The Faculty of Dentistry at the University of Hong Kong (HKU) is using generative AI and dental manufacturing technology to create an innovative method of smart manufacturing for dental crowns, according to leading researchers.
Dr James Tsoi, Associate Professor in Dental Materials Science, and his team have collaborated with colleagues from HKU’s Faculty of Engineering’s Department of Computer Science to advance the production workflow of AI-designed dental prostheses.
Using a true 3D deep learning approach, the researchers created a generative AI algorithm that can accurately produce personalized dental crowns, mimicking the morphology and materials necessary for natural teeth biomechanics. The biomechanical analysis demonstrated that crowns designed with lithium silicate using this AI method can approach the expected lifespan of natural teeth. In comparison, the two current methods of dental crown design often result in crowns that are too thick or too thin and do not achieve the same lifespan as natural teeth.
The publication titled “Morphology and mechanical performance of dental crown designed by 3D-DCGAN” has been released in the esteemed academic journal Dental Materials.
While the Computer-Aided Design and Manufacturing (CAD/CAM) digital workflow has improved dentistry, it still has its drawbacks. The process of designing and manufacturing dental prostheses is time-consuming, labour-intensive, and poses health and environmental risks during 3D printing and milling. The software employs a “tooth library” containing pre-defined crown templates to aid in generating prosthetic designs, but additional adjustments are required by the operator to account for individual conditions.
The research team’s smart manufacturing method has the potential to replace the conventional approach to designing personalised dental crowns.
Dr Hao Ding, a co-investigator on the project, stated that the research team employed a 3D-Deep Convolutional Generative Adversarial Network (3D-DCGAN) approach to training the AI algorithm by providing it with more than 600 samples of healthy natural teeth. Through internal competition between a generator and a discriminator, the algorithm’s design quality is improved.
As a part of the training process, the algorithm was able to learn natural teeth’s morphological characteristics, enabling it to create dental crowns that closely resemble and function similarly to natural teeth.
To evaluate the effectiveness of the 3D-DCGAN AI-designed crowns, they were compared to natural teeth and two other conventional CAD methods of crown design. The comparison demonstrated that the generative AI-designed crowns had the least 3D discrepancy, a cusp angle closest to natural teeth in terms of morphological features, and similar occlusal contacts in terms of functional features.
The research findings suggest that 3D-DCGAN can be used to create personalized dental crowns that closely resemble natural teeth in terms of morphology and biomechanics. The algorithm’s ability to generate designs without the need for further human fine-tuning could result in cost savings during the production process.
According to Dr James Tsoi, the lead researcher of the study, while many AI approaches can create products that resemble natural teeth, this is the first project to implement functional data-driven AI into real dental applications. He hopes that this smart manufacturing technology will pave the way for Industry 4.0 in dentistry, which is essential to tackle the challenges of an ageing society and a shortage of dental personnel in Hong Kong.
Clinical trials are currently underway to assess the effectiveness of using this generative AI technology for dental crowns. Additionally, the research team is exploring the potential applicability of this tool for designing other dental prostheses, such as bridges and dentures.
The study received support from various funding schemes including the General Research Fund (GRF), the Innovation and Technology Fund Mainland-Hong Kong Joint Funding Scheme (ITF-MHKJFS), and the Health and Medical Research Fund (HMRF).
Dr Hao Ding presented the preliminary results at the 35th Annual Scientific Meeting of the International Association of Dental Research (IADR) Southeast Asia (SEA) and was awarded the leading IADR-SEA Research Category Award (Dental Materials and Biomaterials Category) in 2021.
