Dental insurance premiums can be more expensive than simply paying out of your own pocket for routine checkups and cleanings. So if you’re one of the millions of Americans with no dental coverage, is a policy for your pearly whites worth the cost? The answer may depend on whether you expect to face aching bills for your teeth.

Most dental insurance policies emphasize prevention and diagnostics, typically covering two annual exams and cleanings, plus X-rays and, for children and older adults, fluoride treatments, says Evelyn Ireland, executive director of the National Association of Dental Plans, or NADP.

But the real benefit is being covered for bigger-ticket procedures, such as fillings, root canals and crowns, says Carrie McLean, a consumer specialist with eHealthInsurance.com.

“It’s like health insurance — you’re really buying peace of mind,” McLean says.

Fewer than 6 out of every 10 Americans had dental benefits in 2010, according to a report released in late 2011 by the NADP and Delta Dental Plans Association.

Dental policies vary widely, and choosing the right one can be tougher than remembering to brush twice a day.

What’s covered, what’s not

People with dental insurance commonly have what’s described as “100-80-50” coverage, meaning it pays 100 percent of the cost of routine preventive and diagnostic care, such as checkups and cleanings; covers 80 percent for fillings, root canals and other basic procedures; and 50 percent for crowns, bridges and major procedures, Ireland says.

The vast majority of coverage is provided through employee and group policies, plans that charged annual premiums of between $234 and $432 per person in 2011, according to NADP estimates.

The cost for you to buy an individual policy averages about $360 a year, McLean says.

Meanwhile, paying out of your own pocket for two exams and cleanings and a set of X-rays in 2011 would have cost about $370, on average, according to the American Dental Association.