Why would my dentist do a Bone Graft 9 weeks after placing implant and extraction?

I had a tooth extracted and was told after it was infected He still went ahead and put in the implant which on the X-ray looks to me goes across on a angle. I had multiple visits back after 2 weeks he cleaned out the area and put something in. the front part of the gum had a gap. Last visit he claimed it was healing and to return in 4 weeks. I've had 2 rounds of antibiotics during the first few weeks. On my latest visit he says he must go in and clean it up and then he did a bone graft.

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