Federal workers looking for a health plan that provides fully paid, cradle-to-grave dental care benefits are generally out of luck. Most plans provide only partial coverage, and some require you to belong for a year or more before any benefits are paid.

The Washington Consumers Checkbook magazine warns that because most plans have allowance schedules of what they will pay, policyholders often don't know how much they must pay until they get their final bill. At best a plan will pay some dental expenses, according to Checkbook, and none of them offers a catastrophic dental benefit.

Plans offering the best dental benefits, the magazine says, are Aetna (both high and standard option), American Federation of Government Employees standard option; BACE, Blue Cross-Blue Shield standard family plan; Mail Handlers High option; NAPUS; National Treasury Employees Union; Postal Supervisors; Postmaster high option and Rural Carriers. HMOs (health maintenance organizations) that pay about half the dental benefit include CIGNA, MD-IPA, Kaiser, CareFirst and Physicians Care.

Checkbook's Insurance Guide is available at newstands for $5.95, or by ordering it from 806 15th St. NW, Suite 925, Washington, D.C., 20005. Health Plan Problems

One area that insurance hunters should consider is how much red tape they will have to go through with an insurance plan, whether it pays benefits promptly and in the case of HMOs how tough it is to get -- and keep -- a doctor who is happy to take you over a non-HMO patient who may be charged more.

This column has received complaints from people who switched from fee-for-service plans to HMOs who are unhappy with their choice. I can sympathize because I am one of those unhappy people.

HMO complaints tend to center around the turnover of physicians in the plan, or (and again I can sympathize) a lack of enthusiasm from specialists who get HMO patients as referrals.

One section of a new publication called Selecting the Right Health Plan covers customer satisfaction -- as measured in the number of complaints -- with health plans. The publication is available from GRB Inc., 5400 Eisenhower Ave., Alexandria, Va., 22304 for $7.70.

The GRB guide says it is hard to track complaints against HMOs because most are handled internally. For the fee-for-service plans, however, it has a measure in the number of complaints filed by policyholders with the Office of Personnel Management.

The GRB guidebook says that many of the plans with the lowest complaint rates are those limited to special groups of workers. Those plans include the Panama Canal health plan, GEBA, SAMBA and the Foreign Service health plan, which have very low levels of disputed claims.

Among the plans open to all workers and retirees, the fewest complaints in the last two years were racked up by the National Association of Letter Carriers plan, Aetna, American Postal Workers Union, American Federation of Government Employees and GEHA. The highest level of complaints among similar plans were recorded against the Mail Handlers, Postal Supervisors, Postmasters and Alliance health plans, according to GRB.