{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,27]],"date-time":"2026-04-27T18:57:45Z","timestamp":1777316265647,"version":"3.51.4"},"reference-count":50,"publisher":"MDPI AG","issue":"22","license":[{"start":{"date-parts":[[2024,11,10]],"date-time":"2024-11-10T00:00:00Z","timestamp":1731196800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Eureka E!17091 GOLD-GER Project","award":["337-00-00294\/2021-09\/07"],"award-info":[{"award-number":["337-00-00294\/2021-09\/07"]}]},{"name":"Eureka E!17091 GOLD-GER Project","award":["P2-0120 Research Programme"],"award-info":[{"award-number":["P2-0120 Research Programme"]}]},{"name":"Ministry of Education, Science and Technological Development, Serbia","award":["337-00-00294\/2021-09\/07"],"award-info":[{"award-number":["337-00-00294\/2021-09\/07"]}]},{"name":"Ministry of Education, Science and Technological Development, Serbia","award":["P2-0120 Research Programme"],"award-info":[{"award-number":["P2-0120 Research Programme"]}]},{"name":"Slovenian Research Agency ARIS","award":["337-00-00294\/2021-09\/07"],"award-info":[{"award-number":["337-00-00294\/2021-09\/07"]}]},{"name":"Slovenian Research Agency ARIS","award":["P2-0120 Research Programme"],"award-info":[{"award-number":["P2-0120 Research Programme"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>A high-noble Au\u2013Pt\u2013Ge porcelain-fused-to-metal (PFM) dental alloy without the known adverse metallic elements and with the addition of germanium (Ge) was produced as a more cost-effective alternative to other precious alloying metals, with investigations for determining the functionality and clinical use of this alloy. The thermomechanical, biocompatibility, durability, workability and economic characteristics of the produced dental alloy were investigated. These properties were investigated with in vitro biocompatibility testing on human gingival fibroblasts (HGFs); static immersion testing for metal ion release; DSC analysis; hardness, tensile testing, density and coefficient of thermal expansion (CTE) measurements; metallographic and SEM\/EDX microstructure investigations; and finally with the production of a test PFM dental bridge. The results of the thermomechanical testing showed alloy properties suitable for dental restorations and clinical use, with somewhat lower mechanical properties, making the alloy not suitable for extensive multiunit fixed restorations. The microstructure investigations showed segregations of Ge in the homogeneous alloy matrix, which reduce the alloy\u2019s mechanical properties. The produced PFM dental bridge showed excellent workability of the alloy in a dental laboratory setting, as well as a high standard of the final dental restoration. The ion release was negligible, well below any harmful quantities, while the cell viability examination showed significantly higher viability ratings on polished alloy samples as compared to as-cast samples. The results showed that a dental substructure in direct contact with oral tissue and fluids should be highly polished. The performed investigations showed that the produced PFM dental alloy is suitable for clinical use in producing high-quality dental restorations with high biocompatibility for patients prone to metal allergies.<\/jats:p>","DOI":"10.3390\/ma17225491","type":"journal-article","created":{"date-parts":[[2024,11,11]],"date-time":"2024-11-11T11:34:11Z","timestamp":1731324851000},"page":"5491","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["The Thermomechanical, Functional and Biocompatibility Properties of a Au\u2013Pt\u2013Ge Alloy for PFM Dental Restorations"],"prefix":"10.3390","volume":"17","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4313-3412","authenticated-orcid":false,"given":"Peter","family":"Majeri\u010d","sequence":"first","affiliation":[{"name":"Faculty of Mechanical Engineering, University of Maribor, 2000 Maribor, Slovenia"},{"name":"ZlatarnaCelje d.o.o., 3000 Celje, Slovenia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0009-0348-4702","authenticated-orcid":false,"given":"Minja