Magnification--an interesting optical property of dentin

Disks of dentin taken from extracted human teeth demonstrated the optical property of the magnification/reduction effect. When images were transmitted from a pulpal-to-occlusal direction, the images were magnified. When the disks were inverted, the images were reduced in size. The images were slightly distorted but clear. When these disks were decalcified or dehydrated, they still possessed the same magnification/reduction effect property. The clear image transmission is attributed to the passage of light along the dentinal tubules; the magnification is the result of their divergence from the pulpal to the occlusal direction. The degree of tubule divergence was determined to correspond closely with the proportion of magnification and of reduction. In calcified sections, an individual tubule would act as a light-pipe, conducting light as it reflects internally off the dentin walls. Decalcified disks may demonstrate a fiberoptic effect. The magnification of an image is the result of the divergence of hundreds of thousands of minute light conductors.