Chairside - Glidewell Dental Labs

Repair,
Don’t
Replace
Part 1
Resurfacing an Existing Porcelain Fused to
Metal Restoration with a Porcelain Veneer
– ARTICLE and CLINICAL PHOTOS by
Robert A. Lowe
DDS, FAGD, FICD, FADI, FACD, FIADFE
Introduction: The Porcelain “Repair”
Repairing a broken porcelain (or porcelain-fused-to-metal)
restoration is a clinical reality in every dentist’s practice.
The traditional technique is to use composite resin to repair
chipped porcelain. This is an attempt to use unlike materials
to accomplish a long-term repair, but it rarely works.
Early “porcelain repair kits” used 37 percent phosphoric
etch, silane primer, and adhesive and composite resin to
repair chipped porcelain. This system did not work because
37 percent phosphoric acid cannot appreciably etch a
porcelain surface. Without adequate micromechanical retention
to affix the composite resin to the porcelain surface,
any repair will likely not withstand the forces of mastication.
The use of hydrofluoric acid provides an adequate etched
surface to create an improved micromechanical bond of
composite to porcelain. However, the bond of composite
to porcelain is not the only clinical problem. Another is the
finishing and polishing of the porcelain-composite interface.
Regardless of the finishing and polishing technique and
materials used, the fine line of demarcation between the
composite and porcelain is hard to eradicate.
Repair, Don’t Replace – Part 119