1.Clinical application and research progress of digital complete denture.
Yong-Sheng ZHOU ; Yu-Chun SUN ; Yong WANG
West China Journal of Stomatology 2021;39(1):1-8
Digital technologies use high-precision three-dimensional scanning, intelligence-aided design software, and multi-axis numerical control milling or 3D printing, which can produce restorations with reliable precision and suitable function. However, the development of digital technologies in the field of complete denture restoration has been slow due to the complexity of prosthesis. This review article introduces the current research status and clinical applications of digital complete dentures in prosthodontic clinics and dental laboratories to provide beneficial references to prosthodontists and dental technicians.
Computer-Aided Design
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Denture, Complete
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Printing, Three-Dimensional
2.Influence of surface treatments and repair materials on the shear bond strength of CAD/CAM provisional restorations
The Journal of Advanced Prosthodontics 2019;11(2):95-104
PURPOSE: To evaluate the effect of surface treatments and repair materials on the shear bond strength and to measure the fracture toughness of CAD/CAM provisional restoration materials. MATERIALS AND METHODS: Four CAD/CAM (3D printing: Nextdent C&B and ZMD-1000B Temporary, CAD/CAM resin block: Yamahachi PMMA disk and Huge PMMA block) and four conventional (monometacrylate: Jet and Alike, dimetacrylate: Luxatemp and Protemp 4) materials were selected to fabricate disk-shaped specimens and divided into six groups according to surface treatment (n=10). CAD/CAM materials were repaired with Jet or Luxatemp, while conventional materials were repaired with their own materials. The shear bond strength was measured by using universal testing machine. Ten rectangular column-shaped specimens for each material were fabricated to measure the fracture toughness by single edge v notched beam technique. Statistical analysis was performed by one-way ANOVA. RESULTS: The highest shear bond strength of CAD/CAM materials was achieved by SiC paper + sandblasting. It was also accomplished when repairing 3D printing materials with Luxatemp, and repairing CAD/CAM resin blocks with Jet. Yamahachi PMMA disk showed the highest fracture toughness. Nextdent C&B showed the lowest fracture toughness value but no statistically significant difference from Alike and Luxatemp (P>.05). CONCLUSION: In order to successfully repair the CAD/CAM provisional restoration, mechanical surface treatment and appropriate repair material according to the CAD/CAM material type should be selected. The CAD/CAM provisional materials have proper mechanical properties for clinical use as compared to conventional materials.
Computer-Aided Design
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Polymethyl Methacrylate
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Printing, Three-Dimensional
3.Progress in clinical application of 3D printed navigational template in orthopedic surgery.
Sheng LU ; Xin XIN ; Wenhua HUANG ; Yanbing LI
Journal of Southern Medical University 2020;40(8):1220-1224
Orthopedic 3D printed surgical navigational template is an instrument that is prepared by 3D reconstruction based on preoperative radiological data of the patient using computer-aided design (CAD) and 3D printing techniques. The 3D printed navigational template allows accurate intra-operative assessment of the relative spatial distance, angular relationship, direction and depth. The application of 3D printed navigational template technique in orthopedics surgeries achieves the conversion of preoperative planning from 2/3D graphics to 3D models, and provides a new method for individualized and precise treatment. Herein we review the evolution, clinical application, and basic classification of 3D printed navigation template technique, analyze its advantages and disadvantages, and discuss the current problems and the future development of this technique.
Computer-Aided Design
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Humans
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Orthopedic Procedures
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Printing, Three-Dimensional
4.A method to evaluate the trueness of reconstructed dental models made with photo-curing 3D printing technologies.
Ning XIAO ; Yu Chun SUN ; Yi Jiao ZHAO ; Yong WANG
Journal of Peking University(Health Sciences) 2019;51(1):120-130
OBJECTIVE:
To establish a reference dental model used for trueness evaluation of photo-curing 3D printing technologies, and to establish a multidimensional trueness evaluation method based on the reference dental model, which can yield a comprehensive objective evaluating result.
