Fabrication of Provisional Crowns and Bridges
Cynthia M. Cleveland, CDA; Angela D. Allen, CDA;
Niki Henson, RDA, AS
Continuing Education Units: 3 hours
The days of being “just” a dental assistant are gone. As we continually strive to learn new things and
improve our skills, the role of a dental assistant changes. In many states, laws concerning dental assistants
are changing and the dental assistant is now able to perform more, such as fabricating provisional crowns
and bridges. With this growth comes new responsibilities.
This course is designed to teach dental assistants how to fabricate provisional crowns or bridges. The term
provisional also can refer to an interim or temporary restoration. Learning the techniques, materials, and
procedures should give you a better understanding of what it takes to fabricate a provisional restoration.
Conflict of Interest Disclosure Statement
• The authors report no conflicts of interest associated with this course.
ADA CERP
The Procter & Gamble Company is an ADA CERP Recognized Provider.
ADA CERP is a service of the American Dental Association to assist dental professionals in identifying
quality providers of continuing dental education. ADA CERP does not approve or endorse individual courses
or instructors, nor does it imply acceptance of credit hours by boards of dentistry.
Concerns or complaints about a CE provider may be directed
to the provider or to ADA CERP at:
http://www.ada.org/prof/ed/ce/cerp/index.asp
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Overview
The days of being “just” a dental assistant are gone. As we continually strive to learn new things and
improve our skills, the role of a dental assistant changes. In many states, laws concerning dental assistants
are changing and the dental assistant is now able to perform more, such as fabricating provisional crowns
and bridges. With this growth comes new responsibilities.
This course is designed to teach dental assistants how to fabricate provisional crowns or bridges. The term
provisional also can refer to an interim or temporary restoration. Learning the techniques, materials, and
procedures should give you a better understanding of what it takes to fabricate a provisional restoration.
Laws and regulations concerning dental assistant duties vary from state to state. In many states fabricating
and seating provisional crowns or bridges could be considered an expanded function and additional state
approved education may be required. Always refer to the State Dental Practice Act before performing any of
these functions.
Learning Objectives
Upon completion of this course, the dental professional should be able to:
• Explain the purposes and importance of a well-fitting provisional.
• Compare the three techniques available for making provisional crowns and bridges.
• Summarize the advantages and disadvantages of each technique.
• Identify the procedure and material best suited for the needs of the patient and your practice.
• Describe the appropriate protocol for each procedure.
• Discuss special considerations for fabricating the provisional.
• Compare and contrast problems associated with making provisionals directly and indirectly.
• Show the steps of the vacuum adaptation method.
• Explain the importance of assessing the patient’s needs.
• Recite the post-operative instructions given to the patient.
• Describe the polishing procedure.
• Identify ways to keep the patient comfortable while managing the fabrication of the provisional.
• Consider potential concerns of the patient and how to address them.
• Explain how to facilitate the setting of stone and acrylic.
• Describe the cementation procedure and its importance.
• Understand the materials available for fabrication of provisional crowns.
Course Contents
•
•
•
•
Glossary
Importance and Purpose
Provisional Crown and Bridge Materials
Bis-acrylics
Acrylics
Pre-Fabricated
Techniques
Advantages/Disadvantages
Direct Techniques
Polycarbonate Crown Form Technique
Wax Technique
Alginate Paint Thin Shell Technique
Free-hand (Block) Technique
Preformed Metal Crown Technique
•
Aluminum Shell Technique
Pre-fabricated Light-cured Composite Crown
Technique
Acrylic Preliminary Impression Technique
Composite Resin Preliminary Impression
Technique
Vacuum Form Acetate Shell Technique
Reline Previous Crown Technique
Celluloid Crown Form Technique
Indirect Techniques
Indirect/Direct
Advanced Techniques
Inlay and Onlay Provisional Technique
Provisional Over Implant Technique
Long-term Provisional Technique
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•
•
•
•
•
•
•
•
Cure, self – hardening of a material in response
to mixing two chemicals together.
Abutment For Partial Technique
Laminate Provisional Technique
Finishing Procedures
Trimming
Trimming Recommended Materials
Initial Trimming
Try-In Stage
Final Trimming
Polishing
Polishing Recommended Materials
Cementation
Excess Cement Removal
Post Operative Instructions
Arranging Appointments
Conclusion
Course Test
References
About the Authors
Curing – the act of polymerization of a chemical
compound.
Distal – away from the midline.
Embrasure – a V-shaped space in a gingival
direction between the proximal surfaces of two
adjoining teeth.
Exothermic – the heat given off during a
chemical reaction.
Facial – of, or pertaining to, both the labial and
buccal surfaces of the teeth.
Flash – the excess material that extrudes beyond
the intended margins of a restoration or a mold.
Glossary
Abutment – a tooth, root, or implant used for
the support or retention in a fixed removable
prosthesis.
Gingival Margin – the most coronal portion of the
gingiva surrounding the tooth.
Gingival Sulcus – the shallow furrow formed
where the gingival tip meets the tooth enamel.
Acrylic – an organic resin from which various
types of dental restorations, prostheses and
appliances are constructed.
Homogenous – having a uniform quality and
consistency throughout.
Bridge – a fixed prosthetic device consisting of
artificial teeth (pontics) that are supported by
attaching them to abutment teeth.
Hypertrophy – abnormally large growth.
Incisal – of, or pertaining to, the biting edge of an
anterior tooth.
Buccal – of, or pertaining to, the cheek.
Contact – the point on the proximal surface of a
tooth where it touches a neighboring tooth.
Labial – of, or pertaining to, the lip.
Lingual – of, or pertaining to, the tongue.
Contour – the shape, form or surface
configuration of an object.
Mesial – toward the midline.
Copolymers – two or more different monomers.
