Provisional restorations in crowns and bridges

1. PROVISIONAL RESTORATIONS
IN CROWN AND BRIDGES
Paavana
II MDS
1

2. Contents
• Introduction
• Definition
• Synonyms
• Rationale
• Requirements
• Classification of provisional restorations
• Techniques of fabrication of provisional restoration
• Cementation
• Removal, Recementation
• Conclusion
• References
2

3. Introduction
• PROVISIONAL - established for the time being, pending a permanent
arrangement.
• Provisional crowns or fixed partial dentures are essential to prosthodontic
therapy. Even though a definitive restoration may be forthcoming, a provisional
restoration must satisfy the important needs of the dentist and the patient.
• The success of fixed prosthodontics, to a large extent depends on the care and
method in which the provisional restoration is designed and fabricated
3

4. DEFINITION
• “A provisional restoration is a transitional restoration that
provides protection, stabilization, and function before
fabrication of the definitive prosthesis. It may be also used
to determine the aesthetic, functional and therapeutic
effectiveness of a treatment plan”- GPT 9.
4

5. SYNONYMS
• Interim
• Transitional
• Intermediate
• Treatment restoration.
5

6. RATIONALE
• To protect pulp and sedate prepared abutments
• To evaluate parallelism of abutments
• To immediately replace missing teeth
• To prevent migration of abutments
• To improve esthetics
• To provide an environment conducive to periodontal health
• To evaluate and reinforce the patient’s oral home care
• To aid periodontal therapy by providing visibility and access to
surgical sites when removed
• To provide a matrix for the retention of periodontal surgical
dressings
*Federick, D. R. (1975). The provisional fixed partial denture. J Prosthet Dent, 34(5), 520–526
6

7. • To stabilize mobile teeth during periodontal therapy and
subsequent repair
• To anchor orthodontic brackets during minor tooth
movement
• To aid in developing and evaluating an occlusal scheme before
the final prosthesis is made
• To allow evaluation of vertical dimension, phonetics, and
masticatory function
• To aid in determining the prognosis of questionable
abutments in the over-all restorative treatment plan.
*Federick, D. R. (1975). The provisional fixed partial denture. J Prosthet Dent, 34(5), 520–526
7

8. REQUIREMENTS
8

9. Biologicrequirements
1. Pulp protection
• Seal and insulate the prepared tooth surface from
the oral environment to prevent sensitivity and
further irritation to the pulp.
• Restoration must be fabricated of a material that
will prevent the conduction of temperature
extremes.
• The margins should be adapted well enough to
prevent leakage of saliva.
9

10. 2. Periodontal Health
• Good margin fit, proper contours and a smooth surface.
• It is of utmost importance that the margins of a provisional restoration not
impinge upon the gingival tissue
• If the gingival tissues remain healthy while the provisional crown is in place,
there is less likelihood of a problem arising after cementation of the
definitive restoration.
10

11. 3. Occlusal Compatibility and Tooth Position
• Patient comfort, ward off tooth migration, and possibly prevent joint or
neuromuscular imbalance.
• Establish or maintain proper contacts with adjacent and opposing teeth
• Inadequate contacts -supraeruption and horizontal movement
11

12. 4) Prevention of enamel fracture
Provisional restoration should protect crown preparation margin especially in
partial coverage designs in which margins of the preparation is close to the
occlusal surface of the tooth and could be damaged during chewing.
12

13. Mechanical requirements
1) Function
• Greatest stresses in provisional restorations are likely to occur during
mastication.
• Fracture is not usually a problem with a complete crown interim restoration, as
long as the tooth has been adequately reduced. Breaking is more common with
partial restorations; they are weak as they are not covering the tooth
completely.
• A partial FDP must function as a beam in which substantial occlusal forces
are transmitted to the abutments. During function high stresses are created
in the connectors, to reduce the risk of failure, connector size must be
increased in the provisional as compared to the definite restoration.
13

14. 2) Displacement
• A displaced provisional restoration must be re cemented promptly to avoid
irritation to the pulp.
• It is best prevented by proper tooth preparation and a provisional with closely
adapted internal surface.
3) Removal for reuse: Provisional restoration often need to be reused and
should not be damaged when removed from teeth
14

