Reisn bonded prosthesis/ Labial orthodontics

PROVISIONAL RESTORATIONS

1

INDIAN DENTAL ACADEMY

Leader in continuing dental education www.indiandentalacademy.com

www.indiandentalacademy.com

CONTENTS• Introduction• Definition• History• Requirements• Rationale / Functions• Classification • Materials• Techniques

• Influence of material properties on treatment outcome

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• Provisionalization in implant dentistry

• Trouble shooting in provisionalization

• Limitations of provisional restorations

• Recent advances in provisionalization

• Conclusion

• References


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INTRODUCTION

• PROVISIONAL----- “ESTABLISHED FOR TIME BEING,PENDING A PERMANENT

ARRANGEMENT.”

• Synonyms:- INTERIM; TRANSITIONAL; TEMPORARY;

TREATMENT RESTORATIONS.

• FOUNDATION FOR SUCCESS OF FINAL RESTORATION.


DEFINITION

• “A fixed or removable prosthesis, designed

to protect, enhance esthetics, stabilization

and/or function for a limited period of time,

after which it is to be replaced by a

definitive prosthesis. ”


HISTORY• Since 1930s

• 1937 ---- Heat cured acrylic resin

• 1947 ---- Auto polymerizing acrylic resin

• 1952 ---- Brotman introduced prefabricated aluminum or celluloid crown form

• 1959 ---- Amsterdam et al suggested use of copper band splint or thin flexible metal wire for internal reinforcement

• 1960s ---- Vinyl poly-ethyl methacrylate (Snap and Trim) 7www.indiandentalacademy.com

HISTORY• 1969 ---- Ethyl imine derivatives (Suctan)

• 1972 ---- Gerald J described a technique for a modified “shell” type temporary acrylic resin fixed partial denture.

• 1973 ---- Charles et al described the use of polycarbonate resin

• 1980 ---- Composite (Protemp, Visio Gem and Triad)

• 1983 ---- Weiner described technique that use silicone putty impression material in provisional restoration fabrication.


HISTORY• 1984 ---- Morton et al ---- visible light-cured microfilled

composite resin

• 1986 ---- Kinsel described use of an acrylic resin denture tooth for construction of interim restoration.

• 1987 onwards ---- Concept of provisionalization applied and implemented in implant dentistry.


REQUIREMENTS

1. Pulpal protection 2. Periodontal

health3. Occlusal

compatibility & tooth position

4. Prevention of enamel #

1. Resist functional loads

2. Resist removal forces

3. Maintain interabutment alignment

Restore 1.Tooth contour

2.Color

3.Translucency

4.Texture


FUNCTIONS1. Comfort/Tooth vitality: Essential to cover freshly cut

dentine and prevent sensitivity, plaque buildup, and subsequent caries and pulp pathology. It also sedate prepared abutments.

2. Occlusion and Positional Stability: To prevent unwanted tooth movement.

3. Function

4. Gingival Health and Contour: To facilitate oral hygiene and prevent gingival overgrowth.

5. Aesthetics

6. Diagnosis: To assess the effect of aesthetic and occlusal changes.


FUNCTIONS1). Callipers may be used to test the thickness of a provisional restoration to ensure sufficient tooth preparation to accommodate the proposed restorative material

1). Callipers may be used to test the thickness of a provisional restoration to ensure sufficient tooth preparation to accommodate the proposed restorative material

2). A provisional restoration may be used to provide a coronal build up for isolation purposes during endodontic treatment.2). A provisional restoration may be used to provide a coronal build up for isolation purposes during endodontic treatment.

3). Long-term provisional restoration may also be advisable to assess teeth of dubious prognosis.3). Long-term provisional restoration may also be advisable to assess teeth of dubious prognosis.


FUNCTIONS

4). A provisional restoration may find a use as a matrix for core build

ups in grossly broken down teeth, by removing the coronal surface

to allow placement of restorative material.

5). Proposed changes to the shape of anterior teeth are best tried

out with provisional restorations to ensure patient acceptance, and,

approval from friends and family.

6). A patient’s tolerance to changes in anterior guidance or

increased occlusal vertical dimension is best tried out with

provisional restorations.


FUNCTIONS

7). Long-term wear of properly fitting and contoured provisional

restorations allows the health of the gingival margin to improve

and its position to stabilize before impressions are recorded for

definitive restorations.

8). Altered function can be assessed (fine mouth movements and

lip/tooth contact required for speech production or sound

generation in the case of a musical instrument.)


