Pub Date : 1900-01-01DOI: 10.5984/JJPNSOCLASERDENT.22.93
H. Fukuoka, Y. Daigo, M. Ishikawa, H. Amano, Hiroshi Koga, N. Enoki, K. Taniguchi, Hironobu Sato
: Objective: The usefulness of laser irradiation for socket preservation in clinical cases has recently been reported, and the effective laser irradiation conditions for healing of the extraction wound have also been investigated. It was reported by our laboratory that HLLT and LLLT therapies using a CO 2 laser for extraction sockets resulted in characteristic new bone formation and the maintenance of a high alveolar crest in rats. However, the mechanism of healing promotion by CO 2 laser irradiation remains unclear, so we investigated the emergence of myofibroblasts （ α -smooth muscle actin （ α -SMA）） involved in granulation tissue scar contracture in extraction wounds and changes in the expression of transforming growth factor-beta 1 （TGF- β 1） associated with myofibroblast differentiation and apoptosis. Subjects and Methods: Seventy-two 5-week-old male Wistar rats were used. The first molar was extracted to prepare an extraction socket model. The rats were divided into CO 2 laser-irradiated and non-irradiated （control） groups and pathological-ly compared. In the CO 2 laser-irradiated group, HLLT was performed immediately after tooth extraction, followed by LLLT after one day, corresponding to clinical cases. The irradiated tissue including the extraction socket was excised 6 hours and 3, 5, 7, 10, and 21 days after treatment, fixed in 4％ paraformaldehyde, decalcified in 10％ EDTA solution, and paraffin-embedded employing the standard method, and serial sagittal sections were prepared. Granulation tissue of the superficial layer of the extraction socket was immunohistologically investigated using anti- α -SMA and anti-TGF- β 1 antibodies. The number of α -SMA-positive cells and TGF- β 1-positive area were measured, and the significance of differences was tested. Results: On immunostaining with anti- α -SMA antibody, there were many α -SMA-positive cells in the non-irradiated group at 3 and 7 days, whereas significantly fewer positive cells were noted in the CO 2 laser-irradiated group （p ＜ 0.05）. On immunostaining with anti-TGF- β 1 antibody, TGF- β 1-positivity was not marked the CO 2 laser-irradiated group, compared to that in the non-irradiated group, significant difference was noted 5 days treatment Conclusion: The combination of CO 2 HLLT and LLLT for the extraction sockets inhibited scar formation in the sockets, and the involvement of TGF- β 1 suggested.
{"title":"Dynamics of Myofibroblasts and Transforming Growth Factor-beta 1 in CO2 Laser-enhanced Healing Process of Rat Tooth Sockets","authors":"H. Fukuoka, Y. Daigo, M. Ishikawa, H. Amano, Hiroshi Koga, N. Enoki, K. Taniguchi, Hironobu Sato","doi":"10.5984/JJPNSOCLASERDENT.22.93","DOIUrl":"https://doi.org/10.5984/JJPNSOCLASERDENT.22.93","url":null,"abstract":": Objective: The usefulness of laser irradiation for socket preservation in clinical cases has recently been reported, and the effective laser irradiation conditions for healing of the extraction wound have also been investigated. It was reported by our laboratory that HLLT and LLLT therapies using a CO 2 laser for extraction sockets resulted in characteristic new bone formation and the maintenance of a high alveolar crest in rats. However, the mechanism of healing promotion by CO 2 laser irradiation remains unclear, so we investigated the emergence of myofibroblasts （ α -smooth muscle actin （ α -SMA）） involved in granulation tissue scar contracture in extraction wounds and changes in the expression of transforming growth factor-beta 1 （TGF- β 1） associated with myofibroblast differentiation and apoptosis. Subjects and Methods: Seventy-two 5-week-old male Wistar rats were used. The first molar was extracted to prepare an extraction socket model. The rats were divided into CO 