15. Aesthetic requirements
• Contour, colour, translucency and texture are the key elements of coronal
appearance.
• 1. Contour- Diagnostic wax up
• 2. Colour- Custom shade guide
Resin coloring tints
Provisional stain kit.
15

16. 3. Translucency-
• Incisal or occlusal third enamel show pronounced translucency.
• Two resins – one colored to match body and one to match the enamel of the tooth
4. Texture-
• Important in maxillary anterior teeth.
• Developmental lobes – wax pattern.
• Developmental defect – on restoration just before finishing.
• Imbrication lines – coarse diamond rotary instrument in slow rotating speed
slowly moved across the facial surface from proximal to proximal.
16

17. A)ACCORDING TO METHOD OF FABRICATION
• Preformed
• Custom made
B) ACCORDING TO TECHNIQUE OF FABRICATION
• Direct technique
• Indirect technique
• Indirect-direct technique
17
CLASSIFICATION

18. C. ACCORDING TO DURATION OF USE
• SHORT TERM ---- for few days (upto 2 weeks) (Polycarbonate or
aluminum crowns )
• MEDIUM TERM ---- for few weeks ( > 2 weeks) ( Resin based provisionals)
• LONG TERM ---- for months (mostly cast metal crowns)
18

19. D. ACCORDING TO MATERIALS USED:
RESINS METALS
19
• Polycarbonate • Acrylics
• Bis acryl
composites
Preformed Custom made Preformed Custom made
• Aluminium
• Tin-silver
• Ni-Cr
• Cast alloys
• Cellulose
Acetate

20. TECHNIQUES
• STEPS IN FABRICATION
20
Diagnostic wax
up on the
study models
Fabrication of
the matrix /
external
surface form
Contouring of
the tissue
surface form
Cementation
and evaluation
of the
restoration

21. MOLD
EXTERNAL
SURFACE
FORM
PREFORMED CUSTOM
TISSUE
SURFACE
FORM
DIRECT
INDIRECT-
DIRECT
INDIRECT
21

22. 1. Diagnostic wax up
• The diagnostic wax-up is the method or process through which practitioners can
fully visualize the true restorative needs of their patients.
• It is to be done to change or correcting occlusal abnormalities.
• To provide a guide for the technician
• To seek patient consent
• It also helps to fabricate the customized matrix form
22

23. I. PREFORMED RESTORATIONS
• Prefabricated crowns are purchased by the dentist in assortment
kits. They come in a variety of materials and graduated sizes, and
are simply thin, tooth shaped shells.
• Preformed crowns are generally limited to use as single
restorations rather than for fixed partial dentures.
• The various materials from which preformed crowns are made
include polycarbonate, cellulose acetate, aluminium, tin-silver,
and nickel-chromium.
23
2. FABRICATING THE MATRIX OR EXTERNAL SURFACE FORM

24. A. POLYCARBONATE CROWNS
• Generally called "Ion crowns" in deference to the company that first manufactured
them.
• Most natural appearance of all the preformed crown materials.
• hollow, tooth-shaped with walls about 0.3 mm thick.
• Their life expectancy depends upon how much the dentist has to modify them from
their original state to make them fit, and how careful the patient is with them
24

25. • Widely used as temporary crowns for several reasons:-
• It is strong yet flexible enough to contour easily
• It bonds chemically to a self-curing acrylic resin material used to fill
the shell.
Any area of a plastic crown, including the incisal edge, can be
extended by adding layers of acrylic and smooth them.
25

26. 26
Indications Contraindication Advantages Disadvantages
• Single anterior
teeth and
premolars
• Short-term
provisional
restorations
• Long-term
provisional
restorations
• Less time
consuming
• Tooth-colored
making them
aesthetically
pleasing
• Easily adjustable
• Single shade.
• Reline required
for adequate
marginal fit and
retention
• Single tooth
restorations
• Require
extensive
alteration

