A 3-year longitudinal, controlled clinical study of a gallium-based restorative material

The aim of this three-year longitudinal controlled study was to compare the clinical performance of Galloy versus a high copper, mercury based Dispersalloy filling material.

Moderate to large class I and class II cavities or replacement restorations were selected and 25 Galloy restorations and 25 Dispersalloy controls were placed in 14 adult patients by a single operator. Restorations were photographed and a silicone impression recorded at baseline, 6 months, 1 year, 2 years and 3 years.

At 3 years all 22 Dispersalloy restorations but only 4 Galloy restorations were still in situ. Three Dispersalloy restorations were lost to follow-up. Tooth fracture was observed in 15 (60%) of the Galloy restorations by the end of the 3 years, compared to one (4%) Dispersalloy restoration, which failed due to tooth fracture. A further six Galloy restorations had to be removed due to complaints of persistent pain. Four teeth restored with Galloy required endodontic treatment but none of the Dispersalloy restored teeth required endodontics. Of the four Galloy restorations remaining in situ, three were relatively small restorations and the fourth a moderate sized restoration required a marginal repair.

The clinical performance of Galloy restorations was so grossly inferior to the Dispersalloy controls that Galloy cannot be recommended for clinical use in moderate to large or multi-surface cavities.