2. INTRODUCTION
It is important that the prepared tooth or teeth be
protected and that patient be kept comfortable while a
cast restoration is being fabricated by successful
management of this phase of the treatment, the dentist
can gain the patients confidence and favourable
influence for the ultimate success of the final
restoration.If the provisional restoration is not up to
the mark, it may lead to unnecessary repairs as well as
nead to treat gingival inflammation and it can further
prolong the treatment schedule.
3. One of the foremost reasons to be careful during
preparation of provisional restoration is that due to
unforeseen events such as lab delays or patients
unavailability it has to function for extended period so it
has to be adequate to maintain patients health in other
words it should be healing matrix for the surrounding
gingival tissue and adjacent gingival mucosa.
It can be said that provisional restoration is
frequently the patient’s first impression of final
prosthesis so it should be representative of the final
esthetic result. In some cases it is used to help correct
the etiologic factors of T.M.J or periodontal disease.
4. SYNONYMS
Provisional restoration,Treatment restoration
(Temporization), Interim prosthesis, Provisional
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 . Unfortunately
temporary often convey the notion that requirement are
unimportant . Experience reveal that time effort
expended fulfilling the requisites of provisional
restoration are well invested.
5. Definition
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.(GPT-7 1999) .
6. A PROVISIONAL MATERIAL SHOULD SATISFY
FOLLOWING CRITERIA
Convenient handling: adequate working time,easily
moldability, rapid setting time.
Bicompatibility: nontoxic, nonallergic, nonexothermic
.Dimensional stability during solidification .
Ease of contouring and polishing .
Adequate strength and abrasion strength.
Good appearance,transclucent,color controllable,colour
stable.
Good patient acceptance,non irritating ,odorless.
Ease of adding to or reparing .
Chemical compatibility with provisional luting agent.
7.
8. 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.
In the picture at right, the
provisional restoration will be
worn for an extended period of
time while the tissues heal from
periodontal surgery. Note that the
margins of the temporary fit
closely to the finish line of the
preparation.
9. This provisional has
overextended margins that
have caused gingival
irritation. This inflammation
will progress during the time
that the provisional is worn
and could result in necrotic
tissues or bone destruction
around the tooth
10. 2. Occlusion: The
provisional should establish or
maintain adequate occlusal
contacts. Without occlusal contacts,
the prepared tooth may extrude.
This will make the permanent
restoration too high in occlusion
and further adjustment of the final
restoration may result in an occlusal
surface that is too thin or that is
perforated.
Occlusal contacts on the provisional
must not be too high. This will
cause occlusal disharmony and may
result in tooth sensitivity.
11. 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. This will result in a
permanent restoration that will
not fit due to excessive of
deficient proximal contacts.
Proximal contacts must be
present also to prevent food
impaction in those areas.
12. Adequate esthetics:
The temporary must have
adequate contours, color,
translucency and texture. This
is especially important in
anterior teeth. Because acrylic
tends to darken and discolor
over an extended period of
time, a different provisional
restorative material may need
to be selected if the temporary
is to be worn for a long period.
A smooth polished surface is
important for esthetics as well
as plaque removal
13. 5. Proper contours: A
provisional must have
proper contours for
esthetics and for gingival
health. The emergence
profile must be the same
as the original tooth to
facilitate plaque removal.
Embrasure areas must be
contoured to allow for the
interdental papilla.
In a fixed partial denture,
the pontic must be
contoured so that it is as
self cleansing as possible.
14. The photo at right
shows an improperly
contoured fixed
partial denture. There
is not enough
embrasure space. The
dental papilla are
impinged upon and
signs of gingival
inflammation are
present.
15. At left is an
example of tissue
damage that can
occur from
overcontoured or
overextended
margins on a
provisional
16. 6. Strength: The
strength of most
provisional materials is
far less than gold alloy.
Provisionals must be of
adequate thickness to
withstand occlusal forces
without cracking. In a
fixed partial denture, the
connector area may need
to be slightly enlarged to
prevent breakage.
17. Materials
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).
Acrylics These materials have been used to make
provisional restorations since the 1930s and usually
consist of a powder and liquid. They are the most
commonly used materials today for both single-unit
and multiple-unit restorations. In general, their
popularity is due to their low cost, esthetics, and
versatility.
18. They produce acceptable short-term (i.e., three
months) provisionals but tend to discolor over time.
Other disadvantages include an objectionable odor,
significant shrinkage and heat generation during
setting, and messiness during mixing. The three types
of acrylics are polymethyl methacrylates,poly-R’
methacrylates(where R’ represents either
ethyl,vinyl,or isobutyl groups), and epimines.
19. Type Brand Manufacturer Advantages Disadvantages
Poly(methyl
methacrylate
Alike
Cr & Br Resin
Dura lay
GC America LD
Caulk Reliance
Dental Lang
Dental Parkell
Biomaterials
Good marginal fit
Good transverse
strength
Good polishability
Durability
~ High exothermic
heat increase
Low abrasion
resistance
Free monomer toxic to
pulp
High volumetric
shrinkage
Poly( ethyl
methacrylate)
Jet
Snap
Parkell Biomaterials Good polishability
Minimal exothermic
heat increase
Good stain
resistance
Low shrinkage
Surface hardness
Transverse strength
Durability
Fracture toughness
20. Poly(vinylet
hyl
methacryla
te)
Trim Harry Bosworth Good
polishability
Minimal
exothermic
heat increase
Good
abrasion
resistance
Good stain
resistance
Surface hardness
Transverse strength
Esthetics
Fracture toughness
Bis-acryl
composite
Pro temp II ESPE-Premier Good
marginal fit
Low
exothermic
heat increase
Good
abrasion
resistance
Good
transverse
strength
Low
shrinkage
Surface hardness
Less stain resistance
Limited shade selection
Limited polishability
Brittle
Marginal fit
21. VLC
uerthane
dimethacryl
ate
Triad Dentsply York High surface
hardness
Good
transverse
sirength
Good
abrasion
resistance
Controllable
working time
Color stability
Less stain resistance
Limited shade selection
Expensive
Brittle
22. 1 . Polymethyl Methacrylates
Advantages -low cost ,good wear resistance ,good esthetics
,high polishability ,good color stability .
