A federal appeals court has set aside a $625,000 award to Bethesda dentist and inventor Robert I. Schattner, ruling that a jury erred in 1984 in finding that three chemical firms infringed Schattner's patent on a potentially lucrative germicide he had invented.

The Court of Appeals for the Federal Circuit held last Friday that one of the firms, which Schattner contended sold the germicide without his consent, in fact was authorized to do so.

The ruling comes after three years of tangled litigation in which Schattner originally was awarded $10.2 million in damages against Chemed Corp., of Cincinnati, and two of its former subsidiaries. A federal judge in Baltimore set aside $10 million in punitive damages against the companies last August, but ordered actual damages for alleged patent infingement trebled to $546,000. That award, now totaling $625,000 with accrued interest, was set aside yesterday by the appellate court.

Schattner is a 61-year-old dentist-turned-inventor who developed the mouth spray Chloroseptic. The germicide at issue in the lawsuit against Chemed is Sporicidin, a solution for sterilizing medical and dental instruments.

Schattner's attorney, Michael Hays, said he felt the Court of Appeals made "fundamental errors" and he will ask for a rehearing.