Mili\u010di\u0107","family":"Lazi\u0107","sequence":"additional","affiliation":[{"name":"School of Dental Medicine, University of Belgrade, 11000 Belgrade, Serbia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0650-8193","authenticated-orcid":false,"given":"Dijana","family":"Miti\u0107","sequence":"additional","affiliation":[{"name":"School of Dental Medicine, University of Belgrade, 11000 Belgrade, Serbia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1468-5720","authenticated-orcid":false,"given":"Marko","family":"Lazi\u0107","sequence":"additional","affiliation":[{"name":"School of Dental Medicine, University of Belgrade, 11000 Belgrade, Serbia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6865-6423","authenticated-orcid":false,"given":"Ema Krd\u017eovi\u0107","family":"Lazi\u0107","sequence":"additional","affiliation":[{"name":"School of Dental Medicine, University of Belgrade, 11000 Belgrade, Serbia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7672-5380","authenticated-orcid":false,"given":"Gy\u00f6ngyi","family":"Vastag","sequence":"additional","affiliation":[{"name":"Faculty of Sciences, University of Novi Sad, 21000 Novi Sad, Serbia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ivan","family":"An\u017eel","sequence":"additional","affiliation":[{"name":"Faculty of Mechanical Engineering, University of Maribor, 2000 Maribor, Slovenia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Vojkan","family":"Lazi\u0107","sequence":"additional","affiliation":[{"name":"School of Dental Medicine, University of Belgrade, 11000 Belgrade, Serbia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0510-5752","authenticated-orcid":false,"given":"Rebeka","family":"Rudolf","sequence":"additional","affiliation":[{"name":"Faculty of Mechanical Engineering, University of Maribor, 2000 Maribor, Slovenia"},{"name":"ZlatarnaCelje d.o.o., 3000 Celje, Slovenia"},{"name":"Pomurje Science and Innovation Centre, 9000 Murska Sobota, Slovenia"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2024,11,10]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1194","DOI":"10.1016\/j.prosdent.2014.06.004","article-title":"Comparison of the Metal-to-Ceramic Bond Strengths of Four Noble Alloys with Press-on-Metal and Conventional Porcelain Layering Techniques","volume":"112","author":"Khmaj","year":"2014","journal-title":"J. Prosthet. Dent."},{"key":"ref_2","first-page":"3","article-title":"Mechanical Properties of Dental Co-Cr Alloys Fabricated via Casting and Selective Laser Melting","volume":"2","author":"Dolgov","year":"2016","journal-title":"Mater. Sci. Non-Equilib. Phase Transform."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"203758","DOI":"10.1016\/j.wear.2021.203758","article-title":"Orientation Dependence of the Wear Resistance in the Co\u2013Cr\u2013Mo Single Crystal","volume":"478\u2013479","author":"Nakano","year":"2021","journal-title":"Wear"},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Eliaz, N. (2019). Corrosion of Metallic Biomaterials: A Review. Materials, 12.","DOI":"10.3390\/ma12030407"},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Gopalakrishnan, U., Felicita, A.S., Mahendra, L., Kanji, M.A., Varadarajan, S., Raj, A.T., Feroz, S.M.A., Mehta, D., Baeshen, H.A., and Patil, S. (2021). Assessing the Potential Association Between Microbes and Corrosion of Intra-Oral Metallic Alloy-Based Dental Appliances Through a Systematic Review of the Literature. Front Bioeng. Biotechnol., 9.","DOI":"10.3389\/fbioe.2021.631103"},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Urbutyt\u0117, K., Bar\u010di\u016bt\u0117, A., and Lopatien\u0117, K. (2023). The Changes in Nickel and Chromium Ion Levels in Saliva with Fixed Orthodontic Appliances: A Systematic Review. Appl. Sci., 13.","DOI":"10.3390\/app13084739"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"81","DOI":"10.4103\/0975-962X.184649","article-title":"Assessment of Nickel Release from Various Dental Appliances Used Routinely in Pediatric Dentistry","volume":"7","author":"Kulkarni","year":"2016","journal-title":"Indian J. Dent."