The injection volume for local infiltration is approximately which fraction of a cartridge?

The injection volume for local infiltration is approximately which fraction of a cartridge?

• A. 1/3–1/2 of cartridge
• B. Full cartridge
• C. 3/4 of cartridge
• D. 1/8 of cartridge

Answer: (A)

Local infiltration uses a relatively small amount of anesthetic because you’re aiming for a localized effect around the tooth, and the maxillary bone is porous with a thin cortical plate that allows the anesthetic to diffuse to the nerve endings. A standard cartridge contains about 1.8 mL, so the typical infiltration volume is roughly one-third to one-half of a cartridge, about 0.6–0.9 mL. Delivering this modest amount around the tooth’s apex is usually enough to achieve anesthesia without unnecessary tissue distension or spread to adjacent areas. Using a full cartridge would be more than needed for a localized infiltration, and amounts as small as 1/8 of a cartridge are typically insufficient to fully anesthetize the target area.

Local infiltration uses a relatively small amount of anesthetic because you’re aiming for a localized effect around the tooth, and the maxillary bone is porous with a thin cortical plate that allows the anesthetic to diffuse to the nerve endings. A standard cartridge contains about 1.8 mL, so the typical infiltration volume is roughly one-third to one-half of a cartridge, about 0.6–0.9 mL. Delivering this modest amount around the tooth’s apex is usually enough to achieve anesthesia without unnecessary tissue distension or spread to adjacent areas. Using a full cartridge would be more than needed for a localized infiltration, and amounts as small as 1/8 of a cartridge are typically insufficient to fully anesthetize the target area.