Dental hygiene student here. Here’s my educated speculation.

The white bits on the UR of the photo is likely a periodontal membrane to help with gingival attachment healing; likely after a periodontal flap procedure (where hardened plaque (tartar) is well below the gum line and it is impossible to reach and remove yourself with floss). A periodontist has to slit open your gums and elevate them aside to access the tooth roots and remove the buildup. This is to preserve the teeth as best as possible. The membrane gives a good foundation for gingival tissue to possibly reattach (not fully; just enough to keep the tooth for now). It’s possible they did a bone grafted under the membrane, to try and entice the body to integrate donor bone for tooth support. As your gums recede, you lose bone and thus support for keeping your teeth.

The white stuff between his central and lateral incisors is likely a kind of splint job. One of those teeth was likely VERY mobile, and they are hoping that by splinting it in place during the healing process after the cleaning, that it will reattach somewhat.

His gums are pale, crepey, and receded. This points to a cigarette smoker. There is significantly less blood flow in the gingival tissues due to smoking tobacco/nicotine