P was born in Ecuador in 1961. She entered the dental school of the University of Guayaquil in 1980. She attended a five-year, full-time program in dentistry, studying anatomy, chemistry, physiology, and the other courses required for a degree in general dentistry, which she obtained. She then worked for the Ecuadorian government for a year and then received her certificate from the Colegio de Odontologos del Guyas, which she testified at her deposition is the equivalent of the American Dental Association. This certificate, she testified, constitutes a license to practice dentistry in Ecuador. After receiving her certificate, P opened a general dentistry practice in Guayaquil. P came to the United States. She attended courses for the nationally standardized Test of English as a Foreign Language ('TOEFL'). In 1987, P received her green card as a resident alien. She began to work as a dental assistant. P attempted to enroll at the New York University School of Dentistry but was not permitted to do so. In order to enroll in the course of dentistry she wished to take, she was required to pass the first part of the National Board Examination in Dentistry. In 1991, plaintiff failed the National Board Examination in Dentistry. In 1993, P set up an illegal dentistry practice. In 1995, P was charged with practicing dentistry without a license and entered a plea of guilty in state court. She was sentenced to three years' probation. On April 8, 1994, while engaged in the practice of dentistry without a license, P used D's product, a syringe containing phosphoric acid that is used to prepare teeth for drilling and cavity repair. The product is dispensed only to licensed dentists, for use by licensed dentists or under the supervision of a person so licensed. It is to be used with protective eyewear and clothing. P alleges that the product exploded in her hands, causing her severe injury. P sued D alleging various product liability, defect, and failure to warn theories. D moved for summary judgment.