Q&A: How much should implant crowns cost for my front teeth?
It sounds to me that you are getting shrinkage of the gums where the teeth were removed. That is normal. But, as the gums shrink, the replacement removable temporary teeth will no longer touch the gums. You should go back to the dentist to have a reline done so that the temporary partial denture touches the gums again.
Implant crowns can cost anywhere from $1500 tooth all the way up to $3000 per tooth depending on what type of restoration is done. Also, sometimes we don't put 4 implants in to replace 4 teeth. If you only have 2 or 3 implants to replace 4 teeth then the cost will be less.