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Nahas P, Houeis S, Chamboredon R, Heysselaer D, Zeinoun T, Nammour S. Assessment of the Periodontal Cementum Ablation Depth during Root Planing by an Er:YAG Laser at Different Energy Densities: An Ex Vivo Study. Dent J (Basel) 2023; 11:dj11050116. [PMID: 37232767 DOI: 10.3390/dj11050116] [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: 12/09/2022] [Revised: 04/11/2023] [Accepted: 04/25/2023] [Indexed: 05/27/2023] Open
Abstract
INTRODUCTION An important and non-adapted delivered energy of Er:YAG laser can eliminate the total thickness of root cementum during root planing. Conversely, the preservation of a partial layer of cementum covering the roots is vital for any periodontal ligament regeneration. Thus, the assessment of the cementum ablation depth produced by each energy density of Er:YAG laser is essential before considering its use for the periodontal planing and treatment of the cementum and root surfaces. AIM OF THE STUDY Assessment of the cementum ablation depth at different energy densities of the Er:YAG laser is the aim of this study. MATERIALS AND METHODS A total of 48 human caries free molars were collected and used in this study. Areas to be irradiated were delimited by two longitudinal grooves (0.5 mm depth). Roots were divided randomly into four groups (4 × n = 12). An Er:YAG laser (2.94 µm) was used with a side-firing tip (R600T) with a 600 µm diameter and a frequency of 20 Hz combined with a cooling system of air 6 mL/min and water 4 mL/min. We used a super short pulse mode (SSP: pulse duration: 50 μs). We used a single irradiation passage backward from apex to cervical parts at 1 mm/s with a slight contact and at an angle of 15° to 30° between the tip and the root surface. Different energies were selected: 30 mJ, 40 mJ, 50 mJ, and 60 mJ. RESULTS Microscopic observations showed that the average of the ablation depth increased with the increase of the delivered energy from 30 mJ to 60 mJ. Mean values of the ablation depths were respectively as follows: 43.75 ± 4.89 µm for the energy of 30 mJ, 50.05 ± 3.72 µm for 40 mJ, 65.56 ± 10.35 µm for 50 mJ, and 74.80 ± 15.23 µm for 60 mJ. A statistically significant difference existed between the ablation depth of all groups. CONCLUSION Based on our results, the depth of cementum debridement is related to the level of the delivered energy. The lowest energy levels (30 mJ and 40 mJ) can ablate the root cementum surface for a variable depth from 43.75 ± 4.89 μm to 50.05 ± 3.72 μm.
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Affiliation(s)
- Paul Nahas
- Department of Restorative and Esthetic Dentistry, Faculty of Dental Medicine, Lebanese University, Hadath campus, Beirut 1003, Lebanon
| | - Saad Houeis
- Department of Dental Science, Faculty of Medicine, University of Liege, 4000 Liege, Belgium
| | - Remi Chamboredon
- Department of Dental Science, Faculty of Medicine, University of Liege, 4000 Liege, Belgium
| | - Daniel Heysselaer
- Department of Dental Science, Faculty of Medicine, University of Liege, 4000 Liege, Belgium
| | - Toni Zeinoun
- Department of Oral and Maxillo-Facial Surgery, Dean of Faculty of Dental Medicine, Lebanese University, Beirut 1003, Lebanon
| | - Samir Nammour
- Department of Dental Science, Faculty of Medicine, University of Liege, 4000 Liege, Belgium
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García-Sanz V, Paredes-Gallardo V, Bellot-Arcís C, Martínez-León L, Torres-Mendieta R, Montero J, Albaladejo A. Femtosecond laser settings for optimal bracket bonding to zirconia. Lasers Med Sci 2018; 34:297-304. [DOI: 10.1007/s10103-018-2589-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 07/11/2018] [Indexed: 11/29/2022]
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García-Sanz V, Paredes-Gallardo V, Bellot-Arcís C, Mendoza-Yero O, Doñate-Buendía C, Montero J, Albaladejo A. Effects of femtosecond laser and other surface treatments on the bond strength of metallic and ceramic orthodontic brackets to zirconia. PLoS One 2017; 12:e0186796. [PMID: 29049418 PMCID: PMC5648233 DOI: 10.1371/journal.pone.0186796] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 10/07/2017] [Indexed: 11/19/2022] Open
Abstract
