*3.1. Characteristics of Subjects Who Participated in this Study*

All four subjects who participated in this study were women, 100 years old, and wore complete dentures. One subject had five residual roots (sample ID 1), with complete dentures designed over the stump root. Blood tests and medical examinations were conducted to confirm the health of the subjects. Blood tests showed values in the normal range. Two subjects had hypertension. According to this continuous study, one subject had high blood pressure at age 85 (sample ID 1) and one had normal blood pressure at age 90 (sample ID 2). Other than that, there were no specific symptoms on examination.
