The best thing you can do to look after your dog's teeth is regular (daily) brushing. If started as a puppy this needn’t be a chore but should be an enjoyable time where you & your puppy interact. You need to take things very slowly to start with and give lots of praise so that you and your dog will start looking forward to your brushing sessions.
First, have your dog get used to you putting things in his mouth. Dip your finger in meat stock. Call your dog with a voice that means "treat" and let your dog lick the liquid off your finger. Then rub your soaked finger gently over your dog's gums and teeth. After a few sessions, your dog should actually look forward to this and you can move on.
Now, place a gauze around your finger. (You can again dip it in the meat stock.) Gently rub the teeth in a circular motion with your gauzed finger. Repeat this for the number of sessions it takes your dog to feel comfortable with this procedure. Remember to praise him as you go.
After your dog is used to having the flavored gauze in his mouth, you are ready to start with a finger brush or toothbrush. You need to get your dog used to the consistency of these items, especially the bristles on a brush. So, let your dog lick something tasty off of the brush so he gets used to the texture.
Once your dog is used to the cleaning item you are going to use, You can add the toothpaste. Pet toothpastes either have a poultry, malt, or other flavor so your dog will like the taste. Get your dog used to the flavor and consistency of the toothpaste. Let your dog lick some off your finger and then apply some to your pet's gum line with your finger. Praise your pet.
Now your dog is used to the toothbrush and toothpaste and you are ready to start brushing. Talk to your dog in a happy voice during the process and praise your dog at the end. At first, you may just want to brush one or both upper canine teeth (the large ones in the front of the mouth). These are the easiest teeth for you to get at and will give you some easier practice. As before, when your dog accepts having several teeth brushed, slowly increase the number of teeth you are brushing. Again, by making it appear to be a game, you both will have fun doing it.
It may take up to a month or more before you are able to brush your dogs teeth properly but do persevere- it will be worth it when your dog has lovely teeth & fresh breath.
Regular chewing is also important to maintain healthy teeth & gums. We do not recommend feeding bones of any sort but there are a large range of raw hide chews & pigs ear products which are excellent at helping to improve oral hygiene.