My opinion on this comes somewhat from personal experience.Now I know very little about the whole dental implant procedure,but having had complications from a recent dental procedure,I can say categorically,that the last thing I wold have wanted to do days after having had an invasive dental procedure,is have to haul myself to an airport get on a plane and fly.As far as I am aware even without complications,the implant procedure can be very painful without the flight on top of that
Add to this,if for some reason any revisions of the implant can’t be done in the U.K,then that means another flight while feeling like your jaw is going to fall off and/or on fire/being stabbed etc.I wouldn’t say going abroad for surgery is good or bad,but I would say seriously consider,whether potential extra money and severe pain in the long run,is worth saving money in the short term