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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Determination of ablation threshold for composite resins and amalgam irradiated with femtosecond laser pulses

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Author(s):
Freitas, A. Z. [1] ; Freschi, L. R. [2] ; Samad, R. E. [1] ; Zezell, D. M. [1] ; Gouw-Soares, S. C. [2] ; Vieira, Jr., N. D. [1]
Total Authors: 6
Affiliation:
[1] IPEN CNEN SP, Nucl & Energy Res Inst, BR-05508000 Sao Paulo - Brazil
[2] IPEN FOUSP, Master Course Lasers Dent, BR-05508000 Sao Paulo - Brazil
Total Affiliations: 2
Document type: Journal article
Source: LASER PHYSICS LETTERS; v. 7, n. 3, p. 236-241, MAR 2010.
Web of Science Citations: 26
Abstract

The use of laser for caries removal and cavity preparation is already a reality in the dental clinic. The objective of the present study was to consider the viability of ultrashort laser pulses for restorative material selective, removal, by determining the ablation threshold fluence for composite resins and amalgam irradiated with femtosecond laser pulses. Lasers pulses centered at 830 nm with 50 fs of duration and 1 kHz of repetition rate, with energies in the range of 300 to 770 mu J were used to irradiate the samples. The samples were irradiated using two different geometrical methods for ablation threshold fluence determinations and the volume ablation was measured by optical coherence tomography. The shape of the ablated surfaces were analyzed by optical microscopy and scanning electron microscopy. T. he determined ablation threshold fluence is 0.35 J/cm(2) for the composite resins Z-100 and Z-350, and 0.25 J/cm(2) for the amalgam. These values are half of the value for enamel in this temporal regime. Thermal damages were not observed in the samples. Using the OCT technique (optical coherence tomography) was possible to determine the ablated volume and the total mass removed. {[}GRAPHICS] (a) Geometrical representation of the sample movement in the z-axis presenting two lobes, and (b) the two lobes formation process by using the diagonal method (C) 2010 by Astro Ltd. Published exclusively by WILEY-VCH Verlag GmbH \& Co. KGaA (AU)

FAPESP's process: 00/15135-9 - Implementation of a terawatt laser system and its applications
Grantee:Nilson Dias Vieira Junior
Support Opportunities: Research Projects - Thematic Grants