An introductory lecture to orient 2nd year BDS student with RPD terminology, RPD components and classification of partially edetulous arches.

2. Partially Edentulous Terminology
Components of a Removable
Partial Denture (RPD)
Classification of Partially
Edentulous Arches

3. PARTIALLY EDENTULOUS TERMINOLOGY
• Removable
Prosthodontics
The branch of
Prosthodontics concerned
with replacement of teeth
and contagious structures
of edentulous or partially
edentulous patients by
artificial substitutes that are
readily removable from
mouth.
• Removable Dental
Appliance
Devices worn by the patient
in the course of treatment
and that can be inserted
and removed at will.
For example, occlusal
splints, removable partial
denture, orthodontics
appliances, an obturator
etc.

4. PARTIALLY EDENTULOUS TERMINOLOGY

5. PARTIALLY EDENTULOUS TERMINOLOGY
• Removable Partial
Denture Prosthesis
Any prosthesis that
replaces some teeth in
a partially dentate arch.
It can be placed and
removed from mouth at
will.

6. PARTIALLY EDENTULOUS TERMINOLOGY
• Interim or Provisional
Denture
Dental prosthesis used for a
short time for reasons of
esthetics, mastication,
occlusal support,
convenience or for
conditioning a patient to an
artificial substitute for
missing natural teeth until a
more definite dental
prosthesis can be provided.

7. PARTIALLY EDENTULOUS TERMINOLOGY
• SUPPORT : The foundation on which a dental
prosthesis rests.
• STABILITY : Quality of a prosthesis to be firm,
stable or constant and to resist displacement by
functional, horizontal or rotational stresses.
• RETENTION : Quality inherent in the prosthesis to
resist vertical forces acting to displace it away
from its foundation.

8. PARTIALLY EDENTULOUS TERMINOLOGY
• ABUTMENT
An abutment is tooth,
a portion of a tooth or
a portion of an implant
that serves to support
or retain a prosthesis.

9. PARTIALLY EDENTULOUS TERMINOLOGY
• HEIGHT OF CONTOUR
A lines encircling a
tooth, designating its
greatest circumference
at a selected position
determined by a dental
surveyor.

10. PARTIALLY EDENTULOUS TERMINOLOGY
• UNDERCUT :
Portion of a tooth that
lies between the HOC
and the gingiva.

11. PARTIALLY EDENTULOUS TERMINOLOGY
• Angle of Cervical
Convergence
Angle viewed between
a vertical rod contacting
an abutment tooth and
the axial surface of the
abutment cervical to
the height of contour.

12. PARTIALLY EDENTULOUS TERMINOLOGY
• Guiding Planes
Two or more parallel
surfaces of abutment
teeth shaped to direct a
prosthesis during its
placement and removal.

13. PARTIALLY EDENTULOUS TERMINOLOGY
DENTAL CAST SURVEYOR:
An instrument used to
determine the relative
parallelism of two or
more axial surfaces of
teeth or other parts of a
cast of a dental arch.

14. PARTIALLY EDENTULOUS TERMINOLOGY
• IMPRESSSION
A negative likeness or
copy in reverse of a
surface or an object.
(teeth and adjacent
structures)

15. PARTIALLY EDENTULOUS TERMINOLOGY
• DENTAL CAST :
An accurate and a
positive replica of a
maxillary or mandibular
dental arch.

16. COMPONENTS OF A REMOVABLE
PARTIAL DENTURE (RPD)

17. COMPONENTS OF A REMOVABLE PARTIAL
DENTURE (RPD)
– Major connector
– Minor connector
– Direct retainer
– Indirect retainer
– Rests
– Stabilizing/reciprocal component
– Denture base.

18. Framework for mandibular removable partial denture with
the following components:
1, lingual bar major connector.
2a, minor connector by which the
resin denture base will be attached.
2b, minor connector, proximal plate,
which is part of clasp assembly.
2c, minor connector used to connect
rests to major connectors.
3, occlusal rests.
4, direct retainer arm, which is part
of the total clasp assembly.
5, stabilizing or reciprocal
components of clasp assembly
(includes minor connectors).
6, an indirect retainer consisting of a
minor connector and an occlusal rest.

19. Framework for maxillary removable partial denture with the
following components:
A : A-P palatal strap type
major connector
B : Minor connector
C : Direct retainer
D : Occlusal Rest

20. COMPONENTS OF A REMOVABLE PARTIAL
DENTURE (RPD)
• MAJOR CONNECTOR
Connects the parts of a
prosthesis located on
one side of the arch
with those located on
the opposite side.
• Other functions :
Cross arch stability to
help resist displacement
by functional forces.

21. COMPONENTS OF A REMOVABLE PARTIAL
DENTURE (RPD)
• Mandibular major
connectors
– Lingual bar
– Linguoplate
– Sublingual bar
– Lingual bar with cingulum
bar (continuous bar)
– Cingulum bar
– Labial bar
• Maxillary major
– Single palatal strap
– Combination anterior and
posterior palatal strap–
type Connector
– Palatal plate-type
connector
– U-shaped palatal
connector
– Single palatal bar
– Anterior-posterior palatal
bars

22. COMPONENTS OF A REMOVABLE PARTIAL
DENTURE (RPD)
• MINOR CONNECTOR
Connecting link between
the major connector/base
of an PRDP and other
components of the
prosthesis such as, clasp
assembly, occlusal rests.
Etc.