Disadvantages- significant amount of heat given off by
exothermic reaction , high degree of shrinkage (about 8%)
,strong, objectionable odor -short working time , hard to
repair , radiolucent
2 Poly-R' Methacrylates (R' = ethyl, vinyl, isobutyl)
Advantages
-low cost ,less heat given off during reaction than
polymethyl methacrylates , less shrinkage than polymethyl
methacrylates
Disadvantages -extended working time ,less esthetic than
other currently-marketed materials , poor wear resistance
,poor color stability , strong, objectionable odor hard to
repair ,radiolucent
23. 3.Epimines These were the first two-paste
acrylics, commercially introduced in 1968 as Scutan
(ESPE). Although Scutan had relatively low shrinkage
and heat production, it was weak and could not be altered
or repaired.
4 . Bis-Acryl Composites Bis-acryl
provisional materials are resin composites and represent
an improvement over the acrylics because they shrink
less, give off less heat during setting, and can be polished
at chairside. Conveniently, the majority of these products
are provided in cartridges for use in an automix
dispenser gun. However, there are at least two types of
guns for provisional materials, so you should not assume
compatibility between one manufacturers cartridges and
another manufacturers gun.
24. Provisionals made with bis-acryl resins can be
polished to a smooth finish, but are generally not
glossy like the acrylics. They also have a pronounced
air-inhibited layer that should be removed (usually
with alcohol-saturated gauze) prior to finishing and
polishing. Although they are provided in fewer shades
than the acrylics, they can be characterized using
flowable or traditional resin composites. The bis-acryl
composites can be subcategorized according to
method of activation (e.g., chemically activated,
visible light activated, or dual activated).
25. Advantages
-less shrinkage than acrylics ,minimal heat
generated during setting reaction ,relatively high
strength ,minimal odor ,excellent esthetics ,most
products use automix delivery ,can be repaired or
characterized using resin composite ,easy to trim ,
good color stability
Disadvantages - radiopaque ,greater cost than
acrylics ,some do not have a rubbery stage ,viscosity
cannot be altered ,sticky surface layer present after
polymerization ,may be more brittle than acrylics
27. Specific Product Information Protemp 3 Garant is
available in four shades (A1, A3, B1, B3). A
specially designed dispenser syringe of AddOn, a
low-viscosity light-cured resin, is also included
with the product. AddOn is used to correct voids or
defective margins of the provisionals. Provisional
restorations made with Protemp 3 Garant are said
to be more fracture resistant that those made with
other composite products. 3M ESPE also claims
that the restorations have excellent marginal
adaptation and are fast and easy to polish.
28. Integrity is available in three shades (A1, A2, A3.).
Two sizes of mixing tips are available: a small size for
single-unit temporaries and a larger tip for multiple
temporaries and fixed partial dentures. The product
has a snap set and should be used expeditiously; place
it in the mouth within 45 seconds and remove it in
another 45 seconds.
.
Visible Light-Activated (VLA) Composites Very
few provisional materials are available that are
polymerized solely by exposure to a light curing unit.
One, however, is Revotek LC, introduced by GC
America in 2002.
29. Specific Product Information Revotek LC is a VLA,
single-component, sculptable resin composite. It is
supplied in a Putty Stick form in a lightproof plastic
tray. To make a provisional restoration, a small
portion of the material is cut from the stick and
adapted to the preparation directly in the mouth. It is
then sculpted using hand instruments after which the
patient is instructed to occlude into it to establish a
functionally-generated occlusal scheme. The Revotek
LC provisional is then light-activated for 10 seconds
in the mouth, removed, and given a final 20-second
light exposure. After finishing and polishing, the
restoration is cemented with a temporary cement.
Revotek LC is available in only one shade (B2).
30. Dual-Activated Composites One example is Unifast
(GC America), which goes through a chemically-
activated, rubbery, setting stage and is then VLA for
final set. Other such products have appeared in the
past such as TempCare (3M) and Provipont DC
(Ivoclar Vivadent) but have since discontinued.
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.
.
31. They are commercially available in various tooth
sizes and are usually selected for a particular tooth
anatomy. Nonetheless, available sizes and contours
are finite which makes the selection process
important for clinical success. Compared with
custom fabricated restorations, this treatment
method is quick to perform but is more subject to
abuse and inadequate treatment outcome. This can
result in improper fit, contour, or occlusal contact
for a provisional restoration
32. Polycarbonate resin
Polycarbonate resin is commonly used for preformed
crowns and possesses a number of superior properties
relative to polymethyl methacrylate materials.These
crowns combine microglass fibers with a
polycarbonate plastic material. Practitioners
commonly use polycarbonate resin shell crowns as a
matrix material around a prepared tooth that is
relined with acrylic resin to customize the fit. This
material possesses high impact strength, abrasion
resistance, hardness, and a good bond with methyl-
methacrylate resin.
33. 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.
34. An unpleasant taste is sometimes associated with
aluminum materials. Iso- Form Crowns (3M Dental
Products, St. Paul, Minn) are manufactured with
high-purity tin-silver and tin-bismuth alloys. Like
aluminum, they possess reasonable ductility and can
be contoured quickly, but the occlusal table is
reinforced so they are more resistant to wear related
failure. For longer-term use, nickel chrome and
stainless steel crowns are available but may be more
difficult to adapt to a prepared tooth.
