2012 Volume 55 Issue 5 Pages 333-339
Purpose: The purpose of this study was to examine the influence of tooth-surface moisture conditions on optical coherence tomography (OCT) imaging. Methods: Emitted light was coupled in a single-mode fiber-optic Michelson interferometer, and delivered to a sample and reference mirror mounted on a linearly translating galvanometer driven by a triangular voltage waveform at a fringe-modulation frequency of 1 kHz. Backscattered light from the sample was coupled back to the system, digitized and used to create two-dimensional images together with beam scanning. OCT imaging of the surfaces of extracted human teeth was performed soon after mounting ('wet' condition), immediately after air blowing for 10 sec ('air-blow' condition), and at 1-, 5- and 10-min intervals thereafter. Results: For the wet condition, three distinct peaks indicated the water surface, tooth surface and dentino-enamel junction. Backscattered light was detected at levels above noise, possibly causing grainy OCT images. By contrast, two distinct peaks indicating the tooth surface and dentino-enamel junction were observed for the air-blow and 10-min conditions, with greater signal intensities for the latter. The intensity was higher for the air-blow condition than the wet condition. The signal intensities increased during storage in air at room temperature. Conclusion: Tooth-substrate moisture conditions appeared to influence OCT imaging, and water irrigation followed by 10-sec air-blowing might be a suitable procedure for the OCT examination.