Monomer – one unit.
Crown, clinical – the portion of the tooth visible
in the mouth above the gingiva.
Occlusion – the contact of the posterior maxillary
and mandibular teeth when brought together.
Cure, dual – hardening of a material brought
about by both self-curing and light curing.
Polymerization – the conversion of lowmolecular weight compounds called monomers
to high-molecular weight compounds called
polymers. The process of curing a material to
change it from a plastic to a rigid state.
Cure, light – hardening of a material in response
to exposure to a curing light.
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Phonetics – pertaining to speech.
the gingival tissue in establishing good contour,
and with the healing process. Ideally, the tooth
should not be prepared more than 1/2 mm
under the gingiva unless it is necessary for
retention, esthetics, or function.
3. Esthetics – The provisional crown can act
as a “rough draft” for the dentist and patient
to discuss the appearance of the permanent
crown. After wearing the provisional for some
time, the patient may request changes to
the final crown. Changes may include color,
shape, length, embrasure, and many others.
Provisional crowns allow the patient to become
accustomed to the new shape, contour, and
length if these were altered for cosmetic or
functional purposes.
4. Maintaining Space for New Restoration –
The provisional restoration is responsible for
maintaining space for the final restoration. The
provisional must touch the tooth to the mesial
and distal of the prepared tooth as well as the
opposing tooth. This contact will help reduce,
and hopefully prevent, the adjacent teeth
from moving. If the provisional is too small
and does not provide adequate contact, the
adjacent teeth will move into the open space.
When the restoration is complete and ready to
be seated, it may be too tight or not fit at all.
An accurately sized provisional, both mesially
and distally, will also prevent food from being
trapped between the teeth. Trapped food
can cause gingival inflammation, pain, and
infection.
5. Function – Function is one of the most basic
purposes of a provisional crown. The patient
needs to be able to eat (on a modified diet)
during the period of time he/she is waiting
for the permanent crown. Occlusion should
be slightly lighter than traditional occlusion to
allow the pulp and periodontal ligament (PDL)
to heal after the procedure.
Polymer – organic molecules of high molecular
weight, made up of many repeating units.
Pumice – ground volcanic ash that is used for
polishing.
Undercut – the portion of a tooth that lies
between the height of contour and the gingiva.
Also, recessed areas in the surface cast.
Viscosity – the property of a liquid that causes it
not to flow easily.
Importance and Purpose
Provisional restorations are used as a shortterm or interim (medium-term) step. They aid in
diagnosis, treatment planning and communication
to the laboratory for the clinical success of
definitive fixed restorations. They may also
provide coverage and support during periodontal
treatment including implant therapy in developing
the morphology of perio-implant periodontal
tissues, over strategic extraction sites, during
grafting techniques, furcation and endodontic
treatment, and serve as a guide for the final
restoration. Changes can be made during
this phase to correct esthetics, phonetics, and
function. The provisional may only be required
for two to six weeks, or in some situations, must
remain in a satisfactory condition in the oral cavity
for twelve to eighteen months.
It is important to provide protection for the teeth
during these times. The provisional must be
properly fabricated and cemented. The treatment
performed reflects the entire dental practice.
Therefore, when a provisional is esthetically
pleasing, remains intact, cemented and is
comfortable, you have gained much more than a
well-fitting provisional.
With these five primary purposes in mind,
evaluate the tooth, surrounding tissues and teeth,
and identify any special circumstances. Use
this knowledge to determine the best material,
fabrication technique, necessary adjustments,
cementation, and post operative instructions for
the patient’s provisional restoration.
There are five basic purposes for a provisional.
Each purpose relates both to the individual tooth
or teeth and the patient as a whole.
1. Protection of tooth and/or restoration – The
provisional provides protection for the tooth
from the time of preparation until the final
crown is cemented.
2. Tissue conditioning and healing – The
provisional restoration can be used to assist
Provisional Crown and Bridge Materials
Today, we have many choices of materials to
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Figure 1. Properly Trimmed Provisional
Courtesy of 3M ESPE
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fabricate a provisional crown and bridge. We
can choose from the traditional self-cured acrylic
polymers, or the more advanced light-cured
or dual-cured resins, as well as pre-fabricated
provisional crowns.
Materials that are compatible with composite
resins, such as Integrity® by Dentsply Caulk or
Protemp™ Plus by 3M ESPE, are available in an
automix cartridge. This can open up the door to
an almost perfect color match. These materials
are polymerized either by being chemically
activated or visible-light activated. Chemically
activated materials are packaged as a catalyst
and base. They must be stored in two separate
containers and mixed just prior to use. Many
of these materials are dispensed in an automix
cartridge. The automix cartridge prevents operator
error, allows for easy clean up and avoids
unnecessary waste (Figure 2).
Provisional materials can be categorized as
follows:
I. Bis-acrylic
a. Dimethacrylate- identified as:
i. bisphenol A-glycidyl methacrylate (BISGMA)
ii. urethane dimethacrylate (UDMA)
II. Acrylics
a.Methal Methacrylate (MMA)
b.Ethyl Methacrylate (EMA)
c. Polymethyl methacrylate (PMMA)
d.Polyethyl methacrylate (PEMA)
III.Pre-Fabricated
a.Metal (Ion)
i. stainless steel
ii. aluminum
iii. anodized gold
iv. tin
v. tin-silver
b.Polycarbonate
c. Light-cured methacrylate composite crown
There are many advantages and disadvantages
to each of these common materials. You should
thoroughly investigate the brands you are
interested in before you discuss using a new
material with your dentist. Be ready to discuss
the pros and cons of using different materials
and/or techniques.
