SANTA MONICA, Calif. (AP) _ Dental hygienists bit back at the California Dental Association on Wednesday, filing a suit alleging dentists violated antitrust law by fighting hygienists' attempts to clean teeth without supervision.

The suit by the California Dental Hygienists' Association also alleged the dentists filed frivolous suits, libeled the hygienists and caused emotional distress to the CDHA's past president. It seeks at least $900,000 damages.

The suit is the latest shot in a war between dentists and the hygienists, who are licensed to examine and clean teeth, apply cavity-preventing tooth sealants and take X-rays, but not to make diagnoses, fill cavities or perform surgical procedures.

Dentists have fought proposed legislation that would allow hygienists to open offices and practice without dentists' supervision. Hygienists contend they can provide more affordable and accessible dental care.

The new court action is a countersuit to a lawsuit filed in state court in December in which the dental group accused the hygienists of price-fixing.

Dexter Varnum, spokesman for the dental group, said that he hadn't seen the countersuit but that dentists oppose allowing hygienists to establish their own practices.

''These people (elderly, ill and poor patients) can be on medications, have heart problems and are more disposed to oral lesions and cancers, and the hygienist is not trained to diagnose these problems,'' Varnum said.

''Hygienists can practice their profession with only two years post-high school education, where the dentists have eight years.''