1
|
Pu T, Wang J, Wang W, Jing B, Han Q, Li C, Liang H. In vivo biological safety investigation of Yb-CALGO femtosecond laser dental surgery. OPTICS LETTERS 2024; 49:3612-3615. [PMID: 38950222 DOI: 10.1364/ol.525402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Accepted: 05/26/2024] [Indexed: 07/03/2024]
Abstract
While lasers have found their successful applications in various clinical specialties, in clinical dental practice, traditional mechanical drills are still predominantly utilized. Although erbium-doped lasers have been demonstrated for dental therapy, their clinical performance is still not satisfactory due to the long pulse width, low peak power, and small repetition rate. To attain a smaller thermal diffusion thus better biological safety and surgical precision, as well as more rapid ablation, the advancement of femtosecond laser techniques has opened another route of dental surgery; however, no biological safety investigation has been reported. Here, we present a systematic study of dental ablation by a Yb:CaAlGdO4 regenerative amplifier with a central wavelength of 1040 nm and pulse width of 160 fs. The in vivo experiment of dental surgery investigating the inflammatory response has been reported, for the first time to the best of our knowledge. It is demonstrated that dental surgery by Yb:CaAlGdO4 femtosecond laser ablation has better biological safety compared to the turbine drilling, thanks to its non-contact and ultrafast heat dissipation nature.
Collapse
|
2
|
Woodfield PL, Rode AV, Dao D, Dau VT, Madden S, Walsh LJ, Spallek H, Walsh L, Sutton AJ, Zuaiter O, Habeb A, Hirst TR, Rapp L. Optical penetration models for practical prediction of femtosecond laser ablation of dental hard tissue. Lasers Surg Med 2024; 56:371-381. [PMID: 38563442 DOI: 10.1002/lsm.23784] [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] [Received: 10/27/2023] [Revised: 01/30/2024] [Accepted: 03/20/2024] [Indexed: 04/04/2024]
Abstract
OBJECTIVES To develop and practically test high-precision femtosecond laser ablation models for dental hard tissue that are useful for detailed planning of automated laser dental restorative treatment. METHODS Analytical models are proposed, derived, and demonstrated for practical calculation of ablation rates, ablation efficiency and ablated morphology of human dental enamel and dentin using femtosecond lasers. The models assume an effective optical attenuation coefficient for the irradiated material. To achieve ablation, it is necessary for the local energy density of the attenuated pulse in the hard tissue to surpass a predefined threshold that signifies the minimum energy density required for material ionization. A 1029 nm, 40 W carbide 275 fs laser was used to ablate sliced adult human teeth and generate the data necessary for testing the models. The volume of material removed, and the shape of the ablated channel were measured using optical profilometry. RESULTS The models fit with the measured ablation efficiency curve against laser fluence for both enamel and dentin, correctly capturing the fluence for optimum ablation and the volume of ablated material per pulse. The detailed shapes of a 400-micrometer wide channel and a single-pulse width channel are accurately predicted using the superposition of the analytical result for a single pulse. CONCLUSIONS The findings have value for planning automated dental restorative treatment using femtosecond lasers. The measurements and analysis give estimates of the optical properties of enamel and dentin irradiated with an infrared femtosecond laser at above-threshold fluence and the proposed models give insight into the physics of femtosecond laser processing of dental hard tissue.
