{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,29]],"date-time":"2025-10-29T12:03:14Z","timestamp":1761739394034,"version":"build-2065373602"},"reference-count":54,"publisher":"MDPI AG","issue":"21","license":[{"start":{"date-parts":[[2025,10,27]],"date-time":"2025-10-27T00:00:00Z","timestamp":1761523200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>The recent rise in living standards has been accompanied by increased awareness and emphasis on oral health. Non-invasive assessment of gingival microcirculation and accurate evaluation of oxygen supply to oral tissues are critical for the early diagnosis of oral diseases. These factors also play a pivotal role in optimizing treatment planning and improving outcomes in dental implantology. In this study, we report the development and implementation of a novel pulse oximetry device based on reflective photoplethysmography technology, designed for non-invasive, real-time monitoring of gingival health through the measurement of oxygen saturation levels. A detailed description of the technology, including key aspects of sensor probe design, is provided, with particular emphasis on the calibration process and performance evaluation of the prototype. Furthermore, we present and discuss the first proof-of-concept gingival oxygen saturation measurements obtained in a clinical setting during oral rehabilitation consultations.<\/jats:p>","DOI":"10.3390\/s25216604","type":"journal-article","created":{"date-parts":[[2025,10,29]],"date-time":"2025-10-29T05:48:46Z","timestamp":1761716926000},"page":"6604","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Implementation, Validation and Clinical Testing of Oximetry Device for Microcirculation Assessment in Oral Tissue"],"prefix":"10.3390","volume":"25","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7077-6192","authenticated-orcid":false,"given":"Hojat","family":"Lotfi","sequence":"first","affiliation":[{"name":"Laboratory for Instrumentation, Biomedical Engineering and Radiation Physics (LibPhys-UNL), NOVA School of Science and Technology, NOVA University of Lisbon, Campus FCT-UNL, 2896-516 Caparica, Portugal"}]},{"given":"Bibiana","family":"Falc\u00e3o","sequence":"additional","affiliation":[{"name":"Laboratory for Instrumentation, Biomedical Engineering and Radiation Physics (LibPhys-UNL), NOVA School of Science and Technology, NOVA University of Lisbon, Campus FCT-UNL, 2896-516 Caparica, Portugal"},{"name":"Cl\u00ednica Dr. Alexis Mendon\u00e7a, Rua Visconde da Luz, 12 1\u00ba, 2750-414 Cascais, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7913-7047","authenticated-orcid":false,"given":"Valentina","family":"Vassilenko","sequence":"additional","affiliation":[{"name":"Laboratory for Instrumentation, Biomedical Engineering and Radiation Physics (LibPhys-UNL), NOVA School of Science and Technology, NOVA University of Lisbon, Campus FCT-UNL, 2896-516 Caparica, Portugal"},{"name":"NMT, S.A., Edif\u00edcio Madan Parque, Rua dos Inventores, 2825-182 Caparica, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2025,10,27]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2187","DOI":"10.1902\/jop.2005.76.12.2187","article-title":"Strengthening the prevention of periodontal disease: The WHO approach","volume":"76","author":"Petersen","year":"2005","journal-title":"J. Periodontol."},{"key":"ref_2","first-page":"1","article-title":"Periodontal microbiology and microbial etiology of periodontaldiseases: Historical concepts and contemporary perspectives","volume":"2000","author":"Belibasakis","year":"2023","journal-title":"Periodontology"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1533658","DOI":"10.3389\/fcimb.2025.1533658","article-title":"Microbiological and molecular aspects of periodontitis","volume":"15","author":"Yekani","year":"2025","journal-title":"Front. Cell. Infect. Microbiol."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Bhuyan, R., Bhuyan, S.K., Mohanty, J.N., Das, S., Juliana, N., and Juliana, I.F. (2022). Periodontitis and Its Inflammatory Changes Linked to Various Systemic Diseases: A Review of Its Underlying Mechanisms. Biomedicines, 10.","DOI":"10.3390\/biomedicines10102659"},{"key":"ref_5","first-page":"e49","article-title":"A Brief Historical Perspective on Dental Implants, Their Surface Coatings and Treatments","volume":"29","author":"Abraham","year":"2014","journal-title":"Int. J. Oral Maxillofac. Implants"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"646383","DOI":"10.3389\/fmats.2021.646383","article-title":"A Brief Review on the Evolution of Metallic Dental Implants","volume":"8","author":"Kandavalli","year":"2021","journal-title":"Front. Mater."