Finishing of amalgam restorations: to what degree is it necessary?

This paper attempts to elicit from the literature evidence to guide the clinician in deciding what degree of finishing and polishing is appropriate for amalgam restorations. Much of the justification for the polishing of amalgams has, in the past, been empirically based. Comprehensive scientific investigation into the validity of this practice does, however, present a number of methodological problems which have yet to be successfully overcome. An attempt is made to define what is meant by the term 'polished' (in a clinical context) while the benefits of polishing, as far as they are known, are discussed. The roles that cavity preparation, carving and burnishing play in the finishing of a restoration are reviewed, as is the conflicting evidence regarding their respective advantages and disadvantages. The importance of marginal adaptation, the relationship of polishing to secondary caries, and the dilemma in choosing (in appropriate cases) between the replacement of a restoration or its improvement by polishing are also considered.