removablepartialdenture- 2.pdf

REMOVABLE PARTIAL
REMOVABLE PARTIAL
DENTURE
DENTURE
RPDs are components of prosthodontics
RPDs are components of prosthodontics
) branch of Dentistry( pertaining to the
) branch of Dentistry( pertaining to the
restorations and maintenance of oral
restorations and maintenance of oral
function, comfort, appearance, and
function, comfort, appearance, and
health of the) pt( by replacement the
health of the) pt( by replacement the
missing teeth and craniofacial tissues
missing teeth and craniofacial tissues
with artificial substitute
with artificial substitute
.
.
The Basic Objectives of
The Basic Objectives of
prosthodontic Treatment
prosthodontic Treatment
1.
1. Elimination of oral disease.
Elimination of oral disease.
2.
2. Preservation of the health and
Preservation of the health and
relationship of the teeth, and the
relationship of the teeth, and the
health of the oral and
health of the oral and para-oral
para-oral
structure.
structure.
3.
3. Restoration of oral function (comfort,
Restoration of oral function (comfort,
esthetic, speech).
esthetic, speech).
Consequences of Tooth Loss
Consequences of Tooth Loss
1.
1. Aesthetics
Aesthetics
2.
2. Speech.
Speech.
3.
3. Drifting, tilting, over-eruption.
Drifting, tilting, over-eruption.
4.
4. Loss of masticatory efficiency.
Loss of masticatory efficiency.
5.
5. Loss of vertical dimension.
Loss of vertical dimension.
6.
6. Deviation of mandible.
Deviation of mandible.
7.
7. Loss of alveolar bone.
Loss of alveolar bone.
 P.D may:
P.D may:
2.
2. Give support to periodontally diseased teeth.
Give support to periodontally diseased teeth.
3.
3. Restore vertical facial dimension.
Restore vertical facial dimension.
4.
4. Prevent T.M.J problems.
Prevent T.M.J problems.
5.
5. Prevent tooth drifting or over eruption.
Prevent tooth drifting or over eruption.
6.
6. Stimulate non-used tissues.
Stimulate non-used tissues.
7.
7. Support collapsed structure (muscles of lips
Support collapsed structure (muscles of lips
and cheeks).
and cheeks).
8.
8. Prevent attrition of remaining teeth.
Prevent attrition of remaining teeth.
9.
9. Improve oral hygiene by preventing stagnation
Improve oral hygiene by preventing stagnation
of food in disused areas.
of food in disused areas.
Classification Of Partially
Classification Of Partially
Edentulous Arches
Edentulous Arches
 The most familiar classification are those
The most familiar classification are those
proposed by Kennedy, Cummer, and
proposed by Kennedy, Cummer, and
Bailyn, Beckett,…
Bailyn, Beckett,…
 The recent classification has been
The recent classification has been
proposed for partial edentulism that is
proposed for partial edentulism that is
based on diagnostic criteria.
based on diagnostic criteria.
Requirement Of an Acceptable
Requirement Of an Acceptable
Method Of Classification
Method Of Classification
1.
1. It should permit immediate visualization
It should permit immediate visualization
of the type of partially edentulous arch.
of the type of partially edentulous arch.
2.
2. It should permit immediate
It should permit immediate
differentiation b/w tooth- supported and
differentiation b/w tooth- supported and
the tooth and tissue-supported.
the tooth and tissue-supported.
3.
3. Universally acceptable.
Universally acceptable.
Kennedy Classification
Kennedy Classification
 4 basic classes.
4 basic classes.
 Edentulous areas other than those
Edentulous areas other than those
determining the basic classes were
determining the basic classes were
designated as modification spaces.
designated as modification spaces.
Class I : Bilateral edentulous areas located
Class I : Bilateral edentulous areas located
posterior to the natural teeth.
posterior to the natural teeth.
Class II : A unilateral edentulous area
Class II : A unilateral edentulous area
posterior to the remaining natural teeth.
posterior to the remaining natural teeth.
Kennedy Classification
Kennedy Classification
Class III: Unilateral edentulous area with
Class III: Unilateral edentulous area with
natural teeth remaining both ant and post
natural teeth remaining both ant and post
to it.
to it.
Class IV : A single, but bilateral (crossing
Class IV : A single, but bilateral (crossing
the midline), edentulous area located
the midline), edentulous area located
anterior to the remaining natural teeth.
anterior to the remaining natural teeth.
Principal Advantage
Principal Advantage
 It permits immediate visualization of the
It permits immediate visualization of the
partially edentulous arch and allows easy
partially edentulous arch and allows easy
distinction bw tooth-supported versus
distinction bw tooth-supported versus
tooth-tissue supported prostheses.
tooth-tissue supported prostheses.
Applegate's
Applegate's Rules for Applying
Rules for Applying
the Kennedy Classification
the Kennedy Classification
Rule 1 : The classification should follow, not
Rule 1 : The classification should follow, not
precede extractions.
precede extractions.
Rule 2 : If a 3
Rule 2 : If a 3rd
rd
molar is missing and not to
molar is missing and not to
be replaced, it is not considered in the
be replaced, it is not considered in the
classification.
classification.
Rule 3 : If a3rd molar is present and not to
Rule 3 : If a3rd molar is present and not to
be used as an abutment, it is not
be used as an abutment, it is not
considered in the classification.
considered in the classification.
Applegate's
Applegate's Rules
Rules
Rule 4 : If a 2
Rule 4 : If a 2nd
nd
molar is missing and not to
molar is missing and not to
be replaced, it is not considered in the
be replaced, it is not considered in the
classification.
classification.
Rule 5 : The most posterior area always
Rule 5 : The most posterior area always
determines the classification.
determines the classification.
Rule 6 : Edentulous areas other than those
Rule 6 : Edentulous areas other than those
determining the classification are referred
determining the classification are referred
to as modifications and designated by
to as modifications and designated by
their No.
their No.
Applegate's
Applegate's Rule
Rule
Rule 7 : The extent of the modifications is
Rule 7 : The extent of the modifications is
not considered, only the No. of additional
not considered, only the No. of additional
edentulous areas.
edentulous areas.
Rule 8 : There are no modification in Class
Rule 8 : There are no modification in Class
IV.
IV.
Principal Of Partial Denture
Principal Of Partial Denture
Design
Design
 Stresses acting on RPDs are transmitted
Stresses acting on RPDs are transmitted
to the teeth, and to the tissues of the
to the teeth, and to the tissues of the
residual ridges.
residual ridges.
 The stresses, which tend to move the PD
The stresses, which tend to move the PD
in different directions are:
in different directions are:
3.
3. Masticatory stress( Tissue ward movt).
Masticatory stress( Tissue ward movt).
4.
4. Gravity( Tissue away movt).
Gravity( Tissue away movt).
5.
5. Sticky food pull the denture occlusaly
Sticky food pull the denture occlusaly
(Tissue-away movt).
(Tissue-away movt).
4. Muscles and tongue tend to displace
4. Muscles and tongue tend to displace
denture from its foundation.
denture from its foundation.
5. Intercuspation of the teeth may tend to
5. Intercuspation of the teeth may tend to
produce horizontal and rotational
produce horizontal and rotational
stresses unless occlusal is adjusted.
stresses unless occlusal is adjusted.
Properly Constructed PD Must
Properly Constructed PD Must
:Have
:Have
1.
1. Support: Resistance to vertical seating
Support: Resistance to vertical seating
forces( provided by teeth and mucosa).
forces( provided by teeth and mucosa).
2.
2. Retention: Resistance to vertical
Retention: Resistance to vertical
displacing forces.
displacing forces.
3.
3. Stability( bracing) resistance to
Stability( bracing) resistance to
horizontal and lateral displacement.
horizontal and lateral displacement.
 All the above should be within the
All the above should be within the
physiological limits of the tissue involved.
physiological limits of the tissue involved.
A
A
Designing Support
Designing Support
a. Tooth support: When abutment teeth available
a. Tooth support: When abutment teeth available
at both ends of the denture base( bounded
at both ends of the denture base( bounded
saddle). It most commonly obtained by
saddle). It most commonly obtained by
occlusal rests.
occlusal rests.
b. Mucosa support: (mucoperiosteum covering
b. Mucosa support: (mucoperiosteum covering
residual alveolar bone). It allows varying
residual alveolar bone). It allows varying
degree of displacement.
degree of displacement.
 The amount of displacement( tissue ward
The amount of displacement( tissue ward
movt) will depend on:
movt) will depend on:
4.
4. The amount of pressure applied.
The amount of pressure applied.
5.