2 laser-irradiated and non-irradiated （control） groups and pathological-ly compared. In the CO 2 laser-irradiated group, HLLT was performed immediately after tooth extraction, followed by LLLT after one day, corresponding to clinical cases. The irradiated tissue including the extraction socket was excised 6 hours and 3, 5, 7, 10, and 21 days after treatment, fixed in 4％ paraformaldehyde, decalcified in 10％ EDTA solution, and paraffin-embedded employing the standard method, and serial sagittal sections were prepared. Granulation tissue of the superficial layer of the extraction socket was immunohistologically investigated using anti- α -SMA and anti-TGF- β 1 antibodies. The number of α -SMA-positive cells and TGF- β 1-positive area were measured, and the significance of differences was tested. Results: On immunostaining with anti- α -SMA antibody, there were many α -SMA-positive cells in the non-irradiated group at 3 and 7 days, whereas significantly fewer positive cells were noted in the CO 2 laser-irradiated group （p ＜ 0.05）. On immunostaining with anti-TGF- β 1 antibody, TGF- β 1-positivity was not marked the CO 2 laser-irradiated group, compared to that in the non-irradiated group, significant difference was noted 5 days treatment Conclusion: The combination of CO 2 HLLT and LLLT for the extraction sockets inhibited scar formation in the sockets, and the involvement of TGF- β 1 suggested.","PeriodicalId":187459,"journal":{"name":"Journal of Japanese Society for Laser Dentistry","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134181891","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.5984/JJPNSOCLASERDENT.22.85
Yoshishige Yamada, Y. Kimura
The chemo-mechanical method of removing caries is safer and less painful than conventional caries treatment with rotary instruments, but takes longer. Therefore, a prototype of a new caries removal reagent was developed to solve this disadvantage. This reagent (BO reagent) consists mainly of bromelain and orange oil, and removes caries approximately 2 minutes faster than Carisolv, but still takes longer to remove caries completely than the conventional method. To reduce the time further, we evaluated the effects of using this BO reagent with an Nd:YAG laser. Forty-five extracted human permanent teeth with caries were used in this study and were divided into nine groups with various laser irradiation conditions (60, 80, 100, and 120 mJ) with air-cooling or without air-cooling, and no laser irradiation. The time required for caries removal was measured for all specimens. To evaluate the temperature rise, thermal changes were also measured by thermometer during laser irradiation. After caries removal, each cavity was filled with composite resin and a micro-leakage test was performed. Then, all samples were transversely bisected with a diamond saw disc, and observed by stereomicroscopy. The mean time for the group with BO reagent without Nd:YAG laser irradiation was 388 seconds. For the groups irradiated by Nd:YAG laser, the times were 132 to 205 seconds on average and were statistically shorter than for the non-irradiated group. However, there was no statistical difference between the groups with and without air-cooling. The measured temperature rise was 2.1°C (80 mJ) to 4.4°C (120 mJ) for the groups without air-cooling, but was less than 2°C for all the groups with air-cooling. The rate of temperature rise and the time required for caries removal were similar for the 100 and 120 mJ-irradiated groups. In the micro-leakage test, there were no statistical differences among all groups. From these results, the BO reagent with Nd:YAG laser and air-cooling is a new candidate method for caries removal instead of conventional caries removal with rotary instruments. Especially, BO reagent with Nd:YAG laser irradiation of 100-120 mJ and air-cooling might be an effective and safe method of removing caries.