CLASSIFICATION


DEPENDING ON THE METHOD OF FABRICATION

•CUSTOM MADE PROVISIONAL RESTORATION

• PREFABRICATED PROVISIONAL RESTORATION


CUSTOM MADE

PROVISIONALS

• To reproduce the original contours of the tooth

ADVANTAGES • Minimum interference• A wide variety of

materials can be used• Helpful in evaluating the

adequacy of tooth reduction

DISADVANTAGES• Time consuming• Additional lab procedures

involved

PREFABRICATED MADE PROVISIONALS

• Commercially available • Available in various

sizes and materials• Require alteration and

modification before cementation

• ADVANTAGES• Less time consuming• DISADVANTAGES• Rarely satisfies

requirements of contour • Generally limited to a

single tooth restoration. 17www.indiandentalacademy.com

DEPENDING ON THE MATERIAL DEPENDING ON THE MATERIAL AVAILABLE IN PREFORMED CROWNSAVAILABLE IN PREFORMED CROWNS

• Polycarbonate

• Cellulose acetate

• Aluminium and tin-silver

• Nickel-chromium


DEPENDING ON THE TYPE OF MATERIAL USEDDEPENDING ON THE TYPE OF MATERIAL USED• Resin based provisional restoration Cellulose acetate Polycarbonate resin Poly-methyl methacrylate Poly-ethyl methacrylate Microfilled composite Urethane dimethacrylate Bis -acryl composite• Metal provisional restoration Aluminium Nickel-chromium Tin-silver


• SHORT TERM ---- for few days (upto 2 weeks) ( e.g. ---- Polycarbonate or aluminum crowns )• MEDIUM TERM ---- for few weeks ( > 2 weeks) ( e.g. ---- resin based provisionals)• LONG TERM ---- for months ( e.g. ---- mostly cast metal crowns)


Indications

1.Long span posterior FPDs.

2.Patient undergoing implant therapy.

3.Extensive periodontal treatment.

4.Orthodontic stabilization.

5.Evaluation of change in VDO.


DIRECT TECHNIQUE

INDIRECT TECHNIQUE

DIRECT-INDIRECT TECHNIQUE


CHAIR- SIDE FABRICATED

LABORATORY FABRICATED


MATERIALS & TECHNIQUES


MOLD CAVITY• Created by two correlated parts:-

1.Forming the external contour of crown or FDP ---- External surface form (ESF)

Custom made Prefabricated

2. Forming the prepared tooth surfaces and edentulous ridge area ---- Tissue surface form ( TSF)

Direct technique Indirect technique 25www.indiandentalacademy.com

MATERIALS


IDEAL PROPERTIES Convenient handling – adequate working time, easy

moldability, rapid setting time

Biocompatibility-nontoxic, nonallergenic, nonexothermic

Dimensional stability during solidification

Ease of contouring and polishing

Adequate strength and abrasion resistance

Good appearance – translucent, color controllable, color stable


IDEAL PROPERTIES

Good patient acceptance- nonirritating, odorless

Ease of adding to or repairing

Chemical compatibility with provisional luting agents.


TYPES

• Pre-formed crowns (made of plastic or metal),

• Self cured resins

• Light cured resins or

• Composites resins

• Heat cured acrylic resin

• Cast metal.

• Fiber reinforced composite resins


Pre-formed crowns

• Also known as proprietary shells• Come in a series of sizes • Usually need considerable adjustment marginally,

proximally and occlusally• Plastic shells ---- polycarbonate or acrylic• Metal shell ---- aluminium, stainless steel or nickel

chromium• Both can be relined with self cured resin to improve their

fit.


Polycarbonate resin crowns

• Possesses a number of superior properties relative to Polymethyl methacrylate materials

• Crowns combine microglass fibers with a polycarbonate plastic material.

• High impact strength, • High abrasion resistance, • High hardness, and • A good bond with methyl-

methacrylate resin• B- crowns, molar B- crowns 31www.indiandentalacademy.com

Preformed metal crowns

Aluminum shells • Provide quick tooth adaptation due to

the softness and ductility• Rapid wear that results in perforation in

function and/or extrusion of teeth.• An unpleasant taste

Iso-Form Crowns (3M Dental Products)• Manufactured with high-purity tin-silver

and tin-bismuth alloys.• Reasonable ductility and can be

contoured quickly• Occlusal table is reinforced so they are

more resistant to wear related failure. 32www.indiandentalacademy.com

Preformed metal crowns

• For longer-term use, nickel-

chrome and stainless steel crowns are available but

• May be more difficult to adapt to a prepared tooth.

• Gold anodized crowns


Self or light cured resins

• Poly-methyl methacrylate

• Poly-ethyl methacrylate

• Bis- acryl composite

• Urethane dimethacrylate (light cured)

• Restorative composit resins


Poly- methyl methacrylate

ADVANTAGES

• Strong• High wear resistance, • Easy to add • Has good aesthetics, which is

maintained over longer periods.• A good material for indirect

provisional restorations.

( Vita K&B Acrylics), Alike, Trim plus


Poly- methyl methacrylate

3 main disadvantages :-i) Polymerization shrinkage which can affect fit

ii) Polymerization exothermic which can damage pulp

iii)Free monomer may cause pulp and gingival damage

Plant et al ---- “ The intrapulpal temperature rise associated with the polymerization of methyl methacrylate materials could be up to 5 times that associated with the normal consumption of thermally hot liquid.”

Br Dent J 1974;137:233-8. 36www.indiandentalacademy.com

Poly- ethyl methacrylate

• Suitable for intra-oral use as it shrinks less and is less exothermic than poly-methyl methacrylate.

• Strength, wear resistance, aesthetics and color stability are not as good.

• Presentations with only light and dark shades (e.g. Trim).

