That's a teething ring, used to squeeze the gap between teeth. Generally, it is only placed in the front and back of the first molar, so that the band ring for fixing the appliance (that is, the stainless steel ring on the first big tooth) can be installed at the next visit. If you don't squeeze your teeth out of the gap, you won't be able to put that stainless steel ring on your big teeth at your next visit. After consultation, this thing will have the feeling of blocking teeth. You will feel uncomfortable or slightly painful at first, and it will be fine in 2-3 days. Gum bleeding is caused by the pressure of the tooth separation ring on the gums. Just wear an appliance. This thing is usually removed in a week or so. Never mind, don't worry. In the past, the spring tooth separation was made of steel wire, but now it has made great progress.