Removable partial denture Introduction Classification Dilemma after tooth

Removable partial denture Introduction & Classification

Dilemma after tooth extraction

What is prosthetics? • That branch of dentistry that deals with the replacement of missing teeth, and/or the replacement of missing tooth tissues • Fixed prosthodontics (crowns/bridges) • Removable prosthodontics (dentures) • [implant retained/supported prosthodontics]

RPD - definition A prosthesis (denture) that replaces some teeth in a " partially dentate arch. It can be removed from the "mouth (by the patient!) and replaced at will

Treatment options for Edentulous spaces • • • Large diversity of treatment complexity Number of teeth to be replaced Health of residual dentition Health of patient Patient requirements Patient expectations Dentist competence Laboratory competence & liaison TIME!

Partial Denture Fixed Partial Denture FPD Removable Partial Denture Over Teeth or Implant RPD Attachment retained RPD Clasp retained RPD Removable partial overdenture

Components of Removable Partial Denture 1. Denture Base ( Saddle) 2. Supporting Elements( Rests & Embrasure Hock & Onlay ) 3. Retentive Elements ( Direct {clasp & attachments} & Indirect ) 4. Connectors ( Major & Minor )

Denture Base (Saddle) "That part of the denture that rests on the oral mucosa and carry the artificial teeth" or alternatively "The space(s) to be filled by the denture“ • Classification of Saddles • Bounded Saddles – (teeth present at both ends of the saddle area) • Free-end saddles – (teeth present at only the anterior end of the saddle)

Support "The resistance to a vertical displacing force directed towards the mucosa“ 1. 2. 3. Tooth support Mucosa support Tooth and Mucosa support Others i. e. implants, overdenture (tooth)- support

Retention • "That quality inherent in a prosthesis acting to resist movement or displacement away from the mucosa” Mechanical Retention • Achieved in RPD prosthodontics by the use of clasps. Or attachments

Major connector That component of a denture which unites saddles of a denture – • Cast metal (Co-Cr), Gold, Nickel chrome or titanium – • Acrylic resin

Classification of RPD Requirements of an acceptable method of classification 1. 2. 3. 4. It should be permit immediate visualization of the type of partially edentulous arch being considered. It should permit immediate differentiation between the tooth- support and the tooth and tissue- supported RPD. Serve as a guide to the type of design to be used. It should be universally acceptable. The most familiar classifications are those originally proposed by Kennedy, Cummer, and Bailyn. Classifications have also been proposed by Beckett, Godfrey, Swenson, Friedman, Wilson, Skinner, Appligate, Avent, Miller, and others.

Classification of RPD • • Classifications in current use are of two types - those which classify the partial denture and those which classify the partially edentulous arch. A classification which describes partial dentures is based on the nature of the support utilized by a partial denture. Support can be gained from: 1. Teeth-support (born), 2. Mucosa-support, 3. Teeth and mucosa-support.

Classification of RPD According to support: • Teeth-support (born), • Mucosa-support, • Teeth and mucosa-support

Classification of RPD Kennedy’s Classification By Dr. Edward Kennedy, (1925) Kennedy divided all partially edentulous arches into 4 clases based on the location of the edentulous area/s as follows: 1. Class I: Bilateral edentulous areas located posterior to the remaining natural teeth. 2. Class II: A unilateral edentulous area located posterior to the remaining natural teeth. 3. Class III: A unilateral edentulous area located between the remaining natural teeth. 4. Class IV: A single, but Bilateral (crossing the midline), edentulous area located anterior to the remaining natural teeth.

Classification of RPD Kennedy’s Classification Class III Class VI

What about the following cases ?

Kennedy’s Classification Applegate rules Applegate (1960) provided the following 8 rules to governed the application of the Kennedy classification: Rule 1. Classification should follow rather than precede extractions that might alter the original classification. Rule 2. If the third molar is missing and not to be replaced, it is not considered in the classification Rule 3. If the third molar is present and is to be used as an abutment, it is considered in the classification Rule 4. If the second molar is missing and not to be replaced, it is not considered in the classification Rule 5. The most posterior edentulous area/s determine the classification. Rule 6. The edentulous areas other than those determine the classification are referred to as modification spaces and are designated by their number. Rule 7. The extent of the modification is not considered, only the no. of additional edentulous areas. Rule 8. There can be no modification areas in Class IV arches.

(4) (1) (2) (3) Class I, Modification 1. (8) (5) (6) (7) (12) (9) (10) (11) (16) (13) (14) (15)

By using Applegate rules, Kennedy classification is an anatomical classification which describes the number and distribution of edentulous areas present. Class I, Modification 1. Class III, Modification 2. Class II, Modification 1. Class IV, ? ?