{"id":{"repo_id":"aachen","oai_identifier":"oai:publications.rwth-aachen.de:51982"},"canonical_url":"https://search.dev.ndltd.org/etd/aachen/oai:publications.rwth-aachen.de:51982","repository":{"repo_id":"aachen","name":"RWTH Aachen University","base_url":"https://publications.rwth-aachen.de/oai2d"},"display":{"title":"Untersuchung der bakteriziden Wirkung von Nd:YAG-Laserstrahlung am Leitkeim Enterococcus faecalis in bovinem Dentin bei Pulsdauern von 15 und 25 ms : eine In-vitro-Studie","abstract":"The objective of this in vitro study is to determine the bactericidal depth effect of laser irradiation with a wavelength of 1064 nm at pulse durations of 15 and 25 ms. Given that the success of endodontic treatment depends on the effective elimination of microorganisms from the root canal and this cannot always be achieved by conventional root canal treatment or rinsing solutions, it would be desirable to apply laser-supported root canal treatment that meets these requirements. A total of ninety 500 and 1000 µm thick dentine slices were prepared from bovine incisors. These were inoculated with 1 µl of Enterococcus faecalis suspension of defined concentration on one side in an area with a diameter of 3 mm. After the samples had dried, their uncontaminated side was irradiated with a Nd:YAG laser (wavelength: 1064 nm) at pulse durations of 15 and 25 ms for 12 sec. Based on Gutknecht’s in vivo root canal treatment, the following laser settings were chosen: 1.75 W, 0,7 Hz for 4 s, 3 times. 15 dentine slices per thickness were not subjected to laser irradiation to serve as a control group. After this treatment, the samples were put in a test tube with 1 ml of physiological saline and placed on a shaker to solubilise the remaining bacteria under vibration. The resulting eluate was diluted to several concentrations and plated out on Columbia blood agar. After 24 h at 37°C, the colony-forming units could be counted and evaluated. In order to determine the potential bactericidal effect of laser irradiation at different pulse durations, the results of the different test groups were compared. In 500 µm thick slices, the average germicidal effect at 15 and 25 ms was 49% and 70%, respectively. In 1000 µm thick slices, the bacterial reduction achieved at 15 and 25 ms was 29% and 50% respectively.The results of this in vitro study show that Nd:YAG laser irradiation at pulse durations of 15 and 25 ms can eliminate Enterococcus faecalis from dentinal canals. It has hence been proven that it is possible to achieve a bactericidal effect in vitro.","abstract_html":"The objective of this in vitro study is to determine the bactericidal depth effect of laser irradiation with a wavelength of 1064 nm at pulse durations of 15 and 25 ms. Given that the success of endodontic treatment depends on the effective elimination of microorganisms from the root canal and this cannot always be achieved by conventional root canal treatment or rinsing solutions, it would be desirable to apply laser-supported root canal treatment that meets these requirements. A total of ninety 500 and 1000 µm thick dentine slices were prepared from bovine incisors. These were inoculated with 1 µl of Enterococcus faecalis suspension of defined concentration on one side in an area with a diameter of 3 mm. After the samples had dried, their uncontaminated side was irradiated with a Nd:YAG laser (wavelength: 1064 nm) at pulse durations of 15 and 25 ms for 12 sec. Based on Gutknecht’s in vivo root canal treatment, the following laser settings were chosen: 1.75 W, 0,7 Hz for 4 s, 3 times. 15 dentine slices per thickness were not subjected to laser irradiation to serve as a control group. After this treatment, the samples were put in a test tube with 1 ml of physiological saline and placed on a shaker to solubilise the remaining bacteria under vibration. The resulting eluate was diluted to several concentrations and plated out on Columbia blood agar. After 24 h at 37°C, the colony-forming units could be counted and evaluated. In order to determine the potential bactericidal effect of laser irradiation at different pulse durations, the results of the different test groups were compared. In 500 µm thick slices, the average