35. INFLUENCE OF MATERIAL
PROPERTIES ON TREATMENT
OUTCOME
Marginal accuracy
Accurate marginal adaptation of resinous provisional
restorations to the finish line of a prepared tooth
assists in protecting the pulp from thermal, bacterial,
and chemical insults. The accuracy could be
significantly improved by relining the restoration after
the initial polymerization.
36. A number of studies have focused on the effects of
thermocycling on provisional crown margins.They
reported that
(1) acrylic resin provisional crowns demonstrated
dimensional degeneration and enlarged marginal gaps
resulting from thermocycling and occlusal loading;
(2) marginal gap changes were greater after hot
thermocycling than cold thermocycling;
(3) improved marginal accuracy of PMMA
provisional restorations occurred when a shoulder
finish line was used compared with a chamfer
marginal design;
37. (4) light-polymerized materials provided significantly
improved marginal accuracy relative to auto
polymerizing PMMA resin after thermocycling. In
contrast, Keyf and Anif concluded that the marginal
discrepancy found with bisacryl resin was significantly
greater with a shoulder finish line after 1 week relative
to a chamfer design . composite materials would
provide a better marginal fit relative to unfilled
polymethyl methacrylate because of less
polymerization contraction, but marginal fit is not the
only factor affecting the overall retentive quality of
provisional restorations.
38. Nearly 20% improvement in the retention of interim
crowns made with polymethyl methacrylate
compared to those fabricated with composite
materials. They concluded that polymerization
shrinkage occurring with the polymethyl
methacrylate material might have allowed for a
tighter fit of the restoration on the prepared tooth,
which had a direct influence on improved retentive
quality.
39. Color stability
In esthetically critical areas it is desirable for
remain color stable over the course of provisional
treatment. Discoloration of provisional materials can
produce serious esthetic complications, especially
when long term provisional treatment is required.
Modern provisional materials use stabilizers that
decrease chemically induced color changes, but these
materials are susceptible to other factors that will
promote staining..
40. When provisional materials contact pigmented
solutions such as coffee or tea, discoloration is
possible. Porosity and surface quality of provisional
restorations as well as oral hygiene habits, can also
influence color changes.
Crispin and Caputo studied the color stability
of provisional materials. They found that methyl
methacrylate materials exhibited the least darkening,
followed by ethyl methacrylate and vinyl-ethyl
methacrylate materials. They also reported that
increases in surface roughness induced increases in
material darkening and pressure polymerizing did not
influence discoloration relative to air polymerizing.
41. Koumjian included a visible light-polymerized
material in their investigation. They placed test
materials into the flanges of complete dentures and
concluded that for short time periods of 5 weeks or
less, all materials demonstrated acceptable color
stability . They stated, however, that the Triad VLC
material exhibited more adverse color change
relative to other materials at the end of 9 weeks.
Yannikakis et al immersed provisional
materials in various staining solutions for up to 1
month. They reported that all materials showed
perceptible color changes after 1 week. The methyl
methacrylate materials exhibited the best color
stability and bis-acryl materials the worst.
42. Gingival response
Inflammation and recession of the free gingival
margin associated with provisional treatment is a
common occurrence. Donaldson reported the
following observations regarding gingival recession:
(1) the presence of a provisional restoration lead to at
least some recession at about 80% of the free gingival
margin sites evaluated; (2) the degree of recession was
time dependant; (3) placement of the definitive
treatment commonly lead to gingival recovery; (4)
10% of subjects demonstrated recession in excess of 1
mm; and (5) in the presence of gingival recession,
only one third of subjects demonstrated complete
gingival recovery.
43. In a separate report, Donaldson indicated that the
occurrence of gingival recession before provisional
treatment was directly linked to further recession
observed after the completion of definitive
prosthodontic treatment. He also found a direct relation
between the degree of pressure applied by a provisional
restoration and gingival recession. An anatomically
contoured provisional restoration caused less recession
than did a nonanatomically contoured one. periodontal
inflammation associated with provisional treatment
could be expected to be a reversible process provided
that the amount of gingival irritation is minimal and
provisional treatment occurs over a short time span.
44. PULPAL RESPONSE
Dental pulp inflammation can be caused by
either thermal or chemical insult resulting from
materials used to produce direct provisional
restorations. The results of the study suggest the
possibility of thermal damage to dental pulp tissue
and odontoblasts during direct provisional
fabrication, They suggested that by use of air and
water coolants, as well as by use of a matrix material,
that can dissipate heat rapidly, the pulp temperature
rise might be reduced. Additionally, the amount of
heat rise is dependent on the quantity of provisional
restorative material used
45. Temperature rise was greatest with polymethyl
methacrylate and vacuum adapted templates; least with
bis-acryl and relined resin shells; and intermediate
temperature increases were recorded with polyethyl
methacrylate materials and either irreversible
hydrocolloid or polyvinylsiloxane impression materials
used as a matrix for holding acrylic resin provisional
material against a tooth. The authors also identified that
fixed partial denture provisional restorations produced a
greater temperature rise than did single-unit provisional
restorations.
Grajower et al showed that faster polymerizing
acrylic resin materials could generate higher
temperatures than slower polymerizing resins.
46. They indicated that external heat dissipation might be
enhanced with a water spray or by polymerization of
restorations in silicone impressions. Additionally, this
external heat dissipation caused retardation in the
polymerization, which further decreased heat
production. The retardation resulted from the
cooling effect of the spray and not the water itself,
since moisture quickens the polymerization of
autopolymerizing acrylic resins that contain
tertiary amine accelerators. The authors concluded
that (1) provisional acrylic resin restorations might be
fully polymerized on prepared teeth by appropriate
methods such as in impressions or with external
cooling, without causing excessive heating of the
dental pulp;
47. (2) removal of a provisional restoration before
complete polymerization, leading to potential
deformation of the acrylic resin material, is therefore
unnecessary; and (3) a thin insulating layer should
be applied to a prepared tooth before contact with
non polymerized acrylic resin to avoid chemical .