5. The nature of the mucosa (thickness).
The nature of the mucosa (thickness).
3. Area covered by the denture( the wider
3. Area covered by the denture( the wider
the area the less the displacement).
the area the less the displacement).
4. Fit of the denture base.
4. Fit of the denture base.
5. Type of impression( anatomical,
5. Type of impression( anatomical,
functional, or selective pressure).
functional, or selective pressure).
c. Tooth-mucosa support: ( Bilateral free
c. Tooth-mucosa support: ( Bilateral free
end saddle).
end saddle).
 Posterior tissue support, and anterior
Posterior tissue support, and anterior
tooth support.
tooth support.
Designing Retention
Designing Retention
 Retention should be designed to counter act
Retention should be designed to counter act
dislodging forces( sticky food, muscle at
dislodging forces( sticky food, muscle at
periphery of the denture, intercuspation,
periphery of the denture, intercuspation,
gravity).
gravity).
 Retention is gained by mechanical means
Retention is gained by mechanical means
1. direct retainers:
1. direct retainers:
a. Intercoronal( clasps).
a. Intercoronal( clasps).
b. intracronal(percision attachment).
b. intracronal(percision attachment).
2. Indirect retainers.
2. Indirect retainers.
 Physical factors( cohesion, adhesion,
Physical factors( cohesion, adhesion,
atmospheric pressure, surface tension). it
atmospheric pressure, surface tension). it
play a minor role RBD.
play a minor role RBD.
Designing Bracing and Stability
Designing Bracing and Stability
 Bracing( providing resistance to lateral
Bracing( providing resistance to lateral
movt.of RBD).
movt.of RBD).
 Causes of tipping, rocking and
Causes of tipping, rocking and
rotation of P.D.
rotation of P.D.
3.
3. Quality of supporting structure.
Quality of supporting structure.
2. The tissue-ward movt.
2. The tissue-ward movt. Of the free end
Of the free end
base create an axis of rotation around
base create an axis of rotation around
which this appliance is rotated.
which this appliance is rotated.
This axis of rotation is called a fulcrum line
This axis of rotation is called a fulcrum line
(it is imaginary line extending between
(it is imaginary line extending between
the two main abutment.
the two main abutment.
How to counteract lateral shifting?
How to counteract lateral shifting?
1.
1. Bracing the sides of the teeth by means
Bracing the sides of the teeth by means
of rigid clasp arms.
of rigid clasp arms.
2.
2. Use of continuous bar resting on the
Use of continuous bar resting on the
lingual surfaces of the natural standing
lingual surfaces of the natural standing
teeth.
teeth.
Components Of RPDs
Components Of RPDs
1.
1. Major connectors.
Major connectors.
2.
2. Minor connectors.
Minor connectors.
3.
3. Rests.
Rests.
4.
4. Direct retainers.
Direct retainers.
5.
5. Stabilizing or reciprocal components
Stabilizing or reciprocal components
(part of clasp assembly).
(part of clasp assembly).
6.
6. Indirect retainers( if prosthesis has distal
Indirect retainers( if prosthesis has distal
extension).
extension).
Major Connecters
Major Connecters
 Major connector is component of the PD
Major connector is component of the PD
which connect all parts of the prosthesis
which connect all parts of the prosthesis
directly or indirectly.
directly or indirectly.
 It provides the cross-arch stability to help
It provides the cross-arch stability to help
resist displacement by functional stresses.
resist displacement by functional stresses.
Characteristics Of Major Connectors
Characteristics Of Major Connectors
1.
1. Made from material compatible with oral
Made from material compatible with oral
tissue.
tissue.
2.
2. It is rigid.
It is rigid.
3.
3. Doesn't alter the natural contour of the
Doesn't alter the natural contour of the
lingual surfaces of the mandibular
lingual surfaces of the mandibular
alveolar ridge or of the palatal vault.
alveolar ridge or of the palatal vault.
4.
4. Doesn't impinge on oral tissue in
Doesn't impinge on oral tissue in
(insertion, withdrawal. Or in function).
(insertion, withdrawal. Or in function).
6. Cover no more tissue than is absolutely
6. Cover no more tissue than is absolutely
necessary.
necessary.
7. Doesn't contribute to the trapping of food
7. Doesn't contribute to the trapping of food
particles.
particles.
8. Has support from other elements of the
8. Has support from other elements of the
frame work to minimize rotation in
frame work to minimize rotation in
function.
function.
9. Contribute to the support of the
9. Contribute to the support of the
prosthesis.
prosthesis.
Mandibular Major Connectors
Mandibular Major Connectors
1.
1. Lingual bar.
Lingual bar.
2.
2. Linguoplate.
Linguoplate.
3.
3. Sublingual bar.
Sublingual bar.
4.
4. Lingual bar with cingulum bar (continuous
Lingual bar with cingulum bar (continuous
bar).
bar).
5.
5. Cingulum bar (continuous bar).
Cingulum bar (continuous bar).
6.
6. Labial bar.
Labial bar.
 Lingual bar and Linguopslate are most
Lingual bar and Linguopslate are most
common used.
common used.
1.
1. Mandibular lingual Bar
Mandibular lingual Bar
 Indication: Where sufficient space exist
Indication: Where sufficient space exist
b/w elevated alveolar lingual sulcus and
b/w elevated alveolar lingual sulcus and
the lingual gingival tissue.
the lingual gingival tissue.
 Location:
Location:
3.
3. Half-pear shaped, with bulkiest portion
Half-pear shaped, with bulkiest portion
inferiorly.
inferiorly.
4.
4. Superior border tapered, located at least
Superior border tapered, located at least
4mm inferior to gingival margin.
4mm inferior to gingival margin.
4. Inferior border located at site of the
4. Inferior border located at site of the
alveolar lingual sulcus where the pt
alveolar lingual sulcus where the pt´s
´s
tongue is elevated.
tongue is elevated.
 Finishing line: Butt-type joints with minor
Finishing line: Butt-type joints with minor
connector for retention of denture base.
connector for retention of denture base.
.2
.2Mandibular Sublingual Bar
Mandibular Sublingual Bar
 It is modification of lingual bar used when
It is modification of lingual bar used when
the existing space not allow placement of
the existing space not allow placement of
lingual bar.
lingual bar.
 The shape remain the same but placement
The shape remain the same but placement
is inferior and posterior to site of lingual
is inferior and posterior to site of lingual
bar.
bar.
 Contraindication:
Contraindication:
Remaining natural anterior teeth severely
Remaining natural anterior teeth severely
tilted toward the lingual.
tilted toward the lingual.
 Characteristics and location:
Characteristics and location:
4.
4. Half-pear shaped same like the lingual
Half-pear shaped same like the lingual
bar except
bar except that the bulkiest portion is
that the bulkiest portion is
located to the lingual and the tapered
located to the lingual and the tapered
portion is toward the labial.
portion is toward the labial.
2. The superior border of the bar should be
2. The superior border of the bar should be
at least 3mm from the free gingival
at least 3mm from the free gingival
margin of the teeth.
margin of the teeth.
3. The inferior border is located at height of
3. The inferior border is located at height of
the alveolar lingual sulcus when the pt
the alveolar lingual sulcus when the pt´s
´s
tongue is elevated.
tongue is elevated.
4. Functional impression is most.
4. Functional impression is most.
 Finishing line: Butt-type joints with minor
Finishing line: Butt-type joints with minor
connectors for retention of denture base.
connectors for retention of denture base.
.3
.3Mandibular Linguoplate
Mandibular Linguoplate
 Indication for use:
Indication for use:
2.
2. No sufficient space for lingual bar.
No sufficient space for lingual bar.
3.
3. The residual ridge undergone a vertical
The residual ridge undergone a vertical
resoption which offer minimal resistance
resoption which offer minimal resistance
to horizontal rotation.
to horizontal rotation.
4.
4. Periodontally weakened teeth.
Periodontally weakened teeth.
5.
5. When future replacement of one or more
When future replacement of one or more
incisor teeth will be facilitated.
incisor teeth will be facilitated.
 Characteristics and location:
Characteristics and location:
2.
2. Half-pear shaped with bulkiest portion located.
Half-pear shaped with bulkiest portion located.
3.
3. Thin metal apron extending superiorly to
Thin metal apron extending superiorly to
contact cingulum of ant. Teeth.
contact cingulum of ant. Teeth.
4.
4. Apron extended interproximally to the height
Apron extended interproximally to the height
of contact points.
of contact points.
5.
5. Inferior border at ascertained height of the
Inferior border at ascertained height of the
alveolar lingual sulcus where the pt
alveolar lingual sulcus where the pt´s tongue
´s tongue
is slightly elevated.
is slightly elevated.