Figure 2. Automix Cartridge
Courtesy of 3M ESPE
Directions for some chemically activated bisacrylic materials recommend utilizing a pressure
pot for the final cure (Figure 3). Examples of
®
these chemically cured materials are Ultra Trim
®
by The Bosworth Company and BIS-Jet by
Lang Dental Manufacturer. Provipoint® by Ivoclar
Vivadent is a dual-cured material and so is TCB
Dual Cure® by SciCan. Radica® by Dentsply also
uses a tri-ad oven to fully cure the material.
Bis-acrylics
Among the possible materials available are
composite fillers such as dimethacrylate,
identified as bisphenol A-glycidyl methacrylate
(BIS-GMA), or urethane dimethacrylate (UDMA).
These materials are classified as Bis-acrylics.
The final stage of curing using a dual-cured
material can be achieved by self-cure or lightcure. Light curing the material will reduce setting
time by half. Initial polymerization is achieved by
mixing the catalyst and base together. When you
are ready for the final set, you expose the material
to a visible-light curing machine. Light-activated
materials must be stored in a light-proof container
to prevent the material from polymerizing
prematurely. An example of this type of material
is Revotek LC® from G C America.
Bis-acrylics are multi-functional methacrylate
esters filled with glass and/or silica particles. Bisacrylic materials are popular because of their
easy manipulation and comfort for the patient.
They produce minimal odor, heat and shrinkage
during the polymerization process. Shade
variations are somewhat limited, ranging from two
to five shade options.
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Figure 4. PEMA - Monomer and Polymer
Courtesy of The Bosworth Company
acrylic difficult. To overcome this, lubricate the
outer surface of the provisional before placing the
cement inside. Different materials have different
shrinkage rates. When acrylic polymerizes, the
crown undergoes a shrinkage of approximately
seven percent. If the final curing takes place
without a supporting form, there will be distortion
and a less optimal fit. A study of the marginal
adaptation of provisional restorations found that
the marginal fit of ethyl methacrylate provisional
restorations can be improved by nearly 70
percent by fabricating them using the indirect
technique (see Technique section).
Figure 3. Pressure Pot
Courtesy of The Bosworth Company
Acrylics
Traditional acrylic resins are also known as
Methal methacrylate (MMA), Ethyl methacrylate
(EMA), Polymethyl methacrylate (PMMA), and
Polyethyl methacrylate (PEMA). These materials
have been used in dentistry for many years. Selfcured acrylic polymers, which are chemically
activated, require a liquid (monomer) and powder
(polymer) that are mixed to a fluid consistency.
When using acrylics, we recommend that you
submerge the provisional in water if it is kept
outside the mouth for an extended length of time.
Pre-Fabricated
Prefabricated provisionals come in a variety
of materials. They can be used for anterior or
posterior, and are often used when a preliminary
impression is not possible. Metal pre-fabricated
crowns are used in the posterior. They provide
good coverage, strength, and fit best when
the interior is customized. Stainless steel as a
provisional crown will last longer (in most cases)
than the other materials. Metal crowns come in a
variety of sizes and are grouped by type of tooth.
For a slightly more esthetic posterior provisional,
the tooth colored methacrylate composite crown
should be used. Polycarbonates are anterior
prefabricated anterior crowns. They may be used
alone, with acrylic to customize the interior, or as
a template to create a preliminary impression.
Exothermic reactions are part of the
polymerization process of polymethyl
methacrylate. The larger the amount of this
material used, the larger the exothermic reaction.
Completion of the curing process is increased by
this temperature rise and explains why frail, thin
areas of cold-curing acrylic do not reach maximal
hardness.
Polyethyl methacrylate materials have a longer
working time between the initial and final set.
They also produce a lower exothermic reaction.
This material lacks resistance to abrasion,
hardness and color stability. Using a pressure
pot at 20 to 25 psi for 5 minutes will alleviate
the hardness and color stability problem. Trim®
from The Bosworth Company is an example of a
polyethyl methacrylate acrylic resin (Figure 4).
All characteristics of a material should be
acknowledged and proper steps taken to prevent
any undesirable post-operative sensitivity or
Both of these acrylics are affected by the eugenol
in provisional cements. This makes repair of the
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pulp pathology. With the proper knowledge, an
assistant can safely utilize these materials.
provisional until final set is achieved. If the
restoration is not removed from the tooth during
the curing process, it may be necessary to destroy
the provisional in order to remove it from the
preparation.
Techniques
There are many techniques available to provide
provisional coverage for teeth while you are
fabricating permanent restorations. The type
of provisional needed, condition of the gingiva,
desired outcome, and any special circumstances
all should influence which technique you choose.
There are three basic techniques we will explore
in this text: direct, indirect, and a combination of
the two.
The indirect-direct technique is usually chosen
when multiple units are involved. This allows
for relining at the chair with minimal contouring
and improved esthetics. This technique requires
preliminary work, additional chair time and
laboratory costs.
All three techniques described have advantages
and disadvantages. In consultation with the dentist,
an assistant who knows these procedures and
the associated effects can choose an appropriate
technique to meet the needs of the patient.
The direct provisional technique is where a
provisional restoration is made inside the patient’s
mouth. The indirect technique uses a model to
fabricate the provisional (outside of the patient’s
mouth). The indirect/direct technique utilizes both
techniques.
Direct Techniques
The direct technique is performed by making the
provisional directly in the mouth. It is usually
chosen when a single unit or small span bridge is
being fabricated. It is cost-effective to fabricate the
provisional directly and requires less chair time.
Advantages/Disadvantages
The indirect technique has advantages and
disadvantages. When a patient reports a
previous history of tissue irritation after a
provisional crown was fabricated directly, you can
decrease the possibility of sensitivity by utilizing
the indirect technique. You would also use the
indirect technique to fabricate a multiple unit
bridge. This allows the patient to be comfortable
while the bridge is being constructed. It also
allows better visibility of margins, contours and
contacts. By using this technique, you can allow
the material to completely set on the prepared
model. The indirect technique does, however,
require several additional steps. These additional
steps result in increased chair time and materials.
