Amalgam Preclinical Dentistry, 1st. Year Autumn Semestr L Roubalíková Amalgam Metal-like restorative material composed of silver-tin-copper alloy and mercury. 2 Types of amalgam restorative materials Low - Copper Amalc iam (5% or k Composition - - wt% Silver 63 - 70 % Tin 26 - 28 % Copper 2 - 5% Zinc 0 - 2% Types of amalgam restorative materials Hiah- CoDDerAmalaam(13%-30%) Composition - wt% 40 - 70 % 26 - 30 % 2 - 30% 0 - 2% Particles of the alloy ^Irregulary shaped (filings - lathe cut) ^Microsphere ^Combination of the two Particles shape Hiqh - Copper Amalqam Microsphers of the same composition (unicompositional) Mixture of irregular and spherical particles of different or the same composition (admixed) Production of irregular particles Metal ingrediences heated, protected from oxidation, melted and poured into a mold to form an ingot. Phases of the alloy: Ag3Sn - y Cu3Sn - s Cu6Sn5- r| Ag4Sn - ß 7 Production of irregular particles 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 jum in length 10 - 70 jum in width 10-35 jum in thickness Production of irregular particles Molten alloy is spraying into water under high pressue Irregulary shaped high-copper particles 9 Production of spherical particles Molten alloy is spraying under high pressue of inert gas through a fine crack in a crucible into a large chamber Diameter of the spheres: 2 - 43/um 10 Amalgamation processes Metal alloy is mixed with pure mercury Trituration 11 Amalgamation processes Ag3Sn - y Cu3Sn - s 12 Amalgamation processes Low copper amalgam 13 Amalgamation processes High copper amalgam 14 Amalgam - properties 15 Amalgam ear and pressure resistance (2mm thickness ast least) asy handling hermal and electrical conductivity Corrosion Bad aesthetics 16 Trituration and mixing (obsolete) ower driven trituration Amalgama tors 17 19 20 *.-■' ■ ■ i H A 21 Instruments > Preparation instruments > Filling instruments > Carvers > Burnishers 22 Instruments > Preparation instruments - power driven Burs Diamonds PiMJflcl incited P&flř. Bhapad Siraigm Tapered 23 Instruments > reparation instruments - hand Chisel , Excavator Amalgam gun Crucible 25 Amalgam carrier 27 Instruments illing instruments condensors and spatulas 28 ,; ( Condensor -stamen í."Tľílľ." " t*/"™*™1 "" 30 Condensor and burnisher - spatula combined Power driven condensor - stamen Special handpiece Burnisher - spatula Angular- trough edge trough face Burnisher-spatula, angular three face -. ■■urn u . . . ■ ■ Instruments urnishers 35 burnisher at most f ^ Ir'U.V J 36 Instruments arvers Frahm Discoid Cleoid 37 Carver - Frahm 38 Carver - Sapin 39 Carver: Frahm 41 Carver: Discoid - Cleoid ó ŕ= J p -IJ-^J-./. 42 h k Polishing