Articaine Hydrochloride 4%. Septocaine 1:200,000 is preferred for most routine dental procedures. Septocaine 1:100,000 is preferred during operative or surgical procedures when improved visualization of the surgical field is desirable. Fast onset (1 to 9 minutes) to avoid delay before effective analgesia is achieved. Predictable duration of anesthesia: up to 60 minutes for infiltration injections and up to 120 minutes for nerve blocks.