27. B.CELLULOSEACETATECROWNS
• Cellulose acetate is a thin, transparent resin material
available in all tooth shapes and a range of sizes.
• Shades are entirely dependent on the autopolymerizing
resin.
• Once the resin has polymerized, the cellulose acetate is
peeled off and discarded.
27

28. Indications Contraindication Advantages Disadvantages
• Short-term
provisional
restorations
•Provisionalisation
of anterior teeth
• Long-term
provisional
restorations
• Less time
consuming
• Aesthetic
• They can be
made to fit the
preparation
easily, as it can be
shortened by
cutting, or
lengthened by
adding resin
• Additional resin is
needed for establishing
proximal contacts
• Generally limited to
single tooth restorations
28

29. C.ALUMINIUMandTIN-SILVERCROWNS
• Preformed metal temporary crowns typically are produced for both
molars and premolars and differ in size and occlusal anatomy.
• They are thin-walled (slightly less than 0.5 mm) tooth-shaped
shells commercially produced.
• These crowns are so soft, they must be handled gently.
• Provide good adaption due to softness and ductility of the material
29

30. Indication Contraindication Advantages Disadvantages
• molars
• premolars
• aesthetics is a primary
consideration
• Allows for good
occlusal adjustment
• available in a range
of sizes sufficient to
cover most
preparations.
• are inexpensive
• Care must be taken
during try-in
verification to avoid
fracture of their
delicate margins
• Require
modification
• Galvanic shock and
metallic taste
30

31. E.STAINLESSSTEELCROWN
• Most durable of the preformed anatomical crowns, which is used most often in restoring
primary teeth
• Stainless steel ones are used to protect primary teeth from further decay until they fall out
naturally.
31

32. Indications Contraindications Advantages Disadvantages
• Posterior teeth
• Long-term
provisional
restorations
• Aesthetic region
provisionalisation
• Extremely
durable
• Relatively
inexpensive
• Subject to
minimal
technique
sensitivity during
placement
• Poor aesthetic
quality for placing
on an anterior
tooth
• The difficulty of
adapting its rigid
metal margin to
the prepared tooth
margin
32

33. TECHNIQUES-
PREFORMED
PROVISIONAL CROWNS
33

34. FOR
POLYCARBONATECROWNS
• Additions to clinical armamentarium:
1. Assorted polycarbonate crowns
2. Green stone bur
3. Straight handpiece
4. Boley gauge or dividers
34

35. 35

36. 36

37. 37

38. 38

39. PREFORMEDMETALCROWNS
• Additions to clinical armamentarium:
1. Assorted aluminium crowns
2. Boley gauge or dividers
3. Crown-and-collar scissors
4. Contouring pliers
5. Cylindrical green stone, straight handpiece
6. Sandpaper disk (7/8 in diameter)
7. Stretching blocks
39

40. • Mesiodistal width of the crown space using a Boley gauge or
dividers.
40
• Cervical end expansion

41. • Crown tried over preparation
• Gingival margin trimmed till the correct
occlusogingival height
• The axial surface is contoured with pliers to obtain
a convex surface.
41

42. • Place the trimmed shell over the prepared tooth and
apply slight apical seating pressure. Instruct the patient
to close with moderate force
• Apply petroleum jelly to the prepared tooth and adjacent
gingival tissues. Mix poly-R’ methacrylate and fill the
crown.
• When the resin surface becomes matt, place the crown
over the tooth. Instruct the patient to occlude.
42

43. • Remove the marginal excess quickly.
43
• Monitor the polymerization by light probing with a hand
instrument.
• Remove it before it has fully polymerized and place it in
warm water

44. • After about 5 minutes, mark the margins and trim any excess.
• Replace the crown and adjust the occlusion as necessary using marking film and
slow-speed handpiece..
• Polish, clean, and cement the restoration.
44

45. II. CUSTOM-MADE RESTORATION
• A custom ESF is a negative reproduction of either the patient’s teeth before
preparation or a modified diagnostic cast.
• Accurate reseating of the ESF is easier, and the mold cavity produces better results
if thin areas of impression material are trimmed away.
• It provides intimate contact between provisional restoration and prepared tooth.
45