48. Hypersensitivity
Hypersensitivity from provisional materials has
been reported but appears to be rare. Autopolymerizing
methacrylate materials have greater potential for
producing allergic contact stomatitis than similar heat-
polymerized materials. The residual monomer in the
material has been implicated as the causative factor.
One report showed that the residual monomer content
in heat-polymerized acrylic resin ranges from 0.045%
to 0.103%. Autopolymerized acrylic resin has a
residual monomer content of 0.185%. Over time
residual monomer is gradually leached out, leaving a
fraction that is tightly bound to the resin materia1.
49. Allergic reaction to provisional materials will
demonstrate the following features: (1) the patient has
had previous exposure to the provisional material; (2)
the reaction conforms to a known allergic pattern, such
as redness, necrosis, or ulceration; (3) the reaction
resolves when a provisional restoration is removed; 4)
reaction recurs when a provisional restoration is
replaced; and 5) a patch test for the material is positive.
Patch testing has demonstrated less response with
light-polymerized materials relative to
autopolymerizing acrylic resin. Indirect material
processing methods are recommended for individuals
showing evidence of hypersensitivity.
50. Strengthening provisional materials
The studies clearly favors acrylic resin as the
material of choice for provisional restorations. Most
resins used for provisional restorations are brittle.
Repairing and replacing fractured provisional
restorations is a concern for both clinician and patient
because of additional cost and time associated with
these complications. Failure often occurs suddenly and
probably as a result of a crack propagating from a
surface flaw. The strength and serviceability of any
acrylic resin, especially in longspan interim
restorations, is determined by the material's
resistance to crack propagation. Crack propagation
and fracture failure may occur with these materials
because of inadequate transverse strength, impact
strength, or fatigue resistance.
51. Physical properties of strength, density, and hardness
may predict the longevity of provisional restorations.
Donovan et al examined methods to improve the
longevity of these restorations using variable indirect
polymerization techniques. They compared methyl
methacrylate material strength, porosity and hardness
under the following polymerization conditions: (1) in
air; (2) under water; (3) under air pressure; and (4)
under water and air pressure. They found that
polymerization with a pressure vessel with air and
water had the greatest influence on increasing strength
and reducing porosity.
52. Heat-polymerization of acrylic resin materials can be
used when provisional restorative treatment will be
required for extended periods of time or when
additional strength is required. This indirect
laboratory process results in materials that are
denser, stronger, more wear resistant, more color
stable, and more resistant to fracture than their
autopolymerizing counterparts. Both heat-
polymerized acrylic resin and metal provisional
restorations should last longer than autopolymerized
restoration, but the expense and time required for
indirect fabrication can make them less cost effective
for routine use
53. Zuccari et al studied methods to promote a stronger
resin matrix "by decreasing crack propagation. They
reported that when admixed zirconium oxide
powders were added to unfilled methyl methacrylate
resin, the resultant composite material exhibited
significant improvements in the modulus of elasticity,
transverse strength, toughness, and hardness, even
though water sorption over time had a negative
influence on mechanical properties.
54. In a study describing a negative influence on the strength
of provisional materials, Chee et al studied the effect of
chilled monomer on the working time for 3
autopolymerizing acrylic resins. They found that the
working and setting times increased by up to 4 minutes
when chilled monomer was used, but the transverse
strength for the materials were decreased by 17%.
55. 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 common include (1) calcium
hydroxide; (2) zinc-oxide and eugenol; and (3)
noneugenol materials. Generally, all of these possess
poor mechanical properties that likely worsen over
time.
56. 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 paradoxical necessity for good retentive and
sealing quality and easy restoration retrieval may lead
to a compromise in material behavior, particularly
regarding mechanical properties.
57. Baldissara et al recommended that interim restorations
be frequently evaluated and used for only short periods
of time. Literature reports advise that if provisional
treatment is required over a protracted time period, it is
best to remove and replace the provisional luting agent
on a regular basis. Some of the most commonly used
cements with provisional prostheses are those
containing zinc-oxide and eugenol. They provide
sedative effects that reduce dentin hypersensitivity and
possess antibacterial properties. Unfortunately, free
radical production necessary for polymerization of
methacrylate materials can be significantly hampered by
the presence of eugenol found in eugenol based
provisional luting materials.
58. This can interfere with the acrylic resin
polymerization and hardening process .They can also
be incompatible with some resin-based definitive
luting agents for the same reason.
Eugenol-free provisional luting materials are
commercially available and have gained popularity
due to the absence of resin-softening characteristics .
Gegauff and Rosenstiel, however, reported
that Temp- Bond (Kerr Dental, Orange, Calif) a zinc-
oxide and eugenolbased cement did not appear to
have a significant adverse effect on the
polymerization of acrylic resins. They postulated that
the softening effect of eugenol on acrylic resin is
dependent on the presence of unreacted eugenol,
which may be minimal in Temp-Bond cement .
59. CLINICAL CONSIDERATIONS FOR
PROVISIONAL TREATMENT INVOLVING
NATURAL TEETH
The fabrication of provisional restorations is
extensive . Virtually all teeth receiving cast restorations
require provisional restorations. Properly executed
provisional restorative treatment rarely fails and
dislodgment or fracture usually indicates that their form
is unacceptable or that a tooth preparation is inadequate.
Provisional restorations should be smooth, highly
polished, and alterable and for this reason custom made
provisional restorations most consistently meet the
biological,functional, and esthetic needs of a patient.