.4
.4Mandibular Lingual Bar with
Mandibular Lingual Bar with
Continuous Bar) Cingulum Bar
Continuous Bar) Cingulum Bar
(
(
 Indication for use:
Indication for use:
2.
2. When Linguoplate is indicated but the
When Linguoplate is indicated but the
axial alignment of ant. Teeth prevent .
axial alignment of ant. Teeth prevent .
3.
3. When wide diastema b/w mandibular
When wide diastema b/w mandibular
ant. Teeth.
ant. Teeth.
 Characteristics and location:
Characteristics and location:
2.
2. Shaped and located same as lingual bar.
Shaped and located same as lingual bar.
3.
3. Thin, narrow(3mm) metal strap located
Thin, narrow(3mm) metal strap located
on a cingula of anterior teeth. Scalloped
on a cingula of anterior teeth. Scalloped
to follow interproximal embrasures.
to follow interproximal embrasures.
4.
4. Originated bilaterally from incisal, lingual,
Originated bilaterally from incisal, lingual,
or occlusal rests of adjacent principal
or occlusal rests of adjacent principal
abutment.
abutment.
5
5
Mandibular Labial Bar .
Mandibular Labial Bar .
 Indication for use:
Indication for use:
2.
2. When a lingual inclination of remaining
When a lingual inclination of remaining
MPM and incisors teeth cannot be
MPM and incisors teeth cannot be
corrected.
corrected.
3.
3. Severe lingual tori cannot be removed.
Severe lingual tori cannot be removed.
4.
4. Severe tissue undercut.
Severe tissue undercut.
 Characteristics and location:
Characteristics and location:
2.
2. Half –pear shaped with bulkiest portion
Half –pear shaped with bulkiest portion
inferiorly located
inferiorly located on the labial and buccal
on the labial and buccal
aspect of the mandible.
aspect of the mandible.
3.
3. Superior border tapered to soft tissue.
Superior border tapered to soft tissue.
4.
4. Superior border located at least 4mm inferior
Superior border located at least 4mm inferior
to labial and buccal gingival margins and more
to labial and buccal gingival margins and more
if possible.
if possible.
5.
5. Inferior border located in the labial buccal
Inferior border located in the labial buccal
vestibule.
vestibule.
Maxillary Major Connectors
Maxillary Major Connectors
A. Single palatal strap
A. Single palatal strap
 Characteristics and Location:
Characteristics and Location:
3.
3. Anatomic replica form.
Anatomic replica form.
4.
4. Ant. Border follow the valleys b/w rugae at
Ant. Border follow the valleys b/w rugae at
right angle to median suture line.
right angle to median suture line.
5.
5. Posterior border at right angle to median
Posterior border at right angle to median
suture line.
suture line.
6.
6. Strap should be 8mm wide.
Strap should be 8mm wide.
7.
7. Confined with in an area bounded by the four
Confined with in an area bounded by the four
principal rests.
principal rests.
B.
B. Single Broad Palatal Major
Single Broad Palatal Major
Connector
Connector
 Indication:
Indication:
3.
3. Class I.
Class I.
4.
4. V or U shaped palate.
V or U shaped palate.
5.
5. Strong abutments.
Strong abutments.
6.
6. 6 remaining ant teeth.
6 remaining ant teeth.
7.
7. No interfering tori.
No interfering tori.
 Characteristics and location:
Characteristics and location:
2.
2. Anatomic replica form.
Anatomic replica form.
3.
3. Anterior border following valleys of rugae
Anterior border following valleys of rugae
and at right angle to median suture line
and at right angle to median suture line
and extending anterior to occlusal rests
and extending anterior to occlusal rests
or in direct retainer.
or in direct retainer.
3. Posterior border located at junction of
3. Posterior border located at junction of
hard and soft palate. And extended to
hard and soft palate. And extended to
pterygomaxillary notches.
pterygomaxillary notches.
C.
C. Anterior-posterior Strap
Anterior-posterior Strap
 Indication
Indication:
:
3.
3. Class I and II.
Class I and II.
4.
4. Long edentulous span class II MOD 1
Long edentulous span class II MOD 1
arches.
arches.
5.
5. Class IV.
Class IV.
6.
6. Palatal tori.
Palatal tori.
 Characteristics and location:
Characteristics and location:
2.
2. Parallelogram shaped and open in center
Parallelogram shaped and open in center
portion.
portion.
3.
3. Relatively broad(8-10mm) ant. And post.
Relatively broad(8-10mm) ant. And post.
Palatal strap.
Palatal strap.
4.
4. Lateral palatal strap (7-9mm) parallel to
Lateral palatal strap (7-9mm) parallel to
curve of arch. 6mm from gingiva of
curve of arch. 6mm from gingiva of
remaining teeth.
remaining teeth.
4. Anterior palatal strap; ant border not
4. Anterior palatal strap; ant border not
placed further interiorly than ant rests and
placed further interiorly than ant rests and
never closer than 6mm to lingual gingival
never closer than 6mm to lingual gingival
cervices.
cervices.
D.
D. Complete Palatal Coverage
Complete Palatal Coverage
Indication for use:
Indication for use:
3.
3. Situation in which only some or ant teeth
Situation in which only some or ant teeth
remains.
remains.
4.
4. Class II arch with large posterior
Class II arch with large posterior
modification space and some missing
modification space and some missing
anterior teeth.
anterior teeth.
3. Class I arch with 1-4 PM and some or all
3. Class I arch with 1-4 PM and some or all
ant teeth remaining, abutment support is
ant teeth remaining, abutment support is
poor, residual ridge extremely resorbed,
poor, residual ridge extremely resorbed,
direct retention is difficult to obtained
direct retention is difficult to obtained
4. No tori.
4. No tori.
 Characteristics and location:
Characteristics and location:
2.
2. Anatomic replica form supported anteriority by
Anatomic replica form supported anteriority by
rests seats.
rests seats.
3.
3. Palatal Linguoplate supported anteriorly and
Palatal Linguoplate supported anteriorly and
designed for the attachment of acrylic resin
designed for the attachment of acrylic resin
extension posteriorly.
extension posteriorly.
4.
4. Contact all of the teeth remaining in the arch.
Contact all of the teeth remaining in the arch.
5.
5. Posterior border, terminates at the junction of
Posterior border, terminates at the junction of
the hard and soft palate, extended to hasmular
the hard and soft palate, extended to hasmular
notch areas.
notch areas.
D.
D. U-shaped Palatal Major Connector
U-shaped Palatal Major Connector
 Is used only in which inoperable tori
Is used only in which inoperable tori
extended to the posterior limit of the hard
extended to the posterior limit of the hard
palate.
palate.
 It is the least favorable design of all
It is the least favorable design of all
palatal major connector( lack rigidity).
palatal major connector( lack rigidity).
Rests and Rest seats
Rests and Rest seats
 Vertical support provided by rests
Vertical support provided by rests
(occlusal, incisal, or cingulum).
(occlusal, incisal, or cingulum).
 Rests located on properly prepared tooth
Rests located on properly prepared tooth
surface .
surface .
 The prepared surface of an abutment to
The prepared surface of an abutment to
receive the rest is called the rest seat.
receive the rest is called the rest seat.
 The primary purpose of the rest is to provide
The primary purpose of the rest is to provide
vertical support for PD. It also does the
vertical support for PD. It also does the
following:
following:
2.
2. Maintain components in planned position.
Maintain components in planned position.
3.
3. Maintained established occlusal relationship.
Maintained established occlusal relationship.
4.
4. Prevent impingement of soft tissue.
Prevent impingement of soft tissue.
5.
5. Direct and distribute occlusal loads to
Direct and distribute occlusal loads to
abutment teeth.
abutment teeth.
Form Of Occlusal Rest and Rest
Form Of Occlusal Rest and Rest
Seats
Seats
1.
1. The outline form of the occlusal rest
The outline form of the occlusal rest
should be rounded, triangular shaped
should be rounded, triangular shaped
with the apex toward the center of
with the apex toward the center of
occlusal surfaces.
occlusal surfaces.
2.
2. It should be as long as it is wide. The
It should be as long as it is wide. The
base is 2.5mm for M and PM.
base is 2.5mm for M and PM.
3.
3. Reduction in marginal ridge is 1.5mm.
Reduction in marginal ridge is 1.5mm.
4. It should be concave and spoon shaped
4. It should be concave and spoon shaped
(no sharp edges or line angle).
(no sharp edges or line angle).