46. • Most commonly used for fixed partial dentures.
• CUSTOM MADE MATRIX-
1. irreversible hydrocolloid.
2. putty/silicone impression
3. vacuum adapted thermoplastic sheet
4. wax
46

47. Advantages-
• A wide variety of materials can be used.
• Helpful in evaluating the adequacy of the tooth reduction; by measuring the
thickness of the restoration, the preparation can be altered.
Disadvantages-
• Additional lab procedure involved
• Time consuming
47

48. TECHNIQUES FOR CUSTOM
PROVISONAL CROWNS
48

49. IDEAL PROPERTIES OF PROVISIONAL RESTORATIVE MATERIALS
1. Convenient handling: Adequate working time, easy moldability, rapid setting time.
2. Bio compatible: nontoxic, non-allergic, non-exothermic.
3. Dimensionally stable during solidification.
4. Ease of contouring and polishing.
5. Adequate strength and abrasion resistance
49
MATERIALS

50. 6. Good appearance: translucent, colour, colour stable.
7. Good patient acceptance- non irritable, odourless.
8. Ease of repairing.
9. Chemical compatibility with provisional luting agents
50

51. • Currently Available Materials-
• The materials can be divided into four resin groups:
• Poly (methyl methacrylate)
• Poly (R’ methacrylate)
• Bis-acryl composite
• Hybrids
51

52. PolymethylMethacrylate
• These materials resemble those used for complete dentures, except that they
are tinted with tooth-coloured pigments rather than varying shades of pink.
• The material is supplied in two parts: a monomer (methyl methacrylate) and
a powder (polymethyl methacrylate).
• The polymer contains:
•pigments
•initiator (benzoyl peroxide) to start polymerization
•inhibitors ( usually a hydroquinone) to increase shelf life
•cross-linking agents to prevent crazing
52
Duralay, Temp Bridge Resin, Jet

53. Advantages-
 High strength
 Good color stability
 Can be smoothed and polished
 Low cost
 Easily repaired
 High abrasive resistance
53
Disadvantages-
 Highly exothermic
 Prone to Shrinkage
 Odour
 Monomer is irritating to the pulpal and
gingival tissues

54. Composites
• Bis-acryl resins can be used for most types of provisional restorations- chemically, light
activated, dual activated
• Most products are available in automix systems.
• Bis-acryl resins are similar to BIS-GMA resins and possess several advantages:
• less exothermic heat
• minimal polymerization shrinkage
• high tensile strength and surface hardness
• improved marginal fit
• good color stability
54
Protemp II (ESPE), Luxatemp, FlexSpan, Integrity

55. • minimal odour
• high polishability
• Disadvantages-
• Greater cost
• More brittle than acrylic
55

56. PROTEMP 3 GARANT
• It is a self-cured bis-acryl composite recommended by
3M ESPE for the fabrication of provisional crowns,
bridges, inlays, and onlays.
• The material is available in four shades (A1, A3, B0.5,
and B3) and is supplied in cartridge form for use in an
automix dispenser gun
56

57. • The automix gun dispenser makes it easy to mix the product and produces
homogeneous mixes.
• Restorations have excellent marginal adaptation and are fast and easy to polish.
• Protemp provides good detail reproduction in marginal areas and is fracture
resistant
57

58. LUXATEMP
• Luxatemp was the first bis-acrylic composite that was offered in
the advantageous 10:1 mixing ratio for automatic mixing.
• Advantages:
• good adaptation and fitting
• High flexural strength
• High resistance to abrasion
• Six aesthetic shades
• Highly biocompatible
• Automix safety cartridge delivers the ideal mixing ratio 10:1
58

59. PROTEMPII
• Excellent esthetics due to great color stability, high
polishability and the choice of three intensive shades:
A1 extra light, A3 light and B3 yellow.
• Direct chairside temporary restorations
59

60. REVOTEKLC
60
• It is supplied in a "Putty Stick" form in a lightproof plastic
tray.
• Since it is a one-component material, no mixing of powders
and liquids is required
• Revotek LC is less messy than other types of provisional
materials, handles without tackiness, and can be used
quickly and easily to fabricate all types of provisional
restorations.