{"title":"Evaluation of Effectiveness of Carious Dentin Removal by Combination of Nd:YAG Laser and Prototype of Chemo-mechanical Caries Removal Reagent","authors":"Yoshishige Yamada, Y. Kimura","doi":"10.5984/JJPNSOCLASERDENT.22.85","DOIUrl":"https://doi.org/10.5984/JJPNSOCLASERDENT.22.85","url":null,"abstract":"The chemo-mechanical method of removing caries is safer and less painful than conventional caries treatment with rotary instruments, but takes longer. Therefore, a prototype of a new caries removal reagent was developed to solve this disadvantage. This reagent (BO reagent) consists mainly of bromelain and orange oil, and removes caries approximately 2 minutes faster than Carisolv, but still takes longer to remove caries completely than the conventional method. To reduce the time further, we evaluated the effects of using this BO reagent with an Nd:YAG laser. Forty-five extracted human permanent teeth with caries were used in this study and were divided into nine groups with various laser irradiation conditions (60, 80, 100, and 120 mJ) with air-cooling or without air-cooling, and no laser irradiation. The time required for caries removal was measured for all specimens. To evaluate the temperature rise, thermal changes were also measured by thermometer during laser irradiation. After caries removal, each cavity was filled with composite resin and a micro-leakage test was performed. Then, all samples were transversely bisected with a diamond saw disc, and observed by stereomicroscopy. The mean time for the group with BO reagent without Nd:YAG laser irradiation was 388 seconds. For the groups irradiated by Nd:YAG laser, the times were 132 to 205 seconds on average and were statistically shorter than for the non-irradiated group. However, there was no statistical difference between the groups with and without air-cooling. The measured temperature rise was 2.1°C (80 mJ) to 4.4°C (120 mJ) for the groups without air-cooling, but was less than 2°C for all the groups with air-cooling. The rate of temperature rise and the time required for caries removal were similar for the 100 and 120 mJ-irradiated groups. In the micro-leakage test, there were no statistical differences among all groups. From these results, the BO reagent with Nd:YAG laser and air-cooling is a new candidate method for caries removal instead of conventional caries removal with rotary instruments. Especially, BO reagent with Nd:YAG laser irradiation of 100-120 mJ and air-cooling might be an effective and safe method of removing caries.","PeriodicalId":187459,"journal":{"name":"Journal of Japanese Society for Laser Dentistry","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132138456","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.5984/JJPNSOCLASERDENT.9.54
Y. Hamamura, T. Mima, T. Sasabe, T. Matsuya, S. Nakahara
{"title":"Surgical Effects of High Power Semiconductor Laser","authors":"Y. Hamamura, T. Mima, T. Sasabe, T. Matsuya, S. Nakahara","doi":"10.5984/JJPNSOCLASERDENT.9.54","DOIUrl":"https://doi.org/10.5984/JJPNSOCLASERDENT.9.54","url":null,"abstract":"","PeriodicalId":187459,"journal":{"name":"Journal of Japanese Society for Laser Dentistry","volume":"384 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134453727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.5984/JJPNSOCLASERDENT.7.22
K. Okumura, T. Tsuboi, R. Toyoda, M. Isobe, Kenji Yoshida, M. Fukaya, S. Arakawa, A. Togari, S. Matsumoto
To elucidate the in vivo effect of low power diode laser irradiation on mineralization in molar tooth germ, we examined the effect of the laser on the development of mandibular first and second molars in neonatal mouse. In a newborn mouse, the mandibular first molar showed differentiated odontoblast, differentiated ameloblast, slight dentin and enamel formation. The second molar was an early bell stage. In a two day-old neonatal mouse, the developmental stage of the second molar corresponded to the stage of the first molar in a newborn mouse. The laser (50mW, 5min/day) was irradiated to the mandibular tooth germ at twice and the chemical and histological changes in these molars were examined. In the second molar showing an early developmental stage (cell proliferation and differentiation), the laser irradiation increased alkaline phosphatase activity, calcium content and the formation of both dentin and enamel. Also, in the first molar showing a late developmental stage (additional mineralization), the laser irradiation also increased the mineralization in both dentin and enamel. From the in vivo experiment, we confirmed that diode laser irradiation accelerated tooth formation and mineralization at all developmental stages observed in the present study.(J. Jpn. Soc. Laser Dent. 7: 22-29, 1996 Reprint requests to Dr. Okumura)