5. The angle formed by the occlusal rest and
5. The angle formed by the occlusal rest and
the vertical minor connector from which
the vertical minor connector from which
its originate should be less than 90
its originate should be less than 90*.
*.
Extended Occlusal Rest
Extended Occlusal Rest
 In mesially inclined abutment
In mesially inclined abutment the rest
the rest
extend more than one half of the mesio-
extend more than one half of the mesio-
distal width.
distal width.
 In severely tilted abutment the extended
In severely tilted abutment the extended
occlusal rest may take the form of an only
occlusal rest may take the form of an only
to restore the occlusal plane.
to restore the occlusal plane.
 Interproximal Occlusal rests.
Interproximal Occlusal rests.
 Intra-coronal Rest: It is used for both occlusal
Intra-coronal Rest: It is used for both occlusal
support and horizontal stabilization.
support and horizontal stabilization.
Horizontal stabilization is derived from the near
Horizontal stabilization is derived from the near
vertical walls of this type of rest seat.
vertical walls of this type of rest seat.
 The form of the rest should be parallel to path of
The form of the rest should be parallel to path of
placement, slightly tapered occlusaly, and
placement, slightly tapered occlusaly, and
slightly dove-tailed to preve3nt dislodgement
slightly dove-tailed to preve3nt dislodgement
proximally.
proximally.
 The main advantages of the internal rest
The main advantages of the internal rest
are that it facilitates the elimination of the
are that it facilitates the elimination of the
visible clasp arm.
visible clasp arm.
Direct Retainer
Direct Retainer
 It is a clasp or attachments applied to an
It is a clasp or attachments applied to an
abutment tooth for the purpose of holding RPD
abutment tooth for the purpose of holding RPD
in position.
in position.
 Classification
Classification:
:
3.
3. Extracronal direct retainer
Extracronal direct retainer)
) casted clasp,
casted clasp,
wrought wire clasp).
wrought wire clasp).
a/ Occlusaly approaching clasp
a/ Occlusaly approaching clasp
(circumferential) .
(circumferential) .
b/ Gingivally approaching clasps (Bar clasps)
b/ Gingivally approaching clasps (Bar clasps)
2. Intracronal direct retainer( attachments):
2. Intracronal direct retainer( attachments):
a/ Internal attachment.
a/ Internal attachment.
b/ External attachment.
b/ External attachment.
c/ Special attachment.
c/ Special attachment.
 Component parts of the clasp:
Component parts of the clasp:
1. Retentive terminal 2. Retentive arm
1. Retentive terminal 2. Retentive arm
3. Reciprocal arm 4. Occlusal rest
3. Reciprocal arm 4. Occlusal rest
5. Shoulder 6. Body 7. Minor connector
5. Shoulder 6. Body 7. Minor connector
 Height of contour: is greatest convexity
Height of contour: is greatest convexity
of tooth.
of tooth.
 The basic principle of clasp design is
The basic principle of clasp design is
encirclement to obtain more than 180
encirclement to obtain more than 180* of
* of
continuous contact.
continuous contact.
 Types of cast Circumferential clasps:
Types of cast Circumferential clasps:
4.
4. Simple circlet clasp: widely used, tooth
Simple circlet clasp: widely used, tooth
supported PD, approach the undercut
supported PD, approach the undercut
from edentulous space. Not used for
from edentulous space. Not used for
distal extension.
distal extension.
2
2. Reverse clasp.
. Reverse clasp.
3. Multiple circlet clasp) combination of two
3. Multiple circlet clasp) combination of two
circlet clasps(.
circlet clasps(.
4. Embrasure clasp
4. Embrasure clasp
5. Ring clasp; no buccal undercut. Isolated
5. Ring clasp; no buccal undercut. Isolated
abutment, lingually tipped molar, from
abutment, lingually tipped molar, from
disto- buccal to disto-lingual undercut.
disto- buccal to disto-lingual undercut.
6. Hairpin clasp. when undercut is near to
6. Hairpin clasp. when undercut is near to
edentulous space.
edentulous space.
7
7. Combination clasp.
. Combination clasp.
 Bar clasp: Composed of two parts
Bar clasp: Composed of two parts
( Gingivally approaching and retentive
( Gingivally approaching and retentive
tip)
tip)
2.
2. Approach arm: It is a minor connector.
Approach arm: It is a minor connector.
Semi circular in cross section, cross the
Semi circular in cross section, cross the
gingival margin at right angle.
gingival margin at right angle.
3.
3. Retentive terminal : it should end below
Retentive terminal : it should end below
undercut.
undercut.
Advantages:
Advantages:
2.
2. Easy to insert and difficult to remove.
Easy to insert and difficult to remove.
3.
3. More aesthetic, cover less tooth
More aesthetic, cover less tooth
structure.
structure.
– Types of Bar clasps:
Types of Bar clasps:
5.
5. T-Bar clasp.
T-Bar clasp.
6.
6. Y- Bar clasp.
Y- Bar clasp.
7.
7. I- Bar clasp.
I- Bar clasp.
Indirect Retainer
Indirect Retainer
 Apart of RPD which assists the direct
Apart of RPD which assists the direct
retainers in preventing displacement of
retainers in preventing displacement of
distal extension denture base by
distal extension denture base by
functioning through lever action on the
functioning through lever action on the
opposite side of the fulcrum line.
opposite side of the fulcrum line.
 Types of indirect retainer:
Types of indirect retainer:
2.
2. Auxiliary occlusal rest, most frequently
Auxiliary occlusal rest, most frequently
used, located far as possible from distal
used, located far as possible from distal
extension base, placed perpendicular to
extension base, placed perpendicular to
the mid point of the fulcrum line. If this
the mid point of the fulcrum line. If this
perpendicular line ends on the incisal
perpendicular line ends on the incisal
area it is a voided, instead it transfers to
area it is a voided, instead it transfers to
PM in both sides.
PM in both sides.
2. Canine extension from occlusal rest,
2. Canine extension from occlusal rest,
finger like extention(lug seat) from the PM
finger like extention(lug seat) from the PM
rest is placed on the lingual slope of
rest is placed on the lingual slope of
adjacent canine.
adjacent canine.
3. Canine rest.
3. Canine rest.
4. Continuous bar retainers and Linguoplate.
4. Continuous bar retainers and Linguoplate.
Denture Base
Denture Base
 Denture base defined as that part of a
Denture base defined as that part of a
denture which rests on the oral mucosa
denture which rests on the oral mucosa
and to which teeth are attached.
and to which teeth are attached.
 Ideal requirements:
Ideal requirements:
3.
3. Accurate tissue adaptation with minimal
Accurate tissue adaptation with minimal
change in volume.
change in volume.
4.
4. Thermal conductivity.
Thermal conductivity.
5.
5. Sufficient strength to resist fracture or
Sufficient strength to resist fracture or
distortion under function.
distortion under function.
4. Cleansability.
4. Cleansability.
5. Ability to be relined if necessary.
5. Ability to be relined if necessary.
6 Cost effective.
6 Cost effective.
7. Low specific gravity.
7. Low specific gravity.
8. Ability to achieve a good finish.
8. Ability to achieve a good finish.
 Types of denture base:
Types of denture base:
2.
2. Acrylic
Acrylic
3.
3. Metal.
Metal.
4.
4. Combination.
Combination.
 Acrylic Resin denture base; mainly used
Acrylic Resin denture base; mainly used
for distal extension PD- attached to the
for distal extension PD- attached to the
frame work by minor connector-with
frame work by minor connector-with
1.5mm thick to have a adequate
1.5mm thick to have a adequate
strength.
strength.
 Advantages:
Advantages:
2.
2. Anterior teeth can be replaced at their
Anterior teeth can be replaced at their
original position (aesthetic level).
original position (aesthetic level).
3.
3. Restore the contour of the edentulous
Restore the contour of the edentulous
ridge.
ridge.
4.
4. Brings out the normal contour of the lip
Brings out the normal contour of the lip
and cheeks.
and cheeks.
5.
5. Can be relined.
Can be relined.
 Disadvantages:
Disadvantages:
2.
2. May break on usage.
May break on usage.
3.
3. Tend to accumulate mucous deposits
Tend to accumulate mucous deposits
and food debris.
and food debris.
4.
4. Soft tissue irritation.
Soft tissue irritation.
5.
5. Allergy.
Allergy.
 Metal denture base: mainly used for tooth
Metal denture base: mainly used for tooth
supported PD.
supported PD.
 Advantages:
Advantages:
3.
3. Accurate tissue adaptaion( better retention).
Accurate tissue adaptaion( better retention).