The indirect technique is preferred over the direct
technique for pulpal protection and accuracy.
The use of acrylic monomers and polymers on
a freshly cut tooth can be an irritant. The tooth
has probably already had a large restoration, may
have additional caries and has been subjected to
the trauma of a high-speed handpiece.
Using the direct technique can be quite simple.
For instance, choosing a polycarbonate crown
form for an anterior tooth and relining it with
acrylic will save time since it is not necessary
to take impressions, pour models or make a
template. There are numerous ways to fabricate a
provisional utilizing the direct technique. The most
common ones are the polycarbonate crown forms,
alginate impressions, preformed crowns, clear
matrices and baseplate wax.
Polycarbonate Crown Form Technique
A polycarbonate crown is a tooth-colored plastic
form that comes in a variety of sizes. This
technique may only be used for single units. The
technique described does not involve using the
crown form by itself, but requires relining it with
acrylic. You can, however, use a preformed acrylic
crown without relining, if it is properly trimmed and
cemented with a provisional cement (Figure 5).
The direct technique decreases chair time
and material, however the patient is more
uncomfortable because the mouth has to stay
open while the provisional is being fabricated.
The patient may be subjected to the unpleasant
aroma from the materials and to the injurious
effects of the placement and removal of the
Hints
• Keep the plastic tab on the polycarbonate
crown form until it is ready to be trimmed. This
will help in trying in and removing the crown
form during fitting.
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Alginate Paint Thin Shell Technique
This technique utilizes an alginate impression prior
to the tooth preparation. If you cannot obtain an
impression, you cannot use this technique.
Free-hand (Block) Technique
You can choose the freehand technique when you
have become more skilled at making a provisional.
No matrices or impressions are used with this
technique. It allows for good marginal adaptation
and proper occlusion.
Figure 5. Polycarbonate Crown
Forms
Courtesy of www.doctorspiller.com
Preformed Metal Crown Technique
Aluminum, gold anodized and stainless steel
crown forms all fall into this category. They come
in a variety of sizes for premolars and molars.
They can be used by themselves, relined with
acrylic or a combination of both. These crown
forms cannot be utilized for multiple units. They
can provide all the requirements of a well-made
provisional when prepared properly. The technique
• Do not allow the acrylic to completely set on
the model or prepared tooth. This will cause
the provisional to lock onto the preparation.
Wax Technique
This technique can be used to easily fabricate
all single unit provisionals. No crown forms or
alginate impressions are necessary, which make
this technique fairly inexpensive.
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Aluminum Shell Technique
A posterior tooth can be protected by an
aluminum provisional crown. These are available
in a wide range of sizes. Always remember that
crowns tried and not used must be sterilized
before reuse. You may need to use a millimeter
ruler to determine the size, measuring the mesialto-distal distance.
Hint
• If you don’t reline the aluminum crown with
acrylic, cement it using IRM or Zinc Oxide
Eugenol (ZOE).
Figure 6. Preformed Metal Crowns
Courtesy of www.doctorspiller.com
utilized for these crowns is a bit different than
what you may be used to. The gold anodized
forms seem to work the best for this technique
because of the softness of the material (Figure 6).
Pre-fabricated Light-cured Composite Crown
Technique
These crowns are malleable, light cured,
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preformed, and are available in a variety of
shapes and sizes. They are a simple and
esthetic solution for posterior provisionals. These
types of tooth-colored pre-fabricated crowns can
be quickly adjusted prior to light curing. With no
impression or matrix needed, fabrication is quick
and relatively easy (Figure 7).
Hints
• Start with the smaller size crown, as it can
easily be contoured to modify to a slightly
larger size.
• Trim the crown short, rather that leaving it too
long.
• The tack cure should be no longer than 2-3
seconds per surface.
Figure 7. Pre-fabricated Light-cured
Composite Crown Form
Courtesy of 3M ESPE
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Acrylic Preliminary Impression Technique
This procedure requires an accurate impression
prior to and after the tooth preparation. If the
tooth is broken down, or a bridge is being
constructed to replace a missing tooth, this
technique may not be effective without adding
wax to those areas.
Composite Resin Preliminary Impression
Technique
This procedure requires an accurate impression
prior to and after the tooth preparation. If the
tooth is broken down, or a bridge is being
constructed to replace a missing tooth, this
technique may not be effective without adding
wax to those areas.
Hint
• Always remember to place the provisional
on and off during setting to prevent locking
provisional on the tooth.
Hint
• Select the provisional material that is the
closest to the natural tooth color. You can
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adjust the color by mixing colors or by adding
a veneer of flowable composite to the exterior
of the provisional after adjusting.
Vacuum Form Acetate Shell Technique
This procedure utilizes the vacuum forming
machine. It allows you to duplicate existing
teeth prior to preparation. However, it also
duplicates broken or missing portions of the teeth.
Therefore, after the alginate is taken and poured,
you should repair any existing discrepancies
prior to using the vacuum former. If a tooth is
missing, there are many ways to fill the space
prior to making your template. They include: use
of an acrylic tooth (denture tooth), use of a mix of
acrylic formed using opposing model to establish
occlusion, and the use of light-cured resin to form
a tooth (Figure 8).
• Provides a smooth, void-free surface that gives
a better finish to the surface of the provisional.
• Can be used with self- or light-cured materials.
• Is inexpensive to produce.
The clear matrix has the following advantages:
• Allows easy access and visibility throughout
the procedure.
• Can serve as a tooth preparation/reduction
guide.