• Some presentations with a good color range (e.g. Trim II)

• Highest value of fracture resistance

( Snap, Trim)


• Produce less heat and shrinkage• Better marginal fit.• Despite being reasonably strong

but brittle • Aesthetically reasonable • More color stable than poly-ethyl

methacrylate materials and are

therefore better suited for use as

long-term provisionals.• Come in multiple shades, • Can be added to with a flowable composite (margins, contacts,

occlusion)

Bis-acryl composites


• Have good abrasion resistance especially when a glaze is applied, (Glisten™; PermaSeal, BisCover™ LV, Bisco, DuraFinish™, Parkell; G-COAT™ Plus, Lasting Touch)

• Available both as Self cure (Bisjet, integrity, luxatemp , Temptation etc) Dual cure material (Isotemp, luxatemp solar),• Repair material ---- (Luxaflow)

DISADVANTAGES• Fewer shades• Porous • Stain easily • Brittle• Expensive • Decreasing hardness• Left with unpolymerized surface layer


Young et al ---- Compared Bis-acryl and Polymethyl methacrylate materials in terms of occlusion, contour, marginal fidelity, and finish. “For both anterior and posterior teeth, they found the Bis-acryl materials significantly superior to PMMA in all categories”

Luthardt et al ---- Compared the clinical performance of autopolymerizing, dual-polymerizing, and visible light-polymerizing bis-acryl materials.

“The light- and dual-polymerizing materials did not offer a clinical benefit relative to autopolymerizing.”

J Prosthet Dent 2001;85:129-32.

J Prosthet Dent 2000;83:32-9. 40www.indiandentalacademy.com

visible light cured resins• Based on urethane

dimethacrylate e.g. Provipont D.C, Kristall etc.

• Have good mechanical properties

• Operator has some control over the material’s working time.

• More shades are available than Bis acryl composite and the colour is relatively stable.

• No residual monomer

DISADVANTAGES:--

Prone to staining.Marginal fit can be poor,Relatively expensive


Haddix ---- Indicated that VLC materials could produce provisional restorations with quality similar to heat-polymerized, laboratory-processed restorations, but with less time and expense.

Dual-polymerizing composite materials generally incorporate both chemically polymerized Bis-acryl and light-polymerized urethane dimethacrylate resins in variable product-specific combinations.



Cast metal

• Alloys used include nickel chromium, silver and scrap gold.

• Copings can be cast with external retention beads for acrylic or composite.

• In less aesthetically critical areas of the mouth, metal

may be used on its own.

• Very durable, but rarely used unless provisional restorations have to last a long time.


PHYSICAL PROPERTIES PMMA EMMA BIS-GMA VLC- COMPOSITE

Minimal temperature change during polymerization

++ +++ ++++ +

Surface hardness

Marginal fit +++ ++ ++++ +

Wear resistance

Transverse strength ++++ No values -Too rubbery

++++ ++++

Transverse repair strength

Surface roughness & polishability

+++

++++ + + ++

Color stability

Stain resistance +++ ++++ + +

+++ + ++ ++++

+ +++ ++++ ++++

++++ + ++ ++++

++ + +++ ++++44www.indiandentalacademy.com

Provisional cements

• Usually cemented with soft cement.

• Traditionally, a creamy mix of zinc oxide eugenol was

used.

• Most dentists prefer proprietary materials such as Temp Bond Comes with a modifier, which is used to soften the cement, to ease removal of the provisional restoration

from more retentive preparations.• Cling2®; TempBond® ; TempoSIL; TempCEM NE, ZONE,

and UltraTemp, 45www.indiandentalacademy.com

Provisional cements• Temp Bond NE is a non-eugenol cement which may be

used for patients with eugenol allergy or where there is concern over the possible plasticizing effect of residual eugenol on resin cements and dentine bonding agents.


techniques


Provisional restorations — techniques

• As a rule of thumb,

“The time taken to temporise a tooth should be similar to the time taken to prepare it.”

1. Shells (proprietary or custom)

2. Matrices (either formed directly in the mouth or indirectly on a cast)

3. Direct syringing

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British Dental Journal 2002; 192:619–630

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Difference between a shell & matrix

SHELL

Incorporated within the restoration ---

plastic / metal

MATRIX

Just used to make a provisional restoration


Proprietary shells

Prefabricated Custom- made

Plastic Metal Beaded Mill crowns

acrylic


Proprietary plastic shells

• Crown with correct M-D width is chosen and placed on the tooth preparation.

• Cervical margins are trimmed to give reasonable seating and adaptation

• Preparation coated with petroleum jelly and the crown, containing a suitable resin, is reseated


Proprietary plastic shells

• Proximal excess is removed

• Crown removed and replaced several times to prevent resin setting in undercuts

• Crown is adjusted and polished using steel or tungsten carbide burs and Soflex discs.


ANTERIOR POLYCARBONATE CROWN



Proprietary metal shells

• Aluminium crowns ---- Only suitable for short-term use as they are soft resulting

in wear and deformation Can produce galvanic reactions in association with

amalgam restorations. Fit is usually poor unless considerable time is spent

trimming and crimping the margins followed by relining with a resin

• Stainless steel or nickel chromium crowns May occasionally be used on molar teeth opposed by flat

cusps where heavy occlusal loading would quickly wear or break a resin crown.