4.
4. Easy to clean.
Easy to clean.
5.
5. Strong even in thin section.
Strong even in thin section.
6.
6. Heat conductivity( physiologic tissue
Heat conductivity( physiologic tissue
stimulation).
stimulation).
 Disadvantage:
Disadvantage:
2.
2. Difficult to trim and adjust.
Difficult to trim and adjust.
3.
3. Over extension can injure the soft tissue.
Over extension can injure the soft tissue.
4.
4. Poor aesthetic.
Poor aesthetic.
5.
5. Difficult to reline and rebase.
Difficult to reline and rebase.
1 sur 72

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removablepartialdenture- 2.pdf

  • 1. REMOVABLE PARTIAL REMOVABLE PARTIAL DENTURE DENTURE RPDs are components of prosthodontics RPDs are components of prosthodontics ) branch of Dentistry( pertaining to the ) branch of Dentistry( pertaining to the restorations and maintenance of oral restorations and maintenance of oral function, comfort, appearance, and function, comfort, appearance, and health of the) pt( by replacement the health of the) pt( by replacement the missing teeth and craniofacial tissues missing teeth and craniofacial tissues with artificial substitute with artificial substitute . .
  • 2. The Basic Objectives of The Basic Objectives of prosthodontic Treatment prosthodontic Treatment 1. 1. Elimination of oral disease. Elimination of oral disease. 2. 2. Preservation of the health and Preservation of the health and relationship of the teeth, and the relationship of the teeth, and the health of the oral and health of the oral and para-oral para-oral structure. structure. 3. 3. Restoration of oral function (comfort, Restoration of oral function (comfort, esthetic, speech). esthetic, speech).
  • 3. Consequences of Tooth Loss Consequences of Tooth Loss 1. 1. Aesthetics Aesthetics 2. 2. Speech. Speech. 3. 3. Drifting, tilting, over-eruption. Drifting, tilting, over-eruption. 4. 4. Loss of masticatory efficiency. Loss of masticatory efficiency. 5. 5. Loss of vertical dimension. Loss of vertical dimension. 6. 6. Deviation of mandible. Deviation of mandible. 7. 7. Loss of alveolar bone. Loss of alveolar bone.
  • 4.  P.D may: P.D may: 2. 2. Give support to periodontally diseased teeth. Give support to periodontally diseased teeth. 3. 3. Restore vertical facial dimension. Restore vertical facial dimension. 4. 4. Prevent T.M.J problems. Prevent T.M.J problems. 5. 5. Prevent tooth drifting or over eruption. Prevent tooth drifting or over eruption. 6. 6. Stimulate non-used tissues. Stimulate non-used tissues. 7. 7. Support collapsed structure (muscles of lips Support collapsed structure (muscles of lips and cheeks). and cheeks). 8. 8. Prevent attrition of remaining teeth. Prevent attrition of remaining teeth. 9. 9. Improve oral hygiene by preventing stagnation Improve oral hygiene by preventing stagnation of food in disused areas. of food in disused areas.
  • 5. Classification Of Partially Classification Of Partially Edentulous Arches Edentulous Arches  The most familiar classification are those The most familiar classification are those proposed by Kennedy, Cummer, and proposed by Kennedy, Cummer, and Bailyn, Beckett,… Bailyn, Beckett,…  The recent classification has been The recent classification has been proposed for partial edentulism that is proposed for partial edentulism that is based on diagnostic criteria. based on diagnostic criteria.
  • 6. Requirement Of an Acceptable Requirement Of an Acceptable Method Of Classification Method Of Classification 1. 1. It should permit immediate visualization It should permit immediate visualization of the type of partially edentulous arch. of the type of partially edentulous arch. 2. 2. It should permit immediate It should permit immediate differentiation b/w tooth- supported and differentiation b/w tooth- supported and the tooth and tissue-supported. the tooth and tissue-supported. 3. 3. Universally acceptable. Universally acceptable.
  • 7. Kennedy Classification Kennedy Classification  4 basic classes. 4 basic classes.  Edentulous areas other than those Edentulous areas other than those determining the basic classes were determining the basic classes were designated as modification spaces. designated as modification spaces. Class I : Bilateral edentulous areas located Class I : Bilateral edentulous areas located posterior to the natural teeth. posterior to the natural teeth. Class II : A unilateral edentulous area Class II : A unilateral edentulous area posterior to the remaining natural teeth. posterior to the remaining natural teeth.
  • 8. Kennedy Classification Kennedy Classification Class III: Unilateral edentulous area with Class III: Unilateral edentulous area with natural teeth remaining both ant and post natural teeth remaining both ant and post to it. to it. Class IV : A single, but bilateral (crossing Class IV : A single, but bilateral (crossing the midline), edentulous area located the midline), edentulous area located anterior to the remaining natural teeth. anterior to the remaining natural teeth.
  • 9. Principal Advantage Principal Advantage  It permits immediate visualization of the It permits immediate visualization of the partially edentulous arch and allows easy partially edentulous arch and allows easy distinction bw tooth-supported versus distinction bw tooth-supported versus tooth-tissue supported prostheses. tooth-tissue supported prostheses.
  • 10. Applegate's Applegate's Rules for Applying Rules for Applying the Kennedy Classification the Kennedy Classification Rule 1 : The classification should follow, not Rule 1 : The classification should follow, not precede extractions. precede extractions. Rule 2 : If a 3 Rule 2 : If a 3rd rd molar is missing and not to molar is missing and not to be replaced, it is not considered in the be replaced, it is not considered in the classification. classification. Rule 3 : If a3rd molar is present and not to Rule 3 : If a3rd molar is present and not to be used as an abutment, it is not be used as an abutment, it is not considered in the classification. considered in the classification.
  • 11. Applegate's Applegate's Rules Rules Rule 4 : If a 2 Rule 4 : If a 2nd nd molar is missing and not to molar is missing and not to be replaced, it is not considered in the be replaced, it is not considered in the classification. classification. Rule 5 : The most posterior area always Rule 5 : The most posterior area always determines the classification. determines the classification. Rule 6 : Edentulous areas other than those Rule 6 : Edentulous areas other than those determining the classification are referred determining the classification are referred to as modifications and designated by to as modifications and designated by their No. their No.
  • 12. Applegate's Applegate's Rule Rule Rule 7 : The extent of the modifications is Rule 7 : The extent of the modifications is not considered, only the No. of additional not considered, only the No. of additional edentulous areas. edentulous areas. Rule 8 : There are no modification in Class Rule 8 : There are no modification in Class IV. IV.
  • 13. Principal Of Partial Denture Principal Of Partial Denture Design Design  Stresses acting on RPDs are transmitted Stresses acting on RPDs are transmitted to the teeth, and to the tissues of the to the teeth, and to the tissues of the residual ridges. residual ridges.  The stresses, which tend to move the PD The stresses, which tend to move the PD in different directions are: in different directions are: 3. 3. Masticatory stress( Tissue ward movt). Masticatory stress( Tissue ward movt). 4. 4. Gravity( Tissue away movt). Gravity( Tissue away movt). 5. 5. Sticky food pull the denture occlusaly Sticky food pull the denture occlusaly (Tissue-away movt). (Tissue-away movt).
  • 14. 4. Muscles and tongue tend to displace 4. Muscles and tongue tend to displace denture from its foundation. denture from its foundation. 5. Intercuspation of the teeth may tend to 5. Intercuspation of the teeth may tend to produce horizontal and rotational produce horizontal and rotational stresses unless occlusal is adjusted. stresses unless occlusal is adjusted.
  • 15. Properly Constructed PD Must Properly Constructed PD Must :Have :Have 1. 1. Support: Resistance to vertical seating Support: Resistance to vertical seating forces( provided by teeth and mucosa). forces( provided by teeth and mucosa). 2. 2. Retention: Resistance to vertical Retention: Resistance to vertical displacing forces. displacing forces. 3. 3. Stability( bracing) resistance to Stability( bracing) resistance to horizontal and lateral displacement. horizontal and lateral displacement.  All the above should be within the All the above should be within the physiological limits of the tissue involved. physiological limits of the tissue involved. A A
  • 16. Designing Support Designing Support a. Tooth support: When abutment teeth available a. Tooth support: When abutment teeth available at both ends of the denture base( bounded at both ends of the denture base( bounded saddle). It most commonly obtained by saddle). It most commonly obtained by occlusal rests. occlusal rests. b. Mucosa support: (mucoperiosteum covering b. Mucosa support: (mucoperiosteum covering residual alveolar bone). It allows varying residual alveolar bone). It allows varying degree of displacement. degree of displacement.  The amount of displacement( tissue ward The amount of displacement( tissue ward movt) will depend on: movt) will depend on: 4. 4. The amount of pressure applied. The amount of pressure applied. 5. 5. The nature of the mucosa (thickness). The nature of the mucosa (thickness).
