Metal Restorations

 

 

Fixed prostheses require alloys instead of pure metals as the pure metals do not have the needed physical properties to perform in these restorative situations.

Benefits

  • Greater compressive and tensile strength than other materials
  • Minimal wear of surrounding teeth
  • Certified biocompatibility –  US IdentAlloy® certificates verify alloy status
  • Longevity and reliability
  • Long-term durability
  • Cast restorations protect remaining tooth structure
  • Excellent marginal integrity

Considerations

  • Focus on long-term clinical performance of the chosen alloy.
  • Select alloys that suit the needs of the patient. Avoid “one-size-fits-all” approach.
  • Consider Type II alloys for short-span bridges, single crowns, inlays, onlays and partial crowns.
  • Type IV alloys suit single crowns to large bridges and implant superstructures.
  • Composition of alloys will vary according to the constituents of the alloy:

High noble content: (Au + Pt + Pd) ≥ 60% and Au ≥ 40%  
Noble Metal content: (Au + Pt + Pd) ≥ 25%
Base Metal: (Au + Pt + Pd) < 25%

Alloy Properties

  Gold Non-precious Silver non-precious
Material High noble/noble see chart see chart
Aesthetics Limited Limited Limited - poor
Durability ✓✓✓ ✓✓✓ ✓✓✓
Margins chamfer chamfer chamfer
Flexural strength 405-585 MPa 650 MPa 940 MPa
Indications universal universal universal
Colour yellow/white Rose pink/yellow Silver/white
Bonding Can etch/bond Can etch/bond Can etch/bond
Stain resistance ✓✓✓ ✓✓ ✓✓
Span/ingot size Short span Short-long span Short-long span

Alloy Indications

  Bonds To Porcelain Does Not Bond to Porcelain
  High Noble Noble Base
  IPS
d.SIGN 96®
Degunorm® IPS
d.SIGN 53®
Wirobond® Academy Gold™ Minigold® Harmony® 2
Supplier IIVOCLAR VIVADENT DENTSPLY IVOCLAR VIVADENT BEGO IVOCLAR VIVADENT IVOCLAR VIVADENT IVOCLAR VIVADENT
Materials & Metal Content Au 74% Au 74% Pd 54% Co 64% Au 77% Au 40% Pd 33%
Type IV IV IV IV II IV III
Inlays / Onlays -
Partial crowns
Single crowns
PFM crowns - - -
Telescope & conus crowns -
Root canal posts - - -
Short-span bridges
hardened

hardened
Long-span bridges -
Implant super-structures - - -
Partial dentures - - -