Hi Guest!
D4277 - free soft tissue graft procedure (including recipient and donor surgical sites) first tooth, implant or edentulous tooth position in graft
It is not likely this procedure would be covered by Medicare, as Medicare will not cover anything considered routine dental care. The only dental services Medicare states they will cover are ones that are an "integral part of another covered procedure" - for example, extractions prior to radiation therapy or an oral exam prior to heart valve replacement.
Medicare's statements about what is covered & not can be found here:
https://www.cms.gov/Medicare/Coverage/MedicareDentalCoverageHope this helps!