Zinc-containing high copper amalgams: a 3-year clinical evaluation

Dispersalloy with a 0.9% zinc and a non-zinc composition and Tytin with a 1.0%, 0.33% and a non-zinc formula were evaluated. Thirty-nine patients received 247 amalgam restorations, in which these five formulas were randomly placed. Results after 3 years indicate that the zinc-containing alloys had less fracture at the margins than the non-zinc alloys. The data indicate that small amounts of zinc (approximately 1%) play a beneficial role in the serviceability of high copper amalgams.