60. Provisional restorations as part of comprehensive
treatment
Provisional restorations are not devoid of
interactions with other modes of therapy. Patients often
have periodontal, endodontic, orthodontic, or surgical
needs in conjunction with their prosthodontic
treatment. Provisional restorations produce
outcomes that range from microscopic tissue effects
to psychological factors that change a patient's
behavior. Provisional restorations can provide
patients with an increased confidence in treatment.
61. Diagnostic provisional treatment
In the simplest situations, complete oral and
extraoral clinical examinations, as well as radiographic
evaluation, may be all that is necessary before commencing
prosthodontic treatment. In more complex treatments,
however, provisional restorations provide a means of
designing, improving, and assessing the occlusion,
esthetics, and contours for definitive restorations, as well as
to determine their effects on gingival health, phonetics, and
patient adaptability before the initiation of the definitive
treatment. Provisional restorations fit into 2 categories: (1)
those that fit within an arch of fundamentally intact teeth
that provide reference for their occlusion, contours, and
esthetics; and
62. Those that become the reference for the entire
prosthesis. Provisional treatment for patients with more
complex prosthodontic needs demands fabrication and
articulation of diagnostic casts and completion of a
diagnostic wax-up in the maxillomandibular relationship
in which definitive treatment is to be performed.
Occlusal diagnosis and treatment
Casts of provisional restorations mounted opposite
definitive casts transfer contours, clinical crown
dimensions, and maxillomandibular relationships from a
patient to a dental laboratory for developing occlusal
factors, especially anterior guidance, for fixed
prosthodontic treatment.
63. Sometimes treatment feasibility can only be tested via
full-arch provisional restorations and occlusal
problems are best diagnosed during a functional
testing period with provisional treatment .
Esthetic and phonetic diagnosis and
treatment
Provisional restorations assist development and
assessment of esthetic and phonetic values of the
planned fixed prosthesis. Matrixes created from a
diagnostic waxing or from casts of provisional
restorations are useful tools for producing specific
contours in a definitive prosthesis or communicating
those concepts to the dental laboratory.
64. In certain situations phonetics and esthetics of a planned
prosthesis can be assessed before tooth preparation by
use of vacuum or pressure-formed matrixes that hold
autopolymerizing acrylic resin between unprepared
teeth and proposed tooth contours to provide
intraoral treatment simulation.
Periodontal treatment and maintenance
Periodontal treatment is commonly part of
comprehensive prosthodontic care. These provisional
restorations provide a matrix against which the tissue
heals, guiding the generation of correct soft tissue
architecture. According to Shavell, tooth preparations
and provisional restorations should be completed
with retraction cord in place.
65. It has been recommended that when the duration of the
periodontal treatment is less than 6 months, the use of
acrylic resin provisional restorations . Poorly fabricated
provisional restorations have consequences for fixed
prosthodontic treatment including gingival recession
difficulty making impressions; difficulty fitting the
definitive restorations; soft tissue damage; and
inefficient use of time at prosthesis insertion
Slightly convex facial and lingual contours of
provisional restorations and a flat emergence profile
are effective in promoting gingival health. Good
periodontal health can be created by developing the
appropriate contour and good gingival adaptation and
embrasure space of the prosthesis.. Embrasure spaces
that are too broad can cause food impaction and
blunting of the papilla .
66. 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:
Direct: these are constructed with a matrix
lined with provisional material that is placed
directly on the prepared tooth
67. Indirect: these are constructed by placing the
filled matrix over a model of the prepared tooth,
thus the provisional is constructed out of the
patient's mouth.
Indirect-Direct: these are made by forming a
temporary in an indirect manner and then relining
this directly in the patients mouth. This method is
useful when constructing temporary bridges
because most of the work can be done in the
laboratory.
2- Prefabricated temporaries - these are
preformed crowns that can be purchased and may be
modified to fit a prepared tooth. In most cases these
require relining with an acrylic material.
68. Direct fabrication. For select patients, a denture
tooth secured in position and orthodontic wire may be a
suitable provisional restoration for a missing
mandibular incisor. For urgent situations, in the absence
of any matrix or opportunity to create a matrix, a
provisional restoration can be fabricated by adapting a
block of freshly mixed acrylic resin directly to a tooth.
After the acrylic resin block has polymerized, the tooth
contours can be carved with acrylic resin burs of choice
and the restorative margins perfected intraorally.Most
patients, however, require a more conventional
approach. Fabricating provisional restorations directly
on teeth using the "direct method" is suitable for single
units and up to 4-unit fixed partial denture provisional
restorations,
69. Three techniques encompass virtually all of the literature
on direct provisional restorations: (1) use of a pre
manufactured provisional sheIl (2) use of an impression
material ,or pressure or vacuum formed translucent
matrix and (3) use of a custom, prefabricated acrylic
resin shell. Direct provisional restorations made
particularly of PMMA and, to a lesser degree, polyethyl
methacrylate (PEMA) must be cooled if the material is
allowed to polymerize completely on a tooth;
polymethyl methacrylate can increase pulpal
temperatures as much as 7°C. Cooling the material
during polymerization by its removal at initial
polymerization and allowing complete polymerization to
be completed while it is off the tooth,
70. cooling with air-water spray, periodic removal, and
flushing with water and use of a "heat sink" matrix
material such as alginate will limit temperature
increases to less than 4°C, minimizing the exothermic
risk .
Indirect fabrication. The indirect method
has been indicated to fabricate multiple unit
provisional restorations to (1) avoid exposure of a
patient to adverse properties of provisional acrylic
resins; (2) optimize the properties of provisional
acrylic resins; (3) allow the use of materials that are
difficult to polymerize intraorally; (4) make significant
contour or occlusal changes; and (5) provide for the
fabrication of hybrid provisional restorations.