#ed cusp of max. molar Conventional crown

preparation done

M-D tooth diameter measured Cervical end expansion 56www.indiandentalacademy.com

Crown tried over preparation and cervical excess trimmed

Crown finished polished and axially contoured 57www.indiandentalacademy.com


Custom shells

• For multiple tooth preparations.• Relining and careful marginal trimming are necessary

prior to fitting. • Two types – ‘beaded acrylic’ or ‘Mill Crowns’. • Both offer advantage of being able to use the superior

properties of poly-methyl methacrylate, whilst avoiding pulpal damage by constructing the shell out of the mouth.


BEADED ACRYLIC SHELL

• Formed within an impression taken of the teeth prior to preparation or of a diagnostic

wax up.• A thin shell of poly-methyl

methacrylate is constructed by alternately placing small amounts of methyl methacrylate monomer followed by polymer,

• Once set, it is trimmed and then relined in the mouth


MILL CROWNS

• A pre-preparation matrix is fabricated

• First cut minimal crown preparations on a stone cast.

• A pre-preparation matrix is then filled with poly-methyl methacrylate and placed over the preparations.

• The trimmed and adjusted provisional crowns are again relined in the mouth.


Matrices• Matrices closely duplicate the external form of satisfactory

existing teeth, or, if changes are required, a diagnostic wax up.

3 main types of matrix: Impression Vacuum formed thermoplastic Proprietary celluloid


proprietary celluloid matrix

• Can be used if only a single provisional crown is to be formed using light cured resin.

• After tooth preparation, a thin smear of petroleum jelly is placed over the reduced tooth and adjacent teeth.

• The matrix is blown dry and the mixed resin is syringed into the deepest part of the appropriate tooth recess.

• After reseating, the matrix is left until the resin reaches a rubbery stage on light curing

• It is removed and interproximal excess removed

• Crowns are trimmed, polished and cemented 63www.indiandentalacademy.com

Impression matrices

ALGINATE

• Best at absorbing the resin exotherm

ELASTOMER

• Reusable, • Can be stored in case they are

required again.• Ease of handling• long-term stability.• Flexible• Good flow• Affinity, Aquasil, TempSpan

clear matrix, Star VPS clearbite

• QUICK, EASY AND INEXPENSIVE,• DIRECT OR INDIRECT

Int J Prosthodont 1990;3: 299-304.


Utility wax placed in defect Overimpression made

Thin edges of gingival margin trimmed away

Alginate impression of prepared teeth

Overimpression fabricated provisional crown


Untrimmed plaster cast Trimmed cast Cast with overimpression

Separating media applied Acrylic mixing Pouring of material into impression 66www.indiandentalacademy.com

Plaster cast secured with impression

Crown removed from cast cast

Plaster removed from inside

Extra resin removed and smoothened with sand paper disc

Intraoral occlusal adjustment done


Overimpression fabricated Bis-acryl composite crown

Putty overimpression made Gingival margins trimmed

Putty index loaded with mixed Bis-acryl composite resin


Vacuum formed matrices

• Made of clear vinyl sheet produced on a stone duplicate

of the waxed up cast.

• Flexible and can distort when seated, especially if there

are few or no adjacent teeth to aid location

• Indispensable for moulding light cured resins.


Template fabricated provisional crown

Denture tooth placed Putty adapted around the arch

Thermoplastic sheet adapted

Excess removed with scalpel

Alternative method of adapting thermoplastic sheet


Sheet adapted over cast Putty mold forcefully seated

Silicon putty removed Excess trimmed71www.indiandentalacademy.com

Template can be reinforced with putty

Template filled with resin & seated over cast

Putty index placed

Light polymerizing unit72www.indiandentalacademy.com

Direct syringing

• When no shell temporary can be found to fit and, no matrix is available

• Poly-ethyl methacrylate materials are best as they can be mixed to sufficient viscosity not to slump but are still capable of being syringed.---- ‘Shear thinning’

• Start at the finish line and spiral the material up the axial walls.


Indirect provisionals

ADVANTAGES

• Materials which are stronger and more durable can be used e.g. heat cured acrylic or self cured acrylic cured in a hydroflask.

• If aesthetic or occlusal changes are to be made these can be developed on an articulator.

• Can certainly save clinical time, especially with multiple restorations and most particularly where there is to be an increase in vertical dimension ( Bruxers).

• No direct contact of tissues with monomer.• No thermal injury to tissues and pulp.


• Crispin et al ---- Evaluated marginal accuracy with direct and indirect techniques.

• They reported that indirect fabrication provided significant improvements in marginal fit relative to direct methods when methyl and vinyl ethyl methacrylate resins are used. They demonstrated that the marginal fit of Polymethyl methacrylate restorations could be improved by up to 70% with an indirect technique.



Lubrication

• Never use a petroleum jelly lubricant on the teeth, petroleum-based products are almost impossible to remove.

• The remnants can lead to premature loss of the

temporary, and can affect final bond or cementation strength.

• If the dental assistant wants to use a lubricant, a water-soluble lubricant is recommended.

Contemporary Dental Assisting. 2007;Nov/Dec:34-39. 76www.indiandentalacademy.com

PROVISIONAL RESTORATION OF ADHESIVEPREPARATIONS

• Lack of conventional retention provided by most adhesive preparations results in temporary cements being ineffective.

1. No temporary coverage ---- e.g. with veneer preparations involving minimal dentine exposure and not removing intercuspal or proximal contacts.

