Researchers have developed a non-lethal and cost-effective method to study the teeth of fish without harming them. Traditionally, studying dental structures in fish required euthanizing specimens or removing teeth, limiting the ability to track growth and changes over time.
Now, scientists at the Okinawa Institute of Science and Technology (OIST) have adapted human dental techniques using 3D-printed trays and dental putty to capture detailed impressions of fish teeth. The technique, which avoids invasive procedures, can be applied to both living animals and preserved specimens, opening up new possibilities for studying evolutionary and ecological traits in vertebrates.
The researcher developed this new method using Polypterus senegalus, an ancient fish species that has been evolutionarily isolated for approximately 360 million years. It retains primitive traits that provide insights into the early development of bony fish. The method can also be adapted for other species using similar impression materials.
How does the process start?
The process, takes up to 10 minutes, begins by sedating the fish. Researchers then carefully dry the teeth using air and apply a high-viscosity putty to clean the surface. This step is immediately followed by a more precise application of low-viscosity polyvinyl siloxane—an impression material widely used in dentistry—inside customized 3D-printed trays to capture detailed impressions.
Fish’s jaws small size
One of the key challenges researchers faced was working with the fish’s jaws and its small size. With jaws roughly the size of a human finger and individual teeth measuring less than a millimeter, precision was critical. Additional hurdles included cutting the impressions for scanning and the inability to observe internal tooth structures. However, the researchers managed to test their non-lethal dental impression method on 12 individual Polypterus senegalus specimens, conducting 38 impression attempts without causing any fatalities or injuries.
The impressions revealed detailed microwear patterns—minute surface markings caused by use over time—providing valuable information on tooth function and diet.