Femtosecond laser has been proposed as a method for conditioning zirconia surfaces to boost bond strength. However, metallic or ceramic bracket bonding to femtosecond laser-treated zirconia surfaces has not been tested. This study compared the effects of four conditioning techniques, including femtosecond laser irradiation, on shear bond strength (SBS) of metallic and ceramic brackets to zirconia.Three hundred zirconia plates were divided into five groups: 1) control (C); 2) sandblasting (APA); 3) silica coating and silane (SC); 4) femtosecond laser (FS); 5) sandblasting followed by femtosecond laser (APA+SC). A thermal imaging camera measured temperature changes in the zirconia during irradiation. Each group was divided into 2 subgroups (metallic vs ceramic brackets). SBS was evaluated using a universal testing machine. The adhesive remnant index (ARI) was registered and surfaces were observed under SEM. Surface treatment and bracket type significantly affected the bracket-zirconia bond strength. SBS was significantly higher (p<0.001) for ceramic brackets in all groups (APA+FS > APA > FS > SC > control) than metallic brackets (APA+FS > FS > SC > APA > control). For metallic brackets, groups SC (5.99 ± 1.86 MPa), FS (6.72 ± 2.30 MPa) and APA+FS (7.22 ± 2.73 MPa) reported significantly higher bond strengths than other groups (p < 0.05). For ceramic brackets, the highest bond strength values were obtained in groups APA (25.01 ± 4.45 MPa), FS (23.18 ± 6.51 MPa) and APA+FS (29.22 ± 8.20 MPa).Femtosecond laser enhances bond strength of ceramic and metallic brackets to zirconia. Ceramic brackets provide significantly stronger adhesion than metallic brackets regardless of the surface treatment method.
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Affiliation(s)
- Verónica García-Sanz
- Orthodontics Teaching Unit, Department of Stomatology, Faculty of Medicine and Dentistry, University of Valencia. Valencia, Spain
| | - Vanessa Paredes-Gallardo
- Orthodontics Teaching Unit, Department of Stomatology, Faculty of Medicine and Dentistry, University of Valencia. Valencia, Spain
| | - Carlos Bellot-Arcís
- Orthodontics Teaching Unit, Department of Stomatology, Faculty of Medicine and Dentistry, University of Valencia. Valencia, Spain
| | - Omel Mendoza-Yero
- GROC•UJI, Institute of New Imaging Technologies, Universitat Jaume I, Castellón, Spain
| | - Carlos Doñate-Buendía
- GROC•UJI, Institute of New Imaging Technologies, Universitat Jaume I, Castellón, Spain
| | - Javier Montero
- Orthodontics Teaching Unit, Department of Surgery, Faculty of Medicine, University of Salamanca, Salamanca, Spain
| | - Alberto Albaladejo
- Orthodontics Teaching Unit, Department of Surgery, Faculty of Medicine, University of Salamanca, Salamanca, Spain
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Saluja M, Grover HS, Choudhary P. Comparative Morphologic Evaluation and Occluding Effectiveness of Nd: YAG, CO2 and Diode Lasers on Exposed Human Dentinal Tubules: An Invitro SEM Study. J Clin Diagn Res 2016; 10:ZC66-70. [PMID: 27630957 PMCID: PMC5020193 DOI: 10.7860/jcdr/2016/18262.8188] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 04/04/2016] [Indexed: 11/24/2022]
Abstract
INTRODUCTION Dentinal hypersensitivity is one of the most common problem, encountered in dental practice but has least predictable treatment outcome. The advent of lasers in dentistry has provided an additional therapeutic option for treating dentinal hypersensitivity. Although various lasers have been tried over a period of time to treat dentinal hypersensitivity, but still the doubt persist as to which laser leads to maximum dentinal tubular occlusion and is most suitable with minimal hazardous effects. AIM To compare the effects of Nd: YAG, CO2 and 810-nm diode lasers on width of exposed dentinal tubule orifices and to evaluate the morphologic changes on dentinal surface of human tooth after laser irradiation by scanning electron microscope (SEM). MATERIALS AND METHODS Forty root specimens were obtained from ten freshly extracted human premolars, which were randomly divided into four groups of ten each. Group I: control group treated with only saline, Group II: Nd:YAG laser, Group III: CO2 laser and Group IV: 810-nm diode laser. The specimens were examined using SEM. After calculating mean tubular diameter for each group, the values were compared statistically using parametric one-way ANOVA test and Turkey's post hoc multiple comparison test. RESULTS All the three lased groups showed a highly statistical significant result with p-value of <0.001 as compared to non-lased group. On intergroup comparison within the lased groups, all the three groups showed statistically significant difference in the reduction of dentinal tubular diameter (p-value < 0.001). CONCLUSION Nd: YAG laser was found to be most effective, followed by the CO2 laser and 810-nm diode laser was found to be least effective. The morphologic changes like craters, cracks and charring effect of the dentine were seen maximum by the use of CO2 laser.