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Ngeow, W.C., Tan, C.C., Goh, Y.C., Deliberador, T.M., and Cheah, C.W. (2022). A Narrative Review on Means to Promote Oxygenation and Angiogenesis in Oral Wound Healing. Int. J. Environ. Res. Public Health, 9.","DOI":"10.3390\/bioengineering9110636"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1375784","DOI":"10.3389\/fbioe.2024.1375784","article-title":"Precise healing of oral and maxillofacial wounds","volume":"12","author":"Zhao","year":"2024","journal-title":"Front. Bioeng. Biotechnol."},{"key":"ref_9","first-page":"181","article-title":"Topical oxygen as an adjunct to wound healing: A clinical perspective","volume":"11","author":"Kalliainen","year":"2003","journal-title":"Wound Repair Regen."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"439","DOI":"10.1016\/S0022-3913(98)70009-5","article-title":"Biologic determinants of bone formation for osseointegration: Clues for future clinical improvements","volume":"80","author":"Cooper","year":"1998","journal-title":"J. Prosthet. Dent."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"251","DOI":"10.1034\/j.1600-0501.2003.00972.x","article-title":"De novo alveolar bone formation adjacent to endosseous implants","volume":"14","author":"Berglundh","year":"2003","journal-title":"Clin. Oral Implants Res."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"151","DOI":"10.1007\/s00784-006-0043-6","article-title":"Bone microvascular pattern around loaded dental implants in a canine model","volume":"10","author":"Traini","year":"2006","journal-title":"Clin. Oral Investig."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"81","DOI":"10.1186\/s40729-020-00276-w","article-title":"Potential risk factors for early and late dental implant failure: A retrospective clinical study on 9080 implants","volume":"6","author":"Staedt","year":"2020","journal-title":"Int. J. Implant. Dent."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"211","DOI":"10.1563\/1548-1336(2007)33[211:IZOTJI]2.0.CO;2","article-title":"Implant Zones of the Jaws: Implant Location and Related Success Rate","volume":"33","author":"Tolstunov","year":"2007","journal-title":"J. Oral Implant."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"28","DOI":"10.1016\/j.joms.2003.05.024","article-title":"Ultrasound measurement of mandibular arterial blood supply: Techniques for defining ischemia in the pathogenesis of alveolar ridge atrophy and tooth loss in the elderly?","volume":"63","author":"Eiseman","year":"2005","journal-title":"J. Oral Maxillofac. Surg."},{"key":"ref_16","first-page":"83","article-title":"Bone Quality Assessment of Dental Implant Recipient Sites","volume":"23","author":"Vasovic","year":"2022","journal-title":"Exp. Appl. Biomed. Res. (EABR)"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1587821","DOI":"10.3389\/fdmed.2025.1587821","article-title":"Non-invasive and quantitative methods for assessment of microcirculation in dentistry","volume":"6","author":"Rodriguez","year":"2025","journal-title":"Front Dent. Med."},{"key":"ref_18","first-page":"33","article-title":"Comparing Pulse Oximetry and Laser Doppler Flowmetry as a Diagnostic Tool for Pulpal Vitality Laser Doppler flowmetry","volume":"2","author":"Lotfi","year":"2022","journal-title":"Medicon Dent. Sci."},{"key":"ref_19","first-page":"903","article-title":"Review of Laser Doppler Flowmetry and Pulse Oximetry in Dental Pulp Vitality","volume":"5","author":"Nair","year":"2011","journal-title":"J. Clin. Diagn. Res."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"14","DOI":"10.4103\/2229-5194.77191","article-title":"Pulse oximetry and laser Doppler flowmetry for diagnosis of pulpal vitality","volume":"1","author":"Vaghela","year":"2011","journal-title":"J. Interdiscip. Dent."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"283","DOI":"10.1186\/s12903-023-02747-z","article-title":"Laser doppler flowmetry to detect pulp vitality, clinical reference range and coincidence rate for pulpal blood flow in permanent maxillary incisors in Chinese children: A clinical study","volume":"23","author":"Yang","year":"2023","journal-title":"BMC Oral Health"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"199","DOI":"10.1016\/j.archoralbio.2013.11.009","article-title":"Improvement of the detection of human pulpal blood flow using a laser Doppler flowmeter modified for low flow velocity","volume":"59","author":"Qu","year":"2014","journal-title":"Arch. Oral Biol."