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Rapp L, Madden S, Brand J, Maximova K, Walsh LJ, Spallek H, Zuaiter O, Habeb A, Hirst TR, Rode AV. Investigation of laser wavelength effect on the ablation of enamel and dentin using femtosecond laser pulses. Sci Rep 2023; 13:20156. [PMID: 37978230 PMCID: PMC10656487 DOI: 10.1038/s41598-023-47551-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 11/15/2023] [Indexed: 11/19/2023] Open
Abstract
We investigated the effect of femtosecond (fs) laser ablation of enamel and dentin for different pulse wavelengths: infrared (1030 nm), green (515 nm), and ultra-violet (343 nm) and for different pulse separations to determine the optimal irradiation conditions for the precise removal of dental hard tissues with the absence of structural and compositional damage. The ablation rates and efficiencies were established for all three laser wavelengths for both enamel and dentin at room temperature without using any irrigation or cooling system, and the surfaces were assessed with optical and scanning electron microscopy, optical profilometry, and Raman spectroscopy. We demonstrated that 515 nm fs irradiation provides the highest rate and efficiency for ablation, followed by infrared. Finally, we explored the temperature variations inside the dental pulp during the laser procedures for all three wavelengths and showed that the maximum increase at the optimum conditions for both infrared and green irradiations was 5.5 °C, within the acceptable limit of temperature increase during conventional dental treatments. Ultra-violet irradiation significantly increased the internal temperature of the teeth, well above the acceptable limit, and caused severe damage to tooth structures. Thus, ultra-violet is not a compatible laser wavelength for femtosecond teeth ablation.
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Affiliation(s)
- Ludovic Rapp
- Laser Physics Centre, Department of Quantum Science and Technology, Research School of Physics, Australian National University, Canberra, ACT, 2600, Australia.
| | - Steve Madden
- Laser Physics Centre, Department of Quantum Science and Technology, Research School of Physics, Australian National University, Canberra, ACT, 2600, Australia
| | - Julia Brand
- Laser Physics Centre, Department of Quantum Science and Technology, Research School of Physics, Australian National University, Canberra, ACT, 2600, Australia
| | - Ksenia Maximova
- Laser Physics Centre, Department of Quantum Science and Technology, Research School of Physics, Australian National University, Canberra, ACT, 2600, Australia
| | - Laurence J Walsh
- The University of Queensland School of Dentistry, Herston, QLD, 4006, Australia
- Dentroid Pty Ltd, Canberra, ACT, 2601, Australia
| | - Heiko Spallek
- Faculty of Medicine and Health, The University of Sydney School of Dentistry, Surry Hills, NSW, 2010, Australia
| | - Omar Zuaiter
- Dentroid Pty Ltd, Canberra, ACT, 2601, Australia
| | - Alaa Habeb
- Dentroid Pty Ltd, Canberra, ACT, 2601, Australia
| | | | - Andrei V Rode
- Laser Physics Centre, Department of Quantum Science and Technology, Research School of Physics, Australian National University, Canberra, ACT, 2600, Australia
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2
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Zong X, Yang X, Sun Y, Wang Y, Duan C, Chen H. Effect of Optical Wedge Rotary on Ablation Efficiency of Femtosecond Laser on Dental Hard Tissue and Restorative Materials. Photobiomodul Photomed Laser Surg 2023; 41:364-370. [PMID: 37459608 DOI: 10.1089/photob.2023.0001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2023] Open
Abstract
Objective: Femtosecond laser (fs-laser) is a novel tooth preparation tool but its ablation efficiency is insufficient. The purpose is to establish a new fs-laser tooth ablation method based on a dual-wedges path ablation system, and explore the efficiency of tooth hard tissue and dental restorative materials ablation. Materials and methods: Extracted third molars, pure titanium, cobalt-chromium alloy, gold alloy, and 3Y-zirconia were prepared into samples. These samples were rotary ablated by an fs-laser with dual-wedges. The wavelength was 1030 nm and the pulse duration was 250 fsec. Laser parameters were set as a repetition frequency of 25 kHz, the power percentages as 50% for dental tissues, and 60% for restorative materials. The optical wedge angle was set as 0°, 20°, 40°, 60°, and 80° for restorative materials, 0°, 20°, 30°, 40°, and 60° for enamel, and 0°, 10°, 20°, 30°, and 40°for dentin. Three times of ablation was processed at each parameter to obtain total 90 ablation microcavities of 6 kinds of materials. The diameter, depth, and volume of microcavities were measured by confocal laser microscopy and plotted against optical-wedge-angle in curves of different materials. One-way analysis of variance (ANOVA) was used to test whether the ablation efficiency between different angles was statistically significant. Results: The ablation efficiency of each material at different optical-wedge-angle was statistically significant (p < 0.05) and tends to be correlated. For dental hard tissue, the enamel ablation efficiency was 208.1 times and dentin ablation efficiency were 65.2 times than before when the wedge angle was 40°. For pure titanium, zirconia, cobalt-chromium, and gold alloys, the ablation efficiencies were 3.1, 10.7, 81.5, and 128.8 times than before when the rotation angle was 80°. Conclusions: The ablation efficiency of dental hard tissues and restorative materials was significantly increased with the increase of laser oblique incidence angle. Clinical Trial Registration number: PKUSSIRB-201949124.
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Affiliation(s)
- Xiao Zong
- Department of Prosthodontics, Center of Digital Dentistry, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Research Center of Engineering and Technology for Digital Dentistry of Ministry of Health, Beijing Key Laboratory of Digital Stomatology and National Clinical Research Center for Oral Disease, Beijing, PR China
- Faculty of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing, PR China
| | - Xu Yang
- Faculty of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing, PR China
| | - Yuchun Sun
- Department of Prosthodontics, Center of Digital Dentistry, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Research Center of Engineering and Technology for Digital Dentistry of Ministry of Health, Beijing Key Laboratory of Digital Stomatology and National Clinical Research Center for Oral Disease, Beijing, PR China
- Faculty of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing, PR China
| | - Yong Wang
- Department of Prosthodontics, Center of Digital Dentistry, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Research Center of Engineering and Technology for Digital Dentistry of Ministry of Health, Beijing Key Laboratory of Digital Stomatology and National Clinical Research Center for Oral Disease, Beijing, PR China
- Faculty of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing, PR China
| | - Chenggang Duan
- The Fifth Clinical Division, Peking University School and Hospital of Stomatology, Beijing, PR China
| | - Hu Chen
- Department of Prosthodontics, Center of Digital Dentistry, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, Research Center of Engineering and Technology for Digital Dentistry of Ministry of Health, Beijing Key Laboratory of Digital Stomatology and National Clinical Research Center for Oral Disease, Beijing, PR China
- Faculty of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing, PR China
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Rapp L, Madden S, Brand J, Walsh LJ, Spallek H, Zuaiter O, Habeb A, Hirst TR, Rode AV. Femtosecond laser dentistry for precise and efficient cavity preparation in teeth. BIOMEDICAL OPTICS EXPRESS 2022; 13:4559-4571. [PMID: 36187240 PMCID: PMC9484447 DOI: 10.1364/boe.463756] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 07/19/2022] [Accepted: 07/25/2022] [Indexed: 06/16/2023]
Abstract
High fluence focused femtosecond laser pulses were used to perform fast, high precision and minimally damaging cavity cutting of teeth at room temperature without using any irrigation or cooling system. The optimal ablation rates were established for both enamel and dentin, and the surfaces were assessed with optical and scanning electron microscopy, Raman spectroscopy and optical profilometry. No chemical change in the composition of enamel and dentin was observed. We explored temperature variations inside the dental pulp during the laser procedure and showed the maximum increase was 5.5°C, within the acceptable limit of temperature increase during conventional dental treatments.
