DENTURE Prosthesis

any dental prosthesis that can be readily inserted and removed by the patient.

Dr Abu-Naba'a 2010

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Removable Partial prosthesis

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Maxillofacial Prosthesis

Needed

After trauma

Surgical defects

Birth defects

Fixed Dental Prosthesis

any dental prosthesis that is

luted,

screwed or

mechanically attached

or otherwise securely retained

to natural teeth, roots, and/or dental implant abutments.

Dr Abu-Naba'a 2010

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Implant Prosthodontics

the phase of prosthodontics concerning the replacement of missing teeth and/or associated structures by restorations that are attached to dental implants

Dr Abu-Naba'a 2010

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Removable

Complete Dentures

Removable Partial

Dentures

- Conventional

- Attachment

Maxillofacial

Congenital Conditions

Cleft palate

Acquired Conditions

- Injuries

- Cancer

Facial & Intraoral

Prostheses

Can be Supported by

Ridge , teeth or Implants

Fixed

Crowns, Onlays

Fixed Partial

Dentures

(Bridges)

Fixed complete

dentures

Sub Divisions of the Prosthesis

Dental Implant

a prosthetic device or substance that is placed into or/and upon the jaw bone to support a fixed or removable dental prosthesis

Most used is the osseointegrated implant

Dr Abu-Naba'a 2010

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Can be Supported by ,

teeth or Implants

RPD Terminology

Temporary RPDs:They are interim, transitional and

treatment RPDs mainly made from acrylic resin.

•Interrim

•Transitional

•Therapeutic

Definitive RPDs: Final and lasting RPDs that is

made mainly from Co-Cr alloy.

Types of RPD’s

Interim Definitive (permanent?)

RPD Terminology20

Bounded saddle RPD. Tooth born support.

Free end saddle RPD, Tooth-mucosa supported

Transitional RPD, Tissue supported RPD

Copyright © 2006 Thomson Delmar Learning. ALL

RIGHTS RESERVED.

-Abutment teeth border all edentulous areas

-Functional forces are transmitted through

abutment teeth to bone

Kennedy CL III, IV

Tooth borne (dento-alveolar support)

Supporting structures

Tooth

Periodontal ligaments

Alveolar bone

--Distal extension & anterior extension RPDs

--Functional forces are transmitted through

abutment teeth & mucosa to boneKennedy CL I, II

Tooth-Mucosal borne

Mucosal borne (muco-osseous support)

Supporting structures

Mucosa

Submucosa

Residual bone

OTHER Key Terms26

Abutment

Anatomical

Baseplate

Bite rim

Border molding

Centric occlusion

Connectors

Denture base

Framework

Muscle trimming

Non-anatomical

Overdenture

Relined

Rests

Retainer

Vertical dimension

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RIGHTS RESERVED.

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Treatment Options

Treatment Objectives Oral Health

Restore and/or improve mastication

Restore health and comfort

Improve Quality of Life

ESTHETICS

Prevent occlusal disharmony

Consequences of teeth loss

Consequences of teeth loss

Treatment Options Partial Edentulism

No Replacement

Fixed Partial Denture (FPD)

Removable Partial Denture (RPD)

Implant crowns/FPD

Extractions & Complete Denture

No Replacement,

Shortened Dental Arch (SDA)

Patients can function with as few as 20 occluding teeth

No significant difference in

chewing

discomfort

No ReplacementShortened Dental Arch (SDA)

Require Anterior teeth + 4-6 occlusal units

Opposing PM’s = 1 occlusal unit

Opposing PM’s = 2 occlusal units

Symmetric loss need 4 units

Assymetric loss need 6 units

PRESENCE OF STABLE OPPOSING OCCLUSAL CONTACTS

Partial Dentures

Prosthesis replacing one or more, but not all teeth

Supported by teeth (abutments) and/or mucosa

May be fixed or removable

Fixed Partial Denture (FPD)

Removable Partial Denture (RPD)

FPD

Patients prefer to RPD

Porcelain ± Metal

Cemented

Need tooth (abutment) at either end

FPD

Must prepare (grind down abutments)

If too long, flexes, loosens or breaks

More expensive

If too long, flexes, loosens or breaks

Long-span saddles, 4 or more missing

Distal end saddle (extension base)

Need for cross-arch stabilisation

Physical or emotional problems

Esthetics, as when replacing soft tissue and bone.

Immediate replacement

Patients desires

Unfavorable maxillomandibular realationship

Indications

Indications

To replace several teeth in the same quadrant or in both quadrants of the same arch.

As a temporary replacement for missing teeth in a child.

To replace missing teeth for patients who do not want a fixed bridge or implants.