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Grabliauskien\u0117, \u017d., Zamaliauskien\u0117, R., and Lodien\u0117, G. (2021). Pulp Vitality Testing with a Developed Universal Pulse Oximeter Probe Holder. Medicina, 57.","DOI":"10.3390\/medicina57020101"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"11","DOI":"10.17796\/1053-4625-43.1.3","article-title":"In Vivo Evaluation of Customized Pulse Oximeter and Sensitivity Pulp Tests for Assessment of Pulp Vitality","volume":"43","author":"Sharma","year":"2019","journal-title":"J. Clin. Pediatr. Dent."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"26","DOI":"10.29328\/journal.jcad.1001037","article-title":"Laser Doppler Flowmeter as a Periodontal Evaluation Method: A Clinical Pilot Study","volume":"7","author":"Mediavilla","year":"2023","journal-title":"J. Clin. Adv. Dent."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1290","DOI":"10.1186\/s12903-025-06608-9","article-title":"Laser doppler flowmetry as a diagnostic tool to detect gingival inflammation: A systematic review","volume":"25","author":"Katz","year":"2025","journal-title":"BMC Oral Health"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1601","DOI":"10.1093\/clinchem\/38.9.1601","article-title":"Pulse Oximetry: Theory and Applications for Noninvasive Monitoring","volume":"38","author":"Mendelson","year":"1992","journal-title":"Clin. Chem."},{"key":"ref_28","unstructured":"Kyriacou, P.A., and Allen, J. (2021). Photoplethysmography: Technology, Signal Analysis and Applications, Academic Press."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"231","DOI":"10.2147\/MDER.S47319","article-title":"Pulse oximetry: Fundamentals and technology update","volume":"7","author":"Nitzan","year":"2014","journal-title":"Med. Devices"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"789","DOI":"10.1016\/j.rmed.2013.02.004","article-title":"Pulse oximetry: Understanding its basic principles facilitates appreciation of its limitation","volume":"107","author":"Chan","year":"2013","journal-title":"Respir. Med."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"775","DOI":"10.1177\/08850666231185752","article-title":"Everything About Pulse Oximetry\u2014Part 1: History, Principles, Advantages, Limitations, Inaccuracies, Cost Analysis, the Level of Knowledge About Pulse Oximeter Among Clinicians, and Pulse Oximetry Versus Tissue Oximetry","volume":"38","author":"Tekin","year":"2023","journal-title":"J. Intensiv. Care Med."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"887","DOI":"10.1177\/08850666231189175","article-title":"Everything About Pulse Oximetry-Part 2: Clinical Applications, Portable\/Wearable Pulse Oximeters, Remote Patient Monitoring, and Recent Advances","volume":"38","author":"Tekin","year":"2023","journal-title":"J. Intensive Care Med."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"522","DOI":"10.1016\/j.mpaic.2014.08.006","article-title":"Measurement of pulse oximetry, capnography and pH","volume":"15","author":"Patil","year":"2014","journal-title":"Anaesth. Intensive Care Med."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"34","DOI":"10.1016\/j.ijleo.2018.04.039","article-title":"Design of a new reflectance pulse oximeter by obtaining the optimal source-detector spacevol","volume":"168","author":"Mehrabi","year":"2018","journal-title":"Optik"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"137","DOI":"10.1097\/00004311-198702530-00009","article-title":"Pulse Oximetry: Technical Aspects of Machine Design","volume":"25","author":"Pologe","year":"1987","journal-title":"Int. Anesthesiol. Clin."},{"key":"ref_36","unstructured":"Raley, D., and Nichols, R. (1998). Multiple LED Sets in Oximetry Sensors. (US5827182A), United States Patent."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"54023","DOI":"10.1117\/1.2976112","article-title":"Absolute transmitted light plethysmography for assessment of dental pulp vitality through quantification of pulp chamber hematocrit by a three-layer model","volume":"13","author":"Kakino","year":"2008","journal-title":"J. Biomed. Opt."