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Affiliation(s)
- Ludovic Rapp
- Department of Quantum Science and Technology, Research School of Physics, Australian National University, Canberra, ACT 2600, Australia
| | - Steve Madden
- Department of Quantum Science and Technology, Research School of Physics, Australian National University, Canberra, ACT 2600, Australia
| | - Julia Brand
- Department of Quantum Science and Technology, Research School of Physics, Australian National University, Canberra, ACT 2600, Australia
- Centre for Creative and Cultural Research, Faculty of Art and Design, University of Canberra, ACT 2617, Australia
| | - Laurence J. Walsh
- The University of Queensland School of Dentistry QLD 4006, Australia
- Dentroid (Emudent Technologies Pty Ltd), Canberra ACT 2601, Australia
| | - Heiko Spallek
- The University of Sydney School of Dentistry, Faculty of Medicine and Health, NSW 2010, Australia
| | - Omar Zuaiter
- Dentroid (Emudent Technologies Pty Ltd), Canberra ACT 2601, Australia
| | - Alaa Habeb
- Dentroid (Emudent Technologies Pty Ltd), Canberra ACT 2601, Australia
| | - Timothy R. Hirst
- Dentroid (Emudent Technologies Pty Ltd), Canberra ACT 2601, Australia
| | - Andrei V. Rode
- Department of Quantum Science and Technology, Research School of Physics, Australian National University, Canberra, ACT 2600, Australia
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Sharafeddin F, Maroufi S. Effect of Er:YAG, Co2 lasers, papain, and bromelain enzymes dentin treatment on shear bond strength of composite resin. Clin Exp Dent Res 2022; 8:1575-1581. [PMID: 36016491 PMCID: PMC9760143 DOI: 10.1002/cre2.651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 08/03/2022] [Accepted: 08/06/2022] [Indexed: 01/26/2023] Open
Abstract
OBJECTIVE Effective bond strength of composite resin restoration leads to its durability, so evaluation of dentin surface treatment with enzymes and laser for higher bond strength is an important factor. MATERIALS AND METHODS Sixty human molar teeth were cut at a depth of 2 mm of occlusal part and divided into six groups (n = 10). G1: etched with 37% phosphoric, G2 and G3: 10% papain or bromelain enzymes were used on the dentinal surface, G4: 10% papain and bromelain enzyme mixture were used for. Then, the specimens were washed with distilled water. In G5 and G6: Er:YAG or Co2 lasers were used on the dentin surface. An adhesive system was applied and then nanohybrid composite was placed in teflon mold and light cured. Samples were subjected to a shear bond strength (SBS) test by universal testing machines. Statistical analysis was performed, using one-way analysis of variance and Tukey HSD tests (p < .05). RESULTS The mean SBS in G1 was significantly higher in comparison with the other groups (p < .0001). On the other hand, a comparison of mean SBS between groups 2, 3, 4, and 5 shows no significant differences (p = .221). The mean SBS in group 6 (Co2 laser) was significantly lower in comparison with the other groups (p < .0001). CONCLUSION Results showed that SBS of composite resin to dentin was not significantly affected, using either bromelain or papain 10% enzymes or erbium laser. Co2 laser had a negative effect on dentin and decreased the SBS. Phosphoric acid has the best result.
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Affiliation(s)
- Farahnaz Sharafeddin
- Department of Operative Dentistry, Biomaterials Research Center, School of DentistryShiraz University of Medical SciencesShirazIran
| | - Sara Maroufi
- School of DentistryShiraz University of Medical SciencesShirazIran
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Rapp L, Madden S, Rode AV, Walsh LJ, Spallek H, Nguyen Q, Dau V, Woodfield P, Dao D, Zuaiter O, Habeb A, Hirst TR. Anesthetic-, irrigation- and pain-free dentistry? The case for a femtosecond laser enabled intraoral robotic device. FRONTIERS IN DENTAL MEDICINE 2022. [DOI: 10.3389/fdmed.2022.976097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
By leveraging ultrashort pulse laser and micro-electromechanical systems (MEMS) technologies, we are developing a miniaturized intraoral dental robotic device that clamps onto teeth, is remotely controlled, and equipped with a focusing and scanning system to perform efficient, fast, and ultra-precise laser treatments of teeth and dental restorative materials. The device will be supported by a real-time monitoring system for visualization and diagnostic analysis with appropriate digital controls. It will liberate dentists from repetitive manual operations, physical strain and proximity to the patient's oro-pharyngal area that potentially contains infectious agents. The technology will provide patients with high-accuracy, minimally invasive and pain-free treatment. Unlike conventional lasers, femtosecond lasers can ablate all materials without generating heat, thus negating the need for water irrigation, allowing for a clear field of view, and lowering cross-infection hazards. Additionally, dentists can check, analyze, and perform precise cutting of tooth structure with automatic correction, reducing human error. Performing early-stage diagnosis and intervention remotely will be possible through units installed at schools, rural health centers and aged care facilities. Not only can the combination of femtosecond lasers, robotics and MEMS provide practical solutions to dentistry's enduring issues by allowing more precise, efficient, and predictable treatment, but it will also lead to improving the overall access to oral healthcare for communities at large.
