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Light Deposition in Dental Hard Tissue and Simulated Thermal Response

Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299

D. Fried

Eastman Dental Center, Rochester, New York

J.D.B. Featherstone

Eastman Dental Center, Rochester, New York

S.F. Borzillary

Eastman Dental Center, Rochester, New York

Near-IR (- 1 um) lasers are presently used for a variety of intra-oral applications including dental hard tissue ablation, although the light intensity distribution and subsequent heating of the hard tissue are still poorly understood. This paper presents a detailed numerical study of the scattered light intensity distribution along with the corresponding predicted thermal response. The calculations are based on recently published scattering and absorption data for dental hard tissue around 1 um. Our simulations indicate strongly enhanced energy deposition and concomitant heating near the dentino-enamel junction (DEJ), mainly due to the higher absorption in dentin. We predict from 10 to 20 times higher internal temperatures near the DEJ compared with the surface. For example, for 50-ms pulses of 5-J energy on a 3-mm-diameter spot (- 1 kW/cm2 or - 50 J/cm2), one can expect internal temperatures near the DEJ in excess of 100°C. Elevated temperatures are predicted to extend far into the dentin, endangering the vitality of the pulp several millimeters below the surface. Our results are compared with published experimental data taken under similar conditions and are found to be in good general agreement. The results of this study do not contradict recently reported ablation of dentin with Nd:YAG laser radiation by contact fiber probes. In this case, the irradiation intensities are 3 to 4 orders of magnitude higher, so plasma formation and plasma shielding of the interior of the tooth are likely.

Key Words: tissue optics • energy deposition • dental hard tissue • visible and near-IR • Monte Carlo simulations, • thermal response

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Journal of Dental Research, Vol. 74, No. 4, 1086-1092 (1995)
DOI: 10.1177/00220345950740040901


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This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Seka, W. Articles by Borzillary, S.F. Search for Related Content PubMed PubMed Citation Articles by Seka, W. Articles by Borzillary, S.F. Social Bookmarking                         What's this?