{"title":"The Influence of Low Power Laser Local Irradiation on the Mineralization of Tooth Germ in Mice","authors":"K. Okumura, T. Tsuboi, R. Toyoda, M. Isobe, Kenji Yoshida, M. Fukaya, S. Arakawa, A. Togari, S. Matsumoto","doi":"10.5984/JJPNSOCLASERDENT.7.22","DOIUrl":"https://doi.org/10.5984/JJPNSOCLASERDENT.7.22","url":null,"abstract":"To elucidate the in vivo effect of low power diode laser irradiation on mineralization in molar tooth germ, we examined the effect of the laser on the development of mandibular first and second molars in neonatal mouse. In a newborn mouse, the mandibular first molar showed differentiated odontoblast, differentiated ameloblast, slight dentin and enamel formation. The second molar was an early bell stage. In a two day-old neonatal mouse, the developmental stage of the second molar corresponded to the stage of the first molar in a newborn mouse. The laser (50mW, 5min/day) was irradiated to the mandibular tooth germ at twice and the chemical and histological changes in these molars were examined. In the second molar showing an early developmental stage (cell proliferation and differentiation), the laser irradiation increased alkaline phosphatase activity, calcium content and the formation of both dentin and enamel. Also, in the first molar showing a late developmental stage (additional mineralization), the laser irradiation also increased the mineralization in both dentin and enamel. From the in vivo experiment, we confirmed that diode laser irradiation accelerated tooth formation and mineralization at all developmental stages observed in the present study.(J. Jpn. Soc. Laser Dent. 7: 22-29, 1996 Reprint requests to Dr. Okumura)","PeriodicalId":187459,"journal":{"name":"Journal of Japanese Society for Laser Dentistry","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133104689","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.5984/jjpnsoclaserdent.31.31
Yuichi Kimura, Yoshishige Yamada, F. Kurumada, Yasuko Sato, Tomoaki Kanazawa, Y. Hashimoto
Since the development of the ruby laser by Maiman in 1960 and the application of the laser for endodontic field by Weichman in 1971, many papers on the applications of lasers have been reported. However , there are few review articles on laser applications in endodontics. The purpose of this study was to summarize the laser applications in endodontics. This paper includes diagnosis of dental pulp, treatment of dentinal hypersensitivity, applications for the treatment of pulp capping and pulpotomy, effects of laser on root canal walls, sterilization of root canals, root canal preparation by laser, effects of laser on periodontal tissues , application for apicoectomy, and other applications for endodontic treatment. The essential question is whether a laser can provide equal or improved treatment over conventional care. This article reviews the role of lasers in endodontics since the early 1970s, summarizes many research reports from the last decade, and proposes what the future may hold for lasers in endodontics. With the potential availability and future development of different laser wavelengths and methods of pulsing, much interest is developing in this promising field. (J. Jpn. Soc. Laser Dent. 11:46-60, 2000. Reprint requests to Dr. KIMURA) Key words=Laser, Endodontics, Diagnosis and treatment キ ー ワ ー ド=レ ーザ ー,歯 内 療 法,診 断 と治 療
{"title":"Laser Applications in Endodontics","authors":"Yuichi Kimura, Yoshishige Yamada, F. Kurumada, Yasuko Sato, Tomoaki Kanazawa, Y. Hashimoto","doi":"10.5984/jjpnsoclaserdent.31.31","DOIUrl":"https://doi.org/10.5984/jjpnsoclaserdent.31.31","url":null,"abstract":"Since the development of the ruby laser by Maiman in 1960 and the application of the laser for endodontic field by Weichman in 1971, many papers on the applications of lasers have been reported. However , there are few review articles on laser applications in endodontics. The purpose of this study was to summarize the laser applications in endodontics. This paper includes diagnosis of dental pulp, treatment of dentinal hypersensitivity, applications for the treatment of pulp capping and pulpotomy, effects of laser on root canal walls, sterilization of root canals, root canal preparation by laser, effects of laser on periodontal tissues , application for apicoectomy, and other applications for endodontic treatment. The essential