Direct-placement gallium restorative alloy: a 3-year clinical evaluation

A pilot clinical study on a direct-placement gallium restorative alloy was initiated with nine patients who signed a consent form.

Thirty Class I restorations were placed and assessed over a 3-year period. The cavity preparations and surface of the restorations were sealed to prevent oral fluids from contacting the gallium alloy during placement and early setting of the gallium restorative material.

The initial 18-month clinical results were encouraging. But at 21 months, one tooth had fractured, and within another year two molars were diagnosed with cracked-tooth syndrome (incomplete tooth fracture). These three fractured teeth were restored with amalgam and are symptomless at this time. There was little fracture at the margins of the gallium restorative, but tarnish and a rough surface were noted on many of the gallium restorations. The direct-placement gallium restorative alloys must be further assessed in the laboratory to correct dimensional instability.

Results suggested that Galloy, used with either of two sealing resins, is not a suitable restorative material.