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Zong X, Wang Y, Sun Y, Chen H. Femtosecond Laser for Cavity Preparation in Enamel and Dentin: Axial Wall Taper Related Factors. Photobiomodul Photomed Laser Surg 2022; 40:417-423. [DOI: 10.1089/photob.2021.0126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Xiao Zong
- Center of Digital Dentistry, Department of Prosthodontics, Peking University School and Hospital of Stomatology, National Center of Stomatology, National Clinical Research Center for Oral Diseases, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, NHC Research Center of Engineering and Technology for Computerized Dentistry, Beijing, P.R. China
- Shanxi Province Key Laboratory of Oral Diseases Prevention and New Materials, Taiyuan, P.R. China
| | - Yong Wang
- Center of Digital Dentistry, Department of Prosthodontics, Peking University School and Hospital of Stomatology, National Center of Stomatology, National Clinical Research Center for Oral Diseases, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, NHC Research Center of Engineering and Technology for Computerized Dentistry, Beijing, P.R. China
- Shanxi Province Key Laboratory of Oral Diseases Prevention and New Materials, Taiyuan, P.R. China
| | - Yuchun Sun
- Center of Digital Dentistry, Department of Prosthodontics, Peking University School and Hospital of Stomatology, National Center of Stomatology, National Clinical Research Center for Oral Diseases, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, NHC Research Center of Engineering and Technology for Computerized Dentistry, Beijing, P.R. China
- Shanxi Province Key Laboratory of Oral Diseases Prevention and New Materials, Taiyuan, P.R. China
| | - Hu Chen
- Center of Digital Dentistry, Department of Prosthodontics, Peking University School and Hospital of Stomatology, National Center of Stomatology, National Clinical Research Center for Oral Diseases, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, NHC Research Center of Engineering and Technology for Computerized Dentistry, Beijing, P.R. China
- Shanxi Province Key Laboratory of Oral Diseases Prevention and New Materials, Taiyuan, P.R. China
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7
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Zong X, Qin B, Wang Y, Chen H, Peng L, Li X, Sun Y. Preliminary Exploration of a Laser-Based Surface Microtexturing Strategy for Improving the Wear Resistance of Dentin: An In Vitro Study. Photobiomodul Photomed Laser Surg 2022; 40:355-361. [DOI: 10.1089/photob.2021.0138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Xiao Zong
- Center of Digital Dentistry, Department of Prosthodontics, Peking University School and Hospital of Stomatology, National Center of Stomatology, National Clinical Research Center for Oral Diseases, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, NHC Research Center of Engineering and Technology for Computerized Dentistry, Beijing, P.R. China
| | - Bin Qin
- Laser Micro/Nano Fabrication Laboratory, School of Mechanical Engineering, Beijing Institute of Technology, Beijing, P.R. China
| | - Yong Wang
- Center of Digital Dentistry, Department of Prosthodontics, Peking University School and Hospital of Stomatology, National Center of Stomatology, National Clinical Research Center for Oral Diseases, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, NHC Research Center of Engineering and Technology for Computerized Dentistry, Beijing, P.R. China
| | - Hu Chen
- Center of Digital Dentistry, Department of Prosthodontics, Peking University School and Hospital of Stomatology, National Center of Stomatology, National Clinical Research Center for Oral Diseases, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, NHC Research Center of Engineering and Technology for Computerized Dentistry, Beijing, P.R. China
| | - Li Peng
- Center of Digital Dentistry, Department of Prosthodontics, Peking University School and Hospital of Stomatology, National Center of Stomatology, National Clinical Research Center for Oral Diseases, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, NHC Research Center of Engineering and Technology for Computerized Dentistry, Beijing, P.R. China
| | - Xiaowei Li
- Laser Micro/Nano Fabrication Laboratory, School of Mechanical Engineering, Beijing Institute of Technology, Beijing, P.R. China
| | - Yuchun Sun
- Center of Digital Dentistry, Department of Prosthodontics, Peking University School and Hospital of Stomatology, National Center of Stomatology, National Clinical Research Center for Oral Diseases, National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing Key Laboratory of Digital Stomatology, NHC Research Center of Engineering and Technology for Computerized Dentistry, Beijing, P.R. China
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8
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Yuan F, Liang S, Lyu P. A Novel Method for Adjusting the Taper and Adaption of Automatic Tooth Preparations with a High-Power Femtosecond Laser. J Clin Med 2021; 10:3389. [PMID: 34362191 PMCID: PMC8347009 DOI: 10.3390/jcm10153389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 07/20/2021] [Accepted: 07/28/2021] [Indexed: 11/23/2022] Open
Abstract
This study explored the effect of the light-off delay setting in a robotically controlled femtosecond laser on the taper and adaption of resin tooth preparations. Thirty resin teeth (divided into six equal groups) were studied under different light-off delay conditions. Tapers from six vertical sections of the teeth were measured and compared among the light-off delay groups. The mean taper decreased from 39.268° ± 4.530° to 25.393° ± 5.496° as the light-off delay increased (p < 0.05). The average distance between the occlusal surfaces of the scanned data and the predesigned preparation data decreased from 0.089 ± 0.005 to 0.013 ± 0.030 μm as the light-off delay increased (p < 0.05). The light-off delay of the femtosecond laser is correlated with the taper and adaption of automatic tooth preparations; this setting needs to be considered during automatic tooth preparation.
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Affiliation(s)
- Fusong Yuan
- Center of Digital Dentistry, Peking University School and Hospital of Stomatology, Beijing 100081, China;
- Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing 100081, China
- National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing 100081, China
- NHC Key Laboratory of Digital Technology of Stomatology, Beijing 100081, China
- Beijing Key Laboratory of Digital Stomatology, Beijing 100081, China
- National Clinical Research Center for Oral Diseases, Beijing 100871, China
| | - Shanshan Liang
- Second Clinical Division, Peking University Hospital of Stomatology, Beijing 100081, China;
| | - Peijun Lyu
- Center of Digital Dentistry, Peking University School and Hospital of Stomatology, Beijing 100081, China;
- Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing 100081, China
- National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing 100081, China
- NHC Key Laboratory of Digital Technology of Stomatology, Beijing 100081, China
- Beijing Key Laboratory of Digital Stomatology, Beijing 100081, China
- National Clinical Research Center for Oral Diseases, Beijing 100871, China
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9
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Laser fabrication of structural bone: surface morphology and biomineralization assessment. Lasers Med Sci 2020; 36:131-137. [PMID: 32372236 DOI: 10.1007/s10103-020-03023-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 04/16/2020] [Indexed: 10/24/2022]
Abstract
The current work explores the surface morphology of the laser-ablated bone using Yb-fiber coupled Nd:YAG laser (λ = 1064 nm) in continuous wave mode. As the laser-ablated region contains physiochemically modified carbonized and nonstructural region, it becomes unknown material for the body. Thus, biomineralization on such a laser-ablated region was assessed by in vitro immersion test in noncellular simulated body fluid. The presence of hydroxyapatite was detected in the precipitated mineral product using scanning electron microscopy equipped with energy dispersive spectroscopy, and X-ray diffraction analysis. The effect of varying laser parameters on distribution of surface morphology features was identified and its corresponding effect on biomineralization was studied.
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10
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Liang S, Lyu P, Yuan F. Method for Accurately Preparing Cavities on Cortical Bones Using Picosecond Laser. PHOTOBIOMODULATION PHOTOMEDICINE AND LASER SURGERY 2020; 38:301-307. [PMID: 32427550 DOI: 10.1089/photob.2019.4724] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Shanshan Liang
- Centre of Digital Dentistry, Peking University School and Hospital of Stomatology, Beijing, China
- Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing, China
- National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing, China
- Research Centre of Engineering and Technology for Digital Dentistry of Ministry of Health, Beijing, China
- Beijing Key Laboratory of Digital Stomatology, Beijing, China
| | - Peijun Lyu
- Centre of Digital Dentistry, Peking University School and Hospital of Stomatology, Beijing, China
- Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing, China
- National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing, China
- Research Centre of Engineering and Technology for Digital Dentistry of Ministry of Health, Beijing, China
- Beijing Key Laboratory of Digital Stomatology, Beijing, China
| | - Fusong Yuan
- Centre of Digital Dentistry, Peking University School and Hospital of Stomatology, Beijing, China
- Department of Prosthodontics, Peking University School and Hospital of Stomatology, Beijing, China
- National Engineering Laboratory for Digital and Material Technology of Stomatology, Beijing, China
- Research Centre of Engineering and Technology for Digital Dentistry of Ministry of Health, Beijing, China
- Beijing Key Laboratory of Digital Stomatology, Beijing, China
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11
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Pantawane MV, Ho YH, Robertson WB, Khan RJK, Fick DP, Dahotre NB. Thermal Assessment of Ex Vivo Laser Ablation of Cortical Bone. ACS Biomater Sci Eng 2020; 6:2415-2426. [PMID: 33455309 DOI: 10.1021/acsbiomaterials.9b01559] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
As a potential osteotomy tool, laser ablation is expected to provide rapid machining of bone, while generating minimal thermal damage (carbonization) and physical attributes within the machined region conducive to healing. As these characteristics vary with laser parameters and modes of laser operation, the clinical trials and in vivo studies render it difficult to explore these aspects for optimization of the laser machining parameters. In light of this, the current work explores various thermal and microstructural aspects of laser-ablated cortical bone in ex vivo study to understand the fundamentals of laser-bone interaction using computational modeling. The study employs the Yb-fiber Nd:YAG laser (λ = 1064 nm) in the continuous wave mode to machine the femur section of bovine bone by a three-dimensional machining approach. The examination involved thermal analysis using differential scanning calorimetry and thermogravimetry, phase analysis using X-ray diffractometry, qualitative analysis using X-ray photoelectron spectroscopy, and microstructural and semiquantitative analysis using scanning electron microscopy equipped with energy-dispersive spectrometry. The mechanism of efficient bone ablation using the Nd:YAG laser was evaluated using the computational thermokinetics outcome. The use of high laser fluence (10.61 J/mm2) was observed to be efficient to reduce the residual amorphous carbon in the heat-affected zone while achieving removal of the desired volume of the bone material at a rapid rate. Minimal thermal effects were predicted through computational simulation and were validated with the experimental outcome. In addition, this work reveals the in situ formation of a scaffold-like structure in the laser-machined region which can be conducive during healing.
