The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Isao Ishikawa - One of the best experts on this subject based on the ideXlab platform.
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low level er yag Laser Irradiation enhances osteoblast proliferation through activation of mapk erk
Lasers in Medical Science, 2010Co-Authors: Verica Aleksic, Akira Aoki, Isao Ishikawa, Yoshimitsu Abiko, Kengo Iwasaki, Aristeo Atsushi Takasaki, Chenying Wang, Yuichi IzumiAbstract:Although the use of high-level Er:YAG Laser Irradiation has been increasing in periodontal and peri-implant therapy, the effects of low-level Er:YAG Laser on surrounding tissues and cells remain unclear. In the present study, the effects of low-level Er:YAG Laser Irradiation on osteoblast proliferation were investigated. Cells of the osteoblastic cell line MC3T3-E1 were treated with low-level Er:YAG Laser Irradiation with various combinations of Laser settings (fluence 0.7–17.2 J/cm2) and in the absence or presence of culture medium during Irradiation. On day 1 and/or day 3, cell proliferation and death were determined by cell counting and by measurement of lactate dehydrogenase (LDH) levels. Further, the role of mitogen-activated protein kinase (MAPK) pathways in Laser-enhanced cell proliferation was investigated by inhibiting the MAPK pathways and then measuring MAPK phosphorylation by Western blotting. Higher proliferation rates were found with various combinations of Irradiation parameters on days 1 and 3. Significantly higher proliferation was also observed in Laser-irradiated MC3T3-E1 cells at a fluence of approximately 1.0–15.1 J/cm2, whereas no increase in LDH activity was observed. Further, low-level Er:YAG Irradiation induced the phosphorylation of extracellular signal-regulated protein kinase (MAPK/ERK) 5 to 30 min after Irradiation. Although MAPK/ERK 1/2 inhibitor U0126 significantly inhibited Laser-enhanced cell proliferation, activation of stress-activated protein kinases/Jun N-terminal kinase (SAPK/JNK) and p38 MAPK was not clearly detected. These results suggest that low-level Er:YAG Laser Irradiation increases osteoblast proliferation mainly by activation of MAPK/ERK, suggesting that the Er:YAG Laser may be able to promote bone healing following periodontal and peri-implant therapy.
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morphological analysis of cementum and root dentin after er yag Laser Irradiation
Lasers in Surgery and Medicine, 2002Co-Authors: Katia M Sasaki, Shizuko Ichinose, Akira Aoki, Isao IshikawaAbstract:Background and Objectives To investigate the morphology of cementum and root dentin after Er:YAG Laser Irradiation with and without water coolant, compared to that after CO2 Laser Irradiation and an untreated surface. Study Design/Materials and Methods Ten extracted healthy human teeth were used. Er:YAG and CO2 Lasers were applied with energy outputs of 0.4 W, with and without coolant and 0.5 W, without coolant, respectively. Scanning electron microscopy (SEM) analysis was performed at high and ultra-high magnifications. Results The surface of cementum was micro-irregular with numerous projections while that of dentin appeared scaly after Er:YAG Laser Irradiation. Unlike after CO2 Laser treatment, no major melting or cracking was observed with Er:YAG Laser treatment. The use of water spray produced fine micro-irregularities without attached debris. Ultra-high magnification revealed similar microparticles-composed aspects for both cementum and dentin. However, the more porous structure of the surface was observed after Er:YAG Laser Irradiation without water spray. Conclusions Cementum and root dentin presented distinct micro-roughness after Er:YAG Laser Irradiation, possibly due to structural differences in the original tissue. However, under ultra-high magnifications, both cementum and dentin presented similar characteristics of the irradiated surface. In addition, the use of water spray during Laser Irradiation minimized thermal effects and resulted in a cleaner and less porous surface. Lasers Surg. Med. 31:79–85, 2002. © 2002 Wiley-Liss, Inc.
