Dena's practice has broad scope, encompassing corporate and commercial litigation, shareholder disputes and oppression claims, contract issues, professional negligence cases, class action defences, employment/wrongful dismissal matters and administrative and insurance law. She has often appeared in the Ontario Superior Court of Justice and the Ontario Court of Appeal, as well as before administrative tribunals and in private arbitrations. She clerked for the judges of the Court of Appeal before joining Lenczner Slaght. Dena has also taught in continuing legal education programs presented by the Law Society of Ontario. She has mentored law students at the University of Toronto and taught legal ethics at the school's bridge week. In addition, she has led courses in medical ethics for the university's Faculty of Medicine and is a co-chair at the University of Toronto Academic Tribunal.