Outline Research Education Lectures & Courses Clinical Performances
Home page URL https://www.tmd.ac.jp/ddd/

Outline

Department of Digital Dentistry was founded on May 1, 2021, and is responsible for digital dentistry research, clinical practice, and teaching. "Digital dentistry" is an interdisciplinary field consisting of dentistry and engineering. This department provides a smooth connection between clinical dentistry and digital devices (hardware and software) in the field of engineering, and educates and trains individuals in research, clinical practice, and education.
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Research

1) Milled Complete Base Denture
Traditional complete denture manufacturing entails a high number of visits, varying treatment quality due to dentist competence variances, and contamination resistance issues due to the use of acrylic resin. To address these issues, we developed a denture fabrication process based on CAD/CAM technology that reduces the number of visits, improves treatment quality uniformity, and improves the physical qualities of dentures. In the traditional milled denture, only the denture base was milled and the artificial teeth were connected thereafter, resulting in issues such as the adhesive surface of the artificial teeth deteriorating. As a result, we invented the TMDU custom disk method, in which a personalized disk is generated for each patient and the denture base is milled as a single piece with artificial teeth. This custom disk is patented, as well as an application for an overseas patent with the help of the Industry-University Collaboration Office. In a prospective clinical study of complete dentures with CAD/CAM technology, which began in 2019, the findings of employing the TMDU custom disk method revealed better cost-effectiveness compared to fabricating complete dentures using the conventional method. The digital denture fabrication process we've developed incorporates a workflow that starts with an intraoral scanner optical impression of the edentulous jaw crest, then denture design and fabrication on a computer. To further digitalize the process, we intend to integrate AI-assist in denture design in the future. In addition, the company collaborates with manufacturer of milling machine and cutting tool on the creation of milling discs, which are required for milling digital dentures, as well as the verification of acceptable milling machine settings.

2) Digital partial denture
The digital partial denture has not been applied in clinical practice compared to the digital complete denture, because there are few research reports. One reason for this could be that partial dentures must accept a wide range of defect and support methods, and are made comprised of metal and resin materials in a variety of forms to do so. While it is possible to fabricate metal frames using the Selective Laser Melting (SLM), subsequent fabrication processes such as artificial teeth placement and polymerization are still carried out using traditional partial denture fabrication procedures, making it difficult to say that all processes have been digitized. As a result, we developed a method for fabricating a custom plate for partial dentures in which a metal frame created using the SLM method and ready-made artificial tooth is embedded for each patient by adapting the TMDU custom disc method for complete dentures. This allowed for the milling of the artificial tooth, metal frame, and denture base all in one piece, overcoming the issues with traditional digital partial dentures. Dry milling machine is used to create this digital partial denture, but a wet milling machine might be utilized to create partial dentures of any size in the future. In the future, appropriate designs for custom plates will be considered, and fabrication of partial dentures for various defect configurations is assessed.

3) Implant overdenture
For a long period, implant overdentures (IOD) for edentulous mandible patients have been explored. Many research were undertaken in Europe and the United States in the 1980s and 1990s, and many evidence has been amassed in this field since a consensus statement was issued in 2002. We began our clinical research in 2008 at Tokyo Medical and Dental University Hospital, and we now have over 100 patients, with the longest case being followed for over ten years. To date, the following IOD studies have been conducted.

1)Prospective clinical study of 2-IOD using ball attachment (2008-)
2)RCT comparing normal and immediate loading of 2-IOD using magnetic attachments (2011-)
3)Prospective clinical study of mini-IODs using mini-implants(2013-2014 McGill University)
4)Prospective clinical studies of 1-IOD (2015-)
5)Joint clinical research with Showa University on implant-assisted partial denture (IARPD) (2017-)
6)Model experiments on IOD implant placement location and denture movement

On the other hand, only a few clinical trials on maxillary IOD have been conducted worldwide. Based on the evidence of mandibular 2-IOD and our knowledge of edentulous prosthodontics, we believe that if the jaw crest conditions are selected, maxillary IOD can be maintained with two implants, and that this will be an effective treatment choice in the super-aging society. To demonstrate proof, we plan to conduct clinical research of 2-IOD employing two implants as the maintenance source in the maxilla as well as in the mandible to establish evidence.

4)Medical device program
Software intended for illness diagnosis and treatment can now be sold on a stand-alone basis and is regulated as a "medical device program," thanks to the passage of legislation in 2014. This has resulted in the development of medical device programs in a variety of fields. We are currently developing applications (medical device programs) to support oral myofunctional therapy for patients with malocclusion and periodontal disease treatment in our department, and we intend to test their clinical effectiveness, including synergistic effects, with face-to-face examinations.
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Education

Under graduate: In charge of the following lectures and practical training, focusing on the basics of dental technology, complete denture fabrication methods, and digital dentistry.
Basic Technology of Manufacturing, Teeth Morphological Carving, Advanced Teeth Morphological Carving, Complete Denture Prosthodontic Practice, Removable Partial Prosthodontic Practice 1, Basic Fixed Prosthodontic Practice, Advanced Fixed Prosthodontics Practice, Aesthetic Dentistry Practice, CAD/CAM System Technology Practice, Process Device Engineering, Graduation Reseach 1, CAD/CAM System Technology Practice, Oral and Maxillofacial Radiology, Graduation Reseach 2.

Graduate: In charge of research guidance and lectures "Oral Health Engineering" for the master's program of the graduate school.
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Lectures & Courses

Undergraduate: Provide education on cutting-edge technology, particularly in the field of digital dentistry, in order to create digital dental technicians and scientists.

Graduate: Provide professional education in clinical and cutting-edge technologies in the field of digital dentistry, as well as build research skills.
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Clinical Performances

Center for Advanced Interdisciplinary Dentistry: Charge of digital dentistry and prosthetic dentistry as a specialist of denture.

Prosthodontics:A unique intraoral assessment and denture design must be conducted in order to repair the morphological and functional alterations induced by the unique intraoral condition of the edentulous jaw and retention with a complete denture. Complete dentures, in particular, cannot rely on teeth to keep them in oral cavity, instead relying on saliva-mediated adhesion between the oral mucosa and the denture base surface. The subfloor mucosa supports the occlusal stresses on a complete denture through the denture base. It is necessary to retention the denture base, take into account the opposing relationship between the upper and lower jaw crests, and organize the artificial teeth and occlusal style in accordance with jaw movement. The denture should be in a form that harmonizes with the morphology and dynamics of the surrounding muscles and associated soft tissues and improves denture retention in order to restore the significant changes in the facial appearance of edentulous individuals due to missing teeth and tooth-supporting tissues. In addition, when dealing with patients, the psychological impact of tooth loss and the installation of massive prostheses in the mouth should be considered. These alterations in general health, including mental status, are likely to cause changes in the oral mucosa, which will affect denture retention, stability, and function. As a result, periodic recalls are conducted, and the patient's subjective evaluation of the denture and function gained by interview and VAS is continually studied to verify that the recovered function is maintained and enhanced over time. Furthermore, we have created our own evaluation standards to objectively assess the efficacy of prosthetic procedures based on EBM as well as patient subjective opinions.
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