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Affiliation(s)
- Mini Saluja
- Reader, Department of Periodontology, Faculty of Dental Sciences, SGT University, Gurgaon, Haryana, India
| | - Harpreet Singh Grover
- Professor and Head, Department of Periodontology, Faculty of Dental Sciences, SGT University, Gurgaon, Haryana, India
| | - Pankaj Choudhary
- Postgraduate Student, Department of Periodontology, Faculty of Dental Sciences, SGT University, Gurgaon, Haryana, India
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Han SY, Kim JS, Kim YS, Kwon HK, Kim BI. Effect of a New Combined Therapy with Nano-Carbonate Apatite and CO2Laser on Dentin Hypersensitivity in anin SituModel. Photomed Laser Surg 2014; 32:394-400. [DOI: 10.1089/pho.2014.3710] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Sun Young Han
- Department of Preventive Dentistry and Public Oral Health, College of Dentistry, Yonsei University, Seoul, Korea
| | - Ji Sun Kim
- Department of Preventive Dentistry and Public Oral Health, College of Dentistry, Yonsei University, Seoul, Korea
| | - Young Seok Kim
- Department of Preventive Dentistry and Public Oral Health, College of Dentistry, Yonsei University, Seoul, Korea
| | - Ho Keun Kwon
- Department of Preventive Dentistry and Public Oral Health, College of Dentistry, Yonsei University, Seoul, Korea
| | - Baek Il Kim
- Department of Preventive Dentistry and Public Oral Health, College of Dentistry, Yonsei University, Seoul, Korea
- Oral Science Research Center, College of Dentistry, Seoul, Korea
- BK 21 PLUS Project, Yonsei University College of Dentistry, Seoul, Korea
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Hoffmann C, Berganza C, Zhang J. Cold Atmospheric Plasma: methods of production and application in dentistry and oncology. Med Gas Res 2013; 3:21. [PMID: 24083477 PMCID: PMC4016545 DOI: 10.1186/2045-9912-3-21] [Citation(s) in RCA: 159] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Accepted: 09/05/2013] [Indexed: 11/10/2022] Open
Abstract
Cold Atmospheric Plasma is an ionized gas that has recently been extensively studied by researchers as a possible therapy in dentistry and oncology. Several different gases can be used to produce Cold Atmospheric Plasma such as Helium, Argon, Nitrogen, Heliox, and air. There are many methods of production by which cold atmospheric plasma is created. Each unique method can be used in different biomedical areas. In dentistry, researchers have mostly investigated the antimicrobial effects produced by plasma as a means to remove dental biofilms and eradicate oral pathogens. It has been shown that reactive oxidative species, charged particles, and UV photons play the main role. Cold Atmospheric Plasma has also found a minor, but important role in tooth whitening and composite restoration. Furthermore, it has been demonstrated that Cold Atmospheric Plasma induces apoptosis, necrosis, cell detachment, and senescence by disrupting the S phase of cell replication in tumor cells. This unique finding opens up its potential therapy in oncology.
