523.40 Chronic periodontitis, unspecified
The code for generalized marginal pappillary severe gingivitis would depend on if the gingivitis was Acute or Chronic and if it was plaque induced or non-plaque induced your options would range from 523.00 to 523.11/ in order to give the correct code this needs to be more specific.
Bone grafts depend on the size your options would be
CPT 20900 - small dowel bone graft / usually used for a tooth area of an implant site
CPT 21215 - large area mandible
Periodontal mucosal grafting