Connectors –in fpd/certified fixed orthodontic courses by Indian dental academy

INDIAN DENTAL ACADEMY
Leader in continuing Dental Education
www.indiandentalacademy.com

Connectors are those parts of a fixed
partial denture orsplint that join the
individual Retainers and Pontics
together.
 Usually this is accomplished with
-"Rigid connectors” although
nonrigid connectors are used
occasionally.
 The latterare usually indicated
when it is impossible to prepare a
common path of insertion forthe
abutment preparations foran FPDwww.indiandentalacademy.com

CONNECTOR
The portion of an FPDthat unites the
retainer(s) and pontic(s).
RIGIDCONNECTOR
A cast, soldered, orfused union between
the retainer(s) and pontic(s).
NON RIGIDCONNECTOR
Any connectorthat permits limited
movement between otherwise
independent members of an FPD.www.indiandentalacademy.com

RIGID CONNECTORS
Rigid connections in metal can be
made by casting, soldering, or
welding.
Cast connectors
 are shaped in wax as part of a
multiunit wax pattern.
Cast connectors are convenient and
minimize the numberof stepswww.indiandentalacademy.com

The fit of the individual
retainers may be
adversely affected
because distortion more
easily results when a
multiunit wax pattern is
removed from the die
system.

Soldered connectors
involve the use of an
intermediate metal alloy whose
melting temperature is lowerthan
that of the parent metal
The parts being joined are not
melted during soldering but must
be thoroughly wettable by
liquefied solder.

Dirt orsurface oxides on
the connectorsurfaces can
reduce wetting and
impede successful
soldering; forexample,
the soldermay melt but
will not flow into the
soldering gap.

WeldingWelding
is anothermethod of rigidly
joining metal parts.
Here the connection is created
by melting adjacent surfaces
with heat orpressure.
A fillermetal whose melting
temperature is about the same
as that of the parent metal can
be used during welding.www.indiandentalacademy.com

In industrial metalworking, a
distinction is made between soldering,
in which the fillermetal has a melting
point below 450 º C (842º F), and
brazing, in which the fillerhas a
melting point above 450 º C
Rigid connections in dentistry are
generally fabricated above 450 º C,
but the process has almost always
been referred to in the dental literature
as soldering.
 A proposed international standard
uses the term brazing.www.indiandentalacademy.com

NONRIGID CONNECTORSNONRIGID CONNECTORS
Nonrigid connectors are indicated when it is
not possible to prepare two abutments for
an FPDwith a common path of placement.
Segmenting the design of large, complex
FPDs into shortercomponents that are
easierto replace orrepairindividually is
advisable.
This can be helpful if there is uncertainty
about an abutment's prognosis.
If the abutment fails, only a portion of the
FPDmay need to be remade.www.indiandentalacademy.com

In the mandibulararch, nonrigid
connectors are indicated when a complex
FPDconsists of anteriorand posterior
segments.
 During the mandibularopening and
closing stroke, the mandible flexes
mediolaterally.'
 Rigid fixed partial dentures have been
shown to inhibit mandibularflexure, and
extensive splints have been shown to
flex during forced opening
The associated stresses can cause
dislodgment of complex FPDs.
Segmenting complex mandibularFPDswww.indiandentalacademy.com

Nonrigidconnectors aregenerated
throughincorporationof prefabricated
inserts inthewaxpatternorthrough
custommillingprocedures afterthefirst
castinghas beenobtained.
 Thesecondpartis thencustom-fittedto
themilledretainerandcast.
Theyareoftenmadewithprefabricated
plastic patterns.
 Theretainers arethencastseparately
andfittedtoeachotherinmetal.www.indiandentalacademy.com

CONNECTOR DESIGN
The size, shape, and position of
connectors all influence the success
of the prosthesis.
Connectors must be sufficiently
large to prevent distortion or
fracture during function but not too
large; otherwise, they will interfere
with effective plaque control and
contribute to periodontal
breakdown overtime.www.indiandentalacademy.com

Adequate access (i.e., embrasure
space) must be available fororal
hygiene aids cervical to the connector
If a connectoris too large
incisocervically, hygiene is impeded
and overtime periodontal failure will
occurForesthetic FPDs, a large
connectororinappropriate shaping of
the individual retainers may result in
display of the metal connector.