71. Indirect techniques generally use either approximate
tooth preparations made on a duplicate cast or a cast of
the actual tooth preparations made after the clinical
procedure has been accomplished. One advantage of
the indirect technique is that it can be allocated to
auxiliary personnel. Fabricating a provisional
restoration wholly or in part using an indirect method
reduces exposure of oral tissues to monomer, heat,
shrinkage, and reduces the volume of volatile
hydrocarbons inhaled by a patient. Creating an indirect
acrylic resin shell of an unprepared tooth that is later
relined intraorally is one method of reducing patient
exposure.
72. It has been reported that provisional restorations
fabricated indirectly have superior margins to those
from direct techniques because the acrylic resin
polymerizes in an undisturbed manner. Polymerizing
autopolymerizing acrylic resin under heat and pressure
improves the physical properties of the material.
Reinforcing the vacuum or pressure formed matrix
allows it to be secured to the cast on which the
provisional shell is polymerized.
73. Indirect method (Alginate impression technique)
The overimpression frequently is made in the
patient's mouth while waiting for the anesthetic to
take effect. However, if the tooth to be restored has
any obvious defects, the overimpression should be
made from the diagnostic cast .
When the alginate has set, the overimpression is
removed from the diagnostic cast and checked for
completeness. Thin flashes of impression material
that replicate the gingival crevice are removed to
insure that there will be no impediments to the
complete seating of the cast into the overimpression
later .
74.
75. The impression is wrapped in a wet paper towel and
placed in a zip lock plastic bag for later use.
When the tooth preparation is completed, another
quadrant impression is made in alginate. This
impression is poured up with a thin mix of quick-
setting plaster .
Mix tooth-colored acrylic resin in a dappen dish
with a cement spatula. Place the resin in the over
impression so that it completely fills the crown area
of the tooth for which the provisional restoration is
being made .
76.
77.
78. Seat the prepared tooth cast into the over impression,
making sure that the teeth on the cast are accurately
aligned with the tooth impressions.
Once the cast has been firmly seated and the
excess resin has been expressed, hold the cast in place
with a large rubber band.
79. It is important that the cast be oriented securely in
an upright position so that the space between the
cast and the impression that is filled with the resin
forming the provisional restoration will not be
distorted.
If the cast is torque to one side by the rubber band,
the cast may be forced through the soft tissue in
some areas resulting in a provisional restoration that
may be thin in those areas and thicker than desirable
in others. The force used to seal the cast into the
alginate impression is critical.
90. 2TEMPLATE METHOD
To make a template, place a metal crown form
or a denture tooth in the edentulous space on
the diagnostic cast . All of the embrasures should
be filled with putty to eliminate undercuts during
adaptation of the resin template.
To facilitate removal of the template, a thin strand
of putty can be placed around the periphery of the
cast and on the lingual surface of the cast, apical
to the teeth . Use a large acrylic bur to cut a hole
through the middle of the cast (midpalatal or
midlingual). Place a 5 x 5-inch sheet of 0.020-
inch-thick resin . Turn on the heating element of
the machine and swing it into position over the
plastic sheet .
91.
92. As the resin sheet is heated to the proper temperature,
it will droop or sag about 1.0 inch in the frame. If you
are using coping material, it will lose its cloudy
appearance and become completely clear. The cast
should be in position in the center of the perforated
stage of the vacuum forming machine. Turn on the
vacuum.
Grasping the handles on the frame that holds the
heated coping material, forcefully lower the frame over
the perforated stage . Turn off the heating element and
swing it off to the side. After approximately 30
seconds, turn off the vacuum and release the resin
sheet from the holding frame . if a vacuum forming
machine is not available, it is still possible to fabricate
a template for a provisional restoration.
93. Place the softened sheet over the cast. Forcefully seat the
tray of silicone putty over the coping material . To
accelerate cooling, blow compressed air on the plastic
sheet and the impression tray. After about a minute, snap
the tray off the cast . If the silicone putty sticks to the
resin sheet, the putty can be easily removed by pulling it
off in quick jerks. Rapid separation causes the silicone
putty to exhibit brittleness that will result in easy
removal. Replace the putty in its original container for
later re use. Separate the template from the diagnostic
cast.
94.
95. Upon completion of the preparations, make an
alginate impression of them and pour it in fast-setting
plaster. Trim the cast so that it includes only one
tooth on either side of the prepared teeth. Try on the
template to verify its fit .
Coat the cast with separating medium and allow it
to dry. Mix the acrylic resin in a dappen dish and
place some on protected areas of the cast, such as
interproximal spaces and in grooves and boxes. As
the resin begins to lose its surface gloss and becomes
slightly dull, fill the area for which the provisional
fixed partial denture is being made . Place some extra
bulk in the portion that will serve as the pontic.
96.
97. Wrap rubber bands around the template and cast,
being careful not to place them over the abutment
preparations, lest they cause the template to
collapse in that area . Place the cast in a pressure
pot if one is available. Otherwise, place it in warm
(not hot) tap water to hasten polymerization.
Remove the fixed partial denture from the cast. Do
not.hesitate to break the cast if necessary. Trim off
the excess acrylic resin. Use discs to trim the axial
surfaces down to the margins. Remove the saddle
configuration that was created by the crown form in
the edentulous space . The pontic should have the
same general shape that the pontic on the permanent
prosthesis has.
98.
99. Shell-Fabricated Provisional Restoration
A thin shell crown or fixed partial denture can be
made from any of the acrylic resins, and then that
shell can be relined indirectly on a quick-set plaster
cast. It also can be relined directly in the mouth. If
the reline is done directly, a methacrylate other than
poly(methyl) should be used. This technique can
save chair time because the restoration is partially
fabricated prior to the preparation appointment Care
must be taken not to make the shell too thick. If too
thick, the shell will not seat completely over the
prepared teeth and it will need to be trimmed
internally.
100. This can be time-consuming and defects any
advantage gained by making it before the preparation
appointment .
