You ask two questions, and there are two different answers. First, is metal used to hold an implant in rhinoplasty? The answer is YES, tiny metal screws of vitallium, titanium, and other very high grade proprietary alloys are occasionally (if not rarely) incorporated to stabilize implants to bone, but in general, metal is NOT used to stabilize implants because implants are most often stabilized to cartilage instead of bone. Sutures rather than screws secure implants to cartilage. Second, what you feel that is "hard and flat" on the front of your nasal bridge is most likely the graft itself. Grafts may feel firm, even if silicone or cartilage. Porous polyethylene is more firm, polytetrafluoroethylene may feel firm, bone feels firm if stable, and other graft or fixation material may produce a feeling of hardness beneath skin under which it is implanted. This is a question for your surgeon. No RealSelf responder (other than your surgeon) can tell you with absolute certainty what was put into that area of your nose during surgery and what you are feeling that is hard and flat.