61. • Advantages :-
• A lower heat of polymerization (125˚F, 51.5˚C)
• Liquid is less irritating to soft tissues
• do not experience much polymerization shrinkage.
• They exhibit a long working time
61
Trim II , Vita KHB
• Disadvantages-
• Less esthetic
• Poor colour stability
• Poor wear resistance
Polyethyl Methacrylate

62. • The light-cured resin comes in a monomer and polymer form but because the
resin does not cure without light, it allows the operator time for preparation and
correction before curing.
• There are also light-cure resins that do not come in a monomer or polymer form
but in a putty-like consistency.
• The product is available in five Vita shades and a translucent shade.
• The restoration is partially light-cured. It is then removed and final curing is done
for 20 to 60 seconds, depending on the shade and thickness.
62
Unifast LC
Light-Cure Resin-

63. • Advantages-
• Easy to use
• Comes with an adequate number
of shades
• Adequately-long working time
• Ability to be light cured, which
saves chair time
• Exhibits a very low fracture rate
63
Disadvantages-
• Unifast has to be mixed by
hand--it is not available in an automix
form
• Difficult to polish to a high
luster
• Finished provisionals exhibit a
high degree of porosity

64. • They are a combination of two or more types of materials
• A new hybrid material (Kind) is a polymethyl methacrylate filled with a bis-
acrylic resin. It exhibits a very high heat of polymerization. It is also available
with barium glass as a filler to make it radiopaque.
• Another material (Dentalon) is a polymethyl methacrylate meshed with an
isobutyl methacrylate monomer. It has physical and handling properties that
place it between the polymethyl methacrylates and the polyethyl methacrylates
64
Hybrids

65. 65

66. 66

67. REINFORCEMENT
• Glass fibers, nylon fibers,metal strengtheners, and carbon graphite fibers.
• The effectiveness of these strengthening mechanisms varies with bond formation
between the reinforcing material and the parent resin.
• Although the incorporation of materials such as polyethylene and carbon graphite
fibers has shown to increase the moduli of elasticity of commonly used provisional
fixed partial denture materials, but technical difficulties and aesthetic concerns
have prevented their widespread use.
67

68. Reviewofliterature
• Kapri et al in 2015 conducted a study to evaluate fracture load values of
interim FPDs with different locations of glass fiber reinforcement
• It was concluded that occlusal third of the pontic region from mesial to the
distal end of the connector was the best site of placement of the fiber for re
inforcing the PMMA interim restorative resin.
J Indian Prosthodont Soc 2015;15:142-7.
68

69. • Viswambaran et al in 2011 conducted an in vitro study to evaluate fracture resistance of
interim fixed partial denture fabricated using polymethyl methacrylate and reinforced by
different fibers of 10mm length for its optimal placement.
• The favorable site of placement in three different locations was occlusal, middle, and cervical
third of the pontic.
• The results showed that glass fibers showed the highest fracture resistance and
reinforcement in the occlusal third of the interim FPD produced the greatest fracture
resistance
• Because the fiber stopped propagation of the initiating fracture through the restoration
Med J Armed Forces India. 2011;67(4):343–347.
69

70. EXOTHERMICREACTION
• A 10˚F (5.6˚C) increase in pulpal temperature resulted in 40% loss of pulpal vitality,
a 20ºF (11.2ºC) increase in pulpal temperature resulted in a 60% loss of pulpal
vitality and a 30˚F (16.8˚C) increase in pulpal temperature resulted in 100% pulpal
necrosis.
• PMMA exhibits the greatest exothermic reaction, followed by PVEMA, PEMA, bis-
acryl composite resin, and VLC urethane dimethyacrylate resins
• The clinician should limit the thermal insult to the pulp by selecting an appropriate
interim material, minimizing the volume of material, and choosing an appropriate
fabrication technique. 70