},{"key":"ref_38","first-page":"167","article-title":"Design and evaluation of a new reflectance pulse oximeter sensor","volume":"22","author":"Mendelson","year":"1988","journal-title":"Med. Instrum."},{"key":"ref_39","unstructured":"Lopez, S. (2012). Pulse Oximeter Fundamentals and Design, Freescale Semiconductor, Inc.. Application Note AN4327, Rev.2."},{"key":"ref_40","unstructured":"Finnerty, R. (2022, April 21). How to Design a Better Pulse Oximeter. Technical Article Analog Devices 2021. Available online: https:\/\/www.analog.com\/en\/resources\/technical-articles\/how-to-design-a-better-pulse-oximeter.html."},{"key":"ref_41","unstructured":"(2017). Medical Electrical Equipment. Particular Requirements for Basic Safety and Essential Performance of Pulse Oximeter Equipment (Standard No. ISO 80601-2-61:2017)."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"420","DOI":"10.1007\/978-3-030-45124-0_41","article-title":"Device Development for Evaluation of Gingiva Microcirculation","volume":"577","author":"Lotfi","year":"2020","journal-title":"Technological Innovation for Life Improvement"},{"key":"ref_43","unstructured":"(2020). Medical Electrical Equipment\u2014Part 1: General Requirements for Basic Safety and Essential Performance (Standard No. IEC 60601-1:2020)."},{"key":"ref_44","doi-asserted-by":"crossref","unstructured":"Webster, J.G. (1997). Design of Pulse Oximetry, IOP Publishing Ltd.","DOI":"10.1887\/0750304677"},{"key":"ref_45","unstructured":"FLUKE Biomedical (2012). SPOT Light SpO2 Functional Tester. User Manual, Fluke Corporation. PN 4151274 February 2012."},{"key":"ref_46","unstructured":"(2023, November 14). Pulse Oxymeter OXYM9000, Quirumed Health&Care, File No.:2.782.08(QM)SSS\/1.1, March 2015. Available online: https:\/\/www.quirumed.com\/ie\/pulse-oximeter-probe-for-model-oxym9000.html."},{"key":"ref_47","doi-asserted-by":"crossref","unstructured":"Kaner, D., Soudan, M., Zhao, H., Ga\u00dfmann, G., Sch\u00f6nhauser, A., and Friedmann, A. (2017). Early Healing Events after Periodontal Surgery: Observations on Soft Tissue Healing, Microcirculation, and Wound Fluid Cytokine Levels. Int. J. Mol. Sci., 18.","DOI":"10.3390\/ijms18020283"},{"key":"ref_48","doi-asserted-by":"crossref","unstructured":"Martens, A., de Buhr, N., Ishikawa, H., Schroten, H., and von K\u00f6ckritz-Blickwede, M. (2022). Characterization of Oxygen Levels in an Uninfected and Infected Human Blood-Cerebrospinal-Fluid-Barrier Model. Cells, 11.","DOI":"10.3390\/cells11010151"},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"11","DOI":"10.1111\/prd.12398","article-title":"Oral health\u2019s inextricable connection to systemic health: Special populations bring to bear multimodal relationships and factors connecting periodontal disease to systemic diseases and conditions","volume":"87","author":"Kapila","year":"2021","journal-title":"Periodontology 2000"},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"709438","DOI":"10.3389\/fphys.2021.709438","article-title":"Periodontal Inflammation and Systemic Diseases: An Overview","volume":"12","year":"2021","journal-title":"Front. Physiol."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"998313","DOI":"10.3389\/fcimb.2022.998313","article-title":"The impact of periodontitis on vascular endothelial dysfunction","volume":"12","author":"Li","year":"2022","journal-title":"Front. Cell Infect. Microbiol."},{"key":"ref_52","unstructured":"World Health Organization (2022). Global Oral Health Status Report: Towards Universal Health Coverage for Oral Health by 2030, WHO."},{"key":"ref_53","first-page":"7","article-title":"Relationship between periodontal disease and systemic health: Current evidence","volume":"78","author":"Garcia","year":"2019","journal-title":"Periodontology 2000"},{"key":"ref_54","first-page":"e00100","article-title":"Systemic diseases caused by oral infection","volume":"34","author":"Li","year":"2021","journal-title":"Clin. Microbiol. Rev."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/25\/21\/6604\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,29]],"date-time":"2025-10-29T05:57:38Z","timestamp":1761717458000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/25\/21\/6604"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,10,27]]},"references-count":54,"journal-issue":{"issue":"21","published-online":{"date-parts":[[2025,11]]}},"alternative-id":["s25216604"],"URL":"https:\/\/doi.org\/10.3390\/s25216604","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,10,27]]}}}