It
is sometimes said that temporary restorations shouldn‘t be made too ‗good‘ for
the fear that the final restorations won‘t look as good as temporary one
in order to decrease the patient‘s expectations to the final restoration
and be satisfied with the final one. But despite that, scientists discovered
that the better the efficiency of the temporary filling, the more it helped us
produce good final fillings, so we must not neglect them. Temporary
restorations of high quality are aesthetically acceptable,
well-fitting, comfortable and dimensionally stable. Whereas the most
problem is that poor temporaries can add stress and the treatment result
in loss of accuracy for the ultimate restoration and lead to many problems
to the final restorations.
provisional
restorations are designed so as to guard oral structures and promote
function and esthetics for a limited period of time, after which they're
to get replaced by a certain prosthesis, the prepared abutment teeth have
to be shielded from the oral environment and also its relationship with the
adjacent and opposing tooth have to be maintained. They should
resemble the shape and performance of the definite rehabilitation that they
precede. Therefore, interim treatment should satisfy the standards of
marginal adaptation, strength and longevity.so They play a specific
role in diagnostic procedures and continued evaluation of the treatment
plan. They represent a very important step in choose the shade, shape and
contour of the ultimate restoration especially in complex esthetic reconstructions.
Different
authors suggest various techniques of making provisional restorations
which have improved over the time, a range of techniques exist for
fabricating provisional materials.so Provisional restorations is also made
directly on prepared teeth with the utilization of a matrix or indirectly
by making a control of the prepared teeth or a mixture indirect-direct
technique is additionally possible which has evolved as a sequential
application of those that involves fabrication of a preformed shell that's
relined intraorally.The progression of provisional materials to bis-acrylics
has result in such advancements as less demanding is in taking care of
progressed compressive and lastingness, less water sorption and less
shrinkage. The end-result is more choices for clinicians for high-quality
chairside temporary restorations.
Newer
provisional materials are easy to control and convey increased comfort to
the patient. During the pretreatment era, manufacturing technology and
advanced materials such as high density polymers add good possibilities
for restorations.This is especially important in places requiring massive
corrections of color, form or position. Pretreatment periods
are absolutely necessary in refining important factors like lip-position
dynamics moreover because the correct position of the smile line which
can‘t be adequately assessed within the dental laboratory and case
report presented, non-manufactured CAD / CAM preparation restorations were
adhesively applied to the required area with no further loss of the structure
of the tooth.The dental professionals today have advanced information
about the quality of interim restorations(7)And we will talk in
detail about all these points in our research.
Function
Interim restoration is very important as it decides whether the
proposed prosthodontic solution for the introducing condition fulfills the
patient's functional requirements and esthetic desires.(10,11)An
appropriately adjusted and contoured interim restoration decides adequate
retention and resistance form for prosthesis.(8) Changes in
vertical element of occlusion, driven occlusal contact connections, and
anterior direction design interim restoration. Changes in tooth length,
form, incisal edge position, lip support, occlusal or incisal plane,
and tooth shading can likewise assesse with interim restoration.(10,
12) Appropriately designed interim restoration is a guide to
crown protracting, ridge enlargement, and pontic site advancement
techniques and helps in pre-prosthetic endodontic and
orthodontic treatments.(13)When the dental specialist and patient
are satisfied with interim prosthesis function, phonetics, and esthetic,
duplicate interim restoration guides technician in manufacture of
definitive prosthesis. Through that, interim restoration guarantees an
anticipated, functional, and esthetic definitive prosthesis. (10)
Fabrication techniques
Direct technique
The
direct method includes use of mold or matrix that is connected intraorally to
the prepared teeth. After tooth preparation, thematrix is preliminary
fitted in the patient's mouth. The prepared teeth are washed,
tenderlydried, and greased up with petroleum jelly. The chose temporary
material is mixed by the producer's directions and put into the matrix; care is
taken to not fuse any air bubbles. The matrix with the temporary
remedialmaterial is then situated over the prepared teeth and permitted to
polymerize. care must be taken to prevent locking of restoration in any
undercuts.(14) To prevent pulpal harm or locking of interim
restoration on the preparations, some promote that the interim restoration
be expelled after the rubbery stage has been reached and permitted total
polymerization outside the mouth. This procedure is tricky with PMMA
pitches due to their polymerization shrinkage. An ''on-off'' procedure is
upheld to prevent locking interim restoration on to the preparation during
polymerization. After the temporary material has arrived at the rubbery
stage, the interim restoration is prodded incompletely off of the
preparations and reseated a few times all through the setting reaction while
the territory isflushed with water as a coolant until polymerization is
complete.(15)Tragically, this method results in moderately poor
marginal integrity.(16) Different scientists advocate letting
the restoration accomplish last set in situ yet underline the need to
constantly flush the territory with water to prevent thermal damage to the
pulp. the interim prosthesis will probably be hard to remove cause of
presence of interproximal undercut on teeth adjacent to preparation. Its
benefit is that it is the most productive time and materials on the grounds
that no intermediate impression or stone cast is required. The immediate
strategy is appropriate for single crowns and short span fixed halfway
false teeth.
