I had an abutment with a crown placed over the implant about a month ago. Unfortunately the crown fell off and now I have the abutment exposed with the hole in it. This was done in India and I live in UK. The implantologist says that there is absolutely no problem to leave the abutment open to oral cavity and suggested to fill the opening of the abutment with teflon tape to avoid food accumulation and when I revisit India he can cover this with a screw retained prosthesis.