Because of the risk of organs getting infected if the bacteria builds up too much, cleanings are necessary for some dogs. If the teeth are full of tartar, they need to be cleaned. If they are white and the teeth look good, there is no reason to do it. It doesn't need to be done every year for all dogs. It depends on the dog and how clean you can keep the teeth at home. When your dog is under anesthesia I'd talk to your vet about applying OraVet. There are no known side effects and it is a plaque barrier.
Just make sure that they use the correct anesthesia (Isoflurane or Sevoflurane), do surgery on a heated surface, offer pre-op blood work and place an IV before surgery.
If you trust your vet I'd go with their recommendations.
Ellie's vet office says dogs should have dentals twice a year.
Ellie clearly didn't need one at the six month mark and her vet said so.
They will tell you when it is necessary...
