We are using cookies to implement functions like login, shopping cart or language selection for this website. Furthermore we use Google Analytics to create anonymized statistical reports of the usage which creates Cookies too. You will find more information in our privacy policy.
OK, I agree I do not want Google Analytics-Cookies
Quintessence International



Forgotten password?


Quintessence Int 30 (1999), No. 10     1. Oct. 1999
Quintessence Int 30 (1999), No. 10  (01.10.1999)

Page 673-681

Expansion of contaminated amalgams assessed by photoelastic resin
Osborne, John W. / Howell, Maria Lopez
Objective: Eight amalgam alloys, 6 high-copper and 2 low-copper, were assessed for expansion via photoelastic resin. Method and materials: The photoelastic resin sheet was sectioned into 20 x 25-mm blocks, and two 4 x 8-mm holes were drilled into the resin. The amalgam alloys were hand condensed into the prepared holes. Test conditions for each alloy were (1) uncontaminated, (2) contaminated with 5 µL of Ringer's solution, and (3) contaminated with 5 µL of cell culture medium. Results: Contaminated high-copper amalgam alloys may exhibit expansion to varying degrees but do not show the classic delayed expansion. One spherical, nonzinc high-copper alloy showed no expansion, whether it was uncontaminated or contaminated, and 3 high-copper alloys with different amounts of zinc (0% to 1%) showed slight expansion when contaminated. One low-copper alloy displayed delayed expansion; within 17 days after initial expansion in the photoelastic resin, it had exceeded the greatest stress observed in any contaminated, high-copper zinc-containing alloy at 3 months. Conclusion: Contamination of dental amalgam is to be avoided, but a zinc-containing high-copper amalgam will not exhibit classic delayed expansion even if contaminated.