Hi Guest!

D4381 - localized delivery of antimicrobial agents via a controlled release vehicle into diseased crevicular tissue, per tooth

The code listed above does not have a direct crosscode we are aware of, so you can either bill the "D" code on the medical claim (many insurers these days will process "D" codes when they are medically necessary services), or you can try the CPT code below and include a narrative report describing the procedure:
41899 - Unlisted procedure, dentoalveolar structures

Hope this helps!