  • 17. 3. Area covered by the denture( the wider 3. Area covered by the denture( the wider the area the less the displacement). the area the less the displacement). 4. Fit of the denture base. 4. Fit of the denture base. 5. Type of impression( anatomical, 5. Type of impression( anatomical, functional, or selective pressure). functional, or selective pressure). c. Tooth-mucosa support: ( Bilateral free c. Tooth-mucosa support: ( Bilateral free end saddle). end saddle).  Posterior tissue support, and anterior Posterior tissue support, and anterior tooth support. tooth support.
  • 18. Designing Retention Designing Retention  Retention should be designed to counter act Retention should be designed to counter act dislodging forces( sticky food, muscle at dislodging forces( sticky food, muscle at periphery of the denture, intercuspation, periphery of the denture, intercuspation, gravity). gravity).  Retention is gained by mechanical means Retention is gained by mechanical means 1. direct retainers: 1. direct retainers: a. Intercoronal( clasps). a. Intercoronal( clasps). b. intracronal(percision attachment). b. intracronal(percision attachment). 2. Indirect retainers. 2. Indirect retainers.
  • 19.  Physical factors( cohesion, adhesion, Physical factors( cohesion, adhesion, atmospheric pressure, surface tension). it atmospheric pressure, surface tension). it play a minor role RBD. play a minor role RBD.
  • 20. Designing Bracing and Stability Designing Bracing and Stability  Bracing( providing resistance to lateral Bracing( providing resistance to lateral movt.of RBD). movt.of RBD).  Causes of tipping, rocking and Causes of tipping, rocking and rotation of P.D. rotation of P.D. 3. 3. Quality of supporting structure. Quality of supporting structure.
  • 21. 2. The tissue-ward movt. 2. The tissue-ward movt. Of the free end Of the free end base create an axis of rotation around base create an axis of rotation around which this appliance is rotated. which this appliance is rotated. This axis of rotation is called a fulcrum line This axis of rotation is called a fulcrum line (it is imaginary line extending between (it is imaginary line extending between the two main abutment. the two main abutment.
  • 22. How to counteract lateral shifting? How to counteract lateral shifting? 1. 1. Bracing the sides of the teeth by means Bracing the sides of the teeth by means of rigid clasp arms. of rigid clasp arms. 2. 2. Use of continuous bar resting on the Use of continuous bar resting on the lingual surfaces of the natural standing lingual surfaces of the natural standing teeth. teeth.
  • 23. Components Of RPDs Components Of RPDs 1. 1. Major connectors. Major connectors. 2. 2. Minor connectors. Minor connectors. 3. 3. Rests. Rests. 4. 4. Direct retainers. Direct retainers. 5. 5. Stabilizing or reciprocal components Stabilizing or reciprocal components (part of clasp assembly). (part of clasp assembly). 6. 6. Indirect retainers( if prosthesis has distal Indirect retainers( if prosthesis has distal extension). extension).
  • 24. Major Connecters Major Connecters  Major connector is component of the PD Major connector is component of the PD which connect all parts of the prosthesis which connect all parts of the prosthesis directly or indirectly. directly or indirectly.  It provides the cross-arch stability to help It provides the cross-arch stability to help resist displacement by functional stresses. resist displacement by functional stresses.
  • 25. Characteristics Of Major Connectors Characteristics Of Major Connectors 1. 1. Made from material compatible with oral Made from material compatible with oral tissue. tissue. 2. 2. It is rigid. It is rigid. 3. 3. Doesn't alter the natural contour of the Doesn't alter the natural contour of the lingual surfaces of the mandibular lingual surfaces of the mandibular alveolar ridge or of the palatal vault. alveolar ridge or of the palatal vault. 4. 4. Doesn't impinge on oral tissue in Doesn't impinge on oral tissue in (insertion, withdrawal. Or in function). (insertion, withdrawal. Or in function).
  • 26. 6. Cover no more tissue than is absolutely 6. Cover no more tissue than is absolutely necessary. necessary. 7. Doesn't contribute to the trapping of food 7. Doesn't contribute to the trapping of food particles. particles. 8. Has support from other elements of the 8. Has support from other elements of the frame work to minimize rotation in frame work to minimize rotation in function. function. 9. Contribute to the support of the 9. Contribute to the support of the prosthesis. prosthesis.
  • 27. Mandibular Major Connectors Mandibular Major Connectors 1. 1. Lingual bar. Lingual bar. 2. 2. Linguoplate. Linguoplate. 3. 3. Sublingual bar. Sublingual bar. 4. 4. Lingual bar with cingulum bar (continuous Lingual bar with cingulum bar (continuous bar). bar). 5. 5. Cingulum bar (continuous bar). Cingulum bar (continuous bar). 6. 6. Labial bar. Labial bar.  Lingual bar and Linguopslate are most Lingual bar and Linguopslate are most common used. common used.
  • 28. 1. 1. Mandibular lingual Bar Mandibular lingual Bar  Indication: Where sufficient space exist Indication: Where sufficient space exist b/w elevated alveolar lingual sulcus and b/w elevated alveolar lingual sulcus and the lingual gingival tissue. the lingual gingival tissue.  Location: Location: 3. 3. Half-pear shaped, with bulkiest portion Half-pear shaped, with bulkiest portion inferiorly. inferiorly. 4. 4. Superior border tapered, located at least Superior border tapered, located at least 4mm inferior to gingival margin. 4mm inferior to gingival margin.
  • 29. 4. Inferior border located at site of the 4. Inferior border located at site of the alveolar lingual sulcus where the pt alveolar lingual sulcus where the pt´s ´s tongue is elevated. tongue is elevated.  Finishing line: Butt-type joints with minor Finishing line: Butt-type joints with minor connector for retention of denture base. connector for retention of denture base.
  • 30. .2 .2Mandibular Sublingual Bar Mandibular Sublingual Bar  It is modification of lingual bar used when It is modification of lingual bar used when the existing space not allow placement of the existing space not allow placement of lingual bar. lingual bar.  The shape remain the same but placement The shape remain the same but placement is inferior and posterior to site of lingual is inferior and posterior to site of lingual bar. bar.
  • 31.  Contraindication: Contraindication: Remaining natural anterior teeth severely Remaining natural anterior teeth severely tilted toward the lingual. tilted toward the lingual.  Characteristics and location: Characteristics and location: 4. 4. Half-pear shaped same like the lingual Half-pear shaped same like the lingual bar except bar except that the bulkiest portion is that the bulkiest portion is located to the lingual and the tapered located to the lingual and the tapered portion is toward the labial. portion is toward the labial.
  • 32. 2. The superior border of the bar should be 2. The superior border of the bar should be at least 3mm from the free gingival at least 3mm from the free gingival margin of the teeth. margin of the teeth. 3. The inferior border is located at height of 3. The inferior border is located at height of the alveolar lingual sulcus when the pt the alveolar lingual sulcus when the pt´s ´s tongue is elevated. tongue is elevated. 4. Functional impression is most. 4. Functional impression is most.  Finishing line: Butt-type joints with minor Finishing line: Butt-type joints with minor connectors for retention of denture base. connectors for retention of denture base.
  • 33. .3 .3Mandibular Linguoplate Mandibular Linguoplate  Indication for use: Indication for use: 2. 2. No sufficient space for lingual bar. No sufficient space for lingual bar. 3. 3. The residual ridge undergone a vertical The residual ridge undergone a vertical resoption which offer minimal resistance resoption which offer minimal resistance to horizontal rotation. to horizontal rotation. 4. 4. Periodontally weakened teeth. Periodontally weakened teeth. 5. 5. When future replacement of one or more When future replacement of one or more incisor teeth will be facilitated. incisor teeth will be facilitated.
  • 34.  Characteristics and location: Characteristics and location: 2. 2. Half-pear shaped with bulkiest portion located. Half-pear shaped with bulkiest portion located. 3. 3. Thin metal apron extending superiorly to Thin metal apron extending superiorly to contact cingulum of ant. Teeth. contact cingulum of ant. Teeth. 4. 4. Apron extended interproximally to the height Apron extended interproximally to the height of contact points. of contact points. 5. 5. Inferior border at ascertained height of the Inferior border at ascertained height of the alveolar lingual sulcus where the pt alveolar lingual sulcus where the pt´s tongue ´s tongue is slightly elevated. is slightly elevated.
