Hi, as per the history you have given , which includes trauma to the tooth and discoloration with pus discharge,it is quite clear that the tooth is dead. The only way you. An sabe this tooth is by getting a root canal treatment done. This is a good option only when the remaining tooth structure is good enough to hold any filling on the top post root canal treatment. During the root canal you might have to wait for 7 to 15 days between 2 visits, where doctor might place some medicines in the tooth to treat that infection.once the pus discharge has stopped and infection is completely gone only then root can treatment can be completed.
Next Steps
visit a dentist. get a X Ray done. Check how big the infection is. And can the remaining tooth structure can support a filling on top or not
Health Tips
Always check with your doctor for prognosis(success of the treatment) before going for any treatment . Even after spending money for root canal , filling and crown, if that tooth is not going to survive for more then 6 months, a good option would be to remove that tooth and get an artificial tooth in place with dental implants or a ceramic bridge