Shock-absorbing behavior of five restorative materials used on implants.

The damping effect of five restorative materials used to veneer test crowns rigidly connected to a Brånemark implant and subjected to an impact force was measured. These materials included a gold alloy; a noble metal ceramic alloy; porcelain; a laboratory-processed, light-activated microfilled resin; and a heat- and pressure-polymerized poly(methyl methacrylate) resin. The two resins were found to reduce the impact force by about 50% when compared to porcelain or the alloys. The clinical significance of the results is discussed.