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Affiliation(s)
- Clotilde Hoffmann
- Department of Physiology, Loma Linda University School of Medicine, Risley Hall, Room 223, Loma Linda, CA 92354, USA
| | - Carlos Berganza
- Department of Physiology, Loma Linda University School of Medicine, Risley Hall, Room 223, Loma Linda, CA 92354, USA
| | - John Zhang
- Department of Physiology, Loma Linda University School of Medicine, Risley Hall, Room 223, Loma Linda, CA 92354, USA
- Department of Neurosurgery, Loma Linda University School of Medicine, Loma Linda, CA, USA
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Kim JS, Han SY, Kwon HK, Kim BI. Synergistic Effect of Dentinal Tubule Occlusion by Nano-Carbonate Apatite and CO2LaserIn Vitro. Photomed Laser Surg 2013; 31:392-7. [DOI: 10.1089/pho.2012.3470] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Ji Sun Kim
- Department of Preventive Dentistry and Public Oral Health, Research Center for Orofacial Hard Tissue Regeneration, Brain Korea 21 project, College of Dentistry, Yonsei University, Seoul, Republic of Korea
| | - Sun Young Han
- Department of Preventive Dentistry and Public Oral Health, Research Center for Orofacial Hard Tissue Regeneration, Brain Korea 21 project, College of Dentistry, Yonsei University, Seoul, Republic of Korea
| | - Ho Keun Kwon
- Department of Preventive Dentistry and Public Oral Health, Research Center for Orofacial Hard Tissue Regeneration, Brain Korea 21 project, College of Dentistry, Yonsei University, Seoul, Republic of Korea
| | - Baek Il Kim
- Department of Preventive Dentistry and Public Oral Health, Research Center for Orofacial Hard Tissue Regeneration, Brain Korea 21 project, College of Dentistry, Yonsei University, Seoul, Republic of Korea
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Sabaeian M, Shahzadeh M. Simulation of temperature and thermally induced stress of human tooth under CO2 pulsed laser beams using finite element method. Lasers Med Sci 2013; 30:645-51. [PMID: 23868367 DOI: 10.1007/s10103-013-1390-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Accepted: 07/08/2013] [Indexed: 12/13/2022]
Abstract
The authors report the simulation of temperature distribution and thermally induced stresses of human tooth under CO2 pulsed laser beam. A detailed tooth structure comprising enamel, dentin, and pulp with realistic shapes and thicknesses were considered, and a numerical method of finite element was adopted to solve time-dependent bio-heat and stress equations. The realistic boundary conditions of constant temperature for those parts embedded in the gingiva and heat flux condition for those parts out of the gingiva were applied. The results which were achieved as a function of energy density (J/cm(2)) showed when laser beam is irradiated downward (from the top of the tooth), the temperature and thermal stresses decrease quickly as a function of depth that is a result of strong absorption of CO2 beams by enamel. This effect is so influential that one can use CO2 beams to remove micrometer layers while underlying tissues, especially the pulp, are safe from thermal effects.
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Affiliation(s)
- Mohammad Sabaeian
- Physics Department, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran,
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Ramalho KM, de Paula Eduardo C, Heussen N, Rocha RG, Lampert F, Apel C, Esteves-Oliveira M. Protective effect of CO2 laser (10.6 μm) and fluoride on enamel erosion in vitro. Lasers Med Sci 2012; 28:71-8. [DOI: 10.1007/s10103-012-1071-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Accepted: 02/15/2012] [Indexed: 10/28/2022]
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Matsui S, Kozuka M, Takayama J, Ueda K, Nakamura H, Ito K, Kimura M, Miura H, Tsujimoto Y, Kondoh T, Ikemi T, Matsushima K. Stimulatory Effects of CO(2) Laser, Er:YAG Laser and Ga-Al-As Laser on Exposed Dentinal Tubule Orifices. J Clin Biochem Nutr 2011; 42:138-43. [PMID: 18385831 PMCID: PMC2266056 DOI: 10.3164/jcbn.2008020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2006] [Accepted: 10/09/2007] [Indexed: 11/22/2022] Open
Abstract
We investigated the effects of lasers irradiation on the exposed dentinal tubule. Human tooth specimens with exposed dentinal tubule orifices were used. Three types of lasers (CO2 laser, Er:YAG laser and Ga-Al-As laser) were employed. The parameters were 1.0 W in continuous-wave mode with an irradiation time of 30 s for the CO2 laser, 30 mJ in continuous-wave mode with an irradiation time of 60 s for the Er:YAG laser, and 1.0 W in continuous-wave mode with an irradiation time of 60 s for the Ga-Al-As laser. A non-irradiated group was used as a control. After laser irradiation, the dentinal surface of each sample was observed using SEM. Afterwards, all samples were immersed in methylene blue dye solution in order to evaluate the penetration of the dye solution and observe the change in dentinal permeability after laser irradiation. SEM observation showed that the control group had numerous exposed dentinal tubule orifices, whereas these orifices were closed in the laser-irradiated groups. There was consistent dye penetration into the pulp chamber in the control group, whereas no dye penetration was evident in the laser-irradiated groups. Therefore, laser appears to be a promising treatment for reducing permeation through exposed dentinal tubules.