Collapse
Affiliation(s)
- Peter L Woodfield
- School of Engineering and Built Environment, Griffith University, Gold Coast, Queensland, Australia
| | - Andrei V Rode
- Department of Quantum Science and Technology, Research School of Physics, Laser Physics Centre, Australian National University, Canberra, Australian Capital Territory, Australia
| | - Dzung Dao
- School of Engineering and Built Environment, Griffith University, Gold Coast, Queensland, Australia
| | - Van Thanh Dau
- School of Engineering and Built Environment, Griffith University, Gold Coast, Queensland, Australia
| | - Steve Madden
- Department of Quantum Science and Technology, Research School of Physics, Laser Physics Centre, Australian National University, Canberra, Australian Capital Territory, Australia
| | - Laurence J Walsh
- School of Dentistry, The University of Queensland, Herston, Queensland, Australia
- Dentroid Pty Ltd, Canberra, Australian Capital Territory, Australia
| | - Heiko Spallek
- Faculty of Medicine and Health, The University of Sydney School of Dentistry, Surry Hills, New South Wales, Australia
| | - Lee Walsh
- Platypus MedTech Consulting Pty Ltd, Barton, Australian Capital Territory, Australia
| | - Andrew J Sutton
- Centre for Gravitational Astrophysics, The Australian National University, Acton, Australian Capital Territory, Australia
| | - Omar Zuaiter
- Dentroid Pty Ltd, Canberra, Australian Capital Territory, Australia
| | - Alaa Habeb
- Dentroid Pty Ltd, Canberra, Australian Capital Territory, Australia
| | - Timothy R Hirst
- Dentroid Pty Ltd, Canberra, Australian Capital Territory, Australia
| | - Ludovic Rapp
- Department of Quantum Science and Technology, Research School of Physics, Laser Physics Centre, Australian National University, Canberra, Australian Capital Territory, Australia
| |
Collapse
|
3
|
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.
Collapse
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
| |
Collapse
|
4
|
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.
Collapse
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
| |
Collapse
|
5
|
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.
Collapse
|
6
|
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
| |
Collapse
|
7
|
Casarin HH, Mattos VS, de Castro Neto JC, Chinelatti MA. Chemical and morphological changes of femtosecond laser-irradiated enamel using subablative parameters. Microsc Res Tech 2021; 84:2399-2408. [PMID: 33908132 DOI: 10.1002/jemt.23795] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 04/14/2021] [Indexed: 01/30/2023]
Abstract
Chemical composition of dental enamel has a great relationship with the prevention of caries. The objective of the present work was to evaluate the chemical and morphological changes of femtosecond laser-irradiated enamel with subablative parameters using Raman spectroscopy, confocal laser scanning microscopy (CLSM), and scanning electron microscopy (SEM). Bovine incisor teeth were used to obtain 30 enamel specimens (5 × 5 mm2 ). The chemical composition of the control sample was analyzed by Raman spectrometry to acquire the absorption spectrum, delimiting the areas under the carbonate and phosphate bands. This analysis was used to evaluate the change in the chemical composition of the sample after irradiation. The specimens were irradiated (IRR) with a Ti:Sapphire laser system (pulsed and focused modes, femtosecond regime 70 fs, average power of 1 W and exposure time of 15 s). After irradiation, the areas under the carbonate and phosphate absorption bands were delimited in each specimen. Raman spectrometry data were analyzed using Student's t-test (α = 5%). By comparing the spectra of the IRR and non-irradiated (NI) specimens, the results showed a significant increase in the area value for the phosphate peaks and a significant reduction in the area value for the carbonate peak and the carbonate:phosphate ratio. CLSM and SEM analyses did not reveal structural alterations in the subsurface nor morphological alterations in the IRR enamel surface, respectively. It was concluded that femtosecond laser irradiation using subablative parameters reduced the carbonate content and the carbonate/phosphate ratio without altering the structure and morphology of the dental enamel.