METHODS:
A reference dental model was designed in 3ds Max 2018 software based on the statistical analysis results of dental crown and dental arch of Chinese population in previous studies in order to simulate a real dental model. This model was made up of several simple geometrical configurations, which could minimize the manual measurement error. Physical models were fabricated using three types of photo-curing three-dimensional printers using different techniques: Objet30 Pro (PJ), Projet 3510 HD Plus (MJP), and Perfactory DDP (DLP). The models were scanned by a laser-scanning device and the files were exported in a stereolithography file format. In Geomagic Studio 2012, 3D shape deviations (including overall 3D deviation, flatness error, parallelism error and perpendicularity error) were measured by several commands using the data obtained from the scanning. With regard to the feature size of the simulated dental crown and dental arch, linear measurements (including mesiodistal diameter, buccolingual diameter, crown height of each simulated dental crown and feature size of dental arch) were recorded for selected landmarks using a digital caliper. The measurement results of feature sizes were used to analyze the occlusal plane percentage error and the occlusogingival direction percentage error.
RESULTS:
For the 3D shape deviation, the results showed that the printed model made by the Objet30 Pro had the lowest overall 3D deviation, the model made by Projet 3510 HD Plus had the best perpendicularity accuracy and the model made by Perfactory DDP had the best flatness accuracy. In terms of the accuracy of the feature size, the model made by the Objet30 Pro was the most accurate in consideration of the results of the occlusal plane percentage error and the occlusogingival direction percentage error.
CONCLUSION
The reference dental model and the trueness evaluation method using this model is universally applicable in evaluating the trueness of photo-curing three-dimensional printed dental model and can provide a comprehensive objective evaluating result, which can serve as a reference for the clinical use of photo-curing 3D printing technology.
Computer-Aided Design
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Crowns
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Dental Arch
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Imaging, Three-Dimensional
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Models, Dental
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Printing, Three-Dimensional
5.Independent innovation research, development and transformation of precise bionic repair technology for oral prosthesis.
Yu Chun SUN ; Yu Qing GUO ; Hu CHEN ; Ke Hui DENG ; Wei Wei LI
Journal of Peking University(Health Sciences) 2022;54(1):7-12
According to the fourth national oral health epidemiological survey report (2018), billions of teeth are lost or missing in China, inducing chewing dysfunction, which is necessary to build physiological function using restorations. Digital technology improves the efficiency and accuracy of oral restoration, with the application of three-dimensional scans, computer-aided design (CAD), computer-aided manufacturing (CAM), bionic material design and so on. However, the basic research and product development of digital technology in China lack international competitiveness, with related products basically relying on imports, including denture 3D design software, 3D oral printers, and digitally processed materials. To overcome these difficulties, from 2001, Yuchun Sun's team, from Peking University School and Hospital of Stomatology, developed a series of studies in artificial intelligence design and precision bionics manufacturing of complex oral prostheses. The research included artificial intelligence design technology for complex oral prostheses, 3D printing systems for oral medicine, biomimetic laminated zirconia materials and innovative application of digital prosthetics in clinical practice. The research from 2001 to 2007 was completed under the guidance of Prof. Peijun Lv and Prof. Yong Wang. Under the support of the National Natural Science Foundation of China, the National Science and Technology Support Program, National High-Tech R & D Program (863 Program) and Beijing Training Project for the Leading Talents in S & T, Yuchun Sun's team published over 200 papers in the relevant field, authorized 49 national invention patents and 1 U.S. invention patent and issued 2 national standards. It also developed 8 kinds of core technology products in digital oral prostheses and 3 kinds of clinical diagnosis and treatment programs, which significantly improved the design efficiency of complex oral prostheses, the fabrication accuracy of metal prostheses and the bionic performance of ceramic materials. Compared with similar international technologies, the program doubled the efficiency of bionic design and manufacturing accuracy and reduced the difficulty of diagnosis and cost of treatment and application by 50%, with the key indicators of those products reaching the international leading level. This program not only helped to realize precision, intelligence and efficiency during prostheses but also provided functional and aesthetic matches for patients after prostheses. The program was rewarded with the First Technical Innovation Prize of the Beijing Science and Technology Awards (2020), Gold Medal of Medical Research Group in the First Medical Science and Technology Innovation Competition of National Health Commission of the People's Republic of China (2020) and Best Creative Award in the First Translational Medical Innovation Competition of Capital (2017). This paper is a review of the current situation of artificial intelligence design and precision bionics manufacturing of complex oral prosthesis.
Artificial Intelligence
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Bionics
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Computer-Aided Design
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Dental Prosthesis Design
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Humans
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Printing, Three-Dimensional
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Prostheses and Implants
7.Accuracy and retention of denture bases fabricated by injection molding, milling, and three-dimensional printing.