2. A simple coat of zinc phosphate cement to protect exposed dentine e.g. in tooth preparations which are not aesthetically critical and where the occlusion is either not involved.

3. Composite resin bonded to a spot etched on the preparation e.g. veneer preparations


4. Composite resin bonded to the opposing tooth to maintain occlusal contact and prevent over-eruption

5. Conventional provisional restorations cemented with either a non-eugenol temporary cement or a hard cement such as zinc carboxylate.

Effective only in the short -term.


• Standard poly carbonate crown by placing a piece of paper clip or other stiff wire into the canal and placing the resin-filled crown over that.

POST-AND CORE PROVISIONAL RESTORATIONS


INFLUENCE OF MATERIALPROPERTIES ON TREATMENT

OUTCOME


1. Marginal accuracy• Assists in protecting the pulp from thermal, bacterial,

and chemical insults.• Autopolymerizing acrylic resin provisional restorations –

lack of adequate marginal adaptation, can be improved with relining.

• Barghi and Simmons ---- because of hydraulic pressure, 80% of restorations did not fully reseat after the reline procedure.

• Improved marginal accuracy of PMMA ---- when a shoulder finish line was used as compared with a chamfer marginal design. ( not applicable to Bis-acryl)

• Light-polymerized materials better marginal accuracy relative to autopolymerizing PMMA resin.


Koumjian and Holmes ----

Examined a variety of resinous provisional materials and reported that they “All demonstrated continued polymerization shrinkage after storage in air for 1 week. When stored in water for 1week, water absorption compensated for polymerization shrinkage in all of the materials except for polyvinylethyl methacrylate and Bis-

acryl materials.



2. Color stability ---- Discoloration of provisional materials can produce serious esthetic complications.

• Modern provisional materials use stabilizers that decrease chemically induced color changes .

Absorption & adsorption of liquids ( coffee, tea) Porosity and surface roughness Oral hygiene habits,

Crispin and Caputo ---- Found that methyl methacrylate materials exhibited the least darkening, followed by ethyl methacrylate and vinyl-ethyl methacrylate materials.

Yannikakis et al ---- Bis –acryl worst color stability



3. Gingival response

Donaldson ----(1)Presence of a provisional restoration lead to at least

some recession at about 80% of the free gingival margin sites evaluated;

(2)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

1mm; and (5) In the presence of gingival recession, only one third

of subjects demonstrated complete gingival recovery.(6) Direct relation between the degree of pressure

applied by a provisional restoration and gingival recession.

J Periodontol 1973;44:691-6. 84www.indiandentalacademy.com

4. Pulpal response • Dental pulp inflammation can be caused by either thermal

or chemical insult resulting from materials used to produce direct provisional restorations

• Tjan et al use of air and water coolants use of matrix material that can dissipate heat rapidly

(Alginate)

• Moulding and Teplitsky ---- “Temperature rise was • Greatest with Polymethyl-methacrylate and vacuum

adapted templates.• Least with Bis-acryl and relined resin shells. • Intermediate temperature increases were recorded with

polyethylmethacrylate materials and either irreversible hydrocolloid or polyvinylsiloxane impression materials

J Dent1979;7:22-4.

J Prosthet Dent 1989; 62:622-6.


5. Hypersensitivity

• 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 ”

• Indirect material processing methods are recommended• Unpolymerized monomer can be substantially removed

by placing an autopolymerized provisional restoration in a pressure pot with warm water for 20 minutes

Oral Surg Oral Med Oral Pathol1976;41:631-7.


REINFORCEMENT OF PROVISIONAL

RESTORATIONS


Why to reinforce ??????

• Most resin materials brittle

• Repairing & replacing provisionals – concern for both dentist and patients ---- additional cost and time associated

• Failure often occurs suddenly and probably as a result of a crack propagating from a surface flaw. (because of inadequate transverse strength, impact strength, or fatigue resistance.)


1. Covey et al ---- Found that “oven heat treatments at 120°C for 7 minutes could significantly increase the tensile strength for both chemical and light-polymerized composite materials.”

2. Heat-polymerization of acrylic resin materials 3. Metal castings and swaged metal substructures in

combination with resin materials.4. Chemical modification with grafted co-polymers and

stronger cross linkage 5. Inclusion of various organic and inorganic reinforcing

fibers (metal, glass, carbon graphite, sapphire, Kevlar, polyester, and rigid polyethylene.(Most of these materials have had little or no success in increasing resin strength.)


• Powell et al compared Kevlar 49 polyaramid fiber with stainless steel wire , found that wire configuration produced a superior stiffness and toughness.

• Zuccari et al reported that when admixed zirconium oxide powders were added to unfilled methylmethacrylate resin, the resultant composite material exhibited significant improvements in the modulus of elasticity, transverse strength, toughness, and hardness

• Chee et al ---- Chilled monomer reduces transverse strength of autopolymerizing acrylic resin by 17%

Int J Prosthodont 1994;7:81-9.

Biomed Mater Eng 1997;7:327-43.


Hazelton and Brudvik ---- reported the benefits of stainless steel orthodontic band material adapted around abutment teeth, removed, welded, and fitted inside acrylic resin shell crowns to reinforce autopolymerizing acrylic resin materials.





