Like human, a dog will have two sets of teeth in their lives. As we called it the "baby" tooth will be replaced permanently with adult tooth.
Taking care of your adult dog dental health is as important as human dental health.
Slightly into your dog adulthood, about 3-4 years, they may show signs of gum disease.
Worst of all, most of the time, the signs are unnoticeable! Your dog will not able to tell you that he in pain.
Hence, daily brushing of your dog teeth is recommended and take note, do not use human toothpaste!
There are toothpaste specially made for canine.
Lastly, do not belittle the dental health of your dog, it may cause much serious condition if not well taken care of.