title: Alloy particle shape and sensitivity of high-copper amalgams to manipulative variables.
abstract: Compressive strength, dimensional change during hardening and residual mercury content of three high-copper spherical particle amalgams (Tytin, Logic and Valiant), two admix amalgams (Dispersalloy and Permite C) and a conventional lathe-cut amalgam (New True Dentalloy) were determined as a function of condensation pressure and trituration time. The properties of the three amalgams containing non-spherical particles were markedly dependent on condensation pressure in the range 3 MPa to 14 MPa. Specimens condensed at 3 MPa showed substantially lower strength, greater expansion during hardening and higher residual mercury contents than did specimens condensed at 14 MPa. The three high-copper spherical particle amalgams, on the other hand, were comparatively insensitive to condensation pressure. Variations in trituration time between 5 and 12 seconds had little effect on the properties of any of the amalgams.
authors.affiliation: Department of Chemical Engineering (Materials), University of Adelaide, Australia.
authors.forename: I H
authors.initials: IH
authors.lastname: Brown
authors.forename: D R
authors.initials: DR
authors.lastname: Miller
mesh_terms: D003300:Copper; D003722:Dental Alloys / Q000737:chemistry; D003723:Dental Amalgam / Q000737:chemistry*; D008422:Materials Testing; D008628:Mercury / Q000032:analysis; D010316:Particle Size; D011312:Pressure
chemical_list: D003722:Dental Alloys; C072893:Lojic N; C033470:Dispersalloy; C031359:New True Dentalloy; C036886:tytin; D003300:Copper; D003723:Dental Amalgam; C092423:Permite C; C072894:Valiant PhD; D008628:Mercury