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Affiliation(s)
- Satoshi Matsui
- Department of Clinical Oral Physiology, Nihon University School of Dentistry at Matsudo, 870-1, Sakaecho, Nishi-2, Matsudo, Chiba 271-8587, Japan
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Comparison of effects of diode laser and CO2 laser on human teeth and their usefulness in topical fluoridation. Lasers Med Sci 2010; 26:317-24. [DOI: 10.1007/s10103-010-0784-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2009] [Indexed: 10/19/2022]
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Vaderhobli RM, White JM, Le C, Ho S, Jordan R. In vitro study of the soft tissue effects of microsecond-pulsed CO2laser parameters during soft tissue incision and sulcular debridement. Lasers Surg Med 2010; 42:257-63. [DOI: 10.1002/lsm.20888] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Nomelini S, Souza-Gabriel A, Marchesan M, Sousa-Neto M, Silva-Sousa Y. Ultrastructural analysis of radicular dentine surface submitted to CO2laser at different parameters. Microsc Res Tech 2009; 72:737-43. [DOI: 10.1002/jemt.20723] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Firoozmand L, Faria R, Araujo MA, di Nicoló R, Huthala MF. Temperature rise in cavities prepared by high and low torque handpieces and Er:YAG laser. Br Dent J 2008; 205:E1; discussion 28-9. [PMID: 18535534 DOI: 10.1038/sj.bdj.2008.491] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/14/2007] [Indexed: 11/09/2022]
Abstract
OBJECTIVE The aim of this study was to compare intrapulpal temperature increases produced by a high-speed high-torque (speed-increasing) handpiece, a high-speed low-torque handpiece (air-turbine) and an Er:YAG (Erbium: Yttrium-Aluminum-Garnet) laser. SUBJECT AND METHODS Thirty bovine incisors were reduced to a dentine thickness of 2.0 mm. Class V preparations were prepared to a depth of 1.5 mm, measured with a caliper or by a mark on the burs. A thermocouple was placed inside the pulp chamber to determine temperature increases ( degrees C). Analysis was performed on the following groups (n = 10) treated with: G1, low-torque handpiece; G2, high-torque handpiece; and G3, Er:YAG laser (2.94 microm at 250 mJ/4 Hz), all with water cooling. The temperature increases were recorded with a computer linked to the thermocouples. RESULTS The data were submitted to ANOVA and Tukey statistical test. The average temperature rises were: 1.92+/-0.80 degrees C for G1, 1.34+/-0.86 degrees C for G2, and 0.75+/-0.39 degrees C for G3. There were significant statistical differences among the groups (p = 0.095). All the groups tested did not have a change of temperature that exceeds the threshold of 5.5 degrees C. CONCLUSION Temperature response to the low and high torque handpieces seemed to be similar, however the Er:YAG laser generated a lower temperature rise.
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Affiliation(s)
- L Firoozmand
- Faculty of Dentistry UNESP, Restorative Dentistry, Av. Eng. Francisco José Longo, 777 - Jd São Dimas, São José dos Campos 12245-000 SP, Brazil.
