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Esteves-Oliveira M, Wollgarten S, Liebegall S, Jansen P, Bilandzic M, Meyer-Lueckel H, Fischer H, Stollenwerk J, Poprawe R. A New Laser-Processing Strategy for Improving Enamel Erosion Resistance. J Dent Res 2017; 96:1168-1175. [PMID: 28665779 DOI: 10.1177/0022034517718532] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
In the present study, a new automatic laser-processing strategy allowing standardized irradiation of natural tooth areas was investigated. The objective was to find a combination of laser parameters that could cause over a 600°C temperature increase at the enamel surface while not damaging enamel, avoiding temperature change above 5.5°C in the pulp and increasing enamel erosion resistance. Seventy-seven bovine enamel samples were randomly divided into 6 laser groups and 1 negative control (C/no treatment/ n = 11). A scanning strategy (7 × 3 mm) was used for the CO2 laser treatment (λ = 10.6 µm, 0.1-18 J/cm2) with different pulse durations-namely, 20 µs (G20), 30 µs (G30), 55 µs (G55), and 490 µs (G490), as well as 2 modified pulse distances (G33d, G40d). Measurements of temperature change were performed at the surface (thermal camera/50 Hz), at the underside (thermocouples), and at the pulp chamber using a thermobath and human molars ( n = 10). In addition, histology and X-ray diffraction (XRD/ n = 10) were performed. Erosion was tested using an erosive cycling over 6 d, including immersion in citric acid (2 min/0.05 M/pH = 2.3) 6 times daily. Surface loss was measured using a profilometer and statistical analysis with a 2-way repeated-measures analysis of variance (α = 0.05). Only G20 fulfilled the temperature requirements at the surface (619 ± 21.8°C), at the underside (5.3 ± 1.4°C), and at the pulp (2.0 ± 1.0°C), and it caused no mineral phase change and significant reduction of enamel surface loss (-13.2 ± 4.0 µm) compared to C (-37.0 ± 10.1 µm, P < 0.05). A laser-scanning strategy (20 µs/2 kHz/1.25 J/cm2, 3.4 mm/s) has been established that fulfilled the criteria for biological safety and significantly increased enamel erosion resistance (64%) in vitro.
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Affiliation(s)
- M Esteves-Oliveira
- 1 Department of Operative Dentistry, Periodontology and Preventive Dentistry, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - S Wollgarten
- 2 Chair for Laser Technology, RWTH Aachen University, Aachen, Germany
| | - S Liebegall
- 1 Department of Operative Dentistry, Periodontology and Preventive Dentistry, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - P Jansen
- 1 Department of Operative Dentistry, Periodontology and Preventive Dentistry, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - M Bilandzic
- 3 Department of Dental Materials and Biomaterials Research (ZWBF), RWTH Aachen University Hospital, Aachen, Germany
| | - H Meyer-Lueckel
- 1 Department of Operative Dentistry, Periodontology and Preventive Dentistry, Medical Faculty, RWTH Aachen University, Aachen, Germany
| | - H Fischer
- 3 Department of Dental Materials and Biomaterials Research (ZWBF), RWTH Aachen University Hospital, Aachen, Germany
| | - J Stollenwerk
- 4 Fraunhofer Institute for Laser Technology (ILT), Aachen, Germany
| | - R Poprawe
- 2 Chair for Laser Technology, RWTH Aachen University, Aachen, Germany.,4 Fraunhofer Institute for Laser Technology (ILT), Aachen, Germany
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Oldenburg M, Turshatov A, Busko D, Wollgarten S, Adams M, Baroni N, Welle A, Redel E, Wöll C, Richards BS, Howard IA. Photon Upconversion at Crystalline Organic-Organic Heterojunctions. Adv Mater 2016; 28:8477-8482. [PMID: 27500466 DOI: 10.1002/adma.201601718] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 06/28/2016] [Indexed: 06/06/2023]
Abstract
Triplet transfer across a surface-anchored metal-organic-framework heterojunction is demonstrated by the observation of triplet-triplet annihilation photon -upconversion in a sensitizer-emitter heterostructure. Upconversion thresholds under 1 mW cm-2 are achieved. In the broader context, the double-electron-exchange mechanism of triplet transfer indicates that the heterojunction quality is sufficient for electrons to move between layers in this solution-processed crystalline heterostructure.
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Affiliation(s)
- Michael Oldenburg
- Karlsruhe Institute of Technology, Institute of Microstructure Technology (IMT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Andrey Turshatov
- Karlsruhe Institute of Technology, Institute of Microstructure Technology (IMT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Dmitry Busko
- Karlsruhe Institute of Technology, Institute of Microstructure Technology (IMT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Stephanie Wollgarten
- Karlsruhe Institute of Technology, Institute of Microstructure Technology (IMT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Michael Adams
- Karlsruhe Institute of Technology, Institute of Microstructure Technology (IMT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Nicolò Baroni
- Karlsruhe Institute of Technology, Institute of Microstructure Technology (IMT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Alexander Welle
- Karlsruhe Institute of Technology, Institute of Functional Interfaces (IFG), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
- Karlsruhe Institute of Technology, Karlsruhe Nano Micro Facility (KNMF), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Engelbert Redel
- Karlsruhe Institute of Technology, Institute of Functional Interfaces (IFG), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Christof Wöll
- Karlsruhe Institute of Technology, Institute of Functional Interfaces (IFG), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Bryce S Richards
- Karlsruhe Institute of Technology, Institute of Microstructure Technology (IMT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany.
| | - Ian A Howard
- Karlsruhe Institute of Technology, Institute of Microstructure Technology (IMT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany.
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