Pattern of transmission of laser light in teeth.

This study examined the transmission of helium neon laser light in 20 dog and human teeth. The effect of probe position and angulation was observed both macroscopically and at a microscopic level using confocal microscopy. In all teeth in both species, laser light was transmitted through teeth to the pulpal surface with the light following the path of the enamel prisms and dentinal tubules. Probe angulation did not affect the pattern of light transmission, nor did probe position; however, the position of the probe on the tooth surface determined which section of the pulp was illuminated. Enamel and dentine together are able to collect and distribute light within the tooth, with both enamel prisms and dentinal tubules acting as optical fibres.