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Abstract
The cutting of dental hard tissue during restorative procedures presents considerable demands on the ability to selectively remove diseased carious tissue, obtain outline and retention form and maintain the integrity of supporting tooth tissue without structural weakening. In addition, the requirement to preserve healthy tissue and prevent further breakdown of the restoration places the choice of instrumentation and clinical technique as prime factors for the dental surgeon. The quest for an alternative treatment modality to the conventional dental turbine has been, essentially, patient-driven and has led to the development of various mechanical and chemical devices. The review of the literature has endorsed the beneficial effects of current laser machines. However utopian, there is additional evidence to support the development of ultra-short (nano- and femto-second) pulsed lasers that are stable in use and commercially viable, to deliver more efficient hard tissue ablation with less risk of collateral thermal damage. This paper explores the interaction of laser energy with dental hard tissues and bone and the integration of current laser wavelengths into restorative and surgical dentistry.
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Ekworapoj P, Sidhu SK, McCabe JF. Effect of different power parameters of Er,Cr:YSGG laser on human dentine. Lasers Med Sci 2007; 22:175-82. [PMID: 17242868 DOI: 10.1007/s10103-006-0426-6] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2006] [Revised: 08/04/2006] [Accepted: 11/16/2006] [Indexed: 11/28/2022]
Abstract
The aim of this work was to determine the optimal power setting of an Er,Cr:YSGG laser for cutting human dentine to produce a surface that remains suitable as a foundation on which to build and bond a dental restoration. The cutting efficiency and resulting microhardness of the dentine were evaluated for various laser power settings, and representative samples were examined by SEM. The microhardness of the dentine was significantly reduced by 30-50% (p < 0.05, paired t test) after laser irradiation, irrespective of the power setting used. The mean ablation efficiency increased in proportion to the power setting of the laser. Although the laser power setting did not affect the extent of reduction in microhardness, it did affect the microstructure of human dentine.
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Affiliation(s)
- Piyanart Ekworapoj
- School of Dental Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4BW, UK.
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Chinelatti MA, Ramos RP, Chimello DT, Corona SAM, Pécora JD, Dibb RGP. Influence of Er:YAG Laser on Cavity Preparation and Surface Treatment in Microleakage of Composite Resin Restorations. Photomed Laser Surg 2006; 24:214-8. [PMID: 16706702 DOI: 10.1089/pho.2006.24.214] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVE The purpose of this study was to assess microleakage on class V cavities prepared by Er:YAG laser with varying surface treatment. BACKGROUND DATA There has been little reported research on microleakage at cavities prepared and treated with Er:YAG laser. METHODS Fifty preparations using Er:YAG laser or a highspeed handpiece were developed. The surface treatment was performed as follows: Er:YAG laser (group 1); 35% phosphoric acid (group 2); laser + acid (group 3); finishing with low-speed + laser + acid (group 4); conventional preparation developed with a high-speed handpiece + acid (group 5--control). The samples were restored with Single Bond/Z250, thermocycled, isolated, and immersed in a 50% AgNO(3) solution. The restorations were sectioned, and the microleakage was measured in milimeters using a specific computer software. Data were analyzed employing ANOVAand Tukey test. RESULTS Statistical analysis showed that group 5 (G5) obtained the lowest results of microleakage (22.05%), and it was statistically similar (p > 0.05) to G1 (37.7%) and different (p < 0.05) from the other groups (G2 = 50.4%; G3 = 43%; G4 = 44.2%). The occlusal margins (22.62%) demonstrated less microleakage (p < 0.05) than the cervical margins (56.32%). CONCLUSION The use of Er:YAG laser for cavity preparation and surface treatment negatively influenced the marginal sealing of composite resin restorations.
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Affiliation(s)
- Michelle A Chinelatti
- Department of Operative Dentistry, Ribeirão Preto School of Dentistry, University of São Paulo (USP), Brazil
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Steiner-Oliveira C, Rodrigues LKA, Soares LES, Martin AA, Zezell DM, Nobre-dos-Santos M. Chemical, Morphological and Thermal Effects of 10.6-.MU.m CO2 Laser on the Inhibition of Enamel Demineralization. Dent Mater J 2006; 25:455-62. [PMID: 17076314 DOI: 10.4012/dmj.25.455] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Studies have shown that enamel can be modified by pulsed CO2 laser to form a more acid-resistant substrate. This study evaluated the effects of a 10.6-microm CO2 laser on enamel surface morphology and chemical composition as well as monitored intrapulpal temperature changes during irradiation. Human teeth were irradiated with fluences of 1.5-11.5 J/cm2, and pulpal thermal as well as chemical and morphological modifications on enamel were assessed. The teeth were submitted to a pH-cycling model, and the mineral loss was determined by means of cross-sectional microhardness. For all irradiated groups, intrapulpal temperature changes were below 3 degrees C. FT-Raman spectroscopy and scanning electron microscopy indicated that fluences as low as 6.0 J/cm2 were sufficient to induce chemical and morphological changes in enamel. Then, for fluences reaching or exceeding 10.0 J/cm2, laser-induced inhibitory effects on demineralization were observed. It was thus concluded that laser energy density in the range of 10.0 and 11.5 J/cm2 could be applied to dental enamel in order to produce chemical and morphological changes and reduce the acid reactivity of enamel without compromising the pulp vitality.
