{"id":{"repo_id":"ohiolink","oai_identifier":"oai:etd.ohiolink.edu:osu1366286613"},"canonical_url":"https://search.dev.ndltd.org/etd/ohiolink/oai:etd.ohiolink.edu:osu1366286613","repository":{"repo_id":"ohiolink","name":"OhioLINK","base_url":"https://etd.ohiolink.edu/acprod/odb_etd/ws/oai/oai"},"display":{"title":"Microstructural Observations of Laser-Sintered Specimens for Prosthodontic Applications","abstract":"ABSTRACTObjectives: Laser sintering is a recently introduced technology that has been used to prepare dental restorations from a biocompatible Co-Cr base metal alloy. The objectives of this study were to obtain detailed information about dimensional accuracy available with laser sintering, along with the microstructure and Vickers hardness of the alloy.Methods: Representative maxillary coping and implant framework specimens were prepared from STL files by a commercial laser sintering apparatus (Phenix Systems), using the dedicated Co-Cr alloy. Compatible dental porcelain was bonded to the coping specimen (North Shore Dental Labs, Lynn, MA). Specimens were sectioned with a slow-speed diamond saw, prepared for metallographic examination by resin-mounting and polishing with a series of abrasives, and observed with a scanning electron microscope and optical microscope at a range of magnifications. Alloy compositions were obtained by x-ray energy-dispersive spectrometric analyses. A Co-Cr alloy implant framework prepared by conventional milling/polishing and a cast Ni-Cr alloy coping for a conventional metal-ceramic restoration with the dental porcelain served as controls. Microstructures of the laser-sintered and cast alloys were revealed by electrolytic etching. Values of Vickers hardness for the Co-Cr alloy in the laser-sintered implant framework and the coping for the metal-ceramic restoration were compared, along with the cast coping. Dimensions of the milled/polished and laser-sintered implant frameworks were measured microscopically and compared.Results: The laser-sintered Co-Cr alloy had a fine-grained microstructure, and there was some difficulty in revealing full details by electrolytic etching, whereas the cast Ni-Cr alloy had a well-defined dendritic microstructure. The laser-sintered Co-Co alloy coping had intimate interfacial attachment to dental porcelain. The Vickers hardness was slightly (< 10%, but statistically significant), higher for the laser-sintered Co-Cr implant framework, compared to the laser-sintered Co-Cr coping. The laser-sintered Co-Cr alloy was twice as hard as the cast Ni-Cr alloy. Fits on the original cast/die of the implant frameworks and metal-ceramic specimens were judged to be clinically acceptable by two prosthodontists. Dimensions of the laser-sintered and milled/polished implant frameworks were in excellent agreement for well-defined measurement locations.Conclusions: The fine-grained laser-sintered Co-Cr alloy should have high values of strength, indicated by the high measured Vickers hardness. More research is needed for the electrolytic etching process to reveal the laser-sintered microstructure in greater detail. Use of a nanoindenter is recommended to provide further information about any local hardness variations in the microstructure. The laser-sintering process produces representative prostheses with clinically acceptable accuracy, in agreement with previous publications from other research groups.","abstract_html":"ABSTRACTObjectives: Laser sintering is a recently introduced technology that has been used to prepare dental restorations from a biocompatible Co-Cr base metal alloy. The objectives of this study were to obtain detailed information about dimensional accuracy available with laser sintering, along with the microstructure and Vickers hardness of the alloy.Methods: Representative maxillary coping and implant framework specimens were prepared from STL files by a commercial laser sintering apparatus (Phenix Systems), using the dedicated Co-Cr alloy. Compatible dental porcelain was bonded to the coping specimen (North Shore Dental Labs, Lynn, MA). Specimens were sectioned with a slow-speed diamond saw, prepared for metallographic examination by resin-mounting and polishing with a series of abrasives, and observed with a scanning electron microscope and optical microscope at a range of magnifications. Alloy compositions were obtained by x-ray energy-dispersive spectrometric analyses. A Co-Cr alloy implant framework prepared by conventional milling/polishing and a cast Ni-Cr alloy coping for a conventional metal-ceramic restoration with the dental porcelain served as controls. Microstructures of the laser-sintered and cast alloys were revealed by electrolytic etching. Values of Vickers hardness for the Co-Cr alloy in the laser-sintered implant framework and the coping for the metal-ceramic restoration were compared, along with the cast coping. Dimensions of the milled/polished and laser-sintered implant frameworks were measured microscopically and compared.Results: The laser-sintered Co-Cr alloy had a fine-grained microstructure, and there was