26 Mar History of Dental Technology – part 1 – X-rays and Imaging
A dental history in 8 technologies – part 1
Dentistry has changed in the 150-years or so since it became a widely understood, regulated medical profession. But some of the technologies we use today would be unrecognisable to 19th-century dentists. During that time, procedures, materials technologies, microbiology and electronics have all interacted to create increasingly cleaver instruments, tools, gadgets and procedures for dentists.
Following our well-received article on ‘Coal Fired Dentistry‘, we thought we’d take a quick look at some of the key the technologies we take for granted every day.
X-Rays and imaging
X-ray images were first created in 1895 by Wilhelm Roentgen, but perhaps the most famous of the early pioneering of researchers in radioactivity was Marie Curie. The work she carried out goes far beyond her Nobel prizes in Physics (1903, aged 36) and Chemistry (1911, aged 44). She was also directly involved in the development and operation of mobile radiography units to support field hospitals during World War One. The direct descendent of those units are now used in almost every dental practice across the world.
The technology uses X-Ray radiation. These have the ability to pass through human tissues but are increasingly absorbed by denser structures, such as bones and teeth. X-Rays share many properties with visible light, including their influence on photographic film. By passing X-Rays through the body towards a photographic film you can create an image. These images are usually used in their negative form, meaning that areas where few X-Rays meet the show-up white, while areas where many X-Rays reach the film show as darker areas. The practical upshot is that medical professionals can interpret a black and white image of bones, teeth and other dense structures inside the body.
Dr Otto Walkhoff, a German scientist, is credited with creating the first dental radiograph in 1896. It required a 25 minute exposure time, but thankfully, he used himself as the subject. C. Edmond Kells, a dentist from New Orleans, created some of the first practical applications. He also did a fair bit towards the understanding of the damage done by X-rays to human tissue, losing an arm and eventually dying from the effects of radiation.
The first paper published on the risks of radiation was written by William Herbert Rollins. He was a dentist and a physician and suffered radiation burns during the development of his pioneering dental X-ray unit. He was an early advocate using lead shielding to protect against X-rays. He also conducted many experiments to demonstrate the damage X-rays could inflict on tissues and organisms.
Over the course of time, X-Ray machines developed in sophistication and became smaller and more practical to use. Eventually, they also became safer! This meant that it was possible to create films that were small enough to fit inside the mouth, and the familiar dental X-Ray was born. However, it was not until the 1950s that radiographs became a regular tool used by dentists.
Today, standard X-Ray machines have been supplemented by OPG systems (a type of ‘focal plane tomography’ more correctly called a panoramic radiograph). The first experiments to create an image of the whole dentition used an intra-oral radiation source in the very early 20th Century. Safer and more effective technology emerged in the 1920s, but a practical commercial system was not marketed until the 1960s.
Digital detectors are replacing films to provide images instantly with no additional film processing. They are also being supplemented with digital light scanners that create 3-D images of tooth and gum surfaces. These innovations have led improved and quicker diagnosis, and to digitised appliance manufacturing (see further articles in this series).
Using imaging technologies with Pearl
Pearl Dental Software is designed to make integration of digital imaging systems a simple task. We can securely link files from dozens of imaging systems to patient records making it simple to recall previous images for comparisons.