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Affiliation(s)
- Mangesh V Pantawane
- Laboratory for Laser Aided Additive and Subtractive Manufacturing, Virtual Center for Advanced Orthopedics, Department of Materials Science and Engineering, University of North Texas, 1155 Union Circle-305310, Denton, Texas 76203-5017, United States
| | - Yee-Hsien Ho
- Laboratory for Laser Aided Additive and Subtractive Manufacturing, Virtual Center for Advanced Orthopedics, Department of Materials Science and Engineering, University of North Texas, 1155 Union Circle-305310, Denton, Texas 76203-5017, United States
| | - William B Robertson
- Laboratory for Laser Aided Additive and Subtractive Manufacturing, Virtual Center for Advanced Orthopedics, Department of Materials Science and Engineering, University of North Texas, 1155 Union Circle-305310, Denton, Texas 76203-5017, United States.,Australian Institute of Robotics Orthopedics, 2 Centro Avenue, Subiaco, Western Australia 6008, Australia.,Department of Computing School of Electrical Engineering and Computing, Curtin University, Kent Street, Bentley, Western Australia 6102, Australia
| | - Riaz J K Khan
- Laboratory for Laser Aided Additive and Subtractive Manufacturing, Virtual Center for Advanced Orthopedics, Department of Materials Science and Engineering, University of North Texas, 1155 Union Circle-305310, Denton, Texas 76203-5017, United States.,Australian Institute of Robotics Orthopedics, 2 Centro Avenue, Subiaco, Western Australia 6008, Australia.,Department of Computing School of Electrical Engineering and Computing, Curtin University, Kent Street, Bentley, Western Australia 6102, Australia.,The Joint Studio, Hollywood Medical Centre, 85 Monash Avenue, Nedlands, Western Australia 6009, Australia
| | - Daniel P Fick
- Laboratory for Laser Aided Additive and Subtractive Manufacturing, Virtual Center for Advanced Orthopedics, Department of Materials Science and Engineering, University of North Texas, 1155 Union Circle-305310, Denton, Texas 76203-5017, United States.,Australian Institute of Robotics Orthopedics, 2 Centro Avenue, Subiaco, Western Australia 6008, Australia.,Department of Computing School of Electrical Engineering and Computing, Curtin University, Kent Street, Bentley, Western Australia 6102, Australia.,The Joint Studio, Hollywood Medical Centre, 85 Monash Avenue, Nedlands, Western Australia 6009, Australia
| | - Narendra B Dahotre
- Laboratory for Laser Aided Additive and Subtractive Manufacturing, Virtual Center for Advanced Orthopedics, Department of Materials Science and Engineering, University of North Texas, 1155 Union Circle-305310, Denton, Texas 76203-5017, United States
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12
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Tantbirojn D, Walinski CJ, Ross JA, Taylor CR, Versluis A. Composite removal by means of erbium, chromium:yttrium-scandium-gallium-garnet laser compared with rotary instruments. J Am Dent Assoc 2019; 150:1040-1047. [PMID: 31761017 DOI: 10.1016/j.adaj.2019.07.033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 07/22/2019] [Accepted: 07/23/2019] [Indexed: 11/25/2022]
Abstract
BACKGROUND Complete removal of existing composite restorations without unnecessary removal of tooth structure is challenging. The authors compared the amount of tooth structure removed and composite remaining in Class III preparations when using an erbium laser or a rotary instrument. METHODS Mesiolingual and distolingual preparations were prepared in 14 extracted anterior teeth, restored with shade-matched composite, finished, and polished. One restoration was removed with an erbium, chromium:yttrium-scandium-gallium-garnet laser and the other with a rotary instrument (handpiece and carbide burs). Gypsum models made from vinyl polysiloxane impressions of the preparation and removal stages were scanned. The 2 scans were precisely aligned to calculate the amount of tooth structure removed and residual composite, which were statistically compared (t test) between the bur and laser groups. RESULTS Rotary instruments removed significantly more tooth structure than the laser in terms of mean depth (P = .0017) but not maximum depth (P = .0762). Although mean depth of tooth loss was smaller in the laser group, the area of tooth loss was significantly larger (P = .0004) because the rotary instrumentation left significantly more composite than the laser in terms of volume (P = .0104), mean depth (P = .0375), maximum depth (P = .0318), and area (P = .0056). CONCLUSIONS AND PRACTICAL IMPLICATIONS The erbium, chromium:yttrium-scandium-gallium-garnet laser was more selective in removing existing composite restorations than a rotary instrument because it removed less tooth structure and left behind less composite. Unintentional loss of tooth structure and unnoticeable residual composite are inevitable when removing existing composites. Erbium lasers are alternative means of composite removal that may be more selective than a rotary instrument.
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Aljekhedab F, Zhang W, Haugen HK, Wohl GR, El-Desouki MM, Fang Q. Influence of environmental conditions in bovine bone ablation by ultrafast laser. JOURNAL OF BIOPHOTONICS 2019; 12:e201800293. [PMID: 30680962 DOI: 10.1002/jbio.201800293] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2018] [Revised: 01/22/2019] [Accepted: 01/22/2019] [Indexed: 06/09/2023]
Abstract
Ultrafast lasers are promising tools for surgical applications requiring precise tissue cutting. Shallow ablation depth and slow rate as well as collateral damage are common barriers limiting the use of laser in clinical applications. Localized cooling with water and/or air jet is known to reduce collateral thermal damage. We studied the influence of environmental conditions including air, compressed air flow, still water and water jet on ablation depth, ablation rate and surface morphology on bovine bone samples with an 800 nm femtosecond laser. At 15 J/cm2 , no thermal effect was observed by electron microscopy and Raman spectroscopy. The experimental results indicate that environmental conditions play a significant role in laser ablation. The deepest cavity and highest ablation rate were achieved under the compressed air flow condition, which is attributed to debris removal during the ablation process. The shallowest ablation depth and lowest ablation rates were associated with water flushing. For surface morphology, smooth surface and the absence of microcracks were observed under air flow conditions, while rougher surfaces and minor microcracks were observed under other conditions. These results suggest that ultrafast ablation of bone can be more efficient and with better surface qualities if assisted with blowing air jet.
