Week 13 Ch 11/12: Amalgam/Metals & Alloys

alloy

mixture of two or more metals

creep

gradual change in the shape of a restoration usually caused by compression from occlusion or adjacent teeth; can cause amalgam to bulge out of the cavity preparation

tarnish

oxidation affecting a thin layer of the metal at its surface; does not change the metal’s mechanical properties

corrosion

breakdown of a metal by chemical or electrochemical reaction; changes the properties of the amalgam

condensation

pressing the amalgam mix into a cavity preparation to produce a dense mass

burnishing

user to further condense the amalgam mix into the cavity preparation and smooth the amalgam surface

mercury

only metallic element that is known to be liquid at standard temp and pressure; key component that reacts with and binds the alloy particles

lathe-cut alloy

irregularly shaped particles, formed by shaving fine particles

spherical alloy

produced by spraying a mist of molten alloy into an inert glass; small particles form the automized droplets cool

admixed alloy

consist of a mixture of lathe-cut and spherical particles

matrix bands

used to help contain the amalgam during condensation in a class 2 prep; helps to form the proximal contours and contacts

lichenoid lesions

local contact dermatitis on the buccal mucosa or lateral border of the tongue

amalgam tattoo

unintentional, benign, bluish-gray or black mark in the mouth’s soft tissues caused by particles of dental amalgam becoming embedded in the gum, cheek or lip

high-noble alloy

containing at least 60% noble metals, 40% at which must be gold

base-metal alloy

composed of non-noble metals, which corrode more readily

noble alloy

composed of metals that do not corrode readily; at least 25% must be noble metals

solder

an alloy used to join two metals together or to repair cast metal restorations

wrought metal alloy

an alloy that has been mechanically changed into another form to improve its properties

pure metals

composed of multiple small interlocking crystals, arranged in a 3D structure called a lattice

intracoronal

preparation made within the crown of the tooth - ig. inlay

extracoronal

preparation made primarily outside of the crown of the tooth - ig. partial and full coverage crowns