In 2004 and 2005 the journals Science and The Lancet published articles based on, looking back, falsified or fictitious data. In an editorial in The Journal of the American Dental Association, the consequences of scientific fraud are described. Scientific publications in a journal are assigned some authority and fellow-researchers will quote the articles. Reviewers and editors are incapable to examine articles for fraud, since they have no access to the original research data. Consequently, a chance of publishing fraudulent articles can not be precluded. If fraude comes to light, it is not only harmfull for the reliability of science, but also patients can be mislead while hoping for recovery of an illness. Several measures are suggested to prevent scientific fraud as much as possible, for instance by examining the original research data by independent researchers. Editorial boards could impose sanctions on fraudulent authors.