Is it okay to apply 3D crest white (whitestrips) on my teeth if I have an implant among them?

Yes, you can absolutely replace it providing there is no extreme decay. In the photograph, the tooth looks intact and acceptable for a new crown. I recommend an all porcelain crown in this case. The only thing that I have a question about is whether the lower tooth has erupted to touch the...

No, the oral surgeon was more than likely correct. When the teeth supra-erupt (extrude down or up), they usually carry the bone with them. So not only are the teeth longer, but so is the bone. Not only do you have to shorten the teeth to make space, but you also have to reduce the bone. ...

You did not specify if the tooth was cemented with a screwed in abutment(post) or if the tooth was screwed in whole.  It sounds like your implant screw is loose & the dentist cannot engage the internal screw.  Several reasons may be the cause, not limited to;-there is debris on the...