Metal-like restorative material composed of silver-tin-copper alloy and mercury.  Mercury  Metal alloy (Silver, tin, copper, zinc)  Clean, destilled  Heavy metal, liquid (room temperature)  Irregulary shaped (filings - lathe cut)  Microsphers  Combination of the two  Spheroids High – Copper Amalgam Microsphers of the same composition (unicompositional) Mixture of irregular and spherical particles of different or the same composition (admixed) Ingot cooled slowly Ingot heated at 400°C (6 – 8 hours) (homogeneous distribution of Ag3Sn) Ingot cut on the lathe, particles passed trough a fine sieve and ball milled to form the proper particle size. Aging of particles (60 - 100°C, 6 – 8 hours) Particle size: 60 – 120 mm in length 10 – 70 mm in width 10 – 35 mm in thickness Molten alloy is spraying into water under high pressue Molten alloy is spraying under high pressue of inert gas through a fine crack in a crucible into a large chamber Diameter of the sphers: 2 – 43mm  Silver: slow reaction with mercury, accelerates setting process, increaes mechanical properties, increases corrosion resistance.  Tin: fast reaction with mercury, retardates setting time, decreases mechanical propeties, decreases corrosion resistance Copper: difficult slow reaction with mercury, increases hardness and corrosion resistance.  Zinc: antioxidant agent, reason for internal electrochemical corrosion.  Noble metals: increase corrosion resistance and price  Silver 70%  Tin 24-26%  Copper up to 6%  Zinc 0 - 2%  Noble metals (gold, platimun) – in some alloys Alloy contents silver, tin and copper. There are intermetalic compounds – phases Gamma phase Ag-Sn Epsilon phase Cu-Sn Mercury dissolves particles of amalgam, arise new compounds - phases Ag-Hg: gamma 1 phase Sn-Hg: gamma 2 phase The new phases crystallize Part of gamma phase does not dissolve Therefore the amalgam contains after setting gamma 1,gamma 2 and gamma phase. Hg Sn Sn Sn Sn Sn Ag Ag Ag Ag Ag Cu Cu Cu Cu Cu Ag3Sn – g Cu3Sn – e Sn Sn Sn Sn Sn Ag Ag Ag Ag Ag Cu Cu Cu Cu Cu Ag3Sn – g Cu3Sn – e Sn7Hg – g2 Ag2Hg3 – g1 Konvenční amalgám  Gamma 2 phase is not stable, Tin releases easily and disappears, mercury can dissolve gamma phase. The mechanical resistance to occlusal loading decreases The process of degradation of gamma 2 phase is external electrochemic corrosion.  Zinc decomposes water: hydrogen and oxygen cause expansion of the filling, Flow is deformation of amalgam that is not completely set. Creep is deformation of amalgam that is completely set. The filling is beaten during occlusal loading – smal thin spits break – margins of filling become rough.  Content of copper increased up to 12%-30%  Less tin and also silver Better mechanical resistance, lower tendency to corrosion, lower flow and lower creep.  Mercury dissolves particles of amalgam:  Gamma 1 phase a gamma 2 phase  Due high reactivity of cooper and tin eta phase arises, gamma 2 phase dissapears or does not appear (if contenc of copper is around 20% and more) Sn Sn Sn Sn Sn Ag Ag Ag Ag Ag Cu Cu Cu Cu Cu Ag3Sn – g Cu3Sn – e Cu6Sn5 - h Sn7Hg – g2 Ag2Hg3 – g1 Hg Sn Sn Sn Sn Sn Ag Ag Ag Ag Ag Cu Cu Cu Cu Cu Ag3Sn – g Cu3Sn – e  Wear and pressure resistance (2mm thickness ast least)  Easy handling  Thermal and electrical conductivity  Corrosion  Bad aesthetics  Flow  Creep  Hand mixing (obsolete)  Power driven trituration Amalgamators Amalgam gun Crucible Amalgam carrier Portion by portion and condensation Power driven condensor Special handpiece  Preparation instruments  Filling instruments  Carvers  Burnishers  Preparation instruments - power driven Burs Diamonds  Preparation instruments - hand Chisel Excavator  Filling instruments condensors and spatulas Condensor with straight front Carver -Frahm Carver - Sapin Carver Discoid-cleoid Nosič amalgámu Condensor - stamen