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compositional analysis of root cementum and dentin after er yag Laser Irradiation compared with co2 lased and intact roots using fourier transformed infrared spectroscopy
Journal of Periodontal Research, 2002Co-Authors: Katia M Sasaki, Shizuko Ichinose, Akira Aoki, H Masuno, S Yamada, Isao IshikawaAbstract:The present study examines the dental root after Er:YAG Laser Irradiation, compared with CO2 lased and non-treated surfaces, using Fourier Transformed Infrared (FTIR) spectroscopy. Freshly extracted human teeth were irradiated by Er:YAG Laser at an energy output of 40 mJ/pulse, 10 Hz (0.4 watts), with or without water coolant, and by CO2 Laser at an energy output of 0.5 watts in continuous wave mode without coolant. The surfaces were chalky and smooth after Irradiation by Er:YAG Laser with water coolant, were charred and irregular after Irradiation by Er:YAG Laser without water coolant, and were completely carbonized after CO2 Laser Irradiation. The FTIR profiles from samples of the surfaces that were irradiated by Er:YAG Laser with water coolant were similar to those from non-treated samples, except for a slight decrease on the OH and amide bands, which are mainly related to organic components. This decrease was observed to be extreme after CO2 Laser Irradiation and moderate after Er:YAG Laser Irradiation without coolant. The formation of new bands showing toxic substances was observed to a large extent after CO2 Laser Irradiation and to a smaller extent after Er:YAG Laser Irradiation without water coolant. In contrast, no such bands were detected after Er:YAG Laser Irradiation with water coolant. The present results show that these Laser treatments selectively ablated more organic components than inorganic components and that Er:YAG Laser Irradiation with water coolant did not cause major compositional changes or chemically deleterious changes in either root cementum or dentin.
Noriyoshi Shimizu - One of the best experts on this subject based on the ideXlab platform.
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effects of low energy Laser Irradiation on bone remodeling during experimental tooth movement in rats
Lasers in Surgery and Medicine, 2000Co-Authors: Koichiro Kawasaki, Noriyoshi ShimizuAbstract:Background and Objective Low-energy Laser Irradiation has many anabolic effects such as the acceleration of bone formation. However, its effects on tooth movement, performed by bone resorption and formation, have not been well characterized. Study Design/Materials and Methods A total of 10 g of orthodontic force was applied to rat molars to cause experimental tooth movement. A Ga-Al-As diode Laser was used to irradiate the area around the moved tooth, and after 12 days, the amount of tooth movement was measured. Calcein was injected subcutaneously to label the newly formed alveolar bone for quantitative analysis. Immunohistochemical staining of proliferating cell nuclear antigen was performed to evaluate cellular proliferation. TRAPase staining was also performed to facilitate the identification of osteoclasts. Results In the Laser Irradiation group, the amount of tooth movement was significantly greater (1.3-fold) than that of the nonIrradiation group in the end of the experiment. The amount of bone formation and rate of cellular proliferation in the tension side and the number of osteoclasts in the pressure side were all significantly increased in the Irradiation group when compared with the nonIrradiation group (P < 0.01). Conclusion These findings suggest that low-energy Laser Irradiation can accelerate tooth movement accompanied with alveolar bone remodeling. Lasers Surg. Med. 26:282–291, 2000 © 2000 Wiley-Liss, Inc.
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low energy Laser Irradiation stimulates bone nodule formation at early stages of cell culture in rat calvarial cells
Bone, 1998Co-Authors: Yasuhito Ozawa, Noriyoshi Shimizu, Genichiro Kariya, Yoshimitsu AbikoAbstract:Abstract Although the acceleration of bone regeneration by Laser treatment has been reported, the mechanisms of action of Laser on bone are unclear. To determine the target cells responsible for the action of Laser Irradiation and roles of Irradiation on these cells during bone formation, we investigated the effects of low-energy Laser Irradiation at various cell culture stages on cellular proliferation, bone nodule formation, alkaline phosphatase activity, and osteocalcin gene expression, employing rat calvarial cells. Osteoblast-like cells isolated from fetal rat calvariae were irradiated once with a low-energy Ga-Al-As Laser (830 nm, 500 mW) at various cell culture stages (days 1–16). Laser Irradiation at early stages of culture significantly stimulated cellular proliferation, ALP activity, and osteocalcin gene expression thereafter. Furthermore, Laser Irradiation at earlier stages of culture significantly stimulated a greater number (1.7-fold) and larger area (3.4-fold) of bone nodules that had developed in the culture dish on day 21. However, these effects could not be found by Irradiation at a later date. These results suggest that Laser Irradiation may play two principal roles in stimulating bone formation. One is stimulation of cellular proliferation, especially proliferation of nodule-forming cells of osteoblast lineage, and the other is stimulation of cellular differentiation, especially to committed precursors, resulting in an increase in the number of more differentiated osteoblastic cells and an increase in bone formation. Both bone-formation-stimulating roles may be exhibited by Laser Irradiation to immature cells only.
