Retainers- FPD

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RETAINERS
DEFINITION:
Any type of device used for
stabilization or retention of
prosthesis -- GPT
 Retainer
 That
for an FPD…
component of an FPD which
takes support from the abutment
tooth and provides retention to
the prosthesis
SELECTION OF RETAINERS

1)
2)
3)
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5)
6)
Retainer selection for abutment is critical
and is dictated by the followings:
Age
DMF rate
Edentulous space-Partial veneer crown
contraindicated in long span FPD
Periodontal support
Arch position of the tooth
Skeletal relationship
7)
8)
9)
Inter occlusal & intraocclusal
condition such as crown length
Oral hygiene of the patient
Vitality of the abutment teeth--endodontically treated teeth may
have to be restored with core &
post before designing the
retainer
10)
11)
12)
Condition of the abutment teeth
Cost
Preservation of the tooth
structure----Buccal surface
should be conserved. Partial
veneer crown is more
conservative than full crown . All
ceramic crowns are least
conservative
Types of retainers

I.
Classified as:
Based on tooth coverage
Full veneer crown
Partial veneer crown
Conservative (minimal prep.)
retainers
II.
Based on material used
All metal retainers
Metal ceramic retainers
All ceramic retainers
All acrylic retainers
Full veneer crowns
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Covers all 5 surfaces of abutment
Most retentive of the veneer preparations
Compared to partial veneer designs,full
veneer crown exhibits superior resistance
nd retention
Used on those teeth whose restoration
demands max. retention.


Variations—Metal ceramic crowns and all
ceramic crowns used in situations that
requires a good cosmetic results
The full veneer crown should be used
when less extensive and less destructive
design have been considered and found
lacking in retention ,resistance ,coverage
or esthetics to properly restore the tooth
Partial veneer crown
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Preferred than full veneer crown because
they requires less tooth reduction
Crown does not cover the entire abutment
Facial surface is left intact for superior
esthetics
Used when minimal retention is sufficient
and when abutment tooth is healthy
Contra indications
 In
long span FPDs
 Endodontically treated tooth
 Dentition with active caries or
periodontal disease
 Poorly aligned abutment tooth
Advantages
 Conservation
of tooth structure
 Reduced pulpal and periodontal
insult during tooth prep
 Improved access for finishing by
dentist & oral hygiene by patient
 Less
of margin approximate soft
tissues subgingivally and hence
less gingival involvement than
complete coverage
 Remaining
intact facial or buccal
tooth surface permits electric
vitality test
Disadvantages
Less retention & resistance than
complete crowns
 Some metal displayed in completed
restoration—unaesthetic
 Tooth prep is difficult because only
limited
adjustments can be made in the
path of placement

Resin bonded retainers
(Maryland bridges)
 Require
minimal tooth preparation
 Acid etched
 Esthetically appealing
 Economical , conservative ,
functional & do not irritate soft or
hard tissues
Indication
 As
retainers of FPD for abutment
with sufficient enamel to etch
 Splinting of periodontally
compromised teeth
 Stabilizing dentition after
orthodontic treatment
Contraindication
 In
patients with sensitivity to base
metal alloys
 When facial esthetic of abutment
require improvement
 Inadequate enamel surface to
bond eg;caries,existing
restoration
 Incisor with extremely thin faciolingual dimension
Advantages
Non invasive to dentin with lingual
and proximal tooth preparation
including occlusal rest
 Conservative with undeniable patient
appearance
 Tissue tolerant because of
Supragingival margin,without pulpal
irritation
 Reduced cost and less chair side time

Disadvantage
 Demanding
technique and tooth
prep.
 Plaque accumulation
 Bulky contour
 Restricted to single pontic
placement
 Graying out of teeth that are thin
labiolingually
Based on material used
 All
metal retainers
 Metal ceramic retainers
 All ceramic retainers
All metal retainers
 Partial
or full veneer crown
 Require minimal tooth
reduction
 Strong even in thin sections
Metal ceramic retainers
Indicated on teeth that require
complete coverage & esthetic
demand
 Can accommodate cast or soldered
connectors
 Can afford high force—metal
 Require more teeth reduction

Indication
Extensive tooth destruction as a
result of caries or trauma
 Existing previous restoration that
precludes the use of a more
conservative restoration
 Need for superior retention and
strength
 Endodontically treated tooth

Contraindication
Whenever
a more
conservative retainer is
feasible
All ceramic
 Primary
purpose ---to achieve
best possible esthetic results
 Risk of reduced restoration
longevity—potential for fracture
,inferior marginal adaptation than
PFM retainer
Telescopic retainers
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Used when path of insertion of FPD does
not coincide with long axis of abutment
Design involves fabricatin of two copings
one over the other
Internal or primary coping function to
modify the morphology of tooth –path pf
insrtn changed
Secondary coping designed to fit over
primary
REFERENCES
1.
2.
3.
4.
Fundamentals of Fixed Prosthodontics
Herber T.Shillingburg
Contemporary Fixed Prosthodontics
Rosenstiel,Land,Fujimoto
Tylmans Theory and Practice of Fixed
Prosthodontics
Textbook of Prosthodontics-Deepak
Nallaswamy
Thanking you…..
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