71. • Manak and Arora in 2011 did an in vitro study to compare the temperature changes in
the pulpal chamber during fabrication of provisional restorations by direct method.
• Three different self-cure provisional restorative resins (polymethyl methacrylate resin,
polyethyl methacrylate, bis-acrylic composite resin) were tested for variations caused
by them in the temperature of pulp chamber during fabrication of three unit FPDs.
• Results showed that polymethyl methacrylate showed the highest temperature rise
value followed by PEMA and bis-acryl resin.
J Indian Prosthodont Soc. 2011;11(3):149–155 71

72. • Thus the resin material recommended for clinical use when direct technique
was employed was bis-acryl composite resin as it caused minimal
temperature rise in the pulpal chamber
72

73. COLOURSTABILITY
• Provisional restoration colour instability may be due to:
• the incomplete polymerization of the material
• sorption of oral fluids
• surface reactivity
• dietary habits
• oral hygiene
• Surface finish also contribute to staining of provisional materials, with porous
unpolished surfaces exhibiting significantly more darkening than highly polished
material
73

74. • Mazaro et al in 2015 conducted a study to evaluate the color stability of
temporary restorative materials- acrylic and bis-acrylic resins after immersion in
pigmenting solutions for different periods of storage.
• Artificial saliva, saliva + cola type soda, and saliva + coffee at 37 °C and the storage
time intervals were 2, 5, 7 and 15 days
• Acrylic resin presented greater color stability in comparison with bis-acrylic resins
and coffee was the solution responsible for the greatest color change in the
temporary resins .
Journal of odontologia 2015.
74

75. MARGINALINTEGRITY
• The specific technique used in the fabrication of an interim restoration has a
significant impact on the resultant marginal integrity.
• Although the indirect technique has been found to produce significantly
more accurate marginal integrity than the direct technique and it requires a
accurate impression of the preparation finish line.
75

76. • Verma et al in 2012 conducted a study to evaluate the marginal accuracy of
different provisional restoration materials (Bis-GMA, PMMA) used in fixed partial
dentures.
• It was concluded that Bis-GMA provisional restorative material showed the better
marginal fit. This was due to the fact that polymerization shrinkage was less in
composite resins as compared to PMMA resins.
J Indian Prosthodont Soc. 2012.
76

77. • Depending on the brand, the most commonly used monomers –
• methyl methacrylate
• ethyl methacrylate
• isobutyl methacrylate
• bis–GMA, and urethane dimethacrylate.
77
FREE-RADICAL POLYMERIZATION

78. • Each of these monomers, whether used whole or in combinations, may be
converted to a polymer by FREE-RADICAL POLYMERIZATION, although the
conversion process is never perfectly complete.
78
I. INITIATION
II. PROPAGATION
III. TERMINATION

79. • 1. Initiation
• Free-radical polymerization begins with the formation of a free radical (a process
called activation) and the subsequent combination of this free radical with a
monomer.
• Free radicals are formed by the decomposition of a chemical - the initiator).
• Benzoyl peroxide decomposes to free radicals at approximately 50° C or higher in a
process called THERMAL ACTIVATION
79

80. • Benzoyl peroxide also decomposes to free radicals when catalyzed by a tertiary
amine; this process is called CHEMICAL ACTIVATION.
• Chemical activation occurs when the activator, initiator, and monomer are
mixed together, so these materials are usually supplied separately-the
monomer and activator are in one container, and the initiator and filler are in
another.
• Camphorquinone decomposes to free radicals in the presence of both an
aliphatic amine and blue light energy; this process is called VISIBLE-LIGHT
ACTIVATION.
80

81. 2.Propagation
1. The setting material undergoes an increase in density, causing
contraction.
2. The exothermic heat of reaction may cause a substantial increase in
temperature, with subsequent increased contraction.
3. Other physical properties e.g., rigidity, strength, and resistance to
dissolution increase.
81
3. Termination
Due to the randomness of position of the growing chains, some of them may
combine and terminate the growth process.