For the patient who finds it easier to maintain good oral hygiene.

To serve as a splint to support periodontallyinvolved teeth, when there is excessive bone loss

Treatment Option: RPD

Can be removed & replaced by patient

Less expensive

Won’t necessarily improve function if patient has ≥ 4 occlusal units

Indications for RPD's

Edentulous area too long for fixed prosthesis

Longer than 4 units is more complex

Indications for RPD's

No posterior abutment for a fixed prosthesis

Indications for RPD's

Excessive alveolar bone loss (esthetic problem)

Indications for RPD's

Poor prognosis for complete dentures due to residual ridge morphology

Indications for RPD's

Reduced periodontal support of remaining teeth

Won't support a fixed prosthesis)

Treatment Option: Complete Dentures

Remaining teeth are hopeless

Other options are too complex/expensive

Treatment Option: Implant Prostheses

Implant Crowns

Implant Bridges

Implant Dentures

Interim Denture (Provisional; Temporary)Used for short time to provide:

Esthetics

Mastication

Occlusal support

Interim Denture

Partial denture made while crowns are being fabricated for a definitive RPD)

Transitional Denture

Prosthesis to which teeth will be added

Replaced after post-extraction tissue changes

Made with intention of subsequently altering it

Advantages of a Removable Partial

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RIGHTS RESERVED.

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Less expensive

than fixed

prostheses

Proper occlusal

plane is

maintained

Fewer intraoral

procedures

than fixed pros.

May support

periodontally

involved teeth

Stabilizes

the arches

Restores

function when

no distal teeth

present

Restores

long span

of lost

dentition

Easier for good

oral hygiene of

abutments

Easily repaired

and adjusted

Extraoral Factors that Influence the Choice of Removable Prosthesis type

Physical health

Mental health

Motivation

Age

Dietary habits

Socioeconomic factors

Occupation

Intraoral Factors that Influence the Choice of Removable Prosthesis type

Musculature

Salivary flow

Residual alveolar ridge

Oral mucosa

Oral habits

Tori

Contraindications

A lack of suitable teeth in the arch to support,

stabilize, and retain the removable prosthesis.

Rampant caries

Severe periodontal conditions that threaten the

remaining teeth in the arch.

A lack of patient acceptance for esthetic reasons.

Chronic poor oral hygiene with no motivation

to improve oral conditions

When Indicated for a Full Denture

The patient is edentulous.

The remaining teeth cannot be saved.

The remaining teeth cannot support a removable partial denture, and no acceptable alternatives are available.

The patient refuses alternative treatment recommendations.

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RPD Basic Components

Components of an RPD

RetainersDirect

Indirect

Connectors Major

Minor

Rests

Proximal plates

Plastic or acrylic

retention area

Denture base

Teeth

Components of an RPD

Major Connector

• Connects parts together

• Principal functions:

• Unification

• Rigidity

• Minimal

Retention by adhesion

Components of a RPD

Minor Connector • Connects other components to

the major connector

• Principle functions:

• Links major connector to

other components

• Adds to indirect retention

and reciprocation

Components of an RPD

Direct Retainer• Provides retention

against dislodging forces.

Components of an RPD

Direct Retainer

• 'Clasp' or 'clasp unit'

composed of:• Rest• Retentive arm• Reciprocal arm • Minor connector

Rests

Rigid extension that prevents movement towards tissue

Principle functions:

• Support

• Adds to indirect retention

• Adds to reciprocation if in

lingual side

Proximal plate

Rigid vertical extension contacting the proximal surface of tooth

Principle functions:

• Stability

• Adds to indirect retention

• Provides a definitive path of insertion

Plastic retention area

Part of the RPD where acrylic is attached

Principle functions:

• Mechanical retention to the acrylic

Components of an RPD

Denture Base

•Covers the residual ridges

•Supports the

denture teeth

ATTACHMENTS

S E Q U E N C E O F C L I N I C S

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CLINICAL SERVICE

Clinic visit Lab visit

Clinic 1 Exam, Records, Primary impression

Clinic 2 Tooth preparation, secondary impressions

Clinic 3 Metal try-in, altered cast impression, and jaw registration

Clinic 4 Teeth try-in

Clinic 5 Delivery

Lab 1 Surveying and treatment

plan

Lab 2 Metal framework production

Lab 3 Tooth setting

Lab 4 Acrylic processing

Lab5 If needed for repair or

remount

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Part A: Removable Partial Dentures

Replaces one or more teeth in one arch

Retained and supported by underlying tissues and remaining teeth

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Study models

Photographs

Visual aids

Radiographs

Treatment plan

Examination/ Consultation