No, dogs cannot regrow teeth that are lost or broken if they belong to their second set of teeth, called adult teeth. A dog can only regrow his lost or broken teeth if it is his baby teeth.
How Many Teeth Do Dogs Lose?
It is a universal fact that puppies are born toothless. They grow 28 temporary teeth (also known as baby teeth, deciduous teeth, and milk teeth) that will appear when they are around three and four weeks old. They usually fall out when puppies turn around, 14 to 30 weeks, and the second set of 42 adult teeth will take their place.
Your pup’s 28 baby teeth should start showing by the time he is six weeks old, and puppies during this stage are able to start having wet or semi-moist puppy food.
You will notice that from the age of 12 weeks, your puppy’s front or last teeth will fall out. During this stage, a puppy will progressively lose his baby teeth and begin to grow the second and final set of adult permanent teeth.
Since it is a painful process for your puppies to lose their k9 teeth, always ensure that you provide your pup with safe and soft chew toys. You must also follow up with your veterinarian on a regular basis to ensure everything is fine.
Adult dogs, on average, should have 42 teeth, which is approximately ten more teeth than humans. 
Did you Know?
When a puppy turns 6 months, he will lose his baby teeth and grow permanent teeth.
Signs of Dog Dental Problems
- Decreased appetite
- Redness, swelling, and bleeding in gums
- Heavy drooling
- Bloody saliva
- Heavy tartar deposit
- Broken teeth
- Bad breath
If you follow up with your dog’s oral care routine, you will probably observe any symptoms that something is not quite right with your furry friend’s bright teeth. When looking at your pet’s dental health, a broken tooth is often visible. However, if you skip several days without checking inside your pet’s mouth, then you may never find out what is wrong with them.
There are many other additional indicators that suggest dental issues, with a foul smell from their mouth at the top of the list. It is a signal that you can easily observe without having a look inside your pet’s mouth, as it is a clear indicator of dental problems. 
Blood in their saliva or hints that your pet is in discomfort is often the first thing you will notice. When eating, your dog may touch his mouth with a paw, be hesitant to chew or put toys in his mouth, or seem to be in discomfort. They might even appear to have a decreased appetite, suddenly start making a mess during their meals, or have heavy drooling issues. Swelling in their face might also be an indication of a dental issue.
If you notice the above symptoms during a closer examination of your pet’s mouth, it may also show if he has a missing, broken, or loose tooth. But, if you still do not find any issues, it is better to schedule an appointment with your veterinarian. It is equally important to clean the plaque and tartar deposit on your dog’s teeth and gum line as discussed in this post.
Did you Know?
Dogs never get cavities as we humans do.
So, do dogs’ teeth grow back when they fall out? Sharks, for instance, can grow new teeth that are missing and replace them fast, giving them a new set of dazzling whites. Dogs, on the other hand, are not that lucky.
Although it is natural for our pets to lose deciduous teeth when they grow, permanent teeth that are lost or broken can never be regrown. If they accidentally lose their permanent tooth, they will lose it for the rest of their lives, just like humans. That is why it is essential to look after your dog’s teeth.