When performing SRP on the lingual of tooth 13, what is the injection site for infiltration?

When performing SRP on the lingual of tooth 13, what is the injection site for infiltration?

• A. Near apex of tooth
• B. Cervical third of the crown
• C. Buccal mucosa adjacent to tooth
• D. Palatal mucosa near the tooth

Answer: (A)

The key idea is where infiltration anesthesia is placed to reliably numb the targeted tooth and its surrounding tissues. For SRP on the lingual aspect of a maxillary anterior tooth, depositing anesthetic near the apex of the tooth allows the drug to diffuse into the apical region and block the pulpal nerves and surrounding periodontal tissues, providing both pulpal and gingival anesthesia needed during the procedure. Injecting at the cervical third of the crown is too far from the apex to reliably affect the pulp. Injecting into buccal mucosa would numb the cheek-side tissues, not the lingual side or the tooth itself, and palatal mucosa infiltration would numb the palate but not the tooth’s pulpal innervation. So, the most effective site is near the apex of the tooth.

The key idea is where infiltration anesthesia is placed to reliably numb the targeted tooth and its surrounding tissues. For SRP on the lingual aspect of a maxillary anterior tooth, depositing anesthetic near the apex of the tooth allows the drug to diffuse into the apical region and block the pulpal nerves and surrounding periodontal tissues, providing both pulpal and gingival anesthesia needed during the procedure. Injecting at the cervical third of the crown is too far from the apex to reliably affect the pulp. Injecting into buccal mucosa would numb the cheek-side tissues, not the lingual side or the tooth itself, and palatal mucosa infiltration would numb the palate but not the tooth’s pulpal innervation. So, the most effective site is near the apex of the tooth.