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stimulatory effects of low power Laser Irradiation on bone regeneration in midpalatal suture during expansion in the rat
American Journal of Orthodontics and Dentofacial Orthopedics, 1997Co-Authors: Shiro Saito, Noriyoshi ShimizuAbstract:Abstract The purpose of this study was to investigate the effects of low-power Laser Irradiation on bone regeneration during expansion of a midpalatal suture in rats. Gallium-aluminum-arsenide diode Laser 100 mW Irradiation was applied to the midpalatal suture during expansion carried out over 7 days (3 or 10 minutes per day), 3 days (7 minutes per day for day 0-2 or 4-6), and 1 day (21 uninterrupted minutes on day 0). The bone regeneration in the midpalatal suture estimated by histomorphometric method in the 7-day Irradiation group showed significant acceleration at 1.2- to 1.4-fold compared with that in the nonirradiated rats, and this increased rate was Irradiation dose-dependent. Irradiation during the early period of expansion (days 0 to 2) was most effective, whereas neither the later period (days 4 to 6) nor the one-time Irradiation had any effect on bone regeneration. These findings suggest that low-power Laser Irradiation can accelerate bone regeneration in a midpalatal suture during rapid palatal expansion and that this effect is dependent not only on the total Laser Irradiation dosage but also on the timing and frequency of Irradiation. We suggest Laser therapy may be of therapeutic benefit in inhibiting relapse and shortening the retention period through acceleration of bone regeneration in the midpalatal suture. (Am J Orthod Dentofac AOrthop 1997;111:525-32.)
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inhibition of prostaglandin e2 and interleukin 1 beta production by low power Laser Irradiation in stretched human periodontal ligament cells
Journal of Dental Research, 1995Co-Authors: Noriyoshi Shimizu, Masaru Yamaguchi, Takemi Goseki, Yasuko Shibata, Hisashi Takiguchi, Tadamasa Iwasawa, Yoshimitsu AbikoAbstract:It is well-known that orthodontic treatment usually causes some discomfort and pain to the patients. Recently, it has been reported that low-power Laser Irradiation is effective in reducing the pain accompanying tooth movement. However, the mechanism of such pain relief cannot be elucidated. Since high levels of prostaglandin (PG) E2 and interleukin (IL)-1 beta are found in the periodontal ligament (PDL) during tooth movement, and both factors are involved in the induction of pain, the effects of low-power Laser Irradiation on PGE2 and IL-1 beta production in stretched human PDL cells were studied in vitro. The PDL cells, derived from healthy premolars extracted for orthodontic treatment, were utilized for experiments. Cells were seeded in flexible-bottomed culture plates, and the bottom of each plate was elongated (18% increase) under vacuum at 6 cycles per min for 1, 3, or 5 days. The stretched cells were irradiated with a Ga-Al-As low-power diode Laser (60 mW) once a day for 3, 6, or 10 min (from 10.8 to 36.0 J) for 1, 3, or 5 days. PGE2 and IL-1 beta levels in the medium were measured by radioimmunoassay. In response to mechanical stretching, human PDL cells showed a marked elevation in PGE2 production in a time-dependent manner. IL-1 beta production was also elevated, but this remained constant. The increase in PGE2 production was significantly inhibited by Laser Irradiation in a dose-dependent manner. The increase in IL-1 beta production was also significantly inhibited by Laser Irradiation, although the inhibition was only partial.(ABSTRACT TRUNCATED AT 250 WORDS)
Shizuko Ichinose - One of the best experts on this subject based on the ideXlab platform.
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Effects of Dentin Surface Modifications Treated with Er:YAG and Nd:YAG Laser Irradiation on Fibroblast Cell Adhesion
Photomedicine and laser surgery, 2011Co-Authors: Gombo Bolortuya, Arata Ebihara, Shizuko Ichinose, Satoshi Watanabe, Tomoo Anjo, Chizuko Kokuzawa, Hidetoshi Saegusa, Nobuyuki Kawashima, Hideaki SudaAbstract:Abstract Objective: The purpose of this in vitro study was to evaluate the effect of surface modifications induced by erbium (Er):YAG and neodymium (Nd):YAG Laser Irradiation on cell adhesion by co...
