I have a 3 year old implant. No bone grafting was performed. I have gum disease. Scaling and root planning is performed every 6 months. Dentist performed curettage around implant last August and second one in April. The x-rays show bone loss since august. My dentist says nothing can be done to reverse bone loss. I read about Emdogain for tissue regenaration. Could it be used for an existing implant? Are there really no options other than scaling and curettage?