question is whether a laser can provide equal or improved treatment over conventional care. This article reviews the role of lasers in endodontics since the early 1970s, summarizes many research reports from the last decade, and proposes what the future may hold for lasers in endodontics. With the potential availability and future development of different laser wavelengths and methods of pulsing, much interest is developing in this promising field. (J. Jpn. Soc. Laser Dent. 11:46-60, 2000. Reprint requests to Dr. KIMURA) Key words=Laser, Endodontics, Diagnosis and treatment キ ー ワ ー ド=レ ーザ ー,歯 内 療 法,診 断 と治 療","PeriodicalId":187459,"journal":{"name":"Journal of Japanese Society for Laser Dentistry","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125737354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.5984/JJPNSOCLASERDENT.7.37
Kunio Zennyu, M. Inoue, M. Konishi, M. Minami, M. Kumazaki, B. Fujii, C. Lee
Transmission of Nd: YAG laser through human dentin, whose thickness was stepwise decreased, was measured. Four human molars stored in saline solution were used. Dentin specimens with the thickness of approximate 1mm were created by cutting the teeth crossectionally using a diamond disc, followed by being polished by #600 silocone carbide paper and a whetstone. Average dentin thickness (DTh) of each specimen was calculated from five measurements each using a micrometer. Nd: YAG laser equipment used was Dent Lase DCL 8 (S.L.T Japan). An experimental laser tip made of quartz and an experimental gold-plated specimen holder having a central hole were employed. The irradiation conditions of Nd: YAG laser were normal pulse, 170mJ, 20pps and 2-second duration.Three measurements of the intensity of transmitted laser light (T-light) through dentin of approximately 1mm thickness were performed for each specimen by a power monitor (Ophir Optics Ltd). And the power monitor was transferred 2mm perpendicularly from the center of laser light (C-L). And then the measurement of the intensity of scattered laser light (S-light) was trebled. And then the power monitor was further transferred 4, 6, 8, 10 and 12mm from C-L and the measurement of the intensity of S-light was trebled at each displacement from C-L.Then DTh was stepwise decreased with the interval of 100μm, and T-light and S-light was repeatedly measured in the same manner described above.Relationship between DTh and T-light or S-light, and the relationship between the distance from C-L and T-light or S-light were analyzed by regression analysis.The following results were obtained;1. T-light was found to decrease with increasing the thickness of dentin and an exponential relationship was found between DTh and T-light.2. An exponential relationship between DTh and S-light was found when the distance between C-L was within 2mm, but no significant relationship was found if the distance from C-L exceeded 4mm.3. S-light was found to decrease with increasing the distance between C-L and a linear relationship was found between the distance from C-L and S-Light irrespective of DTh.(J. Jpn. Soc. Laser Dent. 7: 37-45, 1996 Reprints request to Dr. Zennyu)
{"title":"Transmission of Nd: YAG Laser through Human Dentin","authors":"Kunio Zennyu, M. Inoue, M. Konishi, M. Minami, M. Kumazaki, B. Fujii, C. Lee","doi":"10.5984/JJPNSOCLASERDENT.7.37","DOIUrl":"https://doi.org/10.5984/JJPNSOCLASERDENT.7.37","url":null,"abstract":"Transmission of Nd: YAG laser through human dentin, whose thickness was stepwise decreased, was measured. Four human molars stored in saline solution were used. Dentin specimens with the thickness of approximate 1mm were created by cutting the teeth crossectionally using a diamond disc, followed by being polished by #600 silocone carbide paper and a whetstone. Average dentin thickness (DTh) of each specimen was calculated from five measurements each using a micrometer. Nd: YAG laser equipment used was Dent Lase DCL 8 (S.L.T Japan). An experimental laser tip made of quartz and an experimental gold-plated specimen holder having a central hole were employed. The irradiation conditions of Nd: YAG laser were normal pulse, 170mJ, 20pps and 2-second duration.Three measurements of the intensity of transmitted laser light (T-light) through dentin of approximately 1mm thickness were performed for each specimen by a power monitor (Ophir Optics Ltd). And the power monitor was transferred 2mm perpendicularly from the center of laser light (C-L). And then the measurement of the intensity of scattered laser light (S-light) was trebled. And then the power monitor was