Do I need gum graft due to recession over All on 5 implant? (Photo)

Gum recession which occurs 4 years after the placement of your implants is not a good sign.  The likely reason for the gum recession is the loss of supporting bone underneath the gums.  Consequently, a gum graft would be of no value - as its the bone which holds the implant in.  Moreover, sensitivity over an implant area is a poor prognostic indicator.  This is a situation which needs to be evaluated radiographically (with x-rays) by a dentist.  

Yes you need a gum draft over that implant. See a periodontist to assess the gums and bone levels around the implants to understand better why you are getting so much recession on these implants. Not a good sign. I'm not a fan of all on 4/5/6 because it's a short cut treatment or UNDER treatment to save some money and unfortunately it's not only too expensive for what you actually end up with, but most dentists don't get the bite right which leads to bite discrepancies, excessive forces on the implants, and resultant bone loss & gum recession that ensues. Go see some specialists before you lose too much gum and bone and it's too late. Good luck. 

Tenderness over an implant can be for a variety of reasons.  Often rebuilding a thicker, healthier gum can help in preventing future deterioration and increase the longevity of the implants.