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Affiliation(s)
- Fahad Aljekhedab
- School of Biomedical Engineering, McMaster University, Hamilton, Ontario, Canada
- National Nanotechnology Center, King Abdulaziz City for Science and Technology (KACST), Riyadh, Saudi Arabia
| | - Wenbin Zhang
- Department of Engineering Physics, McMaster University, Hamilton, Ontario, Canada
- Department of Oral & Cranio-Maxillofacial Surgery, Shanghai 9th People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
- Shanghai Key Laboratory of Stomatology and Shanghai Research Institute of Stomatology, National Clinical Research Center of Stomatology, Shanghai, China
| | - Harold K Haugen
- Department of Engineering Physics, McMaster University, Hamilton, Ontario, Canada
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada
| | - Gregory R Wohl
- School of Biomedical Engineering, McMaster University, Hamilton, Ontario, Canada
- Department of Mechanical Engineering, McMaster University, Hamilton, Ontario, Canada
| | - Munir M El-Desouki
- School of Biomedical Engineering, McMaster University, Hamilton, Ontario, Canada
| | - Qiyin Fang
- School of Biomedical Engineering, McMaster University, Hamilton, Ontario, Canada
- Department of Engineering Physics, McMaster University, Hamilton, Ontario, Canada
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Jain K, Bishnoi A, Adyanthaya R, Singh S, Kapas A. Effect of Er:YAG laser cavity preparation on the bond strength of 2-hydroxyethyl methacrylate-free and 2-hydroxyethyl methacrylate-rich self-etch adhesive systems: An in vitro study. Dent Res J (Isfahan) 2019. [DOI: 10.4103/1735-3327.270789] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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15
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Yuan F, Zheng J, Sun Y, Wang Y, Lyu P. Regulation and Measurement of the Heat Generated by Automatic Tooth Preparation in a Confined Space. Photomed Laser Surg 2018; 35:332-337. [PMID: 28590837 DOI: 10.1089/pho.2016.4242] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
OBJECTIVE The aim of this study was to assess and regulate heat generation in the dental pulp cavity and circumambient temperature around a tooth during laser ablation with a femtosecond laser in a confined space. BACKGROUND DATA The automatic tooth preparing technique is one of the traditional oral clinical technology innovations. In this technique, a robot controlled an ultrashort pulse laser to automatically complete the three-dimensional teeth preparing in a confined space. The temperature control is the main measure for protecting the tooth nerve. METHODS Ten tooth specimens were irradiated with a femtosecond laser controlled by a robot in a confined space to generate 10 teeth preparation. During the process, four thermocouple sensors were used to record the pulp cavity and circumambient environment temperatures with or without air cooling. A statistical analysis of the temperatures was performed between the conditions with and without air cooling (p < 0.05). RESULTS The recordings showed that the temperature with air cooling was lower than that without air cooling and that the heat generated in the pulp cavity was lower than the threshold for dental pulp damage. CONCLUSIONS These results indicate that femtosecond laser ablation with air cooling might be an appropriate method for automatic tooth preparing.
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Affiliation(s)
- Fusong Yuan
- 1 Center of Digital Dentistry, Peking University School and Hospital of Stomatology , Beijing, China .,2 National Engineering Laboratory, Digital and Material Technology of Stomatology , Beijing, China .,3 Research Center of Engineering and Technology for Digital Dentistry , Ministry of Health, Beijing, China
| | - Jianqiao Zheng
- 1 Center of Digital Dentistry, Peking University School and Hospital of Stomatology , Beijing, China .,2 National Engineering Laboratory, Digital and Material Technology of Stomatology , Beijing, China .,3 Research Center of Engineering and Technology for Digital Dentistry , Ministry of Health, Beijing, China
| | - Yuchun Sun
- 1 Center of Digital Dentistry, Peking University School and Hospital of Stomatology , Beijing, China .,2 National Engineering Laboratory, Digital and Material Technology of Stomatology , Beijing, China .,3 Research Center of Engineering and Technology for Digital Dentistry , Ministry of Health, Beijing, China
| | - Yong Wang
- 1 Center of Digital Dentistry, Peking University School and Hospital of Stomatology , Beijing, China .,2 National Engineering Laboratory, Digital and Material Technology of Stomatology , Beijing, China .,3 Research Center of Engineering and Technology for Digital Dentistry , Ministry of Health, Beijing, China
| | - Peijun Lyu
- 1 Center of Digital Dentistry, Peking University School and Hospital of Stomatology , Beijing, China .,2 National Engineering Laboratory, Digital and Material Technology of Stomatology , Beijing, China .,3 Research Center of Engineering and Technology for Digital Dentistry , Ministry of Health, Beijing, China
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Petrov T, Pecheva E, Walmsley AD, Dimov S. Femtosecond laser ablation of dentin and enamel for fast and more precise dental cavity preparation. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2018; 90:433-438. [DOI: 10.1016/j.msec.2018.04.070] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 03/01/2018] [Accepted: 04/24/2018] [Indexed: 11/26/2022]
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Dahotre NB, Santhanakrishnan S, Joshi SS, Khan RJK, Fick DP, Robertson WB, Sheh RK, Ironside CN. Integrated experimental and computational approach to laser machining of structural bone. Med Eng Phys 2017; 51:56-66. [PMID: 29229404 DOI: 10.1016/j.medengphy.2017.11.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 10/26/2017] [Accepted: 11/22/2017] [Indexed: 01/02/2023]
Abstract
This study describes the fundamentals of laser-bone interaction during bone machining through an integrated experimental-computational approach. Two groups of laser machining parameters identified the effects of process thermodynamics and kinetics on machining attributes at micro to macro. A continuous wave Yb-fiber Nd:YAG laser (wavelength 1070 nm) with fluences in the range of 3.18 J/mm2-8.48 J/mm2 in combination of laser power (300 W-700 W) and machining speed (110 mm/s-250 mm/s) were considered for machining trials. The machining attributes were evaluated through scanning electron microscopy observations and compared with finite element based multiphysics-multicomponent computational model predicted values. For both groups of laser machining parameters, experimentally evaluated and computationally predicted depths and widths increased with increased laser energy input and computationally predicted widths remained higher than experimentally measured widths whereas computationally predicted depths were slightly higher than experimentally measured depths and reversed this trend for the laser fluence >6 J/mm2. While in both groups, the machining rate increased with increased laser fluence, experimentally derived machining rate remained lower than the computationally predicted values for the laser fluences lower than ∼4.75 J/mm2 for one group and ∼5.8 J/mm2 for other group and reversed in this trend thereafter. The integrated experimental-computational approach identified the physical processes affecting machining attributes.
