Is there a guideline as to what can/cannot be billed for pre-op/follow up visits for oral surgery procedures? I am looking at 3rds, bone grafting, implants type procedures.

Each carrier will have specific guidelines on this...it is always best to check with the carrier.

In general here is the global period for each procedure

D7220-D7241 Extraction of 3rds has a 10 day global period.
Bone grafting has a 10-30 day global period depending on the procedure.
D6010 Dental implants has a 30 day global period.