Abstract
Effects of the gingiva and pulp on natural teeth color were studied in order to determine the mechanism of crown coloring. Namely, teeth color was measured in 30 left maxillary central incisors of young subjects using a spectroradiometer under the following 4 different conditions:(1) free from artificial matters, (2) wearing of a masking plate, (3) undergoing infiltration anesthesia, and (4) simultaneous loading of (2) and (3).
The results obtained are as follows:
1. In the cervical area, the gingiva showed a greater effect than did the pulp.
2. In the middle area, the pulp showed a little effect, but the gingiva exercised practically no effect.
3. In the incisal area, neither gingiva nor pulp influenced teeth color.
4. These results revealed that the spectral radiance factor of a natural teeth increased as the wavelength increased, showing a characteristic inflection point at about 580 nm, and that the gingiva and pulp had different effects on crown coloring among different areas.
