Pus is produced by action of bacteria signifying active infection. You will first have to start with antibiotics. A dentist
with the help of an Xray can find the root involved, assessing the extent of damage, it might netd a root canal
or apicectomy. If the bridge is already in place, a root canal can be attempted by making an opening through the crown of involved teeth. This can help you save the bridge. However if the infection is involving multiple roots the bridge might have to be removed and root canals done or repeated if done earlier. No reason to worry about cancer.