Provisional restorations

Provisional Restorations

Wael Al-Omari.
BDS, MDentSci, PhD

Functions of Provisional Restorations
 Comfort/tooth vitality
 Occlusion and positional stability
 Function
 Gingival health and contour
 Aesthetics
 Diagnosis
 Other practical uses

Assessment of Aesthetic Changes
 Assess appearance of intended
restorations
 Make directly or use a matrix made
from the wax-up.
 Ensure patient’s acceptance

 Record the temporary crowns and
instruct technician to copy their form
ad shape into the final restoration

Provisional crown can be used to
assess axial and occlusal reduction

Occlusal Changes
 Prevent unwanted tooth movement by maintaining occlusal
and interproximal contacts
 Evaluate patient’s tolerance to change in anterior guidance
or increased occlusal vertical dimension:
 Cement temporary crowns made from diagnostic wax up
and review for aesthetics, guidance, drifting, mobility,
decementation, and comfort
 Copy the provisional crowns guidance by a custom
guidance table, to transfer to definitive restorations.
 It is recommended to assess tolerance to change in vertical
dimension by a reversible method such as splint.

Periodontal Changes
 Allow for resolution of inflammation
 Improve gingival healing and stabilization
of gingival margin position
 Used after surgical crown lengthening
during the healing period before definitive
preparation and impression

Preoperative Polycarbonate provisional
crown cemented

Gingival healing after 2 months

Change in Tooth Shape
 Accurately copy a satisfactory and successful
provisional restoration to:
1. Avoid minor or major changes in tooth shape.
2. Avoid disrupting fine mouth movements and
lip/tooth contact
3. Avoid incorporating wide cervical embrasure to
prevent air leakage

Provisional Restorations
Materials
 Preformed crowns
 Plastic shells: polycarbonate or acrylic. Used for

anterior and premolar teeth.
 Metal Shells: aluminum, stainless steel or nickel

chromium.
 Self or light cured resins

Self or light cured resins
 Polymethyl methacrylate
 Polyethyl methacrylate (Snap, Trim)

 Bis acryl composite (Protemp)

 Urethane dimethacrylate (light cured).

 Restorative composite

A- Polymethyl methacrylate
B- Bis-acryl composite

Cast Metal
 Nickel chromium, silver and scrap gold.
 Durable

 Can be made with external retention beads to
retain acrylic or composite
 Rarely used

Provisional Cements
 Creamy mix of zinc oxide eugenol
 Most practitioners use proprietary cements such as Temp

Bond
 Available with modifier to soften the cement

 Non-eugenol Tem Bond is available and used to:

1. Cement temporary restorations for preparations for
definitive adhesive restorations (eg All ceramic, veneers)
to avoid interference with bonding of resin cements.
 If eugenol containing cement used, eugenol residues
should be removed with pumice and water

Provisional Cement (Temp Bond)

Direct Provisional Restorations Techniques
 Proprietary Shells
 Plastic Shells: Polycarbonate relined with resin,
trimmed, polished and cemented.
 Metal shells:

1. Aluminum shells: relined with resin (short term).
Soft and galvanize with opposing amalgam
2. Stainless steel and nickel chromium: used with
bruxist patients.
 Custom shells: beaded acrylic and Mill crowns

Matrices for Provisional Restorations
 Impressions:
 Alginate: absorbs resin exotherm

 Elastomers: reusable

Advantages: simple, quick, inexpensive.
 Vacuum formed thermoplastic:

 clear vinyl sheet on stone duplicate of the wax up.

 used only in presence of number of adjacent
locating teeth
 could be used with light cured resins.

 Proprietary celluloid crown form

A- Alginate impression as a matrix
B- Provisionals with an excess material

A preoperative silicone
sectional impression

The resin material in injected
into the impression

Techniques
 Direct Syringing: polyethyl methacrylate.
 Indirect Provisionals:

 Used for long term provisionals.

 Strong heat cured materials can be used

 Aesthetics and occlusion made on articulated wax up.

 Indicated or multiple restorations and for an

increased vertical dimension.
 Alginate impression of the preparations, cast in fast
set stone, and fabricate provisionals.

A- Stone duplicate of the wax up
B- Vacuum formed matrix

A- preparation B-Excess film of material
attached to provisional
crown

C-Trimming the excess D- Cemented provisional
crown

Provisionals of Adhesive Restorations

No temporary coverage
 Simple coat of zinc phosphate cement

 Composite resin bonded to a spot

etched on the preparation
 Composite bonded to opposing tooth

Problem Solving
 Insufficient bulk of material: Inadequate
reduction, or make it bulkier by relieving the matrix
(impression).
 Gross occlusal errors, air blows and voids: trim
away suspected areas (interpoximal), an educe
hydrostatic pressure by cutting escape vent.
 Locking in of provisional restorations: material
engaging the adjacent tooth proximal undercut.
 Marginal discrepancy: polymerization shrinkage,
distortion on removal, reline with resin around the
margins

The inside of the alginate is trimmed
to increase the thickness of the
provisional

Problem Solving
 Multiple crowns: joined restorations prevent drifting,
gingival embrasures should be opened to access brushing.
 Premature decementation: Ensure harmony with

occlusion, use stronger cement
 Partial denture abutment: fabricate with the denture fully

seated.
 Eugenol containing cements: do not use if the underlying

core is composite.
 Removing temporary cement: use modifier.

 Removal of excess cement: apply petroleum jelly to

outside of the restorations

Pre-operative view

Linked temporary Crowns made
at chairside using preoperative
clear thermoplastic matrix

Provisional restorations

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