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Affiliation(s)
- Narendra B Dahotre
- Laboratory for Laser Aided Additive and Subtractive Manufacturing, Virtual Center for Advanced Orthopaedics, Department of Materials Science and Engineering, University of North Texas, 1155 Union Circle #305310, Denton, TX 76203-5017, USA.
| | | | - Sameehan S Joshi
- Laboratory for Laser Aided Additive and Subtractive Manufacturing, Virtual Center for Advanced Orthopaedics, Department of Materials Science and Engineering, University of North Texas, 1155 Union Circle #305310, Denton, TX 76203-5017, USA
| | - Riaz J K Khan
- Laboratory for Laser Aided Additive and Subtractive Manufacturing, Virtual Center for Advanced Orthopaedics, Department of Materials Science and Engineering, University of North Texas, 1155 Union Circle #305310, Denton, TX 76203-5017, USA; The Joint Studio, Hollywood Medical Centre, 85 Monash Avenue, Nedlands, WA 6009, Australia; Australian Institute of Robotic Orthopaedics, 2 Centro Avenue, Subiaco, WA 6008, Australia ; Department of Computing, School of Electrical Engineering and Computing, Curtin University, Kent Street, Bentley, WA 6102, Australia
| | - Daniel P Fick
- Laboratory for Laser Aided Additive and Subtractive Manufacturing, Virtual Center for Advanced Orthopaedics, Department of Materials Science and Engineering, University of North Texas, 1155 Union Circle #305310, Denton, TX 76203-5017, USA; The Joint Studio, Hollywood Medical Centre, 85 Monash Avenue, Nedlands, WA 6009, Australia; Australian Institute of Robotic Orthopaedics, 2 Centro Avenue, Subiaco, WA 6008, Australia ; Department of Computing, School of Electrical Engineering and Computing, Curtin University, Kent Street, Bentley, WA 6102, Australia
| | - William B Robertson
- Laboratory for Laser Aided Additive and Subtractive Manufacturing, Virtual Center for Advanced Orthopaedics, Department of Materials Science and Engineering, University of North Texas, 1155 Union Circle #305310, Denton, TX 76203-5017, USA; Australian Institute of Robotic Orthopaedics, 2 Centro Avenue, Subiaco, WA 6008, Australia ; Department of Computing, School of Electrical Engineering and Computing, Curtin University, Kent Street, Bentley, WA 6102, Australia
| | - Raymond K Sheh
- Department of Computing, School of Electrical Engineering and Computing, Curtin University, Kent Street, Bentley, WA 6102, Australia
| | - Charlie N Ironside
- Department of Physics and Astronomy, School of Science and Engineering, Curtin University, Kent Street, Bentley, WA 6102, Australia
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Le QT, Bertrand C, Vilar R. Femtosecond laser ablation of enamel. JOURNAL OF BIOMEDICAL OPTICS 2016; 21:65005. [PMID: 27330005 DOI: 10.1117/1.jbo.21.6.065005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 06/01/2016] [Indexed: 06/06/2023]
Abstract
The surface topographical, compositional, and structural modifications induced in human enamel by femtosecond laser ablation is studied. The laser treatments were performed using a Yb:KYW chirped-pulse-regenerative amplification laser system (560 fs and 1030 nm) and fluences up to 14 J/cm2. The ablation surfaces were studied by scanning electron microscopy, grazing incidence x-ray diffraction, and micro-Raman spectroscopy. Regardless of the fluence, the ablation surfaces were covered by a layer of resolidified material, indicating that ablation is accompanied by melting of hydroxyapatite. This layer presented pores and exploded gas bubbles, created by the release of gaseous decomposition products of hydroxyapatite (CO2 and H2O) within the liquid phase. In the specimen treated with 1-kHz repetition frequency and 14 J/cm2, thickness of the resolidified material is in the range of 300 to 900 nm. The micro-Raman analysis revealed that the resolidified material contains amorphous calcium phosphate, while grazing incidence x-ray diffraction analysis allowed detecting traces of a calcium phosphate other than hydroxyapatite, probably β-tricalcium phosphate Ca3(PO4)2, at the surface of this specimen. The present results show that the ablation of enamel involves melting of enamel’s hydroxyapatite, but the thickness of the altered layer is very small and thermal damage of the remaining material is negligible.
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Affiliation(s)
- Quang-Tri Le
- Lisbon University, Instituto Superior Técnico and CeFEMA Center of Physics and Engineering of Advanced Materials, Avenida Rovisco Pais, 1049-001 Lisboa, PortugalbLaboratoire ICMCB-CNRS-UPR9048, 87, Avenue du Dr Albert Schweitzer, 33608 PESSAC Cedex, Franc
| | - Caroline Bertrand
- Laboratoire ICMCB-CNRS-UPR9048, 87, Avenue du Dr Albert Schweitzer, 33608 PESSAC Cedex, France
| | - Rui Vilar
- Lisbon University, Instituto Superior Técnico and CeFEMA Center of Physics and Engineering of Advanced Materials, Avenida Rovisco Pais, 1049-001 Lisboa, Portugal
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An automatic tooth preparation technique: A preliminary study. Sci Rep 2016; 6:25281. [PMID: 27125874 PMCID: PMC4850428 DOI: 10.1038/srep25281] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 04/13/2016] [Indexed: 11/28/2022] Open
Abstract
The aim of this study is to validate the feasibility and accuracy of a new automatic tooth preparation technique in dental healthcare. An automatic tooth preparation robotic device with three-dimensional motion planning software was developed, which controlled an ultra-short pulse laser (USPL) beam (wavelength 1,064 nm, pulse width 15 ps, output power 30 W, and repeat frequency rate 100 kHz) to complete the tooth preparation process. A total of 15 freshly extracted human intact first molars were collected and fixed into a phantom head, and the target preparation shapes of these molars were designed using customised computer-aided design (CAD) software. The accuracy of tooth preparation was evaluated using the Geomagic Studio and Imageware software, and the preparing time of each tooth was recorded. Compared with the target preparation shape, the average shape error of the 15 prepared molars was 0.05–0.17 mm, the preparation depth error of the occlusal surface was approximately 0.097 mm, and the error of the convergence angle was approximately 1.0°. The average preparation time was 17 minutes. These results validated the accuracy and feasibility of the automatic tooth preparation technique.
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20
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Femtosecond laser for cavity preparation in enamel and dentin: ablation efficiency related factors. Sci Rep 2016; 6:20950. [PMID: 26864679 PMCID: PMC4750072 DOI: 10.1038/srep20950] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2015] [Accepted: 01/13/2016] [Indexed: 12/13/2022] Open
Abstract
To study the effects of laser fluence (laser energy density), scanning line spacing and ablation depth on the efficiency of a femtosecond laser for three-dimensional ablation of enamel and dentin. A diode-pumped, thin-disk femtosecond laser (wavelength 1025 nm, pulse width 400 fs) was used for the ablation of enamel and dentin. The laser spot was guided in a series of overlapping parallel lines on enamel and dentin surfaces to form a three-dimensional cavity. The depth and volume of the ablated cavity was then measured under a 3D measurement microscope to determine the ablation efficiency. Different values of fluence, scanning line spacing and ablation depth were used to assess the effects of each variable on ablation efficiency. Ablation efficiencies for enamel and dentin were maximized at different laser fluences and number of scanning lines and decreased with increases in laser fluence or with increases in scanning line spacing beyond spot diameter or with increases in ablation depth. Laser fluence, scanning line spacing and ablation depth all significantly affected femtosecond laser ablation efficiency. Use of a reasonable control for each of these parameters will improve future clinical application.
