Which explorer is specifically referenced as a tool for examining decay?

The pigtail explorer is a dental instrument specifically designed for examining teeth and detecting decay. Its unique shape allows for effective maneuverability around curves and in the depressions of teeth where decay may form. The pointed end of the pigtail is particularly useful for detecting caries (tooth decay) and for exploring margin integrity of restorations, making it a preferred choice among dental professionals when conducting thorough examinations.

Other explorers, such as the Orban, Shepherd's Hook, and ball-ended explorer, have different designs and uses. For instance, the Orban explorer is also used for assessing decay but has a different shape and is primarily effective for examining the interproximal areas of teeth. The Shepherd’s Hook, with its hook-like design, is more suited for examining pits and fissures. The ball-ended explorer is mainly used for detecting soft calculus and is particularly effective in periodontal examinations rather than directly identifying hard decay.

In this context, the pigtail explorer stands out as the specific tool designed primarily for systematically detecting decay on the tooth surfaces, thus affirming its designation as the correct choice in this scenario.