some difficulty in revealing full details by electrolytic etching, whereas the cast Ni-Cr alloy had a well-defined dendritic microstructure. The laser-sintered Co-Co alloy coping had intimate interfacial attachment to dental porcelain. The Vickers hardness was slightly (&lt; 10%, but statistically significant), higher for the laser-sintered Co-Cr implant framework, compared to the laser-sintered Co-Cr coping. The laser-sintered Co-Cr alloy was twice as hard as the cast Ni-Cr alloy. Fits on the original cast/die of the implant frameworks and metal-ceramic specimens were judged to be clinically acceptable by two prosthodontists. Dimensions of the laser-sintered and milled/polished implant frameworks were in excellent agreement for well-defined measurement locations.Conclusions: The fine-grained laser-sintered Co-Cr alloy should have high values of strength, indicated by the high measured Vickers hardness. More research is needed for the electrolytic etching process to reveal the laser-sintered microstructure in greater detail. Use of a nanoindenter is recommended to provide further information about any local hardness variations in the microstructure. The laser-sintering process produces representative prostheses with clinically acceptable accuracy, in agreement with previous publications from other research groups.","abstract_has_math":false,"creators":["Fathalah, Ahmed A.A"],"institution":"The Ohio State University","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Dentistry","degree_department":null,"school":null,"contributors":["Brantley, William A."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2013,"date_issued":"2013-08-23","date_published":"2013-08-23","updated_at":"2026-07-24T03:37:46Z","subjects":["Dentistry","Laser sintering","Alloys","Prosthodontics","Hardness","Composition","Metals","Structure"],"languages":["English"],"rights":["unrestricted","This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws."],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://rave.ohiolink.edu/etdc/view?acc_num=osu1366286613","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Brantley, William A."]},{"key":"dc:creator","label":"Author","values":["Fathalah, Ahmed A.A"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2013-08-23"]},{"key":"dc:publisher","label":"Institution","values":["The Ohio State University / OhioLINK"]},{"key":"dc:type","label":"Dc Type","values":["Electronic Thesis or Dissertation"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Dentistry"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["The Ohio State University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Dentistry","Laser sintering","Alloys","Prosthodontics","Hardness","Composition","Metals","Structure"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["English"]},{"key":"dc:rights","label":"Dc Rights","values":["unrestricted","This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws."]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://rave.ohiolink.edu/etdc/view?acc_num=osu1366286613"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["ABSTRACTObjectives: Laser sintering is a recently introduced technology that has been used to prepare dental restorations from a biocompatible Co-Cr base metal alloy. The objectives of this study were to obtain detailed information about dimensional accuracy available with laser sintering, along with the microstructure and Vickers hardness of the alloy.Methods: Representative maxillary coping and implant framework specimens were prepared from STL files by a commercial laser sintering apparatus (Phenix Systems), using the dedicated Co-Cr alloy. Compatible dental porcelain was bonded to the coping specimen (North Shore Dental Labs, Lynn, MA). Specimens were sectioned with a slow-speed diamond saw, prepared for metallographic examination by resin-mounting and polishing with a series of abrasives, and observed with a scanning electron microscope and optical microscope at a range of magnifications. Alloy compositions were obtained by x-ray energy-dispersive spectrometric analyses. A Co-Cr alloy implant framework prepared by conventional milling/polishing and a cast Ni-Cr alloy coping for a conventional metal-ceramic restoration with the dental porcelain served as controls. Microstructures of the laser-sintered and cast alloys were revealed by electrolytic etching. Values of Vickers hardness for the Co-Cr alloy in the laser-sintered implant framework and the coping for the metal-ceramic restoration were compared, along with the cast coping. Dimensions of the milled/polished and laser-sintered implant frameworks were measured microscopically and compared.Results: The laser-sintered Co-Cr alloy had a fine-grained microstructure, and there was some difficulty in revealing full details by electrolytic etching, whereas the cast Ni-Cr alloy had a well-defined dendritic microstructure. The laser-sintered Co-Co alloy coping had intimate interfacial attachment to dental porcelain. The Vickers hardness was slightly (< 10%, but statistically significant), higher for