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Affiliation(s)
- Carolina Steiner-Oliveira
- Department of Pediatric Dentistry, Faculty of Dentistry of Piracicaba, State University of Campinas, São Paulo, Brazil
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Horiba N, Itoh A, Yamaguchi M, Matsumoto T, Senda A, Nakamura H. Effects of intracanal carbon dioxide laser irradiation on cultured human fibroblasts. ACTA ACUST UNITED AC 2005; 100:767-71. [PMID: 16301161 DOI: 10.1016/j.tripleo.2005.01.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2004] [Accepted: 01/06/2005] [Indexed: 10/25/2022]
Abstract
OBJECTIVE The purpose of this study was to evaluate, under various conditions, the damage that might occur to viable cells after CO2 laser irradiation of the root canal. STUDY DESIGN A laser tip was placed within the root canal of extracted human teeth that were positioned above cultured fibroblasts (NB cells), and then irradiation was applied. The irradiation modes used were either pulse (40 pps) or super-pulse (151 pps). The laser energy was set at 32 J in both modes, and the tip of the laser beam was positioned to a point 2 mm from the fibroblasts. RESULTS When the pulse mode irradiation was applied, there was significant difference (P < .05) in the percentage of viable cells between teeth with closed apical foramen (1-mm wall between root canal and root apex) and the #15 group (No. 15 K-file used), #30 group (No. 30 K-file), or #50 group (No. 50 K-file). The difference between the #30 group and the #50 group (P < .05) was also significant. The larger the diameter of the apical foramen became, the lower was the percentage of viable cells. CONCLUSION If a CO2 laser irradiates a root canal system enlarged to within 1 mm of the root canal length, little damage to the periapical tissues would be expected to occur.
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Affiliation(s)
- Naoki Horiba
- Department of Endodontics, School of Dentistry, Aichi-Gakuin University, Nagoya, Japan.
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Kojima T, Shimada K, Iwasaki H, Ito K. Inhibitory effects of a super pulsed carbon dioxide laser at low energy density on periodontopathic bacteria and lipopolysaccharidein vitro. J Periodontal Res 2005; 40:469-73. [PMID: 16302925 DOI: 10.1111/j.1600-0765.2005.00826.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE AND BACKGROUND Previous studies have described the effect of irradiation by a carbon dioxide (CO2) laser at high energy density on oral bacteria, and various side-effects have also been observed. However, no published studies have examined the effect of irradiation by a CO2 laser at low energy density on oral bacteria. The purpose of this study was to investigate the effects of super pulsed CO2 laser irradiation on periodontopathic bacteria and lipopolysaccharide (LPS). METHODS Bacterial suspensions of two species of periodontopathic bacteria received laser irradiation at energy densities of 0-12.5 J/cm2. The suspensions were then spread over agar plates and incubated anaerobically. The bactericidal effects were evaluated based on colony formation. Samples of LPS were laser-irradiated at energy densities of 0-12.5 J/cm2. The biological activity was measured, and LPS was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). RESULTS The irradiation at low energy densities of 7.5 and 12.5 J/cm2 killed more than 99.9 and 99.999% of Porphyromonas gingivalis and more than 99% of Actinobacillus actinomycetemcomitans was sterilized by the irradiation at 7.5 J/cm2. LPS biological activity was significantly decreased by laser irradiation at energy densities of more than 7.5 J/cm2 (p < 0.05), and the components of LPS analyzed by SDS-PAGE was diminished non-specifically. CONCLUSION The results indicate that CO2 laser irradiation at low power is capable of bactericidal effect on periodontopathic bacteria and decreasing LPS activity.