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morphological analysis of cementum and root dentin after er yag Laser Irradiation
Lasers in Surgery and Medicine, 2002Co-Authors: Katia M Sasaki, Shizuko Ichinose, Akira Aoki, Isao IshikawaAbstract:Background and Objectives To investigate the morphology of cementum and root dentin after Er:YAG Laser Irradiation with and without water coolant, compared to that after CO2 Laser Irradiation and an untreated surface. Study Design/Materials and Methods Ten extracted healthy human teeth were used. Er:YAG and CO2 Lasers were applied with energy outputs of 0.4 W, with and without coolant and 0.5 W, without coolant, respectively. Scanning electron microscopy (SEM) analysis was performed at high and ultra-high magnifications. Results The surface of cementum was micro-irregular with numerous projections while that of dentin appeared scaly after Er:YAG Laser Irradiation. Unlike after CO2 Laser treatment, no major melting or cracking was observed with Er:YAG Laser treatment. The use of water spray produced fine micro-irregularities without attached debris. Ultra-high magnification revealed similar microparticles-composed aspects for both cementum and dentin. However, the more porous structure of the surface was observed after Er:YAG Laser Irradiation without water spray. Conclusions Cementum and root dentin presented distinct micro-roughness after Er:YAG Laser Irradiation, possibly due to structural differences in the original tissue. However, under ultra-high magnifications, both cementum and dentin presented similar characteristics of the irradiated surface. In addition, the use of water spray during Laser Irradiation minimized thermal effects and resulted in a cleaner and less porous surface. Lasers Surg. Med. 31:79–85, 2002. © 2002 Wiley-Liss, Inc.
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compositional analysis of root cementum and dentin after er yag Laser Irradiation compared with co2 lased and intact roots using fourier transformed infrared spectroscopy
Journal of Periodontal Research, 2002Co-Authors: Katia M Sasaki, Shizuko Ichinose, Akira Aoki, H Masuno, S Yamada, Isao IshikawaAbstract:The present study examines the dental root after Er:YAG Laser Irradiation, compared with CO2 lased and non-treated surfaces, using Fourier Transformed Infrared (FTIR) spectroscopy. Freshly extracted human teeth were irradiated by Er:YAG Laser at an energy output of 40 mJ/pulse, 10 Hz (0.4 watts), with or without water coolant, and by CO2 Laser at an energy output of 0.5 watts in continuous wave mode without coolant. The surfaces were chalky and smooth after Irradiation by Er:YAG Laser with water coolant, were charred and irregular after Irradiation by Er:YAG Laser without water coolant, and were completely carbonized after CO2 Laser Irradiation. The FTIR profiles from samples of the surfaces that were irradiated by Er:YAG Laser with water coolant were similar to those from non-treated samples, except for a slight decrease on the OH and amide bands, which are mainly related to organic components. This decrease was observed to be extreme after CO2 Laser Irradiation and moderate after Er:YAG Laser Irradiation without coolant. The formation of new bands showing toxic substances was observed to a large extent after CO2 Laser Irradiation and to a smaller extent after Er:YAG Laser Irradiation without water coolant. In contrast, no such bands were detected after Er:YAG Laser Irradiation with water coolant. The present results show that these Laser treatments selectively ablated more organic components than inorganic components and that Er:YAG Laser Irradiation with water coolant did not cause major compositional changes or chemically deleterious changes in either root cementum or dentin.
Carlos De Paula Eduardo - One of the best experts on this subject based on the ideXlab platform.
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in vitro evaluation of enamel demineralization after er yag and nd yag Laser Irradiation on primary teeth
Photomedicine and Laser Surgery, 2007Co-Authors: Carina Strano Castellan, Carlos De Paula Eduardo, Ana Claudia Luiz, Leticia Mello Bezinelli, Roberta Marques Da Graca Lopes, Fausto Medeiros Mendes, Patricia Moreira De FreitasAbstract:Objective: This in vitro study evaluated the influence of both Er:YAG and Nd:YAG Laser Irradiation on deciduous enamel demineralization. Background Data: Although there are still few studies on the...