further transferred 4, 6, 8, 10 and 12mm from C-L and the measurement of the intensity of S-light was trebled at each displacement from C-L.Then DTh was stepwise decreased with the interval of 100μm, and T-light and S-light was repeatedly measured in the same manner described above.Relationship between DTh and T-light or S-light, and the relationship between the distance from C-L and T-light or S-light were analyzed by regression analysis.The following results were obtained;1. T-light was found to decrease with increasing the thickness of dentin and an exponential relationship was found between DTh and T-light.2. An exponential relationship between DTh and S-light was found when the distance between C-L was within 2mm, but no significant relationship was found if the distance from C-L exceeded 4mm.3. S-light was found to decrease with increasing the distance between C-L and a linear relationship was found between the distance from C-L and S-Light irrespective of DTh.(J. Jpn. Soc. Laser Dent. 7: 37-45, 1996 Reprints request to Dr. Zennyu)","PeriodicalId":187459,"journal":{"name":"Journal of Japanese Society for Laser Dentistry","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125875691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.5984/JJPNSOCLASERDENT.10.15
Eiichi Sakuraba, Kazuyuki Kobayashi, T. Nomura, A. Yamamoto, H. Yamaguchi, J. Nakamura, T. Arai
The purpose of this study was to research the relation between different energy patterns on the same output power and wound healing by the pulsed Nd: YAG laser irradiation. Five hairless rats were used on this study. The pulsed Nd: YAG laser was irradiated with different energy patterns on the same output power (Group 1: 60 mJ, 100 pps. Group 2: 100 mJ, 60 pps. Group 3: 200 mJ, 30 pps. ; 6 W) in a duration 5 sec. in dorsal skin of rats. Wound healing process after the pulsed Nd: YAG laser irradiation were evaluated over a period of 28 days by clinical photographs and histological observation. In the early period of wound healing (0, 1, 3 days after the laser irradiation), wound size of Group 1 was narrow compared with Group 2 and 3 by clinical photographs and histological observation. Until 14 days of healing, a difference was found between the Group 1 and the other groups. In Group 2 and 3 of laser irradiation, a delay in wound healing was observed. After 21 days of healing, an extensive reduction of the wound size in each groups was observed. This report showed, even if the laser is irradiated on the dorsal skin at the same output power, the irradiated tissues receive a severe damage and a delay in wound healing would be observed in the high energy irradiation.
{"title":"Wound Healing Process after pulsed Nd: YAG Laser Irradiation","authors":"Eiichi Sakuraba, Kazuyuki Kobayashi, T. Nomura, A. Yamamoto, H. Yamaguchi, J. Nakamura, T. Arai","doi":"10.5984/JJPNSOCLASERDENT.10.15","DOIUrl":"https://doi.org/10.5984/JJPNSOCLASERDENT.10.15","url":null,"abstract":"The purpose of this study was to research the relation between different energy patterns on the same output power and wound healing by the pulsed Nd: YAG laser irradiation. Five hairless rats were used on this study. The pulsed Nd: YAG laser was irradiated with different energy patterns on the same output power (Group 1: 60 mJ, 100 pps. Group 2: 100 mJ, 60 pps. Group 3: 200 mJ, 30 pps. ; 6 W) in a duration 5 sec. in dorsal skin of rats. Wound healing process after the pulsed Nd: YAG laser irradiation were evaluated over a period of 28 days by clinical photographs and histological observation. In the early period of wound healing (0, 1, 3 days after the laser irradiation), wound size of Group 1 was narrow compared with Group 2 and 3 by clinical photographs and histological observation. Until 14 days of healing, a difference was found between the Group 1 and the other groups. In Group 2 and 3 of laser irradiation, a delay in wound healing was observed. After 21 days of healing, an extensive reduction of the wound size in each groups was observed. This report showed, even if the laser is irradiated on the dorsal skin at the same output power, the irradiated tissues receive a severe damage and a delay in wound healing would be observed in the high energy irradiation.","PeriodicalId":187459,"journal":{"name":"Journal of Japanese Society for Laser Dentistry","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123869526","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.5984/JJPNSOCLASERDENT.23.124
Takayuki Kusunoki, K. Kakimoto, Kazuya Takahashi, Y. Komasa