Indirect technique
After
tooth preparation, an irreversible hydrocolloid impression or a quick
setting multipurpose nonaqueous elastomeric impression is made of prepared
teeth. The impression is poured in quick setting plaster or stone. The
diminished strength of the plaster is useful while expelling interim
restoration from the cast. The matrix is fitted to the cast, and alterations
are made to the matrix or cast until complete seating of the matrix is
accomplished. A separating medium is applied to prepared teeth, adjacent teeth,
and tissues on the cast. The ideal temporary material stacked into matrix.
The matrix is at that point situated over the cast until complete seating
is occurred. A gypsum core can be utilized related to matrix to guarantee full
seating and to improve interim restoration's occlusal vertical
measurement.(17)Matrix is balanced out with elastic band and the
cast/matrix get together put in warmwater in a constrain pot to
improve density and physical properties. Since the temporary materials
don't polymerize intraorally, the pulpal tissues are not presented to the
exothermic polymerization. Since the measure of heat created is relative
to the volume of material utilized, the indirect system is demonstrated for
the creation of interim restoration for various crowns or complex fixed
halfway false teeth with different pontics where the exothermic response
can't be controlled intraorally. Despite its accuracy (18) its
inability to capture margins requires repairintraorally, also need more time
and material for fabrication
Indirect-direct
technique
This
strategy which produces the most accurate interim prosthesis (12) includes
the manufacture of slight shell indirectly on a diminished cast of the
proposed restoration. These shells are relined with the temporary
restorative material intraorally. It has the best marginal accuracy with
least potential to thermal damage to pulp. in spite that, it requires more time
and laboratory support.
Materials used in temporary
restoration
Different
materials are used for the manufacture of temporary restorations yet till
date none have demonstrated to be the best and stable as each material had
its own benefits and disadvantages that could be owing to various
elements.(19) In choosing a material for a temporary restoration,
importance must be given to the physical properties of the material.
Clinically related physical properties are strength and
rigidity exothermic response, polymerization shrinkage, marginal
integrity, and color stability.(8) But before we dig into physical
properties, we should have a look on the classification of materials used
in temporary restorations. temporary restorations materials may be categorized
as acrylics or resin composites.
Acrylics: materials used in
making temporary restorations and usually accessible as powder and liquid.
They are the most normally utilized materials today for both single-unit and
various unit restorations. By and large, their prominence is because of
their ease, adequate feel, and flexibility.
Composites: Composite temporary materials include a genuinely
factor class by ideals of the way that they are synthetically involved a
mix of at least 2 kinds of materials. The vast majority of these materials
use bis-acryl resin, a hydrophobic material that is like bis-GMA. Composites are
accessible as auto-polymerized, dual polymerized and obvious light polymerized.
Bis-acryl temporary materials are resin composites and speak to an
improvement over the acrylic since they are less shrinking, emit less heat
generation during setting, satisfied appearance, negligible smell and can
be cleaned at seat side. These items are given in cartridges to use in an auto
mix distributor firearm. young et al looked at bis-acryl and polymethyl
methacrylate materials regarding occlusion, shape, back teeth, they
foundthe bis-acryl materials altogether better than PMMA in all
classifications and among the different materials, examineshave presumed
that Protemp IV is most shading stable and with predominant mechanical
properties.
At
the end of this article, the dentist should think about using materials that
are biologically and clinically evaluated, and that provide proof of long
run success. After reading this article we know the importance of
temporary restoration in the field of fixed prosthodontics as without
it the vertical dimension of occlusion is failed, and the permanent
restoration will be affected.so, we must not ignore the importance of it,
and use technologies in producing it. As perfect temporary restoration
will decrease the failure of treatment and increase the successful rate.
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