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effect of low power Laser Irradiation on protein synthesis and ultrastructure of human gingival fibroblasts
Lasers in Surgery and Medicine, 2004Co-Authors: Marcia Martins Marques, Aymann Nassif Pereira, Neusa Akemi Fujihara, Fernando Neves Nogueira, Carlos De Paula EduardoAbstract:Background and Objectives Low-power Lasers improve wound healing. Cell proliferation and protein secretion are important steps of this process. The aim of this study was to analyze both protein synthesis and ultrastructural morphology of human gingival fibroblasts irradiated by a low-power Laser. Study Design/Materials and Methods The cell line FMM1 was grown in nutritional deficit. Laser Irradiation was carried out with a gallium–aluminum–arsenate (Ga–Al–As) diode Laser (904 nm, 120 mW, energy density of 3 J/cm2). The protein synthesis analysis and ultrastructural morphology of control (non-irradiated) and irradiated cultures were obtained. Results There were changes in the structure of cytoplasm organelles of treated cells. The procollagen was not altered by the Laser Irradiation; however, there were a significant reduction of the amount of protein in the DMEM conditioned by irradiated cells. Conclusions Low-power Laser Irradiation causes ultrastructural changes in cultured fibroblasts. We suggest that these alterations may lead to disturbances in the collagen metabolism. Lasers Surg. Med. 34:260–265, 2004. © 2004 Wiley-Liss, Inc.
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in vitro evaluation of er yag Laser Irradiation in apicoectomy and retrofilling cavity preparation compared to two other techniques
BiOS '98 International Biomedical Optics Symposium, 1998Co-Authors: Selma Christina Cury Camargo, Carlos De Paula Eduardo, Giulio Gavini, Jeffrey M CoilAbstract:The aim of this research was to evaluate under SEM observation, the apical cut surface and retrofilling cavity prepared with Er:YAG Laser and two other conventional techniques. Thirty extracted human teeth were divided into two groups of 15 teeth each. For Group 1 apicoectomy was performed using high speed handpiece and diamond burs. For Group 2 Er:YAG* Laser Irradiation (wavelength of 2.94 micrometer, pulse width of 250 - 500 microseconds) was used in 400 mJ of energy, frequency of 6 Hz, on focus mode under destiled water refrigeration. Each group was divided into 3 subgroups. For groups G1A and G2A, retrofilling cavity preparations were performed using low speed handpiece and burs, for groups G1B and G2B Enac technique was indicated. Groups G1C and G2C Er:YAG Laser Irradiation was used under same energy level previously described. All specimens were prepared for SEM observations. Pictures were taken under 30x and 600x magnification. Two different observers analyzed the smoothness and morphological appearance of those preparations. Data's were collected showing a smoothness surface, no debries or smear layer on group 2 (Laser Irradiation) compared to group 1. Differences were also noted when retrofiling cavities were analyzed.
Akira Aoki - One of the best experts on this subject based on the ideXlab platform.
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low level er yag Laser Irradiation enhances osteoblast proliferation through activation of mapk erk
Lasers in Medical Science, 2010Co-Authors: Verica Aleksic, Akira Aoki, Isao Ishikawa, Yoshimitsu Abiko, Kengo Iwasaki, Aristeo Atsushi Takasaki, Chenying Wang, Yuichi IzumiAbstract:Although the use of high-level Er:YAG Laser Irradiation has been increasing in periodontal and peri-implant therapy, the effects of low-level Er:YAG Laser on surrounding tissues and cells remain unclear. In the present study, the effects of low-level Er:YAG Laser Irradiation on osteoblast proliferation were investigated. Cells of the osteoblastic cell line MC3T3-E1 were treated with low-level Er:YAG Laser Irradiation with various combinations of Laser settings (fluence 0.7–17.2 J/cm2) and in the absence or presence of culture medium during Irradiation. On day 1 and/or day 3, cell proliferation and death were determined by cell counting and by measurement of lactate dehydrogenase (LDH) levels. Further, the role of mitogen-activated protein kinase (MAPK) pathways in Laser-enhanced cell proliferation was investigated by inhibiting the MAPK pathways and then measuring MAPK phosphorylation by Western blotting. Higher proliferation rates were found with various combinations of Irradiation parameters on days 1 and 3. Significantly higher proliferation was also observed in Laser-irradiated MC3T3-E1 cells at a fluence of approximately 1.0–15.1 J/cm2, whereas no increase in LDH activity was observed. Further, low-level Er:YAG Irradiation induced the phosphorylation of extracellular signal-regulated protein kinase (MAPK/ERK) 5 to 30 min after Irradiation. Although MAPK/ERK 1/2 inhibitor U0126 significantly inhibited Laser-enhanced cell proliferation, activation of stress-activated protein kinases/Jun N-terminal kinase (SAPK/JNK) and p38 MAPK was not clearly detected. These results suggest that low-level Er:YAG Laser Irradiation increases osteoblast proliferation mainly by activation of MAPK/ERK, suggesting that the Er:YAG Laser may be able to promote bone healing following periodontal and peri-implant therapy.
