Another possibility is the trauma inflamed the pulp cavity inside the tooth.
From the toledoblade.com
This is because prolonged exposure of the dental pulp cavity of heavily worn or damaged teeth to oral bacteria was much greater than in other animals that quickly replaced their teeth.
From the sciencedaily.com
Peter Kertesz, a London-based dentist who treats a variety of exotic animals, as well as people, last week drilled out a pulp cavity which formed after a tooth snapped.