A state appeals panel on Friday upheld an arbitrator’s ruling ordering an Evanston dentist to pay $410,119 to his former business partner for shares in their practice.The 1st District Appellate Court rejected Paul Fischl’s argument that the arbitrator erred in assessing a price for his former partner’s stock.The panel specifically found in its 11-page opinion that Fischl and his company — then known as Fischl & Weiss Dental Associates P.C. — were too late in objecting to the arbitrator …