The production of new dentures imposes financial and physical burdens on elderly patients ; it is preferable for them to keep wearing their old dentures after remodeling and repair. In such denture cases, metal part welding technology may be a problem. Laser welding is frequently applied to the junction of dental cobalt-chromium alloy, considering the shortness of the welding time and narrowness of the heat-affected zone (HAZ). However, welding defects, such as cracks and porosities, occasionally develop in the welding area. Therefore, this study investigated the influence of the casting of dental cobalt-chromium alloy on the occurrence of cracks. Cobalt-chromium alloy ingots for casting (Cobaltan) and castings were used in this study. Using a phosphate bonded investment material (Snow white), castings were produced using a casting machine (Argon caster AE). A dental Nd :YAG laser welding apparatus (Alpha Laser ALP50) was used for welding. The irradiation energy was set to 10.6 or 30.2 J/pulse, and spot welding areas were formed in an argon gas atmosphere. Thereafter, to evaluate the occurrence and causes of cracks, metal tissues of the base material and welded areas were observed using an optical microscope. The fracture surface was observed using a scanning electron microscope (SEM). Element concentration analysis was performed using an energy dispersive X-ray spectrometer (EDX). The metal tissue of the welded area was finer than that of the base material. When the irradiation energy was 10.6 J/pulse, cracks were found in 5 of 15 spots on the ingots, and in 14 of 14 spots on the castings. When the irradiation energy was 30.2 J/pulse, cracks were observed in 1 of 14 spots on the ingots, and in 16 of 18 spots on the castings. Cracks in the welds were more frequently observed in the castings than in the ingots. Observation of the metal tissue and fracture surface showed that those cracks were solidification cracks. It was concluded that casting was the main cause of the solidification cracks. Furthermore, phosphorus may be a cause of the solidification cracks. (J. Jpn. Soc. Laser Dent. 23:124 ~ 130, 2012 Reprint requests to Dr. KUSUNOKI) Key words= Laser welding, Cobalt-chromium alloy, Casting キーワード=レーザー溶接部,コバルトクロム合金,鋳造
{"title":"The Effects of Casting of Dental Cobalt-Chromium Alloy on Crack Initiation by Laser Welding","authors":"Takayuki Kusunoki, K. Kakimoto, Kazuya Takahashi, Y. Komasa","doi":"10.5984/JJPNSOCLASERDENT.23.124","DOIUrl":"https://doi.org/10.5984/JJPNSOCLASERDENT.23.124","url":null,"abstract":"The production of new dentures imposes financial and physical burdens on elderly patients ; it is preferable for them to keep wearing their old dentures after remodeling and repair. In such denture cases, metal part welding technology may be a problem. Laser welding is frequently applied to the junction of dental cobalt-chromium alloy, considering the shortness of the welding time and narrowness of the heat-affected zone (HAZ). However, welding defects, such as cracks and porosities, occasionally develop in the welding area. Therefore, this study investigated the influence of the casting of dental cobalt-chromium alloy on the occurrence of cracks. Cobalt-chromium alloy ingots for casting (Cobaltan) and castings were used in this study. Using a phosphate bonded investment material (Snow white), castings were produced using a casting machine (Argon caster AE). A dental Nd :YAG laser welding apparatus (Alpha Laser ALP50) was used for welding. The irradiation energy was set to 10.6 or 30.2 J/pulse, and spot welding areas were formed in an argon gas atmosphere. Thereafter, to evaluate the occurrence and causes of cracks, metal tissues of the base material and welded areas were observed using an optical microscope. The fracture surface was observed using a scanning electron microscope (SEM). Element concentration analysis was performed using an energy dispersive X-ray spectrometer (EDX). The metal tissue of the welded area was finer than that of the base material. When the irradiation energy was 10.6 J/pulse, cracks were found in 5 of 15 spots on the ingots, and in 14 of 14 spots on the castings. When the irradiation energy was 30.2 J/pulse, cracks were observed in 1 of 14 spots on the ingots, and in 16 of 18 spots on the castings. Cracks in the welds were more frequently observed in the castings than in the ingots. Observation of the metal tissue and fracture surface showed that those cracks were solidification cracks. It was concluded that casting was the main cause of the solidification cracks. Furthermore, phosphorus may be a cause of the solidification cracks. (J. Jpn. Soc. Laser Dent. 23:124 ~ 130, 2012 Reprint requests to Dr. KUSUNOKI) Key words= Laser welding, Cobalt-chromium alloy, Casting キーワード=レーザー溶接部,コバルトクロム合金,鋳造","PeriodicalId":187459,"journal":{"name":"Journal of Japanese Society for Laser Dentistry","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124669383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.5984/JJPNSOCLASERDENT.25.136
