Treatment depends on the type and scope of the fracture. The determining factor is if the fracture has cut into the pulp canal, which is the chamber that houses the pulp tissue, blood vessels and nerves. If just the enamel is fractured, and the dentin is only exposed treatment is less extensive. In these cases, since the fracture does not reach into the pulp canal, smoothing rough enamel edges and applying a bonding agent to seal the tooth should be sufficient.
A fracture that cuts through the enamel and dentin, down to the pulp is an emergency situation. This is because the nerves are exposed, meaning your pet is in intense pain, and also at risk for a serious infection. Baby teeth (primary teeth) will usually be extracted. Permanent teeth will probably require a root canal. Just like humans, dogs can get metal crowns or caps following the root canal procedure.
A fractured tooth can lead to more serious problems if left untreated. Please consult your veterinarian if your dog has any injuries to the mouth to determine what actions should be taken.