PROVISIONALIZATION IN IMPLANT DENTISTRY


• A provisional restoration in combination with an implant retained definitive restoration provides many of the same benefits derived when treating teeth retained fixed restorations.

• Implant-retained treatment can require an extended period of time and provisional treatment can present a challenge.

• Can vary widely, ranging from a removable acrylic resin complete denture to an implant supported fixed prosthesis with several different potential designs that promote esthetics, convenience, the loading of implants, tissue contour control, material strength, and interim prosthesis durability

• When treating a partially edentulous patient, acceptance of a removable interim prosthesis may be objectionable.


Factors affecting selection of treatment options

(1) The number, position or location of the implants

(2) The number of natural teeth remaining in a treatment arch

(3) Opposing occlusion

(4) Whether teeth adjacent to the implant site(s) can act as a abutment teeth for a provisional restoration

(5) Desired protocol for provisional treatment at either first or second-stage surgery.


• A reduction of micro-movement of an implant due to the

potential stability obtained from adjacent teeth as well as

a rigid implant connection when treating both partially

and completely edentulous patients may lead to

successes when providing provisional treatment at first-

stage surgery


Single-tooth, implant provisional treatment

• Depending on the location of an implant, an interim prosthesis may or may not be necessary.

• Kupeyan and May• Brånemark healing abutments modified in the laboratory

before the surgical date. • Acrylic resin copings fabricated to fit the modified healing

abutments• A provisional crown was fabricated from either a

polycarboxylate material or a polystyrene preformed provisional shell

• After surgical implant placement, resin coping fitted to the modified implant healing abutment

• The crown united to the coping with a small amount of autopolymerizing resin. 98www.indiandentalacademy.com

Single-tooth, implant provisional treatment

• Proussaefs and Lozada.

• Preparatory phase ----

(1)Diagnostic casts;

(2) Diagnostic waxing

(3) Duplication of the diagnostic waxing with an impression

(4) Generation of a gypsum cast

(5) A vacuum formed matrix


TECHNIQUE• A light-polymerized acrylic resin template fabricated on

the duplicate cast {used as a surgical guide}

• Implant analogs attached to the surgical guide at registered locations with acrylic resin

• Diagnostic cast modified to accommodate implant analogs and were incorporated into the cast with acrylic resin.

• A “temporary” hexed abutment was placed on the implant analog and, after verifying the appropriate occlusal height and position of the abutment with a clear vacuum formed matrix, a screw-retained provisional was fabricated with the matrix and autopolymerizing acrylic resin


Provisional treatment at first-stage surgery:partially edentulous and edentulous cases

• Horiuchi et al• Heat-polymerized acrylic resin provisional restorations

were fabricated and reinforced with chromium-cobalt castings.

• At the time of stage-1 surgery, implants were immediately loaded and abutments were incorporated within the provisional restoration using “temporary” cylinders

Rigid fixation use of a metal-reinforced, passively fitting provisional

restoration 101www.indiandentalacademy.com

• Balshi and Wolfinger• Four widely distributed implants placed that were

immediately loaded with an interim fixed, implant-retained prosthesis at first-stage surgery.

• The authors used additional implants in a conventional manner to provide sufficient support for a definitive fixed prosthesis, even if all the immediately loaded implants failed.

• Schnitmann et al.• Converted a previously fabricated complete denture into

a fixed-retained provisional partial denture by incorporating gold cylinders in the complete denture with autopolymerizing acrylic resin.

• Recontoured into a fixed partial denture by removal of the flanges and reduction of the distal extension 102www.indiandentalacademy.com

• Balshi and Wolfinger• Described the “conversion prosthesis,” one that at second-stage

surgery was converted from a complete denture to a fixed, interim prosthesis.

• The technique involved incorporation of modified screw-retained impression copings within a wire-reinforced complete denture.

Advantages (1) a fixed prosthesis with improved function, stability, and

distribution of load was provided immediately following second stage surgery;

(2) the prosthesis protected the mucosa; (3) it served as a prototype for a definitive prosthesis; (4) the original vertical dimension of occlusion was preserved; (5) the provisional restoration aided in obtaining and transferring

interocclusal records; (6) it assisted long-term patient maintenance and reduced the

number of treatment visits.


• Zinner et al presented RBFPD techniques

• Dumbrigue et al• Described options for fabrication of provisional

restorations for an ITI solid abutment By using an ITI plastic (burn-out) coping, Fabrication of an acrylic resin coping on a brass ITI

practice solid abutment, With the ITI impression cap where the solid abutment act

as a core, Fabrication a provisional restoration with the ITI

cementable Protictiv Cap


• Stefan Holst and Priv-Doz ---- studied The effect of provisional restoration material type on micromovement of implants

• Concluded that : “The choice of material used for a provisional restoration significantly influences the vertical displacement of implants placed in artificial bone. When loads are applied to distal cantilevers, load distribution with metal reinforcement seems more favorable than with unreinforced acrylic resin.”

J Prosthet Dent 2008;100:173-182


• S. Banerji , A. Sethi studied clinical performance of Rochette bridges used as immediate provisional restorations for single unit implants.

• Conclusion : “ This type of restoration is an effective means of immediate temporization for patients undergoing single tooth implant retained restorations.”

