Three mechanisms, and good chews often use more than one. Mechanical action is the dog's own bite force wiping film off the crown of a tooth. Abrasive action comes from added grit, like baking soda or a mild calcium compound, that scours the surface while the chew is being chewed. Enzymatic action is chemistry rather than friction: enzymes and antimicrobial ingredients that act on the biofilm and the mouth's bacterial population. Mechanical does the heavy lifting, abrasion sharpens it, and enzymes reach places teeth never touch.
Mechanical: force and geometry
This is the oldest mechanism and still the most reliable. A dog holds a chew between opposing teeth, applies pressure, and drags the surface across enamel. Soft plaque gives way under that shearing.
Duration decides how much gets done. Fifteen seconds of chewing is a gesture; two or three minutes of real work is a session. If a chew disappears immediately, the mechanism never engaged.
Abrasive: the grit in the formula
Abrasives are the same principle as the mild polish in human toothpaste. Baking soda, calcium carbonate, and silica-type ingredients add microscopic hardness so the chew scours rather than merely wipes.
Balance is the whole game. Too little and the abrasive is decorative; too much and you risk wearing enamel over years. Reputable formulas stay conservative on purpose, which is why an ingredient panel listing baking soda well down the list is not a weakness.
Enzymatic: chemistry instead of friction
Enzyme systems on pet dental products typically involve glucose oxidase and lactoperoxidase, which generate antimicrobial byproducts in saliva. Other formulas use plant-derived antimicrobials or antioxidants rather than enzymes proper.
The appeal is coverage. Saliva goes everywhere in the mouth, including the inner surfaces and the back of the last molar, where no chew ever presses. The tradeoff is that chemistry works on the film and the environment rather than physically removing established deposits.
The three side by side
What "enzymatic" means on a label
It is a broad word and it is used loosely. Some products contain named enzyme systems; others use the term to describe any ingredient that acts biochemically. Read the panel rather than the front of the bag.
Ingredient order tells you more than adjectives do. A named enzyme sitting near the end of a long list is present in a small amount, and that is worth knowing before you pay a premium.
Where astaxanthin fits
Astaxanthin is a carotenoid, the reddish pigment family that gives salmon and krill their colour, and it behaves as an antioxidant. Ark Naturals uses it in the Asta-Shield coating on Protection+, making that chew a source of the ingredient alongside its mechanical and abrasive work.
The same coating appears on Soft Shield, built for dogs who cannot manage a firm chew. Framing matters here: these are sources of an ingredient and of daily mechanical cleaning, not treatments for anything.
Stacking all three
The practical version of a good chew is unglamorous. Firm ridged structure for the mechanical part, a modest abrasive in the formula, a coating or center that carries the chemistry, and a size that keeps the dog working for a few minutes.
Brushless Toothpaste is the plainest example of that stack in the range. Everything else in the lineup is listed under dog products.
What none of the three can do
Once plaque mineralizes into tartar, no mechanism in a treat bag removes it. Scaling under anesthesia does that, and it is a veterinary procedure with imaging behind it.
Periodontal disease develops below the gumline, out of reach of everything discussed here. Daily care buys time and keeps soft film from sitting undisturbed; it does not substitute for an exam.
The VOHC seal and what it signals
The Veterinary Oral Health Council reviews submitted data and publishes what it accepts at its registry of accepted products. A seal tells you a manufacturer submitted evidence for a specific claim on a specific product.
No seal tells you what your particular dog's mouth is doing. Both the AVMA and AAHA publish owner guidance on where home care ends and professional care begins.
Mouths that need eyes on them
Receding gums, a tooth that looks longer than its neighbours, blood on a chew, or a sudden change in what your dog will eat all sit outside the range of anything a chew addresses. None of this replaces a hands-on look from your own veterinarian, who can see what an owner peering into a wriggling mouth cannot.
FAQ
Which mechanism matters most?
Mechanical, by a wide margin. Consistent daily chewing on a correctly sized product does more than any additive in the formula.
Do enzymatic dental products actually do anything?
They act on the mouth's bacterial environment rather than scraping teeth, so the effect is subtler and harder to see. As a companion to daily mechanical cleaning, they cover surfaces a chew cannot.
Can abrasive chews wear down my dog's teeth?
Dental-chew abrasives are mild by design. Real enamel wear in dogs usually traces back to hard non-food objects like antlers, bones, and tennis balls.
Is a water additive enough on its own?
On its own, no. Additives work chemically and leave the mechanical job undone, which is why most owners pair them with a daily chew or a brush.