TYPES OF CONNECTORS
RIGIDCONNECTORS
Rigid connectors must be
shaped and incorporated into
the wax pattern afterthe
individual retainers and
pontics have been completed
to final contourbut before
reflowing of the margins forwww.indiandentalacademy.com

Cast Connectors
Connectors to be cast are also waxed
on the mastercast before reflowing
and investing of the pattern.
The presence of a cast connector
makes the pattern somewhat more
awkward.
Access to the proximal margin is
impeded, and the pattern cannot be
held proximally during removal from

Restricting cast connectors
to complete coverage
restorations is therefore
advisable, which can be
gripped buccolingually.
Partial-coverage wax
patterns are easily distorted
when they are part of a
single-cast FPD.www.indiandentalacademy.com

Soldered Connectors.
 As with cast connectors,
connectors to be soldered are waxed
to final shape but are then sectioned
with a thin ribbon saw therefore,
when the components are cast, the
surfaces to be joined will be flat,
parallel, and a controlled distance
apart.
 This allows accurate soldering
with a minimum of distortion.www.indiandentalacademy.com

Molten solderwill flow
toward the location where
the temperature is highest.
In metal, the two flat
surfaces previously created
in wax retain heat,
ensuring that the highest
temperature is in the

Soldering Gap Width.
As gap width increases,
soldering accuracy decreases .
 Extremely small gap widths
can prevent propersolderflow
and lead to an incomplete or
weak joint.

An even soldering gap of
about 0.25 mm is
recommended.
If a connectorarea has an
uneven soldering gap width,
obtaining a connectorof
adequate cross-sectional
dimension without resulting
distortion is more difficultwww.indiandentalacademy.com

Loop Connectors
Although they are rarely used,
loop connectors are sometimes
required when an existing
diastema is to be maintained in a
planned fixed prosthesis.
The connectorconsists of a loop on
the lingual aspect of the prosthesis
that connects adjacent retainers
and/orpontics.

The loop may be cast from
sprue wax that is circularin
cross section orshaped from a
platinum-goldpalladium (Pt-
Au-Pd) alloy wire.
Meticulous design is
important so that plaque
control will not be impeded

NON RIGID CONNECTORS
The design of nonrigid
connectors that are
incorporated in the wax
pattern stage consists of a
mortise (also referred to as the
female component) prepared
within the contours of the
retainerand a tenon (male)
attached to the ponticwww.indiandentalacademy.com

The mortise is usually
placed on the distal aspect
of the anteriorretainer.
Accurate alignment of the
dovetail orcylindrically
shaped mortise is critical; it
must parallel the path of
withdrawal of the distal
retainerwww.indiandentalacademy.com

Paralleling is normally
accomplished with a dental
surveyor.
When aligning the cast, the
path of placement of the
retainerthat will be
contiguous with the tenon is
identified.

The mortise in the other
retaineris then shaped so its
path of insertion permits
concurrent seating of the tenon
and its corresponding retainer.
 The mortise can be prepared
freehand in the wax pattern or
with a precision milling
machine.

Anotherapproachis to
useprefabricatedplastic
components forthemorti
andtenonof anonrigid
connector

As analternative, aspecial
mandrelcanbeembeddedin
thewaxpatternandthe
abutmentretainercanbecast,
withrefinementof thefemale
componentas necessary; the
malekeyis thenfabricatedof
autopolymerizingacrylic resin
andattachedtothepontic.

Connectors –in fpd/certified fixed orthodontic courses by Indian dental academy

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Viewers also liked

Viewers also liked (6)

Similar to Connectors –in fpd/certified fixed orthodontic courses by Indian dental academy

Similar to Connectors –in fpd/certified fixed orthodontic courses by Indian dental academy (20)

More from Indian dental academy

More from Indian dental academy (20)

Recently uploaded

Recently uploaded (20)

Connectors –in fpd/certified fixed orthodontic courses by Indian dental academy