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Vastag, G., Majeri\u010d, P., Lazi\u0107, V., and Rudolf, R. (2024). Electrochemical Behaviour of an Au-Ge Alloy in an Artificial Saliva and Sweat Solution. Metals, 14.","DOI":"10.3390\/met14060668"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Rudolf, R., Majeri\u010d, P., Lazi\u0107, V., and Grgur, B. (2022). Development of a New AuCuZnGe Alloy and Determination of Its Corrosion Properties. Metals, 12.","DOI":"10.3390\/met12081284"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"461","DOI":"10.1067\/mpr.2001.115386","article-title":"The Influence of Intracrevicular Crown Margins on Gingival Health: Preliminary Findings","volume":"85","author":"Kancyper","year":"2001","journal-title":"J. Prosthet. Dent."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"153","DOI":"10.11607\/ijp.3440","article-title":"The Clinical Performance of Porcelain-Fused-to-Metal Precious Alloy Single Crowns: Chipping, Recurrent Caries, Periodontitis, and Loss of Retention","volume":"27","author":"Behr","year":"2014","journal-title":"Int. J. Prosthodont."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"682","DOI":"10.1016\/j.dental.2010.03.012","article-title":"Ion Release from Experimental Au\u2013Pt-Based Metal\u2013Ceramic Alloys","volume":"26","author":"Johnson","year":"2010","journal-title":"Dent. Mater."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"265","DOI":"10.1046\/j.1365-2842.2003.01038.x","article-title":"Fracture Reasons in Ceramic-Fused-to-Metal Restorations","volume":"30","year":"2003","journal-title":"J. Oral Rehabil."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Haugen, H.J., Soltvedt, B.M., Nguyen, P.N., Ronold, H.J., and Johnsen, G.F. (2020). Discrepancy in Alloy Composition of Imported and Non-Imported Porcelain-Fused-to-Metal (PFM) Crowns Produced by Norwegian Dental Laboratories. Biomater. Investig. Dent., 7.","DOI":"10.1080\/26415275.2020.1724512"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Uriciuc, W.A., Bo\u0219ca, A.B., B\u0103b\u021ban, A.M., Verme\u0219an, H., Cristea, C., Terti\u0219, M., P\u0103\u0219cu\u021b\u0103, P., Borodi, G., Suciu, M., and Barbu-Tudoran, L. (2022). Study on the Surface of Cobalt-Chromium Dental Alloys and Their Behavior in Oral Cavity as Cast Materials. Materials, 15.","DOI":"10.3390\/ma15093052"},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Lojen, G., Stamboli\u0107, A., \u0160etina Bati\u010d, B., and Rudolf, R. (2020). Experimental Continuous Casting of Nitinol. Metals, 10.","DOI":"10.3390\/met10040505"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"323","DOI":"10.1016\/0040-6031(79)87098-7","article-title":"Melting Behaviour of Nickel\u2014Chromium\u2014Silicon Alloys","volume":"29","author":"Lugscheider","year":"1979","journal-title":"Thermochim. Acta"},{"key":"ref_18","unstructured":"Sakaguchi, R., Ferracane, J., and Powers, J. (2019). Chapter 10\u2014Restorative Materials: Metals. Craig\u2019s Restorative Dental Materials, Elsevier. [14th ed.]."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"109412","DOI":"10.1016\/j.corsci.2021.109412","article-title":"Electrochemical Testing of Noble Metal Dental Alloys: The Influence of Their Chemical Composition on the Corrosion Resistance","volume":"184","author":"Grgur","year":"2021","journal-title":"Corros. Sci."},{"key":"ref_20","unstructured":"International Organization for Standardization (2022). ISO 22674:2022 Dentistry Metallic Materials for Fixed and Removable Restorations and Appliances, International Organization for Standardization. [3rd ed.]."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Lazi\u0107, M., Lazi\u0107, M.M., Kari\u0161ik, M.J., Lazarevi\u0107, M., Jug, A., An\u017eel, I., and Mila\u0161in, J. (2022). Biocompatibility Study of a Cu-Al-Ni Rod Obtained by Continuous Casting. Processes, 10.","DOI":"10.3390\/pr10081507"},{"key":"ref_22","unstructured":"International Organization for Standardization (2009). ISO 10993-5:2009 Biological Evaluation of Medical Devices, Part 5: Tests for In Vitro Cytotoxicity, International Organization for Standardization. [3rd ed.]