Helfman and Bada, along with subsequent researchers, found a high correlation between chronological age and the racemization ratio of aspartic acid in the dentin of teeth. The most serious drawback of the racemization method of age estimation is that several control teeth (natural teeth) of the same kind as the specimen to be estimated are required. Instead of using the control teeth, the current research attempted to prepare standard specimens to derive the equations for age calculation for each kind of tooth of various ages. To prepare standard specimens, researchers determined racemization ratio of the teeth of known age that had actually been used for the appraisal of chronological age (total control teeth). They then mixed commercially available L-Asp and D-Asp in the same D/L ratio as the measured one in the total control teeth. They were able to obtain the racemization rate equations from the age-specific standard specimens of central and lateral incisors. These equations were similar to those derived from actual teeth of known age. The study showed that in estimating chronological age, standard specimens could be substituted for natural teeth. Standard specimens can also be used in other laboratories where the racemization ratio can be measured with sufficient reproducibility. 3 tables, 4 figures, and 22 references