I agree. proper dental care is VERY important for dogs not just as far as having clean teeth, healthy gums, and fresh breath but also to save the dog from literal organ failure that can result from bacteria in a dirty mouth. Many people don't know that so I thank you very much corky/max for posting this. Here are some ways to clean the teeth and some natural remedies that help;
Brush your dog's teeth with pet brush and pet toothpaste. No human paste. That means no Crest

These are not meant to swallow. An alternative method for a home prepared paste is a mixture or baking soda and water. Mix into a toothpaste texture. Warning: Most dogs don't like the taste. I know Lucky doesn't!

What worked best for me was a beef flavored paste. Lucky also hated mint, and I mean HATED!
Give the dog chew toys like raw meaty bones to knock off tartar buildup. Many raw feeders who feed whole bones have dogs with extremely white teeth and an overall healthy mouth because of the crunching action on the bone.
Diet is VERY important. A raw diet is great for healthy teeth and bones. Even a ground raw diet is better for the teeth. Many poor quality kibble diets and canned diets are bad for the teeth because of the ingredients. There is some truth to the fact that crunching on kibble may knock off some tartar but the ingredients in some poor quality kibble is far worse for the teeth and gums than any apparent benefit. A home cooked diet would be better too.
They sell solutions online and at the pet store where you can add some special liquid to your pets water bowel. Some pets are very aggressive or whatever when trying to actually manually brush their teeth so alternative methods are there.
There are also special mist sprays where you spray a solution into the dogs mouth and it loosens tartar buildup.
Spirulina (Arthrospira platenis) is a single celled micro-organism found in the sea and known to be an excellent source of chlorophyll. Widely used for its nutritive properties, Spirulina contains protein, vitamins (including B12 and folic acid) and carotenoids. Spirulina also makes vitamin A available for use in the body. Vitamin A is essential for healthy eyes, teeth and immune functioning. This sea algae has been used in traditional Chinese medicine for thousands of years as a tonic to boost energy, support liver and immune system functioning, and general systemic health. Human studies have shown Spirulina to promote oral health in particular (Mathew, B., Sankaranarayanan, R., Nair, P. P., Varghese, C., Somanathan, T., Amma, B. P., Amma, N. S., and Nair, M. K. “Evaluation of chemoprevention of oral cancer with Spirulina fusiformis.” Nutr Cancer 1995; 24(2):197-202.)
Horsetail (Equisetum arvense) helps to support healthy body tissue due to its high silica content. Silica is essential in the maintenance of healthy and strong teeth, skin, bones, claws and fur and is the main component in all connective body tissues including the myelin sheaths around nerve cells and the membranes of the brain and spinal cord. It also contains health promoting compounds called sterols (D'Agostino, M., Dini, A., Pizza, C., Senatore, F., and Aquino, R. “Sterols from Equisetum arvense.” Boll.Soc Ital.Biol Sper. 12-30-1984;60(12):2241-2245.)
Dandelion (Taraxacum officinale) is known to contain bitter principles which have a beneficial effect on saliva production in the mouth. (Kuusi T, Pyylaso H, and Autio K. “The bitterness properties of dandelion. II. Chemical investigations.” Lebensm-Wiss Technol 1985;18:347-349. ) It is also a source of vitamins and minerals, including Vitamin A, D, C, various B Vitamins, iron, lecithin, silicon, potassium, magnesium, zinc and manganese. These vitamins and minerals are all essential for the health of the digestive system, bones, teeth and gums.
Silica (6C) is a biochemic tissue salt which has a unique ability to cleanse the cells of toxins and purify the body. Silica is naturally occurring in the body, especially in hair, nails, skin, nerve sheaths and all mucous membranes, including the mouth and digestive tract. This biochemic tissue salt is also frequently prescribed for gum health. Silica acts as a natural cleanser and purifier and will also eliminate all foreign matter in the body. For this reason Silica should not be used for pets with any type of prosthesis, metal plates, pins or artificial tubes in the body.
Calc flor (6C) is a biochemic tissue salt which is important for healthy teeth, skin and bones. Calc. fluoride is also useful for teething pets. It is found in the enamel of teeth and bone surfaces and is excellent for maintaining the health and integrity of teeth.
Calc phos (6C) is a biochemic tissue salt useful for healthy teeth and gums and is particularly important in times of growth and development. This salt is found in the bones, connective tissue, teeth etc. and is necessary for supporting the strength/solidity of these tissues. Calc phos is excellent for supporting healthy circulation, bones and teeth.
Seaweed: has been shown in clinical trials to reduce plaque by up to 87 percent and tartar by up to 68 percent when added to wet or dry food daily.
Oregon grape, goldenseal and myrrh are antiseptic herbs that promote growth of new gum tissue. Echinacea may help with oral infections. Calendula aids in healing wounds and stopping your dog's gums from bleeding. Aloe vera soothes inflamed gums.
Vitamin C or ester-C have also been proven to assist in reduction of tartar buildup and cleaner teeth/gums.
Green Tea/Green Tea Extract: Proven to help clean teeth/gums and reduce plaque and tartar buildup. Same with...
Grapefruit Extract.
*Remember: If your dog already has gingivitis or periodontal disease, a veterinarian should remove the plaque and tartar buildup from your dog's teeth and gums before you begin a home care regimen.
*BTW, I have a whole list of other herbs and such but they are in a dog meg. at my house. I am currently on vacation so I will add those when I get back.