It looks like the pain had rather a sudden onset in the area that has healed since the previous regenerative surgery. My first suspicion would be another tooth adjacent to the area where the graft procedure was performed. See your dentist, such things can be easily diagnosed. Good luck !!
Ordinarily any bone graft procedure performed with any approach that enhances local regenerative (healing) response has less postoperative pain than if done without it. The fact that you experience pain and discomfort is an indication that there is something going on with...