82. 82
1.INDIRECT- - Custom made with template
2.DIRECT- -Custom made with index
3.INDIRECT-DIRECT

83. • ARMAMENTARIUM
 Mouth mirror
 Explorer
 Periodontal probe
 Saliva evacuator
 Cotton rolls
 Gingival displacement cord
 Astringent solution
 Cotton-roll pliers
 Articulating ribbon and holder
 Camel hair brush (no.0)
 Cup of warm water
83
 Plastic filling instrument
 Cotton pellets
 Petrolatum jelly
 Autopolymerizing resin
 Dropper
 Dappen dishes
 Cement spatula
 Backhaus towel clamp forceps
 Lead pencil
 Straight handpiece with
Carborundum disks
 Dental floss

84. • Tungsten carbide burs
• High-volume evacuation
• Cup of warm water
84

85. 1. INDIRECT PROCEDURE
• The provisional are fabricated outside the mouth.
• Advantages-
• There is not contact of free monomer with the prepared tooth or gingiva
• The procedure avoids subjecting a prepared tooth to the heat created from
polymerizing resin.
85

86. • The marginal fit of provisional restorations that have been polymerized
undisturbed on stone casts is significantly better than that of provisionals that
have been removed from the mouth before becoming rigid.
• This technique gives the patient a change to rest and lets the dentist perform
other tasks, provided an assistant is trained to carry out the laboratory
procedures.
86
• Disadvantages-
• Takes more time as impressions are made after tooth preparation
• More cost

87. VACUUM/PRESSUREMETHOD
87

88. 88

89. 89

90. 90

91. TEMPLATEFABRIACTEDVLC
PROVISIONAL
91

92. 92

93. OVERIMPRESSIONMatrixfor PROVISIONALCROWN
93
• Diagnostic cast
• Utility wax
• Wax spatula
• Impression trays
• Alginate
• Rubber bowl
• Quick set plaster
• Carmel brush separating medium
• Rubber band
• Acrylic burs
• Straight handpiece
• Abrasive discs
• Cement spatula
• Laboratory knife with no. 25 blade
•
ARMAMENTARIUM-

94. 94

95. 95

96. 96

97. 97

98. 98

99. 99

100. 2.DIRECT PROCEDURE
• Restoration is fabricated directly inside the patient’s mouth.
• This is convenient when assistant training and office laboratory facilities are
inadequate for efficiently producing an indirect restoration.
• Routine use of directly formed provisional restorations is not recommended when
indirect techniques are feasible.
100

101. • Advantages:
101
• Less time-consuming
• less cost
• Disadvantages-
1. Patient cooperation is required
2. Pulpal irritation
3. Offensive odour
4. May be difficult to remove
5. Only used for short span bridges.
6. Difficult to fabricate in case of limited mouth opening

102. 102
CUSTOM MADE WITH INDEX

103. 103

104. 104

105. 105

106. 106

107. 107

108. 108

109. 109

110. 110

111. • Advantages-
• Chairside time is reduced. Most of the procedures are completed before the
patient’s visit.
• Less heat is generated in the mouth. The volume of resin used during lining is
comparatively small.
• Contact between the resin monomer and soft tissues is minimized compared to
the direct procedure
• Disadvantage - Adjustments are frequently needed to seat the shell completely
on the prepared tooth.
111

112. 112

113. • Prasad et al in 2012 published a review that described the various materials used
for provisional restorations and also the techniques used to fabricate them.
• For both anterior and posterior teeth, they found that the bis-acryl materials were
significantly superior to PMMA.
• Compared to custom fabricated restorations, preformed crowns resulted in
improper fit, contour, or occlusal contact for a provisional restoration
• Indirect technique was generally preferred over the direct technique as it had
overcome the potential hazards caused to the tooth during fabrication by the
direct technique. 113

114. CEMENTATION
114

115. • Ideal Properties-
Ability to seal against leakage of oral fluid
Strength consistent with intentional removal
Low solubility
Chemical compatibility with the provisional polymer
Convenience of mixing
Ease of eliminating excess
Adequate working time and short setting time
Compatibility with the definitive luting agent. 115

