Dental anesthetic needles (long and short)

Dental needles are double-ended: the short back end pierces the cartridge and the long front end goes into the tissue. Long needles are about 32 mm and short ones about 20 mm. The gauge is the thickness: a higher number is thinner (30 is thinner than 25). Thicker needles bend less, which matters for deep injections such as the inferior alveolar nerve block.

How to spot it

• A plastic hub with threads, and a cap on each end; the color of the hub often marks the gauge (check the box).
• Long vs. short: compare the length printed on the package.

What it is used for

• The dentist chooses the needle; long needles are common for lower nerve blocks, short ones for upper injections.

Safety and care

• Single-use (disposable) item: use it on one patient, then throw it away. Never clean and reuse it.
• Sharps: dispose of in the sharps container right after use; never bend or break it by hand.
• Recap only with a one-handed scoop or a recapping device.

Related

• Aspirating anesthetic syringe (breech-loading, harpoon type)
• Needle recapping device

Sources: Malamed SF. Handbook of Local Anesthesia, 7th ed. Elsevier, 2020, Inside Dentistry / Dental Aegis. Size Doesn't Matter: Needle Gauge and Injection Pain (2007), OSHA. Standard interpretation, 1994-04-29, recapping of contaminated needles (29 CFR 1910.1030), OSHA. Bloodborne Pathogens Standard, 29 CFR 1910.1030