ABSTRACT
Minimum-preparation retainers are usually made in base metal alloys because they are strong in thin sections and they bond well to adhesive luting resins when they are freshly grit-blasted. Of the conventional retainers, an all-metal retainer is the most conservative of tooth tissue, and the simplest and usually the least expensive to produce. When appearance permits, this should be used in the posterior part of the mouth. In the anterior part of the mouth metal-ceramic is the most suitable material.