the laser-sintered Co-Cr implant framework, compared to the laser-sintered Co-Cr coping. The laser-sintered Co-Cr alloy was twice as hard as the cast Ni-Cr alloy. Fits on the original cast/die of the implant frameworks and metal-ceramic specimens were judged to be clinically acceptable by two prosthodontists. Dimensions of the laser-sintered and milled/polished implant frameworks were in excellent agreement for well-defined measurement locations.Conclusions: The fine-grained laser-sintered Co-Cr alloy should have high values of strength, indicated by the high measured Vickers hardness. More research is needed for the electrolytic etching process to reveal the laser-sintered microstructure in greater detail. Use of a nanoindenter is recommended to provide further information about any local hardness variations in the microstructure. The laser-sintering process produces representative prostheses with clinically acceptable accuracy, in agreement with previous publications from other research groups."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf","p.45","2.31 MB"]},{"key":"dc:title","label":"Title","values":["Microstructural Observations of Laser-Sintered Specimens for Prosthodontic Applications"]}]}],"canonical_facts":{"dc:contributor":["Brantley, William A."],"dc:creator":["Fathalah, Ahmed A.A"],"dc:date":["2013-08-23"],"dc:description":["ABSTRACTObjectives: Laser sintering is a recently introduced technology that has been used to prepare dental restorations from a biocompatible Co-Cr base metal alloy. The objectives of this study were to obtain detailed information about dimensional accuracy available with laser sintering, along with the microstructure and Vickers hardness of the alloy.Methods: Representative maxillary coping and implant framework specimens were prepared from STL files by a commercial laser sintering apparatus (Phenix Systems), using the dedicated Co-Cr alloy. Compatible dental porcelain was bonded to the coping specimen (North Shore Dental Labs, Lynn, MA). Specimens were sectioned with a slow-speed diamond saw, prepared for metallographic examination by resin-mounting and polishing with a series of abrasives, and observed with a scanning electron microscope and optical microscope at a range of magnifications. Alloy compositions were obtained by x-ray energy-dispersive spectrometric analyses. A Co-Cr alloy implant framework prepared by conventional milling/polishing and a cast Ni-Cr alloy coping for a conventional metal-ceramic restoration with the dental porcelain served as controls. Microstructures of the laser-sintered and cast alloys were revealed by electrolytic etching. Values of Vickers hardness for the Co-Cr alloy in the laser-sintered implant framework and the coping for the metal-ceramic restoration were compared, along with the cast coping. Dimensions of the milled/polished and laser-sintered implant frameworks were measured microscopically and compared.Results: The laser-sintered Co-Cr alloy had a fine-grained microstructure, and there was some difficulty in revealing full details by electrolytic etching, whereas the cast Ni-Cr alloy had a well-defined dendritic microstructure. The laser-sintered Co-Co alloy coping had intimate interfacial attachment to dental porcelain. The Vickers hardness was slightly (< 10%, but statistically significant), higher for the laser-sintered Co-Cr implant framework, compared to the laser-sintered Co-Cr coping. The laser-sintered Co-Cr alloy was twice as hard as the cast Ni-Cr alloy. Fits on the original cast/die of the implant frameworks and metal-ceramic specimens were judged to be clinically acceptable by two prosthodontists. Dimensions of the laser-sintered and milled/polished implant frameworks were in excellent agreement for well-defined measurement locations.Conclusions: The fine-grained laser-sintered Co-Cr alloy should have high values of strength, indicated by the high measured Vickers hardness. More research is needed for the electrolytic etching process to reveal the laser-sintered microstructure in greater detail. Use of a nanoindenter is recommended to provide further information about any local hardness variations in the microstructure. The laser-sintering process produces representative prostheses with clinically acceptable accuracy, in agreement with previous publications from other research groups."],"dc:format":["application/pdf","p.45","2.31 MB"],"dc:identifier":["http://rave.ohiolink.edu/etdc/view?acc_num=osu1366286613"],"dc:language":["English"],"dc:publisher":["The Ohio State University / OhioLINK"],"dc:rights":["unrestricted","This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws."],"dc:subject":["Dentistry","Laser sintering","Alloys","Prosthodontics","Hardness","Composition","Metals","Structure"],"dc:title":["Microstructural Observations of Laser-Sintered Specimens for Prosthodontic Applications"],"dc:type":["Electronic Thesis or Dissertation"],"thesis:degree_discipline":["Dentistry"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["The Ohio State University"]},"updated_at":"2026-07-24T03:37:46Z"}