An overimpression is made from a
diagnostic wax-up before the preparation
appointment. Trim off thin flashes of impression
material created by the gingival crevice to produce
an extra bulk of resin near the margins. Use a plastic
squeeze bottle with a fine tip to deposit one drop of
monomer on the facial and one drop on the lingual
surface of the overimpression. Keep the monomer
near the gingival portion of the impression to prevent
excess from accumulating in the incisal or occlusal
area. Extend the coverage by the resin to one tooth
imprint on either side of the teeth being restored.
101.
102. When the teeth have been prepared, make a
quadrant alginate impression and pour it with a thin
mix of quicksetting plaster. Trim off excess plaster
on a model trimmer. Save one tooth on either side of
the prepared tooth, if possible. Remove areas of the
cast that duplicate soft tissues.
Try the shell gently on the cast to make sure it
seats completely without binding. If it does bind,
relieve the inner surfaces of the shells until the
restoration seats completely and passively. Liberally
coat the tooth preparations on the cast with
separating medium and make sure it is dry before
mixing the acrylic resin.
103.
104. Monomer and polymer can be added directly to the
shell and mixed there. The resin also can be mixed in
a dappen dish and then transferred to the shell,
completeIy filling each tooth. Seat the shell onto the
prepared teeth on the cast. Wrap a rubber band
around the shell and cast, and place them in a plaster
bowl full of hot tap water for approximately 5
minutes, preferably in a pressure pot. The use of a
pressure pot will significantly increase the strength
of the restoration .
105. If the direct technique
is employed, seat the shell
on the prepared teeth in the
mouth
A matrix can be made in
many different ways. Most
are from sheets of plastic
that are heated and formed
over the diagnostic cast.
Then the matrix is filled with
acrylic resin and placed over
the prepared teeth in the
patient's mouth.
106. Technique used in the fabrication
of provisionals using light cured
resin.
DIAGNOSTIC WAX UP
& IMPRESSION.
113. PREFABRICATED
CROWN
Polycarbonate Crowns:
These are available in
incisors, canines and
bicuspids. There is a
range of sizes for each
tooth form.It should be
relined with acrylic in
order to provide a good
internal fit. After lining
with acrylic, they may be
trimmed to provide a
good marginal adaptation
and further adjusted into
118. Ion Crown Formers: These are
shells made of cellulose acetate
and are available in all tooth
forms. These shells come in
various sizes for each tooth form
and are lined with acrylic resin.
After the acrylic resin has
polymerized, the cellulose shell
is peeled away from the crown.
This usually necessitated the
further addition of acrylic in the
areas of the proximal contacts.
119. Tin Silver: Tin Silver
preformed crowns are
available for posterior
teeth. This alloy is very
soft and the margin of the
crown can be flexed prior
to seating with a swaging
block. This produces a
close marginal fit after the
shell is trimmed with a bur.
These should also be lined
with acrylic resin to
provide good internal
adaptation and retention of
the temporary.
120. Aluminum Shell Crowns:
Similar to the tin silver,
aluminum shell crowns are
available in the anatomic form as
shown here, or in a cylindrical
form that requires extensive
occlusal contouring. Adjusting
occlusion on an aluminum crown
lined with acrylic sometimes
results in perforation of the
aluminum into the layer of
acrylic beneath it as shown here
121. Provisional treatment for all ceramic
veneer restorations
All-ceramic restorations including laminate veneers
have become a large part of dental practice. Most of what
has been published regarding provisional treatment for
veneers has focused on technical procedures. Provisional
veneers are indicated when (1) esthetics and intelligible
speech are important; (2) mandibular incisors are
veneered; (3) dentin is exposed; (4) proximal contacts are
broken; (5) maxillary teeth are inverted lingually and the
veneer surface affects occlusion; (6) the preparation
margin invades the gingival sulcus; and (7)the final
veneer is dependent on patient approval of form, color,
contour, and position.
122. Provisional restorations allow patients to have a
trial period for making notes about esthetics so that
their desires can be taken into account with the
definitive veneer . Preparations for porcelain veneers
may not have mechanical retentive features and thus
one concern regarding a provisional restoration is tooth
attachment while avoiding irreversible contamination
or alteration of the luting surface of a prepared tooth.
Elledge advocated placing 2 small dimples on
opposing surfaces of the preparation to provide
mechanical retention for the provisional veneer that is
luted with a cement of the clinician's choice. One
method that avoids excess cement while sealing the
margin area is the "peripheral seal technique" that
123. uses a 3-second etch of the preparation periphery and then
bonding a provisional restoration primarily at the etched
periphery. Similarly, a colored luting resin may facilitate
removal of excess resin and reduce contamination of a
tooth surface. Another technique known as the "spot
etch" method incorporates provisional restorations that are
luted with light polymerized acrylic resin to an etched spot
near the center of the preparation. In an in vitro study of
surface contamination associated with provisional
bonding, a polyurethane isocyanate surface treatment left
the cleanest tooth structure whereas a noneugenol provi-
sional cement left: significant but removable residue; a
dual polymerizing resin cement left tenacious residue that
could only be removed with a bur .
124. A variety of methods for fabrication of veneer
provisional restorations have been reported and are not
unlike the methods advocated for conventional
provisional restorations including, a removable
"splint,"with handformed visible light-polymerized
materials, polycarbonate provisional crowns, acrylic
resin shells, and splinting together adjacent provisional
veneers.
125. Esthetics
Patients may be highly motivated by esthetics and
instant improvement can be achieved through
provisional restorations. Custom colored provisional
restorations made with mixtures of acrylic resin
powders creating an incisal polymer, a body polymer,
and a cervical blend are easier to fabricate with an
indirect method. Esthetically enhanced provisional
restorations can fabricated with visible light-
polymerized labial veneers or denture tooth facings in
conjunction with acrylic resin Gingival architecture and
tissue contour are among the many factors other than
materials that influence esthetics.