germicidal effect at 15 and 25 ms was 49% and 70%, respectively. In 1000 µm thick slices, the bacterial reduction achieved at 15 and 25 ms was 29% and 50% respectively.The results of this in vitro study show that Nd:YAG laser irradiation at pulse durations of 15 and 25 ms can eliminate Enterococcus faecalis from dentinal canals. It has hence been proven that it is possible to achieve a bactericidal effect in vitro.","abstract_has_math":false,"creators":["Falken, Silke"],"institution":"Publikationsserver der RWTH Aachen University","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":["Gutknecht, Norbert"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011","date_published":"2011","updated_at":"2026-07-30T19:40:50Z","subjects":["info:eu-repo/classification/ddc/610","Neodym-YAG-Laser","Impulsdauer","Medizin","Pulsdauer","bakterizide Wirkung","pulse duration","bactericidal effect"],"languages":["ger"],"rights":["info:eu-repo/semantics/openAccess"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-114228%22"],"render_values":[{"text":"https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-114228%22","href":"https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-114228%22","code":true}]}]},"links":{"outbound_url":"https://publications.rwth-aachen.de/record/51982","outbound_label":"Repository record","outbound_source":"dc:identifier"},"source_record":{"url":"https://publications.rwth-aachen.de/oai2d?verb=GetRecord&metadataPrefix=oai_dc&identifier=oai%3Apublications.rwth-aachen.de%3A51982","prefix":"oai_dc"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Gutknecht, Norbert"]},{"key":"dc:creator","label":"Author","values":["Falken, Silke"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:coverage","label":"Dc Coverage","values":["DE"]},{"key":"dc:date","label":"Dc Date","values":["2011"]},{"key":"dc:publisher","label":"Institution","values":["Publikationsserver der RWTH Aachen University"]},{"key":"dc:relation","label":"Dc Relation","values":["info:eu-repo/semantics/altIdentifier/urn/urn:nbn:de:hbz:82-opus-37820"]},{"key":"dc:type","label":"Dc Type","values":["info:eu-repo/semantics/doctoralThesis","info:eu-repo/semantics/publishedVersion"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["info:eu-repo/classification/ddc/610","Neodym-YAG-Laser","Impulsdauer","Medizin","Pulsdauer","bakterizide Wirkung","pulse duration","bactericidal effect"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["ger"]},{"key":"dc:rights","label":"Dc Rights","values":["info:eu-repo/semantics/openAccess"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://publications.rwth-aachen.de/record/51982","https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-114228%22"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["The objective of this in vitro study is to determine the bactericidal depth effect of laser irradiation with a wavelength of 1064 nm at pulse durations of 15 and 25 ms. Given that the success of endodontic treatment depends on the effective elimination of microorganisms from the root canal and this cannot always be achieved by conventional root canal treatment or rinsing solutions, it would be desirable to apply laser-supported root canal treatment that meets these requirements. A total of ninety 500 and 1000 µm thick dentine slices were prepared from bovine incisors. These were inoculated with 1 µl of Enterococcus faecalis suspension of defined concentration on one side in an area with a diameter of 3 mm. After the samples had dried, their uncontaminated side was irradiated with a Nd:YAG laser (wavelength: 1064 nm) at pulse durations of 15 and 25 ms for 12 sec. Based on Gutknecht’s in vivo root canal treatment, the following laser settings were chosen: 1.75 W, 0,7 Hz for 4 s, 3 times. 