Just Ask the Expert: Is dental varnish for osteoclastic lesions OK?

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Q: Would you recommend the use of dental varnish as a palliative treatment for osteoclastic lesions? I have used it on occasion for extremely frail elderly cats that I dared not anesthetize. I dried the tooth with forced air and then applied a drop and held the lip off for 60 seconds. Those patients showed improved eating, and it seemed to last for three to six months.

A: At one time fluoride dental varnish was used on small cavities in humans and was the treatment of choice in early stages of tooth resorption in cats. The use appeared to make sense in that the fluoride decreased dental sensitivity and the varnish allegedly stayed on the affected teeth for an extended period of time. That was before we realized that tooth resorption was different than caries (cavities) in humans, which start on the outside of the tooth and progress inward.

Unfortunately tooth resorption starts on the inside of the tooth below the gum line (usually at the cementoenamel junction) and then burrows out the crown. Placing varnish on the outside surface may temporarily-for days or weeks-shield the exposed dental tubules from the oral cavity but does nothing to decrease the progression of the tooth resorption. As soon as it wears off, the cat is in pain again. It is no longer considered the standard of care.

Fortunately, with newer anesthetic medications, protocols and monitoring, most older dogs and cats can be safely anesthetized for oral examination, including intraoral imaging, to properly care for tooth resorption through crown reduction and gingival closure to shield the resorbing tooth from the oral cavity or complete extraction.

Jan Bellows DVM, DAVDC, DABVP

All Pets Dental

Weston, Fla.