Dental cleaning without anesthesia means scraping the surface of the tooth with a hand held instrument. Ultrasonic scaling and mechanical polishing are not possible. There are some dogs that will likely allow for a partial dental prophy, but there are quite a few things to consider:
The incomplete or partial nature of the cleaning
The stress, pain or fear that the dog may feel
Potential injury to the dog if he jerks or moves
Damage to the enamel of the tooth
Possible aspiration pnuemonia
General anesthesia always carries a risk, but that risk can be minimized with certain precautions. Pre-anesthetic bloodwork, IV access, and an experienced staff all help to make for a safe procedure. Having an endotracheal tube in place prevents water/detritus/vomitus from entering the lungs. Polishing after the cleaning smooths the surface of the enamel and slows tarter build-up.
The need for dental prophy varies according to breed predilection and individual need. Some dogs may never require a dental cleaning, some may need it 1–2 times per year (most greyhounds, for example). Preventative measures like brushing, dry kibble, and hard chew toys can help to increase the interval between cleanings.
Not cleaning teeth that are badly decayed carries it’s own risk – bacteria enters the bloodstream through inflamed gum tissue and can seed the organs (primarily the kidneys and heart), leading to serious complications. It also causes pain, tooth loss, and bad breath.