23. COMPONENTS OF A REMOVABLE PARTIAL
DENTURE (RPD)
• DIRECT RETAINER
– Retains a PRDP and prevents its dislodgment.
– May be placed extracoronally (clasp assembly) or
intracoronally (precison attachments)

24. COMPONENTS OF A REMOVABLE PARTIAL
DENTURE (RPD)
• EXTRA CORONAL DR • INTA CORONAL DR

25. COMPONENTS OF A REMOVABLE PARTIAL
DENTURE (RPD)
• REST
Provides vertical support.
• REST SEAT
Prepared surface on an
abutment to receive the
rest.
Types :
• Occlusal rest
• Cingulum rest
• Incisal rest
• Other fuctions :
– Maintains components in
their planned positions.
– Maintains occlusal relation-ships.
– Prevents settling of
denture.
– Prevents impingement on soft
tissues.
– Distributes and directs occlusal
loads along long axis.

26. COMPONENTS OF A REMOVABLE PARTIAL
DENTURE (RPD)

27. COMPONENTS OF A REMOVABLE PARTIAL
DENTURE (RPD)
• INDIRECT RETAINER
– Assists a direct retainer in preventing
displacement of a distal extension denture base
by functioning through lever action on opposite
side of a fulcrum line when denture base moves
away from the tissue in pure rotation around the
fulcrum line.

28. COMPONENTS OF A REMOVABLE PARTIAL
DENTURE (RPD)
• Indirect retainers may consist of / take form
of :
– Auxiliary occlusal rest
– Vertical supporting minor connector
– Proximal plates adjacent to edentulous areas.

29. COMPONENTS OF A REMOVABLE PARTIAL
DENTURE (RPD)

30. COMPONENTS OF A REMOVABLE
PARTIAL DENTURE (RPD)
• STABILIZING/RECIPROCAL
COMPONENTS:
• Imparts stability to RPDP
against functional,
horizontal and rotational
stresses.
• Provided by:
– Reciprocal/ stabilizing arm
of clasp assembly.
– Major connector (CAS)
– Vertical supporting minor
connector (together with
Maj. Connector.)

31. COMPONENTS OF A REMOVABLE PARTIAL
DENTURE (RPD)

32. COMPONENTS OF A REMOVABLE PARTIAL
DENTURE (RPD)
• DENTURE BASE :
Rests on the foundation
tissues and to which
teeth are attached.

33. CLASSIFICATION OF PARTIALLY
EDENTULOUS ARCHES

34. CLASSIFICATION OF PARTIALLY EDENTULOUS
ARCHES
• Requirements of an Acceptable
Method of Classification
• It should permit immediate visualization of the type of
partially edentulous arch that is being considered.
• It should permit immediate differentiation between the tooth-supported
and the tooth- and tissue-supported removable partial
denture.
• It should be universally acceptable.

35. CLASSIFICATION OF PARTIALLY EDENTULOUS
ARCHES
• KENNEDY CLASSIFICATION
• Dr. Edward Kennedy in 1925
• Kennedy divided all partially edentulous arches into
four basic classes.
• Edentulous areas other than those that determine the
basic classes were designated as modification spaces.

36. KENNEDY CLASSIFICATION
• Class I :
– Bilateral edentulous
areas located posterior
to the natural teeth.

37. KENNEDY CLASSIFICATION
• Class II :
– A unilateral edentulous
area located posterior to
the remaining natural
teeth.

38. KENNEDY CLASSIFICATION
• Class III :
– A unilateral edentulous
area with natural teeth
remaining both anterior
and posterior to it.

39. KENNEDY CLASSIFICATION
• Class IV :
– A single, but bilateral
(crossing the midline),
edentulous area located
anterior to the
remaining natural teeth.

40. RULES GOVERNING APPLICATION OF THE
KENNEDY METHOD
• Rule 1
– Classification should follow rather than precede
any extractions of teeth that might alter the
original classification.
• Rule 2
– If a third molar is missing and is not to be
replaced, it is not considered in the classification.

41. RULES GOVERNING APPLICATION OF THE
KENNEDY METHOD
• Rule 3
– If a third molar is present and is to be used as an
abutment, it is considered in the classification.
• Rule 4
– If a second molar is missing and is not to be
replaced, it is not considered in the classification
(e.g., if the opposing second molar is likewise
missing and is not to be replaced).

42. RULES GOVERNING APPLICATION OF THE
KENNEDY METHOD
• Rule 5
– The most posterior edentulous area (or areas)
always determines the classification.
• Rule 6
– Edentulous areas other than those that determine
the classification are referred to as modifications
and are designated by their number.

43. RULES GOVERNING APPLICATION OF THE
KENNEDY METHOD
• Rule 7
– The extent of the modification is not considered,
only the number of additional edentulous areas.
• Rule 8
– No modification areas can be included in Class IV
arches. (Other edentulous areas that lie posterior
to the single bilateral areas crossing the midline
would instead determine the classification; see
Rule 5.)

44. EXERCISE

45. EXERCISE