Reline Previous Crown Technique
An existing crown can be used as a provisional
if it remains intact upon removal and is smooth
and aesthetically pleasing. When a crown is
removed or remade, keep in mind the reasons
Figure 8. Vacuum Form Acetate Shell
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patient is not subjected to the unpleasant odor
and taste of the acrylic resin materials, and the
resin is allowed to completely cure under pressure
on a cast of the prepared teeth. This results in a
well-fitting, nonporous provisional restoration. The
indirect technique is the most effective technique
to fabricate a large multiple unit provisional.
Hints
• Use separating mediums to prevent the
provisional material from sticking to the tooth or
model. In most cases, a tooth moist with saliva
will not allow the acrylic to adhere. It is a good
idea to use the air/water syringe and, using the
air, blow the excess separating medium off the
tooth.
• When taking an alginate, apply a small
amount of impression material to the critical
areas before placing the tray. Make sure the
teeth remain moist. If the teeth are too dry,
the alginate will remain on the preparation
and the impression will not be accurate. It is
important to obtain an accurate impression so
that the secondary retentive features, such as
grooves, box forms and the gingival third of the
perforations are accurately reproduced.
• Slurry water: To facilitate the setting time
of the stone, slurry water can be used. You
can sometimes obtain slurry water from the
water residue of your model trimmer. Some
model trimmers are set up in such a way that
it is impossible to obtain slurry water. In such
cases, you can make a solution of slurry water.
You can use a plastic jug to save such water
so it is on hand when needed. Always shake
the bottle of slurry water before adding the
water to stone. From start to finish, the setting
time should be about 5 minutes. Work fast
when using slurry water or the stone will start
to set.
• Take care to avoid incorporating air bubbles
into the acrylic, as air bubbles can cause voids
in the restoration. When you use vacuum
Figure 9. Vacuum Former
Courtesy of Keystone Industries
for replacement. If it is for esthetics, you would
want to make a new provisional. If it is because
of poor fit, you can reline with acrylic to serve as
a provisional. In most cases, it is best to make a
new well-fitting provisional.
Celluloid Crown Form Technique
A celluloid crown form can be used to fabricate
a single unit provisional. It is extremely helpful
when using light-cured materials because the
material can be cured through the clear form.
Indirect Techniques
The indirect fabrication of provisional restorations
has several advantages over the direct technique.
The main advantage is the patient does not have
to keep their mouth open during the fabrication
of the provisional. In addition, if acrylic material
is used in fabrication, injurious effects of applying
acrylic monomer to the tooth are eliminated, the
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Indirect/Direct
When the doctor chooses to use the indirect/direct
technique, he/she has chosen to have the laboratory fabricate a thin acrylic shell over mocked
preparations that were done on a study model
of the patient. This provisional shell will then be
relined in the patient’s mouth. The laboratory
formed acetate templates, you should not see
air bubbles. You can eliminate air bubbles
by penetrating the template with a sharp
instrument, such as an explorer.
• To ensure proper alignment of your core,
you may need to make index marks using a
permanent marker (Figure 10).
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Figure 11.
Figure10.
Provisional Over Implant Technique
To fabricate a provisional over an implant, the
assistant must be familiar with implants and their
coordinating parts. We suggest using the indirect
technique.
indirectly fabricates the provisional on the model
and the doctor or assistant relines it directly in the
mouth, giving the technique its name. Refer to
steps 3 through 8 in the polycarbonate technique.
Advanced Techniques
Long-term Provisional Technique
Provisional crowns may have to be fabricated to
last several months. In such instances, metal
bars or a mesh material may be used to help
provide durability. For an anterior provisional, the
material should be placed on the lingual surface;
for posterior teeth, the material should be placed
on the occlusal surface.
Once an assistant has mastered the single unit
and multiple units, he/she can move on to more
challenges, such as fabricating a provisional
over an implant or fabricating a provisional as an
abutment for an existing partial. The following
are a few advanced techniques.
Inlay and Onlay Provisional Technique
An inlay and onlay should be fabricated by a
proficient assistant. This technique requires
skill to achieve good marginal adaptation. The
small size and intricate margins require precise
fabrication and trimming. This technique closely
relates to the freehand technique discussed
earlier. The only difference with this technique is
that the whole clinical crown is not covered.
Placing mesh prior to pouring material can be
very difficult. The mesh may move during the
pouring process and be in the wrong position
while final set occurs. For the inexperienced, it
is easier to cut a long groove in the occlusal or
lingual surface. Then place the bar or mesh and
cover with material.
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Hint
• Before placing the material over a metal bar
reinforcement, make sure the bar will not
interfere with the patient’s occlusion.
composite temporarily. This technique is rather
simple, but does tend to stain around the edges
over time. Make sure to tell the patient that this
can happen. When a patient is aware of what
to expect, there will be no phone calls to ask
questions later.
Abutment For Partial Technique
When making a provisional as an abutment for
an existing partial, use a free-hand or custommade technique. This will allow for proper clasp
placement, rests and correct size. This technique
requires some practice. It also requires a skillful
eye to know how much and where to trim.
Finishing Procedures
Finishing a provisional crown or bridge takes
skill using materials and a proper slow speed
technique. This entails correct positioning of the
handpiece in relation to the area being trimmed.
A well-finished provisional will provide a smooth
and an esthetically pleasing appearance.
Laminate Provisional Technique
Depending upon the length of time between
preparation and cementation appointments, a
provisional may be placed. If the laboratory can
process the laminate within a week, a provisional
might not be necessary.
Trimming
An operator must have general knowledge of
proper handpiece operation, including how to
correctly position the handpiece in relation to the
area to be trimmed. Check state regulations
for laws or rules regarding assistant permitted
duties to see if you are permitted to adjust
intraorally.
For multiple units, the provisional is made
using a matrix and acrylic. However, laminate
provisionals tend to come off frequently and you
should cement the final restoration as soon as
possible.