  • 35. .4 .4Mandibular Lingual Bar with Mandibular Lingual Bar with Continuous Bar) Cingulum Bar Continuous Bar) Cingulum Bar ( (  Indication for use: Indication for use: 2. 2. When Linguoplate is indicated but the When Linguoplate is indicated but the axial alignment of ant. Teeth prevent . axial alignment of ant. Teeth prevent . 3. 3. When wide diastema b/w mandibular When wide diastema b/w mandibular ant. Teeth. ant. Teeth.
  • 36.  Characteristics and location: Characteristics and location: 2. 2. Shaped and located same as lingual bar. Shaped and located same as lingual bar. 3. 3. Thin, narrow(3mm) metal strap located Thin, narrow(3mm) metal strap located on a cingula of anterior teeth. Scalloped on a cingula of anterior teeth. Scalloped to follow interproximal embrasures. to follow interproximal embrasures. 4. 4. Originated bilaterally from incisal, lingual, Originated bilaterally from incisal, lingual, or occlusal rests of adjacent principal or occlusal rests of adjacent principal abutment. abutment.
  • 37. 5 5 Mandibular Labial Bar . Mandibular Labial Bar .  Indication for use: Indication for use: 2. 2. When a lingual inclination of remaining When a lingual inclination of remaining MPM and incisors teeth cannot be MPM and incisors teeth cannot be corrected. corrected. 3. 3. Severe lingual tori cannot be removed. Severe lingual tori cannot be removed. 4. 4. Severe tissue undercut. Severe tissue undercut.
  • 38.  Characteristics and location: Characteristics and location: 2. 2. Half –pear shaped with bulkiest portion Half –pear shaped with bulkiest portion inferiorly located inferiorly located on the labial and buccal on the labial and buccal aspect of the mandible. aspect of the mandible. 3. 3. Superior border tapered to soft tissue. Superior border tapered to soft tissue. 4. 4. Superior border located at least 4mm inferior Superior border located at least 4mm inferior to labial and buccal gingival margins and more to labial and buccal gingival margins and more if possible. if possible. 5. 5. Inferior border located in the labial buccal Inferior border located in the labial buccal vestibule. vestibule.
  • 39. Maxillary Major Connectors Maxillary Major Connectors A. Single palatal strap A. Single palatal strap  Characteristics and Location: Characteristics and Location: 3. 3. Anatomic replica form. Anatomic replica form. 4. 4. Ant. Border follow the valleys b/w rugae at Ant. Border follow the valleys b/w rugae at right angle to median suture line. right angle to median suture line. 5. 5. Posterior border at right angle to median Posterior border at right angle to median suture line. suture line. 6. 6. Strap should be 8mm wide. Strap should be 8mm wide. 7. 7. Confined with in an area bounded by the four Confined with in an area bounded by the four principal rests. principal rests.
  • 40. B. B. Single Broad Palatal Major Single Broad Palatal Major Connector Connector  Indication: Indication: 3. 3. Class I. Class I. 4. 4. V or U shaped palate. V or U shaped palate. 5. 5. Strong abutments. Strong abutments. 6. 6. 6 remaining ant teeth. 6 remaining ant teeth. 7. 7. No interfering tori. No interfering tori.
  • 41.  Characteristics and location: Characteristics and location: 2. 2. Anatomic replica form. Anatomic replica form. 3. 3. Anterior border following valleys of rugae Anterior border following valleys of rugae and at right angle to median suture line and at right angle to median suture line and extending anterior to occlusal rests and extending anterior to occlusal rests or in direct retainer. or in direct retainer.
  • 42. 3. Posterior border located at junction of 3. Posterior border located at junction of hard and soft palate. And extended to hard and soft palate. And extended to pterygomaxillary notches. pterygomaxillary notches.
  • 43. C. C. Anterior-posterior Strap Anterior-posterior Strap  Indication Indication: : 3. 3. Class I and II. Class I and II. 4. 4. Long edentulous span class II MOD 1 Long edentulous span class II MOD 1 arches. arches. 5. 5. Class IV. Class IV. 6. 6. Palatal tori. Palatal tori.
  • 44.  Characteristics and location: Characteristics and location: 2. 2. Parallelogram shaped and open in center Parallelogram shaped and open in center portion. portion. 3. 3. Relatively broad(8-10mm) ant. And post. Relatively broad(8-10mm) ant. And post. Palatal strap. Palatal strap. 4. 4. Lateral palatal strap (7-9mm) parallel to Lateral palatal strap (7-9mm) parallel to curve of arch. 6mm from gingiva of curve of arch. 6mm from gingiva of remaining teeth. remaining teeth.
  • 45. 4. Anterior palatal strap; ant border not 4. Anterior palatal strap; ant border not placed further interiorly than ant rests and placed further interiorly than ant rests and never closer than 6mm to lingual gingival never closer than 6mm to lingual gingival cervices. cervices.
  • 46. D. D. Complete Palatal Coverage Complete Palatal Coverage Indication for use: Indication for use: 3. 3. Situation in which only some or ant teeth Situation in which only some or ant teeth remains. remains. 4. 4. Class II arch with large posterior Class II arch with large posterior modification space and some missing modification space and some missing anterior teeth. anterior teeth.
  • 47. 3. Class I arch with 1-4 PM and some or all 3. Class I arch with 1-4 PM and some or all ant teeth remaining, abutment support is ant teeth remaining, abutment support is poor, residual ridge extremely resorbed, poor, residual ridge extremely resorbed, direct retention is difficult to obtained direct retention is difficult to obtained 4. No tori. 4. No tori.
  • 48.  Characteristics and location: Characteristics and location: 2. 2. Anatomic replica form supported anteriority by Anatomic replica form supported anteriority by rests seats. rests seats. 3. 3. Palatal Linguoplate supported anteriorly and Palatal Linguoplate supported anteriorly and designed for the attachment of acrylic resin designed for the attachment of acrylic resin extension posteriorly. extension posteriorly. 4. 4. Contact all of the teeth remaining in the arch. Contact all of the teeth remaining in the arch. 5. 5. Posterior border, terminates at the junction of Posterior border, terminates at the junction of the hard and soft palate, extended to hasmular the hard and soft palate, extended to hasmular notch areas. notch areas.
  • 49. D. D. U-shaped Palatal Major Connector U-shaped Palatal Major Connector  Is used only in which inoperable tori Is used only in which inoperable tori extended to the posterior limit of the hard extended to the posterior limit of the hard palate. palate.  It is the least favorable design of all It is the least favorable design of all palatal major connector( lack rigidity). palatal major connector( lack rigidity).
  • 50. Rests and Rest seats Rests and Rest seats  Vertical support provided by rests Vertical support provided by rests (occlusal, incisal, or cingulum). (occlusal, incisal, or cingulum).  Rests located on properly prepared tooth Rests located on properly prepared tooth surface . surface .  The prepared surface of an abutment to The prepared surface of an abutment to receive the rest is called the rest seat. receive the rest is called the rest seat.
  • 51.  The primary purpose of the rest is to provide The primary purpose of the rest is to provide vertical support for PD. It also does the vertical support for PD. It also does the following: following: 2. 2. Maintain components in planned position. Maintain components in planned position. 3. 3. Maintained established occlusal relationship. Maintained established occlusal relationship. 4. 4. Prevent impingement of soft tissue. Prevent impingement of soft tissue. 5. 5. Direct and distribute occlusal loads to Direct and distribute occlusal loads to abutment teeth. abutment teeth.
  • 52. Form Of Occlusal Rest and Rest Form Of Occlusal Rest and Rest Seats Seats 1. 1. The outline form of the occlusal rest The outline form of the occlusal rest should be rounded, triangular shaped should be rounded, triangular shaped with the apex toward the center of with the apex toward the center of occlusal surfaces. occlusal surfaces. 2. 2. It should be as long as it is wide. The It should be as long as it is wide. The base is 2.5mm for M and PM. base is 2.5mm for M and PM. 3. 3. Reduction in marginal ridge is 1.5mm. Reduction in marginal ridge is 1.5mm.
  • 53. 4. It should be concave and spoon shaped 4. It should be concave and spoon shaped (no sharp edges or line angle). (no sharp edges or line angle). 5. The angle formed by the occlusal rest and 5. The angle formed by the occlusal rest and the vertical minor connector from which the vertical minor connector from which its originate should be less than 90 its originate should be less than 90*. *.