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21
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Mozaffari HR, Ehteshami A, Zallaghi F, Chiniforush N, Moradi Z. Microleakage in Class V Composite Restorations after Desensitizing Surface Treatment with Er:YAG and CO 2 Lasers. Laser Ther 2016; 25:259-266. [PMID: 28765670 DOI: 10.5978/islsm.16-or-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Aims: Glutaraldehyde, CO2 and Er:YAG lasers can be used for treatment of dentin hypersensitivity. However, their application may have adverse effects on the clinical service of restorations. This study aimed to assess the microleakage in composite restorations following surface treatment with Glutaraldehyde desensitizer, CO2 and Er:YAG laser irradiation for treatment of dentin hypersensitivity. Materials and methods: This experimental study was conducted on 60 extracted sound human teeth. Class V cavities were prepared measuring 3×3 mm using a diamond bur. Specimens were randomly divided into 4 groups of 15. Group one:no surface treatment, Group two:applying Glutaraldehyde desensitizer, Groups of three and four were irradiated with CO2 and Er:YAG lasers, respectively. Surfaces were restored with bonding agent (Single Bond 2, 3M, USA) and Z250 composite (3M, USA). Specimens were thermocycled and immersed in 1% methylene blue solution for 24 hours. Microleakage scores were assessed under a stereomicroscope at ×20 magnification. Data were analyzed using SPSS and the Kruskal Wallis test (P=0.05). Results: There was no significant difference between microleakage of groups in enamel margins (P=0.694). The difference in microleakage at the dentin margin was significant between groups (P=0.018). Conclusions: Application of Glutaraldehyde-desensitizer and CO2 laser irradiation of surfaces prior to composite restoration do not increase microleakage at the enamel or dentin margins but tooth surface treatment with Er:YAG laser significantly increased the microleakage at the dentin margins.
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Affiliation(s)
- Hamid Reza Mozaffari
- Oral Medicine Department, School of Dentistry, Kermanshah University of Medical Sciences
| | | | | | - Nasim Chiniforush
- Laser Research Center of Dentistry, Tehran University of Medical Sciences
| | - Zohreh Moradi
- Operative Department, School of Dentistry, Tehran University of Medical Sciences
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Chen H, Liu J, Li H, Ge W, Sun Y, Wang Y, Lü P. Femtosecond laser ablation of dentin and enamel: relationship between laser fluence and ablation efficiency. JOURNAL OF BIOMEDICAL OPTICS 2015; 20:28004. [PMID: 25695161 DOI: 10.1117/1.jbo.20.2.028004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 01/30/2015] [Indexed: 05/03/2023]
Abstract
The objective was to study the relationship between laser fluence and ablation efficiency of a femtosecond laser with a Gaussian-shaped pulse used to ablate dentin and enamel for prosthodontic tooth preparation. A diode-pumped thin-disk femtosecond laser with wavelength of 1025 nm and pulse width of 400 fs was used for the ablation of dentin and enamel. The laser spot was guided in a line on the dentin and enamel surfaces to form a groove-shaped ablation zone under a series of laser pulse energies. The width and volume of the ablated line were measured under a three-dimensional confocal microscope to calculate the ablation efficiency. Ablation efficiency for dentin reached a maximum value of 0.020 mm3∕J when the laser fluence was set at 6.51 J∕cm2. For enamel, the maximum ablation efficiency was 0.009 mm3∕J at a fluence of 7.59 J∕cm2.Ablation efficiency of the femtosecond laser on dentin and enamel is closely related to the laser fluence and may reach a maximum when the laser fluence is set to an appropriate value.
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Affiliation(s)
- Hu Chen
- Peking University School and Hospital of Stomatology and National Engineering Laboratory for Digital and Material Technology of Stomatology, and Research Center of Engineering and Technology for Digital Dentistry of Ministry of Health, Center of Digital D
| | - Jing Liu
- Peking University School and Hospital of Stomatology and National Engineering Laboratory for Digital and Material Technology of Stomatology, and Research Center of Engineering and Technology for Digital Dentistry of Ministry of Health, Center of Digital D
| | - Hong Li
- Peking University School and Hospital of Stomatology and National Engineering Laboratory for Digital and Material Technology of Stomatology, and Research Center of Engineering and Technology for Digital Dentistry of Ministry of Health, Center of Digital D
| | - Wenqi Ge
- Chinese Academy of Sciences, Academy of Opto-Electronics, No. 9, Deng Zhuang South Road, Haidian District, Beijing 100094, China
| | - Yuchun Sun
- Peking University School and Hospital of Stomatology and National Engineering Laboratory for Digital and Material Technology of Stomatology, and Research Center of Engineering and Technology for Digital Dentistry of Ministry of Health, Center of Digital D
| | - Yong Wang
- Peking University School and Hospital of Stomatology and National Engineering Laboratory for Digital and Material Technology of Stomatology, and Research Center of Engineering and Technology for Digital Dentistry of Ministry of Health, Center of Digital D
| | - Peijun Lü
- Peking University School and Hospital of Stomatology and National Engineering Laboratory for Digital and Material Technology of Stomatology, and Research Center of Engineering and Technology for Digital Dentistry of Ministry of Health, Center of Digital D
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Huang H, Yang LM, Bai S, Liu J. Smart surgical tool. JOURNAL OF BIOMEDICAL OPTICS 2015; 20:28001. [PMID: 25649628 DOI: 10.1117/1.jbo.20.2.028001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 01/08/2015] [Indexed: 05/04/2023]
Abstract
A laser-induced breakdown spectroscopy (LIBS) guided smart surgical tool using a femtosecond fiber laser is developed. This system provides real-time material identification by processing and analyzing the peak intensity and ratio of atomic emissions of LIBS signals. Algorithms to identify emissions of different tissues and metals are developed and implemented into the real-time control system. This system provides a powerful smart surgical tool for precise robotic microsurgery applications with real-time feedback and control.
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Affiliation(s)
- Huan Huang
- PolarOnyx, Inc., 2526 Qume Drive, Suite 17 & 18, San Jose, California 95131, United States
| | - Lih-Mei Yang
- PolarOnyx Laser, Inc., 2526 Qume Drive, Suite 18, San Jose, California 95131, United States
| | - Shuang Bai
- PolarOnyx, Inc., 2526 Qume Drive, Suite 17 & 18, San Jose, California 95131, United States
| | - Jian Liu
- PolarOnyx, Inc., 2526 Qume Drive, Suite 17 & 18, San Jose, California 95131, United States
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Wang L, Wang D, Zhang Y, Ma L, Sun Y, Lv P. An automatic robotic system for three-dimensional tooth crown preparation using a picosecond laser. Lasers Surg Med 2014; 46:573-81. [PMID: 25138097 DOI: 10.1002/lsm.22274] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/11/2014] [Indexed: 11/09/2022]
Affiliation(s)
- Lei Wang
- State Key Lab of Virtual Reality Technology and Systems; Beihang University; Beijing China
| | - Dangxiao Wang
- State Key Lab of Virtual Reality Technology and Systems; Beihang University; Beijing China
| | - Yuru Zhang
- State Key Lab of Virtual Reality Technology and Systems; Beihang University; Beijing China
| | - Lei Ma
- State Key Lab of Virtual Reality Technology and Systems; Beihang University; Beijing China
| | - Yuchun Sun
- School and Hospital of Stomatology; Peking University; Beijing China
| | - Peijun Lv
- School and Hospital of Stomatology; Peking University; Beijing China
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Sozzi M, Fornaini C, Cucinotta A, Merigo E, Vescovi P, Selleri S. Dental ablation with 1064 nm, 500 ps, Diode pumped solid state laser: A preliminary study. Laser Ther 2013; 22:195-9. [PMID: 24204093 DOI: 10.3136/islsm.22.195] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2013] [Accepted: 07/29/2013] [Indexed: 12/26/2022]
Abstract
BACKGROUND The Er:YAG laser in conservative dentistry is. good alternative to conventional instruments. Though several studies show the advantages of these devices, some drawbacks and unsolved problems are still present, such as the cost of the device and the large dimensions of the equipment. PURPOSE In the present study, the effectiveness of dental surface ablation with a picosecond infrared diode-pumped solid-state (DPSS) laser was investigated. In vitro tests on extracted human teeth were carried out, with assessment of the ablation quality in the tooth and thermal increase inside the pulp chamber. MATERIALS AND METHODS A solid-state picosecond laser was used for the experiments. The samples were exposed to laser energy at 1064 nm at a frequency of 30 kHz and a 500 ps pulse width. The target teeth were cooled during exposures. The internal temperature of the pulp chamber was monitored with. thermocouple. RESULTS Optical microscope images showed effective ablation with the absence of carbonisation and micro-cracks. The cooling maintained the temperature rise in the pulp chamber below the permitted 5.5°C. DISCUSSION The main problem with the use of lasers in dentistry when teeth are the target is the heat generated in the pulp chamber of the target teeth. With lasers operating in the femtosecond mode, a better management of the internal temperature is possible, but is offset by the high cost of such devices. With the ps domain system used in the present study together with cooling using chilled water, effective and clean ablation could be achieved with a controlled thermal effect in the pulp chamber. CONCLUSIONS In this preliminary study with a picosecond domain DPSS laser using water cooling for the target, effective hard tissue ablation was achieved keeping the thermal increase in the pulp within the permitted range. The results suggest that this system could be used in clinical practice with appropriate modifications.
