Implant thread is exposed from gum recession or car accident ? Worried and confused... (Photo)

Interesting question. Unless you were chewing rock hard candies and somehow were struck so hard that you bit down hard on impact, lodging part of the candy into the gum, it's unlikely this is from an accident. Although anything is possible as I have come to learn over 20 years of experience. You may have traumatized the site OR there is recession due to other factors such as repeated bouts of inflammation at the site for reasons such as retention of cement or over contouring of the crown. Hard to tell really. You our should see the surgeon soon. 

Without seeing xrays of the implant, it is difficult to comment on its stability or prognosis, but it is unlikely that an accident would impact thread exposure on an implant... unless you suffered a direct blow in the area. I would suggest seeking consultation with your dentist and having them examine the implant. From the picture, it looks like what you're seeing is an exposure of the abutment and/or perhaps a bit of the implant collar. If the implants are loose or painful, that could be a red flag, but your dentist would best be able to inform you, especially if they have a radiograph showing the bone levels upon initial placement of the implants.