When trimming margins, place the cone-shaped
acrylic bur parallel to the crown, but avoid
disturbing contact points. A cone-shaped bur
has a sharp point for definition and a large base
For single units, the doctor can etch a few spots
on the facial and you can form and place the
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Final Trimming
Trim excess again and adjust occlusion using
articulating paper. At this point you should check:
• margins to make sure they are closed and
there are no overhangs.
• for proper contours.
• occlusion with articulating paper. Confirm
fit by asking patient how it feels. If it feels
strange, make adjustments.
• for any irregularities that might make the
provisional uncomfortable.
for bulk reduction. A larger bur will be easier to
maneuver since it requires less revolutions and/or
vibrations.
Trimming Recommended Materials
Straight handpiece using the following
attachments:
• Diamond disc for separating teeth and opening
the embrasure areas.
• #8 bur for hollowing out prior to relining or
removing any internal imperfections and
reduction in occlusal height.
• #35 bur to help define anatomy on the occlusal
surface.
• Long, pointed acrylic bur to define embrasure
areas and final contours.
• Carbide egg shaped bur to adjust occlusion.
• Cone-shaped acrylic bur for bulk reduction and
initial trimming of margins.
Polishing
The polishing of a provisional crown is an
important step. A non-polished crown will have
a rough surface which can cause plaque to build
up. This is especially dangerous around gingival
margins. Periodontal problems can result from
a non-polished crown. Because of the constant
movement of the tongue, the patient may also
become uncomfortable if the surface is rough.
Initial Trimming
1. Determine your margins first. You may mark
the margins with pencil to clearly identify them.
Start with a cone-shaped bur and trim close to
margins. Continue until all margins are clearly
trimmed. Margins should be trimmed to 1 mm.
The margins must remain thin and intact.
2. When constructing a multiple unit provisional
• Change burs to a separating disc, such
as a diamond disc. Start by separating
the teeth following the original lines on the
provisional.
• Separate and open the embrasure areas.
• To shape further, switch to a cone shaped
bur.
• Use the long, pointed acrylic bur to further
open your embrasure areas from the buccal
and lingual. This is best done on the
prepared model. This will help you see any
additional trimming and shaping that you
will need to do.
Polishing Recommended Materials
You will need a sterile rag wheel and pumice.
To use the dental lathe:
1. Moisten the rag wheel and place it on the lathe
mandrel.
2. Cover the tray with aluminum foil and place the
pumice on top.
3. Mix a small amount of water with the pumice
in a dappen dish or small paper cup to make a
thick consistency.
4. Make sure the protective plastic shield is in
position and the operator is wearing personal
protective equipment (PPE) and turn the
machine on low.
5. Using gloves, coat the provisional with pumice,
and secure your grasp on the crown. Use care
because a rag wheel can cause overheating
and warpage during polishing.
6. The incisal edge or occlusal surface should be
facing you. With a back-to-front motion, run
the provisional along the bottom side of the rag
wheel. Carefully turn provisional to polish all
sides except the contact areas. When you use
all acrylic resins, take care when polishing so
as not to buff away margin areas.
7. Replenish the provisional with pumice when
necessary.
8. Once you have completely polished the
provisional with pumice, place a dry rag wheel
Try-In Stage
Try the provisional in the mouth at this point. It
may be necessary to remove additional undercuts
internally, which may prevent the provisional from
seating properly. A #8 acrylic bur is sometimes
used to hollow out the inside of the crown. Close
marginal discrepancies by using a small brush,
powder and liquid to fill the deficient areas when
using acrylic.
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on the lathe and add polishing compound to
the turning rag wheel. Completely polish the
provisional with the compound.
4. Continue polishing using increasingly less
coarse discs until the provisional is smooth.
5. Use your gloved finger to feel for any sharp
edges, and look closely to observe any
significant texture change.
6. For an ultra smooth finish, follow the
sandpaper discs up with a composite
polishing cup or disc without without polishing
compound.
7. For an extra touch, brush on a light glaze
(such as Luxa Glaze) and light cure.
You can do the same technique utilizing the
slow speed and laboratory handpiece. This
also provides a high shine. You also may use a
glaze to provide a high gloss. If the provisional
restoration is on an anterior tooth, the patient
may insist on a close color match. This can be
accomplished with stains and glazes after the
provisional has been polished. Minute stains
cure and bond to all dental resins, including
ethyl and methyl methacrylates, polycarbonates,
vinyl methacrylate copolymers, resin crowns and
laminates.
Cementation
Remember that eugenol containing cements can
interfere with the setting of acrylic and prevent
bonding of the final restoration. This may become
important if repairs are needed. Cements that are
light-cured and dual-cured are also available.
• Isolate the area with cotton rolls and/or 2 x 2’s
and keep area dry. (Use air/water syringe to
blow dry tooth.)
• Mix the cement according to directions.
• Coat the inside of the crown with cement. (Be
careful not to overfill the crown. This could
result in improper placement and the need for
excessive cement to be removed).
• Request patient to bite down.
To Use Sandpaper Discs:
1. This technique is typically only used for tooth
color composite resin based materials, but can
be used in with other materials.
2. Beginning with the most coarse disc, attach
the disc to a mandrel (Figure 13).
3. Using the slow speed handpiece, lightly polish
any areas of the provisional that were rough or
had been adjusted with a handpiece.
Excess Cement Removal
Insuring all excess cement is removed is
important to the health of the gingiva. If all the
cement is not removed, the gingiva can become
irritated and inflamed.
• When the cement has set, use an explorer
to remove the excess along the margins and
contacts.
• Use the air/water syringe to keep the area
clean and give you a view into the gingival
sulcus.