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Ultrashort pulsed laser (USPL) application in dentistry: basic investigations of ablation rates and thresholds on oral hard tissue and restorative materials. Lasers Med Sci 2013; 29:1775-83. [DOI: 10.1007/s10103-013-1315-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2012] [Accepted: 04/03/2013] [Indexed: 11/26/2022]
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Luengo MCL, Portillo M, Sánchez JM, Peix M, Moreno P, García A, Montero J, Albaladejo A. Evaluation of micromorphological changes in tooth enamel after mechanical and ultrafast laser preparation of surface cavities. Lasers Med Sci 2012; 28:267-73. [DOI: 10.1007/s10103-012-1144-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2011] [Accepted: 06/21/2012] [Indexed: 10/28/2022]
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Precise ablation of dental hard tissues with ultra-short pulsed lasers. Preliminary exploratory investigation on adequate laser parameters. Lasers Med Sci 2012; 28:171-84. [DOI: 10.1007/s10103-012-1107-2] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Accepted: 04/16/2012] [Indexed: 11/27/2022]
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Lü T, Xiao Q, Li Z. Influence of water environment on holmium laser ablation performance for hard tissues. APPLIED OPTICS 2012; 51:2505-2514. [PMID: 22614434 DOI: 10.1364/ao.51.002505] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Accepted: 01/31/2012] [Indexed: 06/01/2023]
Abstract
This study clarifies the ablation differences in air and in water for hard biological tissues, which are irradiated by fiber-guided long-pulsed holmium lasers. High-speed photography is used to record the dynamic characteristics of ablation plumes and vaporization bubbles induced by pulsed holmium lasers. The ablation morphologies and depth of hard tissues are quantitatively measured by optical coherence microscopy. Explosive vaporization effects in water play a positive role in the contact ablation process and are directly responsible for significant ablation enhancement. Furthermore, water layer depth can also contribute to ablation performance. Under the same laser parameters for fiber-tissue contact ablation in air and water, ablation performances are comparable for a single-laser pulse, but for more laser pulses the ablation performances in water are better than those in air. Comprehensive knowledge of ablation differences under various environments is important, especially in medical procedures that are performed in a liquid environment.
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Affiliation(s)
- Tao Lü
- School of Mathematics and Physics, China University of Geosciences, Wuhan 430074, China.
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LIN M, LUO ZY, BAI BF, XU F, LU TJ. FLUID DYNAMICS ANALYSIS OF SHEAR STRESS ON NERVE ENDINGS IN DENTINAL MICROTUBULE: A QUANTITATIVE INTERPRETATION OF HYDRODYNAMIC THEORY FOR DENTAL PAIN. J MECH MED BIOL 2011. [DOI: 10.1142/s0219519411003983] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Noxious thermal and/or mechanical stimuli applied to dentine can cause fluid flow in dentinal microtubules (DMTs). The fluid flow induces shear stress (SS) on intradental nerve endings and may excite pulpal mechanoreceptors to generate dental pain sensation. There exist numerous studies on dental thermal pain, but few are mathematical. For this, we developed a computational fluid dynamics (CFD) model of dentinal fluid flow (DFF) in innervated DMTs. Based on this model, we systematically investigated the effects of various parameters (e.g., biological structure, DFF velocity, and fluid properties) on the SS experienced by intradental nerve endings and thus provide a quantitative interpretation to the hydrodynamic theory. The dimensions of biological structures, odontoblastic process (OP) movement, dentinal fluid velocity, and viscosity were found to have significant influences on the SS while dentinal fluid density showed negligible influence under conditions studied. The results indicate that: (i) dental pain study of animal models may not be directly applied to human being and the results may even vary from one person to another and (ii) OP movement caused by DFF changes the dimension of the space for the fluid flow, affecting thus the SS on nerve endings. The present work enables better understanding of the mechanisms underlying dental pain sensation and quantification of dental pain intensity resulted from clinical procedures such as dentine sensitivity testing and dental restorative processes.
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Affiliation(s)
- M. LIN
- Biomedical Engineering and Biomechanics Center, School of Aerospace, Xi'an Jiaotong University, Xi'an 710049, P. R. China
| | - Z. Y. LUO
- State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University Xi'an 710049, P. R. China
| | - B. F. BAI
- State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University Xi'an 710049, P. R. China
| | - F. XU
- Biomedical Engineering and Biomechanics Center, School of Aerospace, Xi'an Jiaotong University, Xi'an 710049, P. R. China
- HST-Center for Biomedical Engineering, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - T. J. LU
- Biomedical Engineering and Biomechanics Center, School of Aerospace, Xi'an Jiaotong University, Xi'an 710049, P. R. China
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31
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A review of heat transfer in human tooth—Experimental characterization and mathematical modeling. Dent Mater 2010; 26:501-13. [DOI: 10.1016/j.dental.2010.02.009] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2009] [Revised: 01/04/2010] [Accepted: 02/23/2010] [Indexed: 12/28/2022]
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Abstract
Femtosecond laser ablation permits non-invasive surgeries in the bulk of a sample with submicrometer resolution. We briefly review the history of optical surgery techniques and the experimental background of femtosecond laser ablation. Next, we present several clinical applications, including dental surgery and eye surgery. We then summarize research applications, encompassing cell and tissue studies, research on C. elegans, and studies in zebrafish. We conclude by discussing future trends of femtosecond laser systems and some possible application directions.
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Affiliation(s)
- Samuel H Chung
- School of Engineering and Applied Sciences, Harvard University, 9 Oxford Street, Cambridge, MA 02138, USA.
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Faktorovich EG. Femtodynamics: optimizing femtosecond laser settings and procedure techniques to optimize outcomes. Int Ophthalmol Clin 2008; 48:41-50. [PMID: 18209556 DOI: 10.1097/iio.0b013e31815eba62] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Affiliation(s)
- Ella G Faktorovich
- Pacific Vision Institute, One Daniel Burnham Court, San Francisco, CA 94109, USA
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34
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Laser literature watch. Photomed Laser Surg 2004; 22:261-76. [PMID: 15315736 DOI: 10.1089/1549541041438588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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