We will never get tired promoting all things dental. Having paid thousands of dollars to vets, having tried various "dental" treats and supplements, we came up with what works for us and are happy to share this experience.
There are a few components to better dental health: food with less carbs, regular brushing, harder chews and professional teeth cleaning. Raw food, daily brushing, daily antler or hoofer and annual check-ups work for us. To our knowledge, there is no "magic" ingredient or product that can make all that tartar and gingivitis go away.
There are two options to clean teeth professionally. Vets do a good job. They put the dog under general anesthesia, make an X-ray scan to identify the condition of the teeth under the gum line. General anesthesia means that you will have to pay for the blood panel work. And most importantly it means that there is always a risk that the dog may not wake up. The chance is slim but they always give you the form to sign.
Anesthesia-free cleaning happens with no anesthesia and no sedation. There is absolutely no medicine involved. Therefore no waiver form, no medical risk. Sometimes a towel is used with smaller dogs to keep them contained. Believe it or not, most dogs are fine with the procedure. The procedure is not painful. In fact anyone is invited to come and watch. You may even learn some dog whispering.
And lastly, as we have witnessed many times, if during the initial check that precedes the cleaning the technicians see any concerns they will be communicated to you in a truthful way. We have seen a few dogs that needed the vet's help. The owners were advised accordingly and were not charged a penny. It is a pleasure to partner with a clinic that has such a high level of ethics.