  • 54. Extended Occlusal Rest Extended Occlusal Rest  In mesially inclined abutment In mesially inclined abutment the rest the rest extend more than one half of the mesio- extend more than one half of the mesio- distal width. distal width.  In severely tilted abutment the extended In severely tilted abutment the extended occlusal rest may take the form of an only occlusal rest may take the form of an only to restore the occlusal plane. to restore the occlusal plane.
  • 55.  Interproximal Occlusal rests. Interproximal Occlusal rests.  Intra-coronal Rest: It is used for both occlusal Intra-coronal Rest: It is used for both occlusal support and horizontal stabilization. support and horizontal stabilization. Horizontal stabilization is derived from the near Horizontal stabilization is derived from the near vertical walls of this type of rest seat. vertical walls of this type of rest seat.  The form of the rest should be parallel to path of The form of the rest should be parallel to path of placement, slightly tapered occlusaly, and placement, slightly tapered occlusaly, and slightly dove-tailed to preve3nt dislodgement slightly dove-tailed to preve3nt dislodgement proximally. proximally.
  • 56.  The main advantages of the internal rest The main advantages of the internal rest are that it facilitates the elimination of the are that it facilitates the elimination of the visible clasp arm. visible clasp arm.
  • 57. Direct Retainer Direct Retainer  It is a clasp or attachments applied to an It is a clasp or attachments applied to an abutment tooth for the purpose of holding RPD abutment tooth for the purpose of holding RPD in position. in position.  Classification Classification: : 3. 3. Extracronal direct retainer Extracronal direct retainer) ) casted clasp, casted clasp, wrought wire clasp). wrought wire clasp). a/ Occlusaly approaching clasp a/ Occlusaly approaching clasp (circumferential) . (circumferential) . b/ Gingivally approaching clasps (Bar clasps) b/ Gingivally approaching clasps (Bar clasps)
  • 58. 2. Intracronal direct retainer( attachments): 2. Intracronal direct retainer( attachments): a/ Internal attachment. a/ Internal attachment. b/ External attachment. b/ External attachment. c/ Special attachment. c/ Special attachment.  Component parts of the clasp: Component parts of the clasp: 1. Retentive terminal 2. Retentive arm 1. Retentive terminal 2. Retentive arm 3. Reciprocal arm 4. Occlusal rest 3. Reciprocal arm 4. Occlusal rest 5. Shoulder 6. Body 7. Minor connector 5. Shoulder 6. Body 7. Minor connector
  • 59.  Height of contour: is greatest convexity Height of contour: is greatest convexity of tooth. of tooth.  The basic principle of clasp design is The basic principle of clasp design is encirclement to obtain more than 180 encirclement to obtain more than 180* of * of continuous contact. continuous contact.  Types of cast Circumferential clasps: Types of cast Circumferential clasps: 4. 4. Simple circlet clasp: widely used, tooth Simple circlet clasp: widely used, tooth supported PD, approach the undercut supported PD, approach the undercut from edentulous space. Not used for from edentulous space. Not used for distal extension. distal extension.
  • 60. 2 2. Reverse clasp. . Reverse clasp. 3. Multiple circlet clasp) combination of two 3. Multiple circlet clasp) combination of two circlet clasps(. circlet clasps(. 4. Embrasure clasp 4. Embrasure clasp 5. Ring clasp; no buccal undercut. Isolated 5. Ring clasp; no buccal undercut. Isolated abutment, lingually tipped molar, from abutment, lingually tipped molar, from disto- buccal to disto-lingual undercut. disto- buccal to disto-lingual undercut. 6. Hairpin clasp. when undercut is near to 6. Hairpin clasp. when undercut is near to edentulous space. edentulous space. 7 7. Combination clasp. . Combination clasp.
  • 61.  Bar clasp: Composed of two parts Bar clasp: Composed of two parts ( Gingivally approaching and retentive ( Gingivally approaching and retentive tip) tip) 2. 2. Approach arm: It is a minor connector. Approach arm: It is a minor connector. Semi circular in cross section, cross the Semi circular in cross section, cross the gingival margin at right angle. gingival margin at right angle. 3. 3. Retentive terminal : it should end below Retentive terminal : it should end below undercut. undercut.
  • 62. Advantages: Advantages: 2. 2. Easy to insert and difficult to remove. Easy to insert and difficult to remove. 3. 3. More aesthetic, cover less tooth More aesthetic, cover less tooth structure. structure. – Types of Bar clasps: Types of Bar clasps: 5. 5. T-Bar clasp. T-Bar clasp. 6. 6. Y- Bar clasp. Y- Bar clasp. 7. 7. I- Bar clasp. I- Bar clasp.
  • 63. Indirect Retainer Indirect Retainer  Apart of RPD which assists the direct Apart of RPD which assists the direct retainers in preventing displacement of retainers in preventing displacement of distal extension denture base by distal extension denture base by functioning through lever action on the functioning through lever action on the opposite side of the fulcrum line. opposite side of the fulcrum line.
  • 64.  Types of indirect retainer: Types of indirect retainer: 2. 2. Auxiliary occlusal rest, most frequently Auxiliary occlusal rest, most frequently used, located far as possible from distal used, located far as possible from distal extension base, placed perpendicular to extension base, placed perpendicular to the mid point of the fulcrum line. If this the mid point of the fulcrum line. If this perpendicular line ends on the incisal perpendicular line ends on the incisal area it is a voided, instead it transfers to area it is a voided, instead it transfers to PM in both sides. PM in both sides.
  • 65. 2. Canine extension from occlusal rest, 2. Canine extension from occlusal rest, finger like extention(lug seat) from the PM finger like extention(lug seat) from the PM rest is placed on the lingual slope of rest is placed on the lingual slope of adjacent canine. adjacent canine. 3. Canine rest. 3. Canine rest. 4. Continuous bar retainers and Linguoplate. 4. Continuous bar retainers and Linguoplate.
  • 66. Denture Base Denture Base  Denture base defined as that part of a Denture base defined as that part of a denture which rests on the oral mucosa denture which rests on the oral mucosa and to which teeth are attached. and to which teeth are attached.  Ideal requirements: Ideal requirements: 3. 3. Accurate tissue adaptation with minimal Accurate tissue adaptation with minimal change in volume. change in volume. 4. 4. Thermal conductivity. Thermal conductivity. 5. 5. Sufficient strength to resist fracture or Sufficient strength to resist fracture or distortion under function. distortion under function.
  • 67. 4. Cleansability. 4. Cleansability. 5. Ability to be relined if necessary. 5. Ability to be relined if necessary. 6 Cost effective. 6 Cost effective. 7. Low specific gravity. 7. Low specific gravity. 8. Ability to achieve a good finish. 8. Ability to achieve a good finish.
  • 68.  Types of denture base: Types of denture base: 2. 2. Acrylic Acrylic 3. 3. Metal. Metal. 4. 4. Combination. Combination.  Acrylic Resin denture base; mainly used Acrylic Resin denture base; mainly used for distal extension PD- attached to the for distal extension PD- attached to the frame work by minor connector-with frame work by minor connector-with 1.5mm thick to have a adequate 1.5mm thick to have a adequate strength. strength.
  • 69.  Advantages: Advantages: 2. 2. Anterior teeth can be replaced at their Anterior teeth can be replaced at their original position (aesthetic level). original position (aesthetic level). 3. 3. Restore the contour of the edentulous Restore the contour of the edentulous ridge. ridge. 4. 4. Brings out the normal contour of the lip Brings out the normal contour of the lip and cheeks. and cheeks. 5. 5. Can be relined. Can be relined.
  • 70.  Disadvantages: Disadvantages: 2. 2. May break on usage. May break on usage. 3. 3. Tend to accumulate mucous deposits Tend to accumulate mucous deposits and food debris. and food debris. 4. 4. Soft tissue irritation. Soft tissue irritation. 5. 5. Allergy. Allergy.
  • 71.  Metal denture base: mainly used for tooth Metal denture base: mainly used for tooth supported PD. supported PD.  Advantages: Advantages: 3. 3. Accurate tissue adaptaion( better retention). Accurate tissue adaptaion( better retention). 4. 4. Easy to clean. Easy to clean. 5. 5. Strong even in thin section. Strong even in thin section. 6. 6. Heat conductivity( physiologic tissue Heat conductivity( physiologic tissue stimulation). stimulation).
  • 72.  Disadvantage: Disadvantage: 2. 2. Difficult to trim and adjust. Difficult to trim and adjust. 3. 3. Over extension can injure the soft tissue. Over extension can injure the soft tissue. 4. 4. Poor aesthetic. Poor aesthetic. 5. 5. Difficult to reline and rebase. Difficult to reline and rebase.