The unknown ray discovered by Roentgen in 1895, which he called X-ray, played an essential role in medicine as well as in dentistry. In medicine, it assisted in the study of the human body, especially in orthopedics. While in dentistry, this ray simplified the diagnosis process either by revealing the simple caries or by solving the more complicated problems in periodontics, orthodontics, endodontics, and maxillofacial surgery. And after Walkhoff recorded his first dental radiograph in early 1896, dentists from different countries competed to record their dental images with various techniques. Throughout the history of dental radiology, many people have played an important role in the development of this radiation, either by putting different principles for different imaging modalities, or even by presenting precautions and directions that helped others use this discovery correctly. The aim of this article, besides reviewing the history of dental radiology in detail, is to honor and pay respect to all those departed souls who sacrificed their health and lives for x-rays.