Wooden Plate Denture Reproduced Using Materials and Methods From 400 Years Ago

This study aimed to reproduce a complete wooden plate denture, which was the first in the world to retain suction under negative pressure, using the same materials and methods from 400 years ago (i.e., the Edo period) to verify its masticatory performance. A complete wooden plate denture was fabricated based on the maxilla of a 90-year-old female. An impression of the maxilla was made using beeswax, which was pressed onto the negative impression to create a working model. Red food coloring was applied to the working model and pressed onto a wooden denture base made of boxwood, and the marked areas were then carved with chisels and carving knives. Food coloring was applied to the alveolar ridges of the subject and the fit was adjusted. Ivory was used to create artificial teeth, which were carved in a dovetail form and embedded in Japanese raw lacquer. Masticatory performance was assessed using the gummy-jelly test and occlusal force measurement, and the results of current and wooden dentures were compared. The masticatory ability of the wooden denture (185 mg/dL) was lower than that of the current denture (209 mg/dl). In contrast, the mean occlusal force was slightly higher with the wooden denture (31.8 MPa) than with the current denture (31.4 MPa). This study suggests that wooden plate dentures were likely functional during the period when they were used. Japanese wooden dentures hold significant importance in the evolution of denture technology.