If you are looking for a federal health plan with good dental coverage, one of the best places to go for advice is to your dentist.

He or she probably doesn't have time to analyze 25 health plans in detail, however, so the Washington Consumer Checkbook has rated "best buys" for workers and retirees, who can consult with dentists on their top choices.

The publication has based its survey on how much participants can afford to pay, the kind of coverage they want and their particular medical problems.

Between now and Dec. 6, government workers and retirees will shop for the health plan they want to cover them for 1986. If they don't make a selection, they will remain in their current health plans.

Most people here are eligible for between 20 and 25 plans. On Monday, we listed Checkbook's "best buys" for overall coverage for the average family of four.

Today, let's take a look at dental coverage. Bear in mind that many plans offering otherwise excellent coverage pay a very limited dental benefit. None, according to the Checkbook rating, offers full coverage for a catastrophic dental benefit.

But the publication says that a number of the plans provide excellent overall dental coverage. It gives high ratings to plans offered by local health maintenance organizations, including the George Washington University plan, HealthPlus high option, CapitalCare and Network.

Checkbook also recommends that persons looking for good dental coverage consider the Aetna high option plan, Government Employees Benefit Association high option, the Mail Handlers high option, National Association of Government Employees high option and the National Association of Postmasters.

Also, American Federation of Government Employees standard option, National Alliance of Postal and Federal Employees high option, Federal Managers Association plan, MD/IPA plan, the National Treasury Employees Union standard option and the Postmasters and Rural Letter Carriers plans.

The Checkbook guide, available by calling 347-9612, suggests that if you are interested in dental coverage you should get several brochures from plans you are considering, then ask your dentist to check them out.

The next health plan update will be published here Sunday, when we will rate the "best buys" for people anticipating heavy medical bills; Tuesday we will list "best buys" for retirees.