Hiroaki Suzuki, Y. Kakei, Daisuke Yasuoka, Yui Enomoto, Midori Kitayama, A. Kimoto, Kousuke Matsumoto, T. Asai, Maho Murata, T. Komori
In an effort to improve the safety of surgery, we investigated the incidents related to surgery using a laser or an electric scalpel, not to mention other equipment. The subjects included in this study were 86 cases who experienced incidents related to their surgery that we found in the reports of the Japan Council for Quality Health Care. We searched for a breakdown of the medical equipment used and the influence on the patient, and analyzed the causes of the incidents to determine whether new recommendations might reduce the risk of incidents. The breakdown of the medical equipment included 61 electric scalpels, 11 light sources, 7 radio wave cautery devices, 5 lasers, and 2 supersonic wave coagulation incision devices. The incidents were 46 burns, including 18 with no adverse outcomes, 8 cases with a foreign body left after surgery, 6 cases of damage to a proximal organ, 3 cases with perforations and 5 other incidents. The causes were 33 errors in the use of the equipment, 20 malfunctions and/or damage to the equipment, 17 cases of sudden ignition, 9 cases in conjunction with the use of a counter electrode plate, and 7 other causes. Many incidents were related to the use of a heat source apparatus, such as an electric scalpel or laser. Because most incidents were due to a lack of knowledge and recognition, taking countermeasures including increased education may be able to prevent the majority of incidents. Medical workers can reduce incidents by recognizing the risks, increasing their knowledge about the devices and sharing countermeasures as a team. (J. Jpn. Soc. Laser Dent. 25:136 ~ 139, 2014 Reprint requests to Dr. SUZUKI) Key words= Laser, Electric scalpel, Incident キーワード=レーザー,電気メス,インシデント
{"title":"Incidents Related to Surgery Using an Electric Scalpel, Laser, etc.","authors":"Hiroaki Suzuki, Y. Kakei, Daisuke Yasuoka, Yui Enomoto, Midori Kitayama, A. Kimoto, Kousuke Matsumoto, T. Asai, Maho Murata, T. Komori","doi":"10.5984/JJPNSOCLASERDENT.25.136","DOIUrl":"https://doi.org/10.5984/JJPNSOCLASERDENT.25.136","url":null,"abstract":"In an effort to improve the safety of surgery, we investigated the incidents related to surgery using a laser or an electric scalpel, not to mention other equipment. The subjects included in this study were 86 cases who experienced incidents related to their surgery that we found in the reports of the Japan Council for Quality Health Care. We searched for a breakdown of the medical equipment used and the influence on the patient, and analyzed the causes of the incidents to determine whether new recommendations might reduce the risk of incidents. The breakdown of the medical equipment included 61 electric scalpels, 11 light sources, 7 radio wave cautery devices, 5 lasers, and 2 supersonic wave coagulation incision devices. The incidents were 46 burns, including 18 with no adverse outcomes, 8 cases with a foreign body left after surgery, 6 cases of damage to a proximal organ, 3 cases with perforations and 5 other incidents. The causes were 33 errors in the use of the equipment, 20 malfunctions and/or damage to the equipment, 17 cases of sudden ignition, 9 cases in conjunction with the use of a counter electrode plate, and 7 other causes. Many incidents were related to the use of a heat source apparatus, such as an electric scalpel or laser. Because most incidents were due to a lack of knowledge and recognition, taking countermeasures including increased education may be able to prevent the majority of incidents. Medical workers can reduce incidents by recognizing the risks, increasing their knowledge about the devices and sharing countermeasures as a team. (J. Jpn. Soc. Laser Dent. 25:136 ~ 139, 2014 Reprint requests to Dr. SUZUKI) Key words= Laser, Electric scalpel, Incident キーワード=レーザー,電気メス,インシデント","PeriodicalId":187459,"journal":{"name":"Journal of Japanese Society for Laser Dentistry","volume":"233 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126005408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：