BRITISH DENTAL JOURNAL 2005; 199(12) : 771-75 106www.indiandentalacademy.com

CAD- CAM,CT Imaging & Immediate provisionalization

• A working master model of the soft tissue anatomy can be generated stereolithographically from the computer data. This model incorporates detail of implant orientations allowing construction of surgical stent and temporary immediate load prosthesis.

• CT denture can be seated accurately onto the master model to provide an index and occlusal guide for tooth positions during the construction of an accurate temporary immediate load prosthesis which is built around known implant positions and axes.

British Dental Journal 2008; 204: 377-381 107www.indiandentalacademy.com

LIMITATIONS OF TEMPORIZATION

Lack of Inherent Strength

Poor Marginal Adaptation Color Instability Poor Wear Properties Detectable Odor Emission Inadequate Bonding Characteristics Poor Tissue Response to Irritation Arduous Cement Removal Time Expenditure for Fabrication Can be Prohibitive


TROUBLE – SHOOTING IN PROVISIONALIZATION


INSUFFICIENT BULK OF MATERIAL

• Axial walls --- e.g. preparations for gold crowns• To prevent damage, the provisional should be made

temporarily wider by relieving the appropriate part of the impression with a large excavator


GROSS OCCLUSAL ERRORS, AIR BLOWS AND VOIDS

• May occur for two reasons:

1. Fins of interproximal impression material being displaced and sandwiched between the impression and the occlusal surface — trim away any suspect areas from the inside of the impression with a scalpel or scissors before reseating

2. Hydrostatic pressure built up within the unset resin during reseating of the impression matrix — consider cutting escape vents cut from the crown margin to the periphery of the impression with a large excavator.

3. Avoid voids by syringing material directly onto preparations. ensuring the tip is always in the resin, to prevent the incorporation of air.


LOCKING IN OF PROVISIONAL RESTORATIONS

• By material engaging the undercuts formed by the

proximal surfaces of adjacent teeth.

------- Cut out a triangular wedge of material from the gingival embrasure space with a half Hollenbeck instrument


MARGINAL DISCREPANCIES

• Can occur due to polymerization shrinkage.

--------- flare out the inside of the crown margin with a bur. This provides a greater bulk of reline material.

• To facilitate seating it is best not to fill the whole crown with resin, but to confine the reline material to the inner aspect of the crown margin, thus reducing hydrostatic pressure.


MULTIPLE CROWNS

• Invariably results in all the restorations being joined together as material passes through the thin and often torn interproximal area ----- Splinting teeth has the advantage of preventing drift in case of poor interproximal and occlusal contacts.

• Ideally, provisional crowns should be separate, but separation can result in unwanted gaps between them. ------- One way of overcoming this is to place small pieces of celluloid strip, roughly 1cm long, between the teeth to be prepared. Holes punched in their buccal and lingual portions.


PREMATURE DECEMENTATION

• Can be largely avoided by ensuring harmony with the

occlusion.

EUGENOL CONTAINING TEMPORARY CEMENTS AND ADHESION• Eugenol-containing cements should be avoided where it is intended to cement the definitive restoration to an underlying composite core


REMOVING TEMPORARY CROWNS

1. when impressions are taken,

2. Certain adjustments are needed,

3. Definitive restorations need cementing.

To make removal easier, the cement should be applied in a ring around the inner aspect of the margin.

Alternatively, the manufacturer’s modifier should be added to the cement


REMOVAL OF EXCESS CEMENT

• Facilitated by pre-applying petroleum jelly to the outside

of the restorations and placing floss under each

connector of linked crowns before seating


REMOVAL OF PROVISIONAL CEMENT FROM INTAGLIO SURFACE OF CASTINGS

• Intaglio surfaces of cast restorations may be airborne-particle abraded using 50-mm aluminum oxide

• Alternative methods ---- steam cleaning, ultrasonic, and organic solvents. [ alcohol (ethanol),soap, chloroform, and eucalyptus oil , Solitine ( containing isoparaffin hydrocarbon oil & lanolin ]


Provisionalization of a tooth with short crown height

• In these cases, adequate retention can only be possible with a good grip on the root surface.

• Copper-band temporary can grip the root for adequate retention and be fabricated thin enough to promote periodontal health.

• Copper has amazing antimicrobial properties, a factor that also might assist in preventing recurrent decay.

• A thin, snug-fitting margin whether copper is readily accepted by the peridontium.

NYSDJ • 2010 : 22-26 119www.indiandentalacademy.com

RECENT ADVANCES IN PROVISIONALIZATION


Protemp™ Crowns (3M ESPE)

• A Bis-GMA light-cured composite

• Come in single units, • Adaptable, • Have a single shade only, • Have good wear resistance • Good polishability,• But because of their single

shade are somewhat limited unless one is prepared to custom stain


Luxatemp Ultra

• Incorporating proprietary nano technology

• Luxatemp Ultra surpasses all leading provisional materials in flexural strength

• The key to provisional stability and long-term durability, especially with multi-unit temporaries.

• Luxatemp Ultra delivers improved initial hardness and superior break resistance.


