Which tooth requires an infiltration technique for profound anesthesia (rather than a block)?

Correct answer: C. Mandibular primary molar (tooth T)

• A. Mandibular second premolars typically require IAN block for permanent teeth due to cortical bone thickness.
• B. Permanent mandibular molars typically require IAN block for reliable anesthesia due to thick cortical bone.
• C. Correct. Primary (deciduous) mandibular molars (including tooth T) can be effectively anesthetized with local infiltration because the cortical bone is thin and porous in children, allowing the anesthetic to penetrate readily. Infiltration is more predictable for primary teeth than for permanent mandibular teeth.
• D. Maxillary second molars are anesthetized by infiltration normally — but the question focuses on the mandibular arch where infiltration is predictable.