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Affiliation(s)
- Taro Kojima
- Department of Periodontology, Dental Research Center, Nihon University School of Dentistry, Tokyo, Japan
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Klein ALL, Rodrigues LKA, Eduardo CP, Nobre dos Santos M, Cury JA. Caries inhibition around composite restorations by pulsed carbon dioxide laser application. Eur J Oral Sci 2005; 113:239-44. [PMID: 15953249 DOI: 10.1111/j.1600-0722.2005.00212.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This in vitro study aimed to evaluate whether laser irradiation of cavity margins reduces enamel demineralization around composite restoration. Enamel cavities were prepared in 33 human enamel slabs, which were randomly divided into three groups. One group was kept as a control, and the cavosurface margin of the cavities of the other groups were irradiated, using a CO(2) laser (lambda = 10.6 microm), at 8 J.cm(-2) or 16 J.cm(-2). The cavities were restored with a resin-based composite, according to the manufacturer's specifications. Before restoration, scanning electron microscopy was performed on one specimen of each group. The remaining slabs were submitted to thermal and pH-cycling models. Enamel mineral loss, at 50 and 100 microm from the restoration margin, was assessed by cross-sectional microhardness analyses. Fusion and melting were observed in the irradiated groups. Mineral loss at 50 microm from the restoration margin was significantly inhibited in the irradiated groups compared to the control group, but at 100 microm from the restoration margin, mineral loss at only the highest laser energy density differed statistically from the control group. The difference between the irradiated groups was not statistically significant at either 50 or 100 microm from the restoration margin. In conclusion, irradiation of the cavosurface margin of cavities, using a pulsed CO(2) laser, is able to inhibit enamel demineralization around composite restorations, and an energy density of 16 J.cm(-2) is efficient, even at 100 microm from the cavity margin.
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Affiliation(s)
- André L L Klein
- Faculty of Dentistry of Umuarama, University of Paraná, Umuarama, PR, Brazil
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Keller OR, Weber FE, Grätz KW, Baltensperger MM, Eyrich GK. Laser-induced temperature changes in dentine. ACTA ACUST UNITED AC 2004; 21:375-81. [PMID: 14709223 DOI: 10.1089/104454703322650194] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
OBJECTIVE The purpose of this work is to study the temperature rise and potential thermal damage caused during ablation of human dentine using a super pulsed carbon dioxide laser of 9.6-microm wavelength, equipped with a water-cooling spray and scanner system. BACKGROUND DATA There have been no reports on thermal effects of super pulsed CO2 laser of 9.6 microm wavelength on human dentine recently. MATERIALS AND METHODS Two different types of samples were investigated to yield data most consistent with a typical clinical situation. Human dentine slices and crown segments were studied at a drilling depth of 1.0 +/- 0.1 mm and 2.5 +/- 0.5 mm, respectively. A control group treated with a conventional hand piece was compared to four laser groups with settings varying from 2 to 8 W. RESULTS In the laser group demonstrating the highest elevation in temperature of the four studied, dentine slices lased at 2 W for 15 sec showed a mean temperature rise of less than 1.68 degrees C at an ablation rate of 0.86 +/- 0.08 mm. Conventional drilling with a comparable ablation rate of 0.76 +/- 0.59 mm resulted in a mean rise of 2.87 degrees C. The laser groups of crown segments revealed a constant decrease in temperature. SEM observations were lacking the typical morphological changes seen in earlier studies, specifically extensive melting, charring or cracking. CONCLUSION A maximum rise of mean temperature to 1.68 degrees C in closest vicinity to the pulpal chamber and the morphological unaltered dentine surfaces demonstrate the safe and tissue preserving character of the superpulsed 9.6 microm CO2 laser. The laser caused an even lower temperature rise than conventional drilling. Moreover, the laser showed acceptable efficacy with ablation rates that did not significantly differ from the conventional dental drill.
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Affiliation(s)
- O R Keller
- Department of Cranio-Maxillofacial Surgery, University Hospital Zurich, Zurich, Switzerland.
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