."},{"key":"ref_23","unstructured":"International Organization for Standardization (2020). ISO 10271:2020 Dentistry\u2014Corrosion Test Methods for Metallic Materials, International Organization for Standardization. [3rd ed.]."},{"key":"ref_24","unstructured":"International Organization for Standardization (1997). ISO 6507-1:1997 Metallic Materials\u2014Vickers Hardness Test, Part 1: Test Method, International Organization for Standardization. [2nd ed.]."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"122","DOI":"10.1590\/S1678-77572009000200010","article-title":"Correlation between Metal-Ceramic Bond Strength and Coefficient of Linear Thermal Expansion Difference","volume":"17","author":"Lopes","year":"2009","journal-title":"J. Appl. Oral Sci."},{"key":"ref_26","first-page":"121","article-title":"Investigation of Mechanical and Biomedical Properties of New Dental Alloy with High Content of Au","volume":"14","author":"Rudolf","year":"2008","journal-title":"J. Metall."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"185","DOI":"10.1111\/j.1600-0536.2011.01878.x","article-title":"Metal Allergen of the 21st Century\u2014A Review on Exposure, Epidemiology and Clinical Manifestations of Palladium Allergy","volume":"64","author":"Faurschou","year":"2011","journal-title":"Contact Dermat."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"306","DOI":"10.1016\/S0301-0546(08)75227-3","article-title":"Palladium Allergy: A Frequent Sensitisation","volume":"36","year":"2008","journal-title":"Allergol. Immunopathol."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"193","DOI":"10.1111\/cod.12846","article-title":"Prevalence of Nickel Allergy in Europe Following the EU Nickel Directive\u2014A Review","volume":"77","author":"Thyssen","year":"2017","journal-title":"Contact Dermat."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"82","DOI":"10.1111\/cod.12238","article-title":"Palladium-Based Dental Alloys Are Associated with Oral Disease and Palladium-Induced Immune Responses","volume":"71","author":"Muris","year":"2014","journal-title":"Contact Dermat."},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Shigematsu, H., Kumagai, K., Suzuki, M., Eguchi, T., Matsubara, R., Nakasone, Y., Nasu, K., Yoshizawa, T., Ichikawa, H., and Mori, T. (2020). Cross-Reactivity of Palladium in a Murine Model of Metal-Induced Allergic Contact Dermatitis. Int. J. Mol. Sci., 21.","DOI":"10.3390\/ijms21114061"},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Kokubo, T. (2008). 23\u2014Dental Ceramics. Bioceramics and Their Clinical Applications, Woodhead Publishing.","DOI":"10.1533\/9781845694227"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"57","DOI":"10.1007\/BF03214598","article-title":"Dental Gold Alloys: Composition, Properties and Applications","volume":"14","author":"Knosp","year":"1981","journal-title":"Gold Bull."},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Farzin, M., Giti, R., and Asalforush-Rezaiye, A. (2018). The Effect of Multiple Firings on the Shear Bond Strength of Porcelain to a New Millable Alloy and a Conventional Casting Alloy. Materials, 11.","DOI":"10.3390\/ma11040478"},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Rudolf, R., Lazi\u0107, V., Majeri\u010d, P., Ivani\u010d, A., Kravanja, G., and Rai\u0107, K.T. (2022). Dental Gold Alloys and Gold Nanoparticles for Biomedical Applications, Springer International Publishing. SpringerBriefs in Materials.","DOI":"10.1007\/978-3-030-98746-6"},{"key":"ref_36","unstructured":"Peretti, D., Di Siro, M., and Di Siro, S. (2017, January 21\u201324). Nickel\u2014And Palladium-Free Master Alloys for All Karats of White Gold\u2014The Santa Fe Symposium. Proceedings of the Santa Fe Symposium on Jewelry Manufacturing Technology, Albuquerque, NM, USA."},{"key":"ref_37","first-page":"71","article-title":"Ion Release from Three Different Dental Alloys\u2014Effect of Dynamic Loading and Toxicity of Released Elements","volume":"7","author":"Haugli","year":"2020","journal-title":"Biomater. Investig. Dent."