Serendipity or Luck: Stumbling on Gingival Crevicular Fluid

The word "serendipity" comes from the tale "The Three Princes from Serendip" by Horace Walpole. It is defined as "an aptitude for making fortunate discoveries accidentally". The demonstration of crevicular fluid was truly an accidental discovery. Niels Brill, a successful private practitioner in Copenhagen with prosthodontics as a specialty, and Bo Krasse, associate professor of cariology, were examining the microflora of gingival pockets in a dog. Before the samples were taken, gingiva and teeth were disinfected with an iodine solution. The solution disappeared from different pockets at different speeds. After intravenous injection of a fluorescein solution, the occurrence of fluorescein could be recorded on filter paper strips. Thus, after stumbling on the disappearance of iodine from the cervical areas of the teeth, two nonperiodontologists managed to demonstrate why it disappeared. This article describes the details of the discovery and subsequent studies, and offers some reflections by one of the original authors 37 years later.