To effectively anesthetize tooth #15 for periodontal surgery after administering a PSA, which additional injection is necessary?

To anesthetize tooth #15 effectively for periodontal surgery after administering a PSA (Posterior Superior Alveolar nerve block), an additional injection of the greater palatine nerve block is necessary. The reason for this is that the PSA primarily provides sensory innervation to the maxillary molars, including tooth #15, but does not adequately anesthetize the buccal soft tissues and palatal tissue surrounding this area.

The greater palatine nerve block specifically targets the palatal area of the maxilla, providing anesthesia to the palatal tissue adjacent to the molars. This is crucial for periodontal procedures as it ensures that both the teeth and the surrounding soft tissues are adequately anesthetized, allowing for a pain-free treatment experience. By addressing both sensory innervation of the tooth and the surrounding tissues, the dentist can perform the necessary surgical procedures effectively without causing discomfort to the patient.

In summary, the greater palatine nerve block complements the PSA by ensuring complete anesthesia in the area of tooth #15, which is vital for successful periodontal surgery.