Provisional restn

TEMPORIZATION &TEMPORIZATION &
PROVISIONALPROVISIONAL
RESTORATIONS INRESTORATIONS IN
FIXED PARTIALFIXED PARTIAL
RESTORATIONSRESTORATIONS
INDIAN DENTAL ACADEMY
Leader in continuing dental education
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PROVISIONAL RESTORATION
{TEMPORARY RESTORATION,TEMPORARISATION}:
It is defined as a fixed or removal prosthesis designed
to enhance esthetics stabilization and function for a
limited period of time after a which it is to be replaced
by definitive prosthesis.

The word provisional means established for the time
being pending a permanent arrangement . This type of a
restoration has also been known for many years as
temporary restoration .

The criteria for a provisional material are as follows
1. Convenient handling: adequate working time,easily
moldability, rapid setting time.
2. Bicompatibility: nontoxic, nonallergic, nonexothermic
3. .Dimensional stability during solidification .
4. Ease of contouring and polishing .

5.Adequate strength and abrasion strength.
6.Goodappearance,transclucent,colorcontrollable,
colour stable.
7.Good patient acceptance,non irritating ,odorless.
8.Ease of adding to or reparing .
9.Chemical compatibility with provisional luting
agent.

Requirements of a Provisional Restoration:
1. Fit : A temporary crown must fit closely at the
finish line of the preparation. This will help
prevent tooth sensitivity and promote health of
the surrounding gingiva.

2. Occlusion: The provisional should establish or
maintain adequate occlusal contacts. Without occlusal
contacts, the prepared tooth may extrude
Occlusal contacts on the
provisional must not be too
high. This will cause occlusal
disharmony and may result in
tooth sensitivity.

3. Proximal contacts: The provisional must establish or
maintain adequate proximal contacts to prevent
movement of the prepared tooth in a lateral direction.
Without proximal contacts, the tooth may drift.

Adequate esthetics: The temporary must have adequate
contours, color, translucency and texture. This is
especially important in anterior teeth

5. Proper contours: A provisional must have proper
contours for esthetics and for gingival health. In a fixed
partial denture, the pontic must be contoured so that it is
as self cleansing as possible.

The photo at right
shows an improperly
contoured fixed partial
denture.

6. Strength: Provisionals must be of adequate thickness
to withstand occlusal forces without cracking.

Material used to fabricate provisional
restorations can be classified as acrylics or resin
composites. Subcategories are based on method
of polymerization (e.g., chemically activated,
light activated, dual activated).

AcrylicsAcrylics :
They are the most commonly used materials today
for both single-unit and multiple-unit restorations. due
to their low cost, esthetics, and versatility.
They produce acceptable short-term provisionals
but tend to discolor over time. Other disadvantages are
an objectionable odor, significant shrinkage and heat
generation during setting, and messiness during mixing.

The three types of acrylics used are :
1. polymethyl methacrylates
2. poly-R’ methacrylates(where R’ represents either
ethyl,vinyl,or isobutyl groups), and
3. epimines.

Preformed materials
Preformed provisional crowns or matrices usually
consist of tooth-shaped shells of plastic, cellulose acetate,
or metal. They are commonly relined with acrylic resin
to provide a more custom fit before cementation, but the
plastic and metal crown shells can also be cemented
directly onto prepared teeth using a stiff luting material
following adjustment.

Metal
Metal provisional materials are generally esthetically
limited to posterior restorations. Aluminum shells
provide quick tooth adaptation due to the softness and
ductility of the material, but this same positive quality
can also promote rapid wear that results in perforation
in function and or extrusion of teeth.

Pulpal response
Dental pulp inflammation can be caused by either
thermal or chemical insult resulting from materials used
to produce direct provisional restorations.
Hypersensitivity
Hypersensitivity from provisional materials has
been reported but appears to be rare.

Provisional luting materials
Provisional luting agents should possess good
mechanical properties, low solubility, and tooth adhesion
to resist bacterial and molecular penetration. The most
important function of these materials is to provide an
adequate seal between the provisional restoration and
prepared tooth. This is necessary to prevent marginal
leakage and pulpal irritation.

There are a variety of luting materials used for
interim purposes. The most commonly used luting
materials include :
(1)Calcium hydroxide
(2) Zinc - oxide and eugenol
(3) Non - eugenol materials.
Generally, all of these possess poor mechanical
properties that likely worsen over time.

This can have a negative influence on marginal leakage
but also provides an advantage by allowing easier
dislodgment and removal of provisional restorations
from teeth.
The retentive requirements for provisional luting
materials are that they be strong enough to retain a
provisional restoration during the course of treatment
but allow easy restoration removal when required. This
necessity for good retentive and sealing quality and easy
restoration retrieval may lead to a compromise in
material behavior, particularly regarding mechanical
properties.

Types of provisional restorations:
Many different types of procedures are used to construct
provisional. Provisional construction can be
categorized into two main methods:
1. Custom temporaries - those that are made with a
matrix derived from the original tooth or a modified
diagnostic cast. Custom temporaries can be
constructed in three different manners:
2. Direct: these are constructed with a matrix lined with
provisional material that is placed directly on the
prepared tooth www.indiandentalacademy.comwww.indiandentalacademy.com

Provisional restn

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