},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Tomova, Z., Vlahova, A., Zlatev, S., Stoeva, I., Tomov, D., Davcheva, D., and Hadzhigaev, V. (2023). Clinical Evaluation of Corrosion Resistance, Ion Release, and Biocompatibility of CoCr Alloy for Metal-Ceramic Restorations Produced by CAD\/CAM Technologies. Dent. J., 11.","DOI":"10.3390\/dj11070166"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"289","DOI":"10.1016\/B978-0-12-822946-0.00012-X","article-title":"Germanium","volume":"Volume 2","author":"Keith","year":"2022","journal-title":"Handbook on the Toxicology of Metals"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"1539","DOI":"10.1177\/00220345900690081801","article-title":"Cytotoxicity of Experimental Casting Alloys Evaluated by Cell Culture Tests","volume":"69","author":"Craig","year":"1990","journal-title":"J. Dent. Res."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"341","DOI":"10.1111\/j.1600-0714.1988.tb01547.x","article-title":"Reaction of Fibroblasts to Various Dental Casting Alloys","volume":"17","author":"Craig","year":"1988","journal-title":"J. Oral Pathol."},{"key":"ref_42","first-page":"129","article-title":"Evaluation of the Biocompatibility of Various Dental Alloys: Part I\u2014Toxic Potentials","volume":"4","author":"Kansu","year":"1996","journal-title":"Eur. J. Prosthodont. Restor. Dent."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1007\/s10856-015-5481-8","article-title":"Assessment of Human Gingival Fibroblast Interaction with Dental Implant Abutment Materials","volume":"26","author":"Rutkunas","year":"2015","journal-title":"J. Mater. Sci. Mater. Med."},{"key":"ref_44","first-page":"41","article-title":"Corrosion in the Oral Cavity--Potential Local and Systemic Effects","volume":"36","author":"Bergman","year":"1986","journal-title":"Int. Dent. J."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"98","DOI":"10.1016\/0142-9612(92)90002-6","article-title":"Human Cell Culture Studies with Dental Metallic Materials","volume":"13","author":"Berstein","year":"1992","journal-title":"Biomaterials"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"396","DOI":"10.1016\/S0109-5641(01)00063-X","article-title":"Biological Interactions of Dental Cast Alloys with Oral Tissues","volume":"18","author":"Schmalz","year":"2002","journal-title":"Dent. Mater."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"1772","DOI":"10.1177\/00220345980770100401","article-title":"Cytotoxicity of Dental Alloy Extracts and Corresponding Metal Salt Solutions","volume":"77","author":"Schmalz","year":"1998","journal-title":"J. Dent. Res."},{"key":"ref_48","unstructured":"Celinski, A.I. (2006). The Influence of Oxide-Forming Elements on Corrosion and Biocompatibility of Experimental PFM Alloys, Eberhard Karls University of T\u00fcbingen."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"798","DOI":"10.1046\/j.1365-2842.1999.00455.x","article-title":"Initial versus Subsequent Release of Elements from Dental Casting Alloys","volume":"26","author":"Wataha","year":"1999","journal-title":"J. Oral Rehabil."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"583","DOI":"10.1111\/j.1365-2842.1996.tb00896.x","article-title":"Effect of Alloy Surface Composition on Release of Elements from Dental Casting Alloys","volume":"23","author":"Wataha","year":"1996","journal-title":"J. Oral Rehabil."}],"container-title":["Materials"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1996-1944\/17\/22\/5491\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T16:29:48Z","timestamp":1760113788000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1996-1944\/17\/22\/5491"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,11,10]]},"references-count":50,"journal-issue":{"issue":"22","published-online":{"date-parts":[[2024,11]]}},"alternative-id":["ma17225491"],"URL":"https:\/\/doi.org\/10.3390\/ma17225491","relation":{},"ISSN":["1996-1944"],"issn-type":[{"value":"1996-1944","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,11,10]]}}}