Collapse
Affiliation(s)
- Heitor Hussni Casarin
- School of Dentistry, Central Paulista University Center - UNICEP São Carlos, São Carlos, Brazil
| | | | | | | |
Collapse
|
8
|
Loganathan S, Santhanakrishnan S, Bathe R, Arunachalam M. Physiochemical characteristics: A robust tool to overcome teeth heterogeneity on predicting laser ablation profile. J Biomed Mater Res B Appl Biomater 2020; 109:486-495. [PMID: 32869958 DOI: 10.1002/jbm.b.34717] [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: 05/05/2020] [Revised: 08/08/2020] [Accepted: 08/18/2020] [Indexed: 11/11/2022]
Abstract
To avoid excessive tissue removal and collateral damage, the high-power density laser is apt for dental surgery also need to have high precision. For high-precision dental surgery with minimal tissue damage, the present work frames a method to predict laser ablation profile based on surface morphology and chemical composition of dentin. The surface morphology and chemical composition were studied on different dentin samples using scanning electron microscope (SEM) and Energy Dispersive X-ray Analysis (EDAX), respectively. The key laser ablation parameters (ω0 , Deff , and Fth ) were determined by laser irradiation study using 800 nm, Ti:Sapphire femtosecond laser at processing condition of 100 fs, 10 kHz and 10 mm/s. The dentin samples show a strong linear correlation between physiochemical characteristics and laser ablation parameters. The surface morphology exhibits a negative linear correlation with threshold fluence, whereas the converse is true for chemical composition. The laser ablation parameters of a random dentin sample are derived from the knowledge of linearity data. From the obtained laser ablation parameters, the complete theoretical ablation profile is constructed and validated with experimental ablation profile. Even though the surface morphology of dentin shows high linearity, the concentration of Ca and P can be used as the most feasible probe in clinical settings. Furthermore, the laser ablation rate and ablation efficiency are predicted by the method to optimize the laser processing condition for any specific teeth. The versatility of the method overcomes the problem of heterogeneity on various teeth and simplifies the method of finding optimal laser processing condition for immaculate laser surgery.
Collapse
Affiliation(s)
- Sarathkumar Loganathan
- Manufacturing Engineering Section, Department of Mechanical Engineering, Indian Institute of Technology, Chennai, India
| | | | - Ravi Bathe
- Centre for Laser Processing of Materials, International Advanced Research Centre for Powder Metallurgy and New Materials (ARCI), Hyderabad, India
| | | |
Collapse
|
9
|
Özdoğan MS, Karaokutan I, Yıldırım M, Aydemir KA, Karatay A, Aykent F. Shear bond strength of a self-adhesive resin cement to dentin surface treated with Nd:YAG and femtosecond lasers. Lasers Med Sci 2020; 36:219-226. [PMID: 32869119 DOI: 10.1007/s10103-020-03138-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 08/27/2020] [Indexed: 10/23/2022]
Abstract
This study aims to evaluate the effect of Nd:YAG and femtosecond lasers irradiation on the shear bond strength (SBS) of a self-adhesive resin cement to the human dentin surface. One hundred extracted third molar teeth were randomly divided into 10 experimental groups according to dentin surface treatments; with and without the bonding agent, Nd:YAG 302 J/cm2 and 440 J/cm2, femtosecond 4 J/cm2 and 7 J/cm2, and control groups were prepared. After surface treatments, a self-adhesive resin cement was luted by using a bonding jig (Ultradent Products Inc.). The specimens were then subjected to shear test at a crosshead speed of 0.5 mm/min, and failure loads were recorded as megapascal (MPa). Two-way analysis of variance and Tukey HSD tests were performed (p ˂ 0.05). Representative specimens from each experimental subgroup were examined by means of SEM. The highest SBS values were obtained in Group 302 J/cm2 Nd:YAG with bonding agent, and there is no statistical difference between Group 440 J/cm2 Nd:YAG with bonding and Group 7 J/cm2 femtosecond with bonding (p > 0.05). The lowest SBS values were observed in Group control without bonding agent. Nd:YAG and femtosecond laser treatments improved the adhesion between the dentin surface and the self-adhesive resin cement.