Figure 12. Dental Lathe
Courtesy of National Dental Supplies
Figure 13. Sandpaper Discs
Courtesy of Shofu Dental
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• Take a piece of floss and pass it down through
the occlusal contact and out the buccal or
lingual. Do not remove the floss through the
contact area. If cementing a bridge, you need
floss threaders.
• Take a wet cotton roll and wipe crown clean.
• Instruct the patient to bite down to see how it
feels.
should also avoid chewing on the side of the
provisional for a few hours. This will allow some
materials, such as cements, to fully set. During
the time the provisional is in place, the patient
should avoid sticky foods, such as gum, caramel
and taffy. Instruct the patient to contact the office
as soon as possible if the provisional becomes
dislodged. In the meantime, the patient can place
a little petroleum jelly in the crown and place it
back on the prepared tooth. It is always important
to give post operative instructions to the patient
both verbally and in written form.
Hints
• If it feels high, the provisional may not be
seated correctly or the occlusion may not have
been adjusted properly during try in. To see
which is the case, check your margins. If they
are open, you have not seated the provisional
correctly. In this case, remove the provisional,
clean out the cement and repeat the process.
If the margins are closed, the provisional is
seated properly, but the occlusion is high.
Mark it with articulating paper and have your
dentist adjust the height. This should only
take a few minutes to do. It should, however,
be avoided by checking your occlusion several
times before cementation. Make sure to have
the patient bite down several times and slide
teeth from side to side to check for proper
occlusion.
• Coat the outside of the crowns with petroleum
jelly before placing the cement internally.
• Tie knots in the floss. This will help remove
large pieces of cement interproximally.
• Tie floss around the pontic of a bridge and
make a loop prior to cementation. This will
avoid the need for floss threaders. Make
sure to tie the floss loosely and have the
ends easily accessible so it can be untied and
manipulated for cleaning cement under the
pontic areas of a bridge.
Arranging Appointments
It is important to establish a routine technique
for provisionals, so you can determine how long
to make appointments. To achieve the desired
results in provisional therapy, the dentist must
allot adequate time to fabricate the interim
restoration. You should allow adequate time to
prepare the teeth and make a final impression.
A properly trained assistant can take over the
role of fabricating and cementing the provisional
restoration. Appointment times must be altered
to accommodate these changes in staff and roles.
The dentist/assistant time with the patient must be
shortened and assistant-only time be lengthened.
This time will include time for final cementation
and clean up after fabrication of provisional.
Once a routine has been established, a
designated amount of time should be allotted
for each unit of the provisional. During this
time, utilizing an assistant, the dentist can be
performing another procedure, making full use of
his/her talents.
Conclusion
Post Operative Instructions
The provisional restoration is an important stage
in the prosthetic treatment. It must provide a
suitable means for an provisional restoration. It
is the responsibility of the dentist and dental
assistant to provide the best possible coverage
with the minimal amount of discomfort, and to
meet the criteria for a well fitting provisional.
Inform the patient to continue brushing the area
as usual. Good home care is essential. Flossing
is necessary, but the floss should be pulled
through the buccal or lingual. The patient should
use a floss threader to floss under a bridge.
Pulling the floss through the contact can help
prevent the crown from dislodging. The patient
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Course Test Preview
To receive Continuing Education credit for this course, you must complete the online test. Please go to
www.dentalcare.com and find this course in the Continuing Education section.
1.
The indirect technique is preferred _______________.
a. for cost effectiveness
b. for efficient use of time
c. for pulpal protection
d. because of a low shrinkage rate
2.
Light activated materials should be _______________.
a. stored in a warm room
b. stored in a dark container
c. mixed well
d. fluid in consistency
3.
A good provisional should provide _______________.
a. stability
b. provide occlusal function
c. promote temperature changes
d. Both A and B
4.
Margins that are impinging on the gingival tissue can cause inflammation, resulting in
_______________.
a. gingival recession
b. hemorrhage
c. hypertrophy
d. All of the above.
5.
Exothermic reaction increases when _______________.
a. used with increasing amounts of acrylic
b. using light cured materials
c. working time is increased
d. the final set has occurred
6.
Provisional materials include __________ cured.
a. chemically
b. light
c. dual
d. All of the above.
7.
When determining your margins, you should _______________.
a. start trimming right away
b. take a lead pencil and outline your margins
c. look for bubbles or discrepancies in the provisional
d. allow the material to set completely
8.
When polishing with a lathe, make sure _______________.
a. a sterile rag wheel is used
b. the protective shield is down
c. PPE is worn
d. All of the above.
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9.
The switch(es) left on during the “suck down” stage when using a vacuum former is(are)
the ____________.
a. heat switch
b. vacuum switch
c. Both A and B
d. None of the above.
10. Pre-Fabricated Light-cured Composite Crowns are complicated to fabricate. Prefabricated
Light cured Composite Crowns need an impression and matrix for fabrication.
a. The first statement is true. The second statement is false.
b. The first statement is false. The second statement is true.
c. Both statements are true.
d. Both statements are false.
11. Dental assistants should _______________.
a. choose their own materials and techniques
b. consult the doctor when choosing materials and techniques
c. not talk to the patient during the procedure
d. not worry about the characteristics of materials
12. Post operative instructions should include _______________.
a. telling the patient to floss regularly
b. instructing patient to snap the floss through the contacts
c. not to change diet
d. not to brush area involved
13. The setting time for the stone mixed with slurry water should take approximately
____________.
a. 10 minutes
b. 3 minutes
c. 2 minutes
d. 5 minutes
14. Bis-acrylic materials are popular because there is _______________.
a. minimal odor
b. easy manipulation
c. minimal shrinkage during polymerization
d. All of the above.