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morphological analysis of cementum and root dentin after er yag Laser Irradiation
Lasers in Surgery and Medicine, 2002Co-Authors: Katia M Sasaki, Shizuko Ichinose, Akira Aoki, Isao IshikawaAbstract:Background and Objectives To investigate the morphology of cementum and root dentin after Er:YAG Laser Irradiation with and without water coolant, compared to that after CO2 Laser Irradiation and an untreated surface. Study Design/Materials and Methods Ten extracted healthy human teeth were used. Er:YAG and CO2 Lasers were applied with energy outputs of 0.4 W, with and without coolant and 0.5 W, without coolant, respectively. Scanning electron microscopy (SEM) analysis was performed at high and ultra-high magnifications. Results The surface of cementum was micro-irregular with numerous projections while that of dentin appeared scaly after Er:YAG Laser Irradiation. Unlike after CO2 Laser treatment, no major melting or cracking was observed with Er:YAG Laser treatment. The use of water spray produced fine micro-irregularities without attached debris. Ultra-high magnification revealed similar microparticles-composed aspects for both cementum and dentin. However, the more porous structure of the surface was observed after Er:YAG Laser Irradiation without water spray. Conclusions Cementum and root dentin presented distinct micro-roughness after Er:YAG Laser Irradiation, possibly due to structural differences in the original tissue. However, under ultra-high magnifications, both cementum and dentin presented similar characteristics of the irradiated surface. In addition, the use of water spray during Laser Irradiation minimized thermal effects and resulted in a cleaner and less porous surface. Lasers Surg. Med. 31:79–85, 2002. © 2002 Wiley-Liss, Inc.
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compositional analysis of root cementum and dentin after er yag Laser Irradiation compared with co2 lased and intact roots using fourier transformed infrared spectroscopy
Journal of Periodontal Research, 2002Co-Authors: Katia M Sasaki, Shizuko Ichinose, Akira Aoki, H Masuno, S Yamada, Isao IshikawaAbstract:The present study examines the dental root after Er:YAG Laser Irradiation, compared with CO2 lased and non-treated surfaces, using Fourier Transformed Infrared (FTIR) spectroscopy. Freshly extracted human teeth were irradiated by Er:YAG Laser at an energy output of 40 mJ/pulse, 10 Hz (0.4 watts), with or without water coolant, and by CO2 Laser at an energy output of 0.5 watts in continuous wave mode without coolant. The surfaces were chalky and smooth after Irradiation by Er:YAG Laser with water coolant, were charred and irregular after Irradiation by Er:YAG Laser without water coolant, and were completely carbonized after CO2 Laser Irradiation. The FTIR profiles from samples of the surfaces that were irradiated by Er:YAG Laser with water coolant were similar to those from non-treated samples, except for a slight decrease on the OH and amide bands, which are mainly related to organic components. This decrease was observed to be extreme after CO2 Laser Irradiation and moderate after Er:YAG Laser Irradiation without coolant. The formation of new bands showing toxic substances was observed to a large extent after CO2 Laser Irradiation and to a smaller extent after Er:YAG Laser Irradiation without water coolant. In contrast, no such bands were detected after Er:YAG Laser Irradiation with water coolant. The present results show that these Laser treatments selectively ablated more organic components than inorganic components and that Er:YAG Laser Irradiation with water coolant did not cause major compositional changes or chemically deleterious changes in either root cementum or dentin.