Collapse
Affiliation(s)
- Mahmut Sertaç Özdoğan
- Department of Prosthodontics, Ankara Yıldırım Beyazıt University, Etlik-Keçiören, 06010, Ankara, Turkey.
| | - Işıl Karaokutan
- Department of Prosthodontics, Pamukkale University, Denizli, Turkey
| | - Mesut Yıldırım
- Department of Prosthodontics, Ankara Yıldırım Beyazıt University, Etlik-Keçiören, 06010, Ankara, Turkey
| | - Kübra Aybüke Aydemir
- Department of Prosthodontics, Ankara Yıldırım Beyazıt University, Etlik-Keçiören, 06010, Ankara, Turkey
| | - Ahmet Karatay
- Department of Engineering Physics, Faculty of Engineering, Ankara University, 06100 Beşevler, Ankara, Turkey
| | - Filiz Aykent
- Department of Prosthodontics, Ankara Yıldırım Beyazıt University, Etlik-Keçiören, 06010, Ankara, Turkey
| |
Collapse
|
10
|
Loganathan S, Santhanakrishnan S, Bathe R, Arunachalam M. Prediction of femtosecond laser ablation parameter on Human teeth using chemical compositional analysis. ACTA ACUST UNITED AC 2019. [DOI: 10.1016/j.promfg.2019.06.181] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
11
|
Prediction of femtosecond laser ablation profile on human teeth. Lasers Med Sci 2018; 34:693-701. [DOI: 10.1007/s10103-018-2644-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 09/17/2018] [Indexed: 11/29/2022]
|
12
|
Al-Hadeethi Y, Al-Jedani S, Razvi MAN, Saeed A, Abdel-Daiem AM, Ansari MS, Babkair SS, Salah NA, Al-Mujtaba A. Data Fitting to Study Ablated Hard Dental Tissues by Nanosecond Laser Irradiation. PLoS One 2016; 11:e0156093. [PMID: 27228169 PMCID: PMC4882067 DOI: 10.1371/journal.pone.0156093] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 05/09/2016] [Indexed: 12/03/2022] Open
Abstract
Laser ablation of dental hard tissues is one of the most important laser applications in dentistry. Many works have reported the interaction of laser radiations with tooth material to optimize laser parameters such as wavelength, energy density, etc. This work has focused on determining the relationship between energy density and ablation thresholds using pulsed, 5 nanosecond, neodymium-doped yttrium aluminum garnet; Nd:Y3Al5O12 (Nd:YAG) laser at 1064 nanometer. For enamel and dentin tissues, the ablations have been performed using laser-induced breakdown spectroscopy (LIBS) technique. The ablation thresholds and relationship between energy densities and peak areas of calcium lines, which appeared in LIBS, were determined using data fitting. Furthermore, the morphological changes were studied using Scanning Electron Microscope (SEM). Moreover, the chemical stability of the tooth material after ablation has been studied using Energy-Dispersive X-Ray Spectroscopy (EDX). The differences between carbon atomic % of non-irradiated and irradiated samples were tested using statistical t-test. Results revealed that the best fitting between energy densities and peak areas of calcium lines were exponential and linear for enamel and dentin, respectively. In addition, the ablation threshold of Nd:YAG lasers in enamel was higher than that of dentin. The morphology of the surrounded ablated region of enamel showed thermal damages. For enamel, the EDX quantitative analysis showed that the atomic % of carbon increased significantly when laser energy density increased.
Collapse
Affiliation(s)
- Y. Al-Hadeethi
- Physics Department, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
- Lithography in Devices Fabrication and Development Research Group, DSR, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - S. Al-Jedani
- Physics Department, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - M. A. N. Razvi
- Physics Department, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - A. Saeed
- Physics Department, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
- Thamar University, Thamar, Yemen
| | - A. M. Abdel-Daiem
- Physics Department, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
- Physics Department, Faculty of Science, Zagazig University, Zagazig, Egypt
| | | | - Saeed S. Babkair
- Physics Department, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| | - Numan A. Salah
- Physics Department, Faculty of Science, Zagazig University, Zagazig, Egypt
| | - A. Al-Mujtaba
- Physics Department, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
| |
Collapse
|
13
|
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.
Collapse
|