How much is injected when using local infiltration?

How much is injected when using local infiltration?

• A. 0.6–0.9 ml (1/3–1/2 of cartridge)
• B. 1.5–2.0 ml
• C. 0.1–0.2 ml
• D. 2.0–2.5 ml

Answer: (A)

Local infiltration relies on depositing a small amount of anesthetic near the tooth apex so it can diffuse to the nearby nerve endings. In the maxilla, the tissue is quite porous, so a modest volume is enough to achieve anesthesia without needing to fill a large area. A standard cartridge contains about 1.8 mL, and using roughly one third to one half of that—about 0.6 to 0.9 mL—per infiltration is typically sufficient for a localized effect. Using more than this isn’t usually necessary and can increase tissue distortion or systemic exposure, while too little (0.1–0.2 mL) may not provide adequate numbness.