Objective: It is well known that tooth color changes under various conditions such as drying and lighting. Chinically, there are some problems with color differences of resin and teeth after resin filling. The purpose of this study was to analyze tooth color changes under the condition of drying. Materials and Methods: Six healthy incisors of maxillae from two men and four women were used for this study. The changes of tooth color were measured every 30 seconds using a spectrum color meter (SE-2000, Nippon Denshoku) under the rubber dam dry field technique. Results: The value of Δa* did not differ during the experimental period, the value of ΔL* increased and the value of Δb* decreased time-dependently. The ΔE*ab value was increased by drying. On the other hand, these color changes were induced in the early stage of drying. Conclusions: The result of the ΔL* value indicated that the white level of teeth increases after drying. The change of Δb* means that the yellow level of teeth decreases after drying. These findings suggest that it is suitable to measure the teeth color before resin filling.
