China
Africa
Explore chapters and articles related to this topic
Dental Radiography
Published in Paolo Russo, Handbook of X-ray Imaging, 2017
Panoramic radiography is an extremely common technique in the dental world, providing an overview over the dental arch (teeth and the tooth-bearing parts of the maxilla plus the mandible) on a wide landscape-formatted radiograph (Figure 22.21).
3D Nanoprinting in Oral Health Care Applications
Published in Ajit Behera, Tuan Anh Nguyen, Ram K. Gupta, Smart 3D Nanoprinting, 2023
Gaetano Isola, Alessandro Polizzi, Simona Santonocito
CAD/Computer-aided manufacturing (CAD/CAM) systems have totally revolutionised the way dentures are made. In the fabrication of total dentures, the workflow involves: taking virtual impressions using intra-oral and extra-oral scanners and recording the patient's occlusion; the design of the denture using computer software; and the fabrication of the denture using additive or subtractive manufacturing methods [53,54]. With the additive manufacturing technique, both the denture bases and the denture teeth are now printed with 3D printing technology using methacrylate-based light-curing resins [55]. The prosthetic and artificial teeth are printed independently and then fixed in place using a light-curing adhesive [55,56]. Recently, 3D printing technology has been used to fabricate crowns and bridges. In addition, lower cost 3D printers have been utilised to manufacture accurate temporary crown and bridge restorations using SLA printing technology [57], which provides high efficiency and a high level of precision [58]. Using the SLA technique, it is possible to obtain a printed object with a resolution of up to 0.05 mm, resulting in a superior technician in terms of precision, even compared to some newer techniques like digital light projection (DLP) [59]. However, the photopolymer-curing procedure in the DLP printer is quicker than SLA, as SLA employs laser light photopolymer arrays working layer by layer [60]. The workflow involves use of intraoral optical scanners or laboratory scanners that allow the development of accurate virtual models of the preparatin tooth [61,62], implant position [63], and dental arch [64]. This allows prosthetic or implant-prosthetic treatment to be planned using CAD software. This scan information and CAD design can be utilised to cut or print crown or bridge caps, implant abutments, bridge frames, and prostheses. 3D printing can also be used to metal structures either indirectly by printing in burn-out resins or wax for a lost wax procedure, or directly in metals or metallic alloys [39,65]. Direct metal printing involves the need for more expensive technology and requires a large amount of post-processing before the parts are finished [66], compared to printing in resin/wax and later using a traditional casting approach [67]. When printing intricate implant bridge structures, 3D printing may be used in combination with milling/machining techniques to create a very precise mechanical attachment to the implant. [13].
Human Age Estimation Using Deep Convolutional Neural Network based on Dental Images (Orthopantomogram)
Published in IETE Journal of Research, 2023
Orthopantomogram images of about 3508 are considered for the age prediction after pre-processing. 80 percent of the total images are used for training and 20% are used for testing. The following two characteristics of CNNs are essential for determining tooth age ranges: CNNs acquire a tooth with distinct features, as well as distinct features from the same tooth, based on the age group that is utilized for the learning process. Targeted first molar teeth for the age prediction is the first teeth to be formed for any individual at an early age. So, considering that teeth would help us to determine the age with higher accuracy. The last tooth, i.e. third molar to erupt in the oral cavity, and because the human dental arch has shrunk over time, there may not be enough room for it to do so.
A preliminary approach in the prediction of orthodontic bone remodeling by coupling experiments, theory and numerical models
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2019
Daniel George, Delphine Wagner, Yves Bolender, Pascal Laheurte, Boris Piotrowski, Paul Didier, Morad Bensidhoum, Valentin Herbert, Camille Spingarn, Yves Rémond
An experimental setup was developed in order to quantify the developed mechanical forces in 3D on each tooth of a maxillary dental arch when inserting an initial 0.014” Nickel Titanium orthodontic archwire within the brackets (Wagner et al. 2017a). Once the forces were measured, static equilibrium of the dental arch was considered to obtain the moments developed at the center of each bracket (Wagner et al. 2017b). In parallel, histological studies were carried out to extract the cellular distribution and densities within the PDL and adjacent bone (Wagner et al. 2018). These information’s made possible correlations between mechanical forces and cellular activations.