126. Anterior provisional restorations should provide the
following esthetic benefits: (1) optimum periodontal
health; (2) visualization of the anticipated esthetic
outcome; (3) ability to test the incisal edge position and
cervical emergence; (4) development of appropriate
anterior guidance; and (5) determination of the need for
periodontal surgery. Methods for improving or
customizing colors also include coloring provisional
luting cements and coloring a provisional restoration
with porcelain stains and visible light-polymerized
acrylic resin. In Custom color guides for provisional
restorations have also been recommended.
127. REMOVAL OF PROVISIONAL
RESTORATION
The provisional is removed when the patient returns
for the definitive restoration or for continued
preparation. The prepared tooth or foundation must
be avoided. Risk of this can be minimized if removal
forces are directed parallel to the long axis of the
preparation. The Backhans or hemostatic forceps are
effective for obtaining purchase on a single unit.A
slightl buccolingual rocking motion will help break
the cement seal. Damage can occur when a FPD is
being removed. If one abutment retainer suddenly
breaks loose, the other abutment can be supported to
severe leverage.
128. Care must be exercised to remove the prosthesis alongthe
path of withdrawl. Sometimes it is helpful to loop dental
floss under the connector at each end of the FPD,
providing a more even force distribution for removal.
RECEMENTATION OF PROVISIONAL
RESTORATION
If provisional is to be recemented clean out the bulk
of cement with aspoon excavator then place the
provisional in a cement dissolving solution in an ultrasonic
cleaner. Line it with a fresh mix of resin if necessary
(as when a toothpreparation has been modified, eg).
The internal surface is relieved slightly and painted
with monomerto ensure good bonding of the new lining.
129. SUMMARY
Although provisional restorations are usually
intended for shortterm use and then discarded, they
can be made to provide pleasing esthetics, adequate
support, and good protection for teeth while
maintaining periodontal health. They may be
fabricated in the dental office or in laboratory from
any of several commercially available materials and
by a number of practical methods. The success of
fixed prosthodontics is often depends on the care with
which the provisional is designed and fabricated.
130. In 1990, Ernest DaBreo et al gave "clinical report on a
provisional restoration for a patient with cleft lip and
palate. The provisional prosthesis provides on alternative
treatment option that allows the dentist to plan the
definitive restoration while providing the patient with a
temporary but esthetic and functional restoration.
In 1991, Conrad Bodai described expedient and
effective interim restoration for compromised posterior
teeth.The restoration can beethyl methacrylate, visible-
lightactivated resin, and a Bis-acrylplaced quickly,
exhibits excellent adaptations provides exceptional
retention and maintains proximal and occlusal contacts.
Review OF LITERATURE
131. In 1991, Jack Koumi Jian et al did a study on the
'Colour stability of provisional materials in view.
Colour stability of provisional restorations is an
important quality of the resin used, particularly for
extensive reconstruction over a long period of
time.This study evaluated the invitro discoloration of
seven resins over a 9 week period. Resin specimens
were prepared and placed in the facialflange of
maxillary complete dentures and the lingual flange of a
mandibular complete dentures. Patients were given
tooth brushes and tooth paste and told not to use any
chemical agents for choosing the dentures.
Observations were made at 1, 5 and 9 weeks,
132. No change was detected at the first two evaluations.
At the 9 week evaluation, four materials, methyl
methacrylate, polyminylethyl methacrylate and bis-
arylcomposite resin showed significantly less staining
than did the other three resins tested. All materials
tested were acceptable from the standpoint of colour
stability for short term (5 weeks or less) provisional
restorations. Therefore, the dentist using provisional
restorations for a short period of time may consider
other properties of the materials, such as resistance of
fracture, marginal accuracy, rase of fabrication and
cost.
133. In 1991, Millstein et al studied the effect of aging an
temporary cement retention in vitro. The primary
function of temporary cements isto act as an interim
cementing media for provisional or fixed restorations.
Temporary cements may be medicated and are often
used for toothsedation as well as for retention. Retention
of restorations cemented with temporary cement varies.
Some cements are adhesive and others are '"'work in
retention. In addition, cement retention may vary over
time. this study determined:1. The retentive properties
of four temporary cements. 2. The effects of aging on
temporary cement retention Retention of restoration was
studied at 1 and 6 week intervals. Retention varied with
the 4 cements tested, and one cement (Temp-
bond)became significantly less significant over time
134. In 1992, Timothy M. Campbell and Nagy described
the use of avinyl polysiloxane to make interim
restorations.The rationals andprocedures is described.
vinyl polysiloxane is a commonly used impression
material that flows readily, is accurate and sets to a fins
consistency- properties that are useful a for this
procedure .
135. In 1992, Douglass B. Roberts described a method of
making indirect interim restorations using flexible
costs. A procedure isdescribed for making interim
restorations from a cast and dies made of polyvinyl
siloxane impression, material. The use of these
flexible castsand dies facilitate the removal of the
polymerised resin from the cast especially in arches
that have significant undercuts caused by anatomicfor
or tooth alignment. The rapid set of the polyvinyl
materials reducesthe time involved in making, the
indirect interim restorations.Thepolyvinyl cast is
reusables if necessary. The polyvinyl cast is reusables
if necessary. One disadvantage of this procedure is the
cost of the material.
136. William H. Lienberg in 1994 described a technical
procedure of wire reinforced light cured glass ionomer
resin provisional restoration. aprocedure to use round
practical provisional restorations is presented. The
viability of the use of glass ionomer resin cement and
the need forembrasure perfection in provisional
restoration where extensive coronal destruction has
occurred. The inherent disadvantage of the procedure is
the need to involve occlusal surfaces of the proximal
teeth; thus its use isrestricted to mouth in which the
adjacent teeth are to receive simultaneous restorative
treatment.
