The first question you need to ask would be "Why is an Endodontist performing a 6 month check-up?" If it is to check the status of a RCT performed on a patient, this is typically considered inclusive. None-the-less, since there is no specific examination code for a 6 month check-up from an Endodontist and no real reason for an Endodontist to be performing a 6 month check-up the most appropriate code to use would be D3999 (unspecified endodontic procedure, by report). The carrier would have to decide if the 6 month check-up is a valid charge.