Dogs cannot grow new teeth after the original ones have been broken or removed. Dogs do have deciduous teeth, commonly known as baby or puppy teeth, that fall out and are replaced by adult teeth.
Adult dogs commonly lose their teeth due to fractures or other damage that requires the tooth to be removed. Severe periodontal disease also sometimes causes dogs to lose teeth. Once the teeth are gone, they do not grow back, so veterinarians recommend that owners take preventative measures such as brushing their dogs' teeth.
Some police dogs and other working dogs are fitted with dental implants after damaging their natural teeth. These implants are often made of titanium and allow the dogs to continue working.