had 3 dental implants W/ bridge . 2 weeks after bridge, entire bridge came off. It was recemented but there was now a space between natural teeth and bridge. Then bridge became loose again after 2 weeks, dentist stated it was screws. he tightened them . Now not only space but bridge shifted forward. 2 days after tightening - the bridge is loose again. Am concerned about the way this bridge looks & why this keeps happening. I have lower implants next but hesitant to proceed.