Zest Caries Finder Caries Detection Dye, 10 mL · Green

• Handpieces & Motors — The powered part that turns a bur or a file, as against the parts and consumables that fit it. Handpieces and attachments are semicritical items that must be heat sterilized between patients according to the maker’s instructions.
• Endo Equipment Parts & Accessories — Fits an endodontic unit; it is not the unit itself. Sonic activation uses much lower frequencies, roughly 150 to 300 Hz, with polymer tips that oscillate to stir the irrigant.
• Pulp Vitality Testers — Reads whether the nerve in the pulp responds, not how long the canal is. A scoping review of pulpotomy studies found markedly higher positive response rates with electric pulp testing than with cold testing.
• Root Canal & Caries Locators — Shows where something is rather than how the tooth responds. Published studies disagree about the dyes: some report that they overstain and lead to unnecessary removal of sound dentin, others that without them carious tissue goes undiagnosed.
• Apex Locators — Measures length; the pulp tester on the same shelf measures nerve response. A scoping review concluded that the accuracy of these devices is acceptable in most cases but that a radiograph alongside remains advisable to confirm the measurement.
• Measuring & Marking Instruments — Reads or holds a measurement by hand, with no power supply and no electrode.

Pages for curing lights, canal preparation gels, files, posts, irrigating devices and scaler tips also sit on this shelf; those types have homes of their own elsewhere.

Reading conditions: a scoping review identified twenty factors that affect how accurate an apex locator reading is, among them canal curvature and length, tooth type, file size and alloy, apical patency, resorption, perforation, irrigants and medicaments.

Motor settings: corded and cordless motors differ in what they let you set, and reciprocation was introduced to reduce cyclic and torsional stress on the file. Some motors carry an apex locator inside, usable on its own or during instrumentation.

Pulp testing: cold, heat and electric tests all read nerve response rather than the blood supply of the pulp, and none has consistently achieved ideal sensitivity and specificity across clinical situations.

Patients with implanted cardiac devices: the ADA reports that at a distance of at least 15 centimetres, interference from ultrasonic scalers, apex locators and other dental devices is not considered likely to present any clinical risk. In laboratory tests apex locators were a low risk for light electromagnetic interference, though one in-vivo study induced a symptomatic interruption of pacing.