15. An explorer is used to _______________.
a. remove air bubbles from the template during the pouring of acrylic
b. remove the template off the model
c. mix the acrylic
d. Both A and C
16. During the try on stage, you should _______________.
a. be concerned if you break the preparations off the model
b. be concerned if the provisional does not seat properly
c. force the provisional in place
d. cement the crown
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17. A provisional may remain in the oral cavity for _______________.
a. two to four weeks
b. two weeks to eighteen months
c. four weeks to one year
d. two years
18. When using the indirect technique, a vacuum formed matrix must _______________.
a. be trimmed along the margin
b. fit exactly on the model of the prepared teeth
c. rest on the frenum
d. include three or more teeth mesially and distally
19. The bur that would not be used in trimming a provisional bridge is the ____________.
a. #330
b. #35 acrylic bur
c. #8 round bur
d. diamond disc
20. Diamond discs are used for _______________.
a. trimming the margins of the provisional
b. placing anatomy on the occlusal portion of the provisional
c. separating the teeth of the provisional
d. polishing the provisional
21. Bis-acrylic materials _______________.
a. produce extreme heat during polymerizing
b. are cost effective
c. have a wide range of shades
d. produce minimal heat when polymerizing
22. The pressure pot should be pressurized to _____ p.s.i.
a. 32
b. 20
c. 10
d. 5
23. Traditional acrylics _______________.
a. are affected by eugenol
b. have a 7% shrinkage rate
c. produce an exothermic reaction
d. All of the above.
24. Polishing is important because _______________.
a. it allows for ease of cleaning of the provisional
b. it aids in placement of the provisional
c. a non-polished provisional would be rough
d. Both A and C
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25. Traditional acrylic resins are also known as _______________.
a. polyethyl methacrylate
b. polymethyl methacrylate
c. monomer and polymer
d. All of the above.
26. A provisional crown or bridge is also called a/an _______________.
a. temporary restoration
b. immediate restoration
c. interim restoration
d. Both A and C
27. A long span and long term provisional bridge should be _______________.
a. cemented permanently
b. reinforced with metal or mesh
c. removed periodically
d. None of the above.
28. Esthetics is considered one of the five basic purposes for a provisional. Prefabricated
provisionals should only be used in the posterior.
a. The first statement is true. The second statement is false.
b. The first statement is false. The second statement is true.
c. Both statements are true.
d. Both statements are false.
29. When cementing the provisional _______________.
a. it is not necessary to floss
b. you should not dry the teeth
c. use a plastic instrument to remove cement
d. instruct the patient to bite down
30. Bis-acrylics are _______________.
a. composite fillers
b. diamethacrylates
c. BIS-GMA
d. All of the above.
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References
1. Anusavice KJ. Phillips’ Science of Dental Materials, 11th Edition. W. B. Saunders, (2003).
2. Berry T, Troendle K. Provisional restorations. Guidelines for proper selection, placement. Dent
Teamwork. 1995 Nov-Dec;8(6):25-31.
3. Craig RG, O’Brien W, Powers J. Dental Materials. Missouri: Mosby-Year Book Inc., 6th Edition,
(1996): 60-69, 267-277, 286-289.
4. Clinical Research Associates Newsletter, Provo, Utah, February 1997, Pg. 3.
5. Dietz-Bourguignon E. Materials and Procedures for Today’s Dental Assistant. Thomson/Delmar
Learning, 2006.
6. Dofka CM. Dental Terminology. Thomson/Delmar Learning, 2000.
7. Frederick DR, George Taub Products & Fusion Company, Pamphlet on Stains and Glazes.
8. Miyasaki-Ching C. Chasteen’s Essentials of Clinical Dental Assisting. Missouri: Mosby-Year Book
Inc., (1997): 290-298, 304-311.
9. Anderson PC, Pendleton AE. The Dental Assistant. 007 ed. Thomson/Delmar Learning, 2001.
10. Phinney DJ, Halstead JH. Delmar’s Dental Assisting: A Comprehensive Approach. 3rd ed. Albany,
NY: Delmar Learning/A part of Thomson Corp., 2008.
11. Reisback MH. Dental Materials in Clinical Dentistry. Massachusetts: PSG Publishing Co., (1982):
259-279.
12. Robinson DS, Bird DL. Ehrlich and Torres Essentials of Dental Assisting. 4th ed. Philadelphia:
Elsevier/Saunders Publishing Company, 2007.
13. Bird D, Robinson D. Torres and Ehrlich Modern Dental Assisting . Pennsylvania: W. B. Saunders,
(2009): 694-702.
About the Authors
Cynthia M. Cleveland, CDA
Cynthia Cleveland graduated from the Dental Assisting Program at Robert Morris Junior College in June
1976. She obtained her Expanded Duties through Broward Community College. Working with many
doctors through the years, she has gained a tremendous enjoyment for fabricating provisionals and
learned techniques from all of them. She has particularly benefited from the knowledge that Dr. Gene
Tonn has shared with her. She assisted Dr. Tonn in presenting the course for making provisionals at
Broward Community College. For the last two years she has worked hand in hand with Angela Allen to
present this same course to Dental Assistants through the Continuing Education Department at Broward
Community College.
Angela D. Allen, CDA
Angela Allen is a graduate of the Dental Assisting Program at Broward Community College. She
has worked with numerous general dentists from whom she has gained valuable experience. She is
currently working for the Dental Assisting and Hygiene Programs at Broward Community College. She
has worked with Cynthia Cleveland for the past two years providing hands-on experience to dental
professionals in the fabrication of provisional crowns at Broward Community College.
Niki Henson, RDA, AS
Niki Henson is a graduate of North Harris College. She is the President of
Cornerstone Dental Academy where she authored the curriculum and provides
continuing education to dentists, hygienists, and dental auxiliaries. She travels as
a speaker, consultant, and presents a variety of seminars and clinical programs
including provisional workshops at dental meetings across the country.
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