<prompt> The highest mercury concentration in amalgam filling is found:At the margin of the restorationIn the centre of the restorationIn the deepest part of the restorationNone of the above  <response>: Mercury analysis of a large number of restorations reveals that the mercury content of the marginal areas averages between 2 to 3 higher than the bulk of the restoration. This is true regardless of the condensation method or the dryness of the increments used to build the restoration.Reference: PHILLIPS SCIENCE OF DENTAL MATERIALS, 12th ed page no 352 