15 dentine slices per thickness were not subjected to laser irradiation to serve as a control group. After this treatment, the samples were put in a test tube with 1 ml of physiological saline and placed on a shaker to solubilise the remaining bacteria under vibration. The resulting eluate was diluted to several concentrations and plated out on Columbia blood agar. After 24 h at 37°C, the colony-forming units could be counted and evaluated. In order to determine the potential bactericidal effect of laser irradiation at different pulse durations, the results of the different test groups were compared. In 500 µm thick slices, the average germicidal effect at 15 and 25 ms was 49% and 70%, respectively. In 1000 µm thick slices, the bacterial reduction achieved at 15 and 25 ms was 29% and 50% respectively.The results of this in vitro study show that Nd:YAG laser irradiation at pulse durations of 15 and 25 ms can eliminate Enterococcus faecalis from dentinal canals. It has hence been proven that it is possible to achieve a bactericidal effect in vitro."]},{"key":"dc:source","label":"Dc Source","values":["Aachen : Publikationsserver der RWTH Aachen University 86 S. : Ill., graph. Darst. (2011). = Aachen, Techn. Hochsch., Diss., 2011"]},{"key":"dc:title","label":"Title","values":["Untersuchung der bakteriziden Wirkung von Nd:YAG-Laserstrahlung am Leitkeim Enterococcus faecalis in bovinem Dentin bei Pulsdauern von 15 und 25 ms : eine In-vitro-Studie"]}]}],"canonical_facts":{"dc:contributor":["Gutknecht, Norbert"],"dc:coverage":["DE"],"dc:creator":["Falken, Silke"],"dc:date":["2011"],"dc:description":["The objective of this in vitro study is to determine the bactericidal depth effect of laser irradiation with a wavelength of 1064 nm at pulse durations of 15 and 25 ms. Given that the success of endodontic treatment depends on the effective elimination of microorganisms from the root canal and this cannot always be achieved by conventional root canal treatment or rinsing solutions, it would be desirable to apply laser-supported root canal treatment that meets these requirements. A total of ninety 500 and 1000 µm thick dentine slices were prepared from bovine incisors. These were inoculated with 1 µl of Enterococcus faecalis suspension of defined concentration on one side in an area with a diameter of 3 mm. After the samples had dried, their uncontaminated side was irradiated with a Nd:YAG laser (wavelength: 1064 nm) at pulse durations of 15 and 25 ms for 12 sec. Based on Gutknecht’s in vivo root canal treatment, the following laser settings were chosen: 1.75 W, 0,7 Hz for 4 s, 3 times. 15 dentine slices per thickness were not subjected to laser irradiation to serve as a control group. After this treatment, the samples were put in a test tube with 1 ml of physiological saline and placed on a shaker to solubilise the remaining bacteria under vibration. The resulting eluate was diluted to several concentrations and plated out on Columbia blood agar. After 24 h at 37°C, the colony-forming units could be counted and evaluated. In order to determine the potential bactericidal effect of laser irradiation at different pulse durations, the results of the different test groups were compared. In 500 µm thick slices, the average germicidal effect at 15 and 25 ms was 49% and 70%, respectively. In 1000 µm thick slices, the bacterial reduction achieved at 15 and 25 ms was 29% and 50% respectively.The results of this in vitro study show that Nd:YAG laser irradiation at pulse durations of 15 and 25 ms can eliminate Enterococcus faecalis from dentinal canals. It has hence been proven that it is possible to achieve a bactericidal effect in vitro."],"dc:identifier":["https://publications.rwth-aachen.de/record/51982","https://publications.rwth-aachen.de/search?p=id:%22RWTH-CONV-114228%22"],"dc:language":["ger"],"dc:publisher":["Publikationsserver der RWTH Aachen University"],"dc:relation":["info:eu-repo/semantics/altIdentifier/urn/urn:nbn:de:hbz:82-opus-37820"],"dc:rights":["info:eu-repo/semantics/openAccess"],"dc:source":["Aachen : Publikationsserver der RWTH Aachen University 86 S. : Ill., graph. Darst. (2011). = Aachen, Techn. Hochsch., Diss., 2011"],"dc:subject":["info:eu-repo/classification/ddc/610","Neodym-YAG-Laser","Impulsdauer","Medizin","Pulsdauer","bakterizide Wirkung","pulse duration","bactericidal effect"],"dc:title":["Untersuchung der bakteriziden Wirkung von Nd:YAG-Laserstrahlung am Leitkeim Enterococcus faecalis in bovinem Dentin bei Pulsdauern von 15 und 25 ms : eine In-vitro-Studie"],"dc:type":["info:eu-repo/semantics/doctoralThesis","info:eu-repo/semantics/publishedVersion"]},"updated_at":"2026-07-30T19:40:50Z"}