116. Cements used-
1. Eugenol-containing
2. Non-Eugenol–containing (also called eugenol-free)
116

117. 117

118. 118

119. 119

120. • The benefit of these eugenol-containing cements was that eugenol acts as an
obtundent to the pulp
• Eugenol has been known to affect bonding quality by inhibition of the setting
reaction i.e. the free-radical polymerization of the dental resins
• Acrylic provisional may soften over time because of the eugenol in the provisional
cement, leading to the possibility of early failure of the provisional.
• Because eugenol is a water-insoluble oil it is not readily removed through rinsing
the tooth
120

121. • Zinc phosphate, zinc polycarboxylate, and glass ionomer cements are not
recommended because their comparatively high strength makes intentional
removal difficult
• When a span is greater or long-term use is anticipated, or when Para function
exists, using higher-strength cement may be desirable
121

122. • Armamentarium-
• Provisional luting agent
• Mixing pad
• Cement spatula
• Plastic filling instrument
• Petrolatum
• Mirror and explorer
• Dental floss
122

123. Step-by-stepProcedure
• To facilitate removal of excess cement, lubricate the polished
external surfaces of the restoration with petroleum
• Mix the two pastes together rapidly and apply a small
quantity just occlusal to the cavosurface margin
123

124. • Seat the restoration and allow the cement to set
• Carefully remove excess with an explorer and dental floss
124

125. REMOVALandRECEMENTATION
• PROCEDURE-
• 1. If the provisional restoration is going to be recemented, clean out the bulk of
cement with a spoon excavator
• 2. Then place the provisional in a cement-dissolving solution in an ultrasonic
cleaner
• 3. Line it with a fresh mix of resin if necessary (as when a tooth preparation has
been modified, for example)
125

126. Digitalinterimfixedrestorations
• The emergence of computer-aided design/ computer-aided manufacture (CAD/CAM)
technology in dentistry has allowed the successful use of different materials.
• Interim restorations can be fabricated by means of digital workflow.
126

127. ComparativeinvitroevaluationofCAD/CAMvs
conventionalprovisionalcrowns
ABDULLAHet.alJApplOralSci.2016;24(3):258-63
This study compared marginal gap , internal gap and fracture strength of
CAD/CAM provisional crowns with that of direct provisional crowns .
127

128. The materials tested were: VITA CADTemp ®, Polyetheretherketone “PEEK”, Telio CAD-Temp, and
Protemp™4 (control group).
Each crown was investigated for marginal fit, internal gap and fracture strength.
CAD/CAM fabricated provisional crowns demonstrated superior fit , better strength than direct
provisional crowns.
128

129. Conclusion
• Although provisional restorations are usually intended for short term use
and then discarded, they can be made to provide pleasing esthetics,
adequate support, and good protection for teeth while maintaining
periodontal health. The success of fixed prosthodontic often depends on
the care with which the provisional is designed and fabricated.
129

130. References
 Rosensteil, Land. Contemporary fixed prosthodontics.4th ed.
 Shillinburgh. Fundamentals of Fixed prosthodontics. 3rd ed.
 Tylman’s theory and practice of fixed prosthodontics 8th ed.
 Federick, D. R. (1975). The provisional fixed partial denture. J Prosthet Dent, 34(5), 520–
526
 Marginal integrity of provisional resin restoration materials: A review of the literature-
Rakhshan V 2015
 Evaluation of color stability of different temporary restorative materials – MAZARO. Journal of
odontologia 2015
 A Comparative Evaluation of Temperature Changes in the Pulpal Chamber during Direct
Fabrication of Provisional Restorations: An In Vitro Study- J Indian Prosthodont Soc July-Sept
2011
 An evaluation of fracture resistance of interim fixed partial denture fabricated using
polymethylmethacrylate and reinforced by different fibres for its optimal placement: an in vitro
study- 2011, AFMS 130

131.  Influence of Matrix Type on Surface Roughness of Three Resins for Provisional
Crowns and Fixed Partial Dentures—Montero et al. Journal of Prosthodontics 2009
 The effect of glass fiber reinforcement on the fracture resistance of a provisional fixed
partial denture- Journal of prosthetic dentistry 1998
 Constructing direct porcelain laminate veneer provisionals. Kurtz et al, JADA
131

132. THANKYOU
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