Wooden full dentures were invented in Japan around the early 16th century. Softened bees wax was inserted into the patient's mouth to create an impression, which was then filled with harder bees wax. Wooden dentures were then meticulously carved based on that model. The earliest of these dentures were entirely wooden, but later versions used natural human teeth or sculpted pagodite, ivory, or animal horn for the teeth. These dentures were built with a broad base, exploiting the principles of adhesion to stay in place. This was an advanced technique for the era; it would not be replicated in the West until the late 18th century. Wooden dentures continued to be used in Japan until the Opening of Japan to the West in the 19th century.