Provisional Restorations Wael Al-Omari. BDS, MDentSci, PhD

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Provisional Restorations

• Wael Al-Omari.
• BDS, MDentSci, PhD

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Functions of Provisional Restorations

• Comfort/tooth vitality
• Occlusion and positional stability
• Function
• Gingival health and contour
• Aesthetics
• Diagnosis
• Other practical uses

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Assessment of Aesthetic Changes

• Assess appearance of intended restorations
• Make directly or use a matrix made from the
  wax-up.
• Ensure patients acceptance
• Record the temporary crowns and instruct
  technician to copy their form ad shape into the
  final restoration

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Provisional crown can be used to assess axial
and occlusal reduction
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Occlusal Changes

• Prevent unwanted tooth movement by maintaining
  occlusal and interproximal contacts
• Evaluate patients 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.

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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

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Preoperative
Polycarbonate provisional crown cemented
Gingival healing after 2 months
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Change in Tooth Shape

• Accurately copy a satisfactory and successful
  
• provisional restoration to
• Avoid minor or major changes in tooth shape.
• Avoid disrupting fine mouth movements and
  lip/tooth contact
• Avoid incorporating wide cervical embrasure to
  prevent air leakage

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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

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Aluminum provisional crown
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Self or light cured resins

• Polymethyl methacrylate
• Polyethyl methacrylate (Snap, Trim)
• Bis acryl composite (Protemp)
• Urethane dimethacrylate (light cured).
• Restorative composite

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A- Polymethyl methacrylate B- Bis-acryl composite
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Cast Metal

• Nickel chromium, silver and scrap gold.
• Durable
• Can be made with external retention beads to
  retain acrylic or composite
• Rarely used

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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
• 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

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Provisional Cement (Temp Bond)
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Direct Provisional Restorations Techniques

• Proprietary Shells
• Plastic Shells Polycarbonate relined with
  resin, trimmed, polished and cemented.
• Metal shells
• Aluminum shells relined with resin (short
  term). Soft and galvanize with opposing amalgam
• Stainless steel and nickel chromium used with
  bruxist patients.
• Custom shells beaded acrylic and Mill crowns

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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

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A- Alginate impression as a matrix B-
Provisionals with an excess material
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A preoperative silicone sectional impression
The resin material in injected into the
impression
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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.

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A- Stone duplicate of the wax up B- Vacuum formed
matrix
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A- preparation
B-Excess film of material attached to provisional
crown
C-Trimming the excess
D- Cemented provisional crown
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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

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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

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

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Pre-operative view
Linked temporary Crowns made at chairside using
preoperative clear thermoplastic matrix