VISIBLE LIGHT CURED RESINS

• Many clear composites, glazes, or lighter composite shades may not use a camphorquinone photocatalyst because it imparts a yellowish or orange hue,

• Here it is critical to use a broad-spectrum light like the VALO™ (Ultradent Products) or bluephase® 20i (Ivoclar Vivadent) that cures all photo-initiators and composites 123www.indiandentalacademy.com

Cling 2 provisional cement

• A resin-optimized non-eugenol temporary cement with a unique polycarboxylate resin

• This optimizes adhesion, • Soothes the tooth,• Bacteriostatic, and

• Provides an excellent seal to

promote tissue health.


MATERIALS FOR MAKING OVERIMPRESSION

• Polyvinyl substitutes for alginate, CounterFIT™ (Clinician’s Choice) Position™ Penta™ Quick (3M ESPE) AlgiNot® (Kerr Corporation) StatusBlue® (DMG America) Silgimix™ (Sultan Healthcare) can be used as a matrix

in an impression tray. • Essentially low-cost polyvinyl siloxanes• Have good flow, • Excellent detail reproduction, • Ability to be re-used because of their long-term stability.125www.indiandentalacademy.com

Trays for making overimpression• President Tray (Coltene/Whaledent ) • Spacer Trays (GC America). • The metal TempTray™ (Clinician’s Choice) Designed to be a customizable, Distortion-free, and Disposable temporary tray.

• When used as a posterior matrix tray, the handle that is facing the retro-molar area is bent over on top of the tray so as not to impinge on the tissue,

• The anterior is bent at a 45° angle to facilitate insertion, providing a convenient handle.

• When used anteriorly, the lingual wall is bent slightly toward the palate and both ends are bent at 45° angles to provide a handle on both ends.


How to take care of undercuts??????

• OraSeal® Putty or OraSeal® Caulking (Ultradent Products)

• A cellulose material that sticks to wet teeth, • Easily placed into the undercuts, and can be

simply shaped with a plastic instrument to eliminate the undercut.

• This makes removal of the temporary much more predictable. It does not harden and can be removed with a plastic instrument and water after the temporary is fabricated.


CAD-CAM Generated Provisionals• Can be milled out of the blocks of temporary restorative

materials.• Telio CAD (Ivoclar Vivadent),

artBloc®Temp (Merz), VITA CAD-Temp®

monoColor (VITA)• Telio CAD is a block made of

polymethyl methacrylate (PMMA) and is used to mill both full-contour single-tooth and multiple-unit temporary restorations using CAD/CAM technology.

• Enables restorations to be milled both in the laboratory (labside) and the dental practice (chairside).

• Additional layering materials and stains can be used to enhance the esthetic appearance


CAD-CAM Generated Provisionals• Alt V, Hannig M, Wostmann B

• STUDY: Fracture strength of temporary fixed partial dentures: CAD/CAM versus directly fabricated restorations.

• CONCLUSION : CAD/CAM fabricated FPDs exhibit a higher mechanical strength compared to directly fabricated FPDs, when manufactured of the same material. Composite based materials seem to offer clear advantages versus PMMA based materials and should, therefore, be considered for CAD/CAM fabricated temporary restorations.

DENTAL MATER 2011 Apr;27(4):339-47.


CONCLUSION• Quality restorative dentistry needs quality provisional

restorations for predictable results.

• Dentists therefore need to be familiar with the range of

materials and techniques for short term, medium-term and

long-term temporization.

• Forethought and planning are also needed to ensure the most

appropriate provisional is used, especially when multiple teeth

are to be prepared or where occlusal or aesthetic changes are

envisaged.


REFERENCES• Fundamentals of tooth preparations for cast metal and

porcelain restorations : H. T. Shillinburg /Jacobi/Brackett

• Contemporary fixed prosthodontics : S F Rosensteil/M. F. Land /Junhei Fujimoto

• Tylman’s theory and practice of fixed prosthodontics• J Prosthet Dent 2003;90:474-97• Br Dent J 1974;137:233-8• J Prosthet Dent 2001;85:129-32• J Prosthet Dent 2000;83:32-9• J Prosthet Dent 1988;59:512-4• British Dental Journal 2002; 192:619–630• Int J Prosthodont 1990;3: 299-304• J Prosthet Dent 1980;44:283-90 131www.indiandentalacademy.com

REFERENCES• Contemporary Dental Assisting. 2007;Nov/Dec:34-39• J Prosthet Dent 1990;63:639-42• J Prosthet Dent 1979;42:27-33• J Prosthet Dent 1998;80:533-9.• J Periodontology 1973;44:691-6.• J Prosthet Dent 1989; 62:622-6• J Dent1979;7:22-4• Oral Surg Oral Med Oral Pathol1976;41:631-7• J Prosthet Dent 1997;77:93-6• Int J Prosthodont 1994;7:81-9• Biomed Mater Eng 1997;7:327-43• J Prosthet Dent 1988;60:124-6• J Prosthet Dent 1995;74:110-3


REFERENCES• BDJ 2005; 199(12) : 771-75 • BDJ 2008; 204: 377-381• J Prosthet Dent 2008;100:173-182• NYSDJ 2010 : 22-26• DENTAL MATER 2011 Apr;27(4):339-47• Internet sources• Inside Dentistry 2008;4(5)• Compendium continued dental education


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Education

Reisn bonded prosthesis/ Labial orthodontics