Dan LI ; Sheng Tao YANG ; Quan YUAN ; An Chun MO ; Li YUE
Chinese Journal of Stomatology 2022;57(9):927-931
Objective: To compare the accuracy and retention of denture bases fabricated by injection molding, milling, and three-dimensional (3D) printing fabricating, in order to provide some references for clinical practice. Methods: A maxillary edentulous jaw model made was used to duplicated 10 working casts. The casts were numbered and scanned. The wax pattern was designed by digital ways and conventional methods and then the denture bases were fabricated by injection molding, milling, and 3D printing. The tissue surface of experimental denture base was obtained using a dental laboratory scanner. The deviation between the tissue surface of the fabricated denture bases and the working model was evaluated. A digital force gauge was used to measure the traction force. Results: The milling group [(0.076±0.026) mm] was more accurate than the 3D printing group [(0.117±0.041) mm] (P<0.05) and the injection group [(0.120± 0.025) mm] (P<0.05). The accuracy of 3D printing group and that of injection group were not statistically significant (P>0.05). The milling group [(9.55±2.44) N] demonstrated greater retentive force than 3D printing group [(5.19±0.06) N] and injection molding group [(1.52±0.52) N] (P<0.05). Conclusions: The denture base fabricated by milling was more accurate and showed the greatest retentive force than the other groups. And 3D printing group showed better retentive force than the injection molding group. Both digital manufacturing methods can meet the requirements of clinical application.
Computer-Aided Design
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Denture Bases
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Humans
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Jaw, Edentulous
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Maxilla
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Printing, Three-Dimensional
8.In vitro evaluation of the application of digital individual tooth tray in the impression making of mandibular full-arch crown abutments.
Xiao Xiang XU ; Ye CAO ; Yi Jiao ZHAO ; Lu JIA ; Qiu Fei XIE
Journal of Peking University(Health Sciences) 2020;53(1):54-61
OBJECTIVE:
To establish a method for the production of digital individual tooth tray based on three-dimensional (3D) scan, computer-aided design (CAD) and 3D printing, and to evaluate the effect of impression taking of full-arch crown abutments by digital individual tooth tray technique and conventional method through in vitro study.
METHODS:
The full crown preparation was performed on all the fourteen resin teeth in a standard model of mandibular dentition. The surface data of prepared abutments was collected by 3D scanning. A new project was created in a dental CAD software including all the fourteen teeth in the mandibular dentition. The design modules of anatomy crown and coping were selected for each tooth. The dentition was divided for three sections: right posterior teeth, anterior teeth, and left posterior teeth areas. The connector design was added between the abutments within the same section. The scanned data of the abutments were imported. The occlusal plane and insertion path were determined. The position of margin line, as well as the shape of anatomy crown and connector as the main body of the individual tooth tray were designed for each abutment. The shape of coping was generated as the space for holding the impression material. The finalized data of the main body was imported into Geomagic software. The retentive attachment was added at the external surface and the tissue stop was formed at the internal surface. The completed individual tooth tray was manufactured by 3D printing with resin material. The data of full-arch crown abutments were modified and printed. The conventional dentition trays A and B, as well as digital individual tooth tray were designed and printed for four copies each. The polyether impressions of the full-arch abutments were made by conventional one-step method using dentition tray A, and by sectional-impression technique using digital individual tooth tray and dentition tray B for four times each. The time spent for each impression taking and the numbers of defects at the shoulder and axial/occlusal surface in each impression were recorded. The impression quality of each abutment was evaluated. The overall quality distribution and the pass rate of abutments between the two methods were analyzed.
RESULTS:
The impressions made by conventional method had more defects at shoulder than those made by digital individual tooth tray technique. No difference of the number of defects at axial/occlusal surface between the two methods was observed. The digital individual tooth tray technique for the full-arch abutment impression exhibited higher pass rate of abutments and better quality of impression, compared with conventional methods.
CONCLUSION
A new method for the production of digital individual tooth tray based on digital scanning, CAD and 3D printing was established. Compared with conventional method, using digital individual tooth tray technique for impression taking of full-arch abutments can achieve better effect.
Computer-Aided Design
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Crowns
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Dental Impression Materials
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Dental Impression Technique
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Models, Dental
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Printing, Three-Dimensional
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Software
9.Application of bionics in spinal surgery.
Chinese Journal of Surgery 2022;60(3):208-212
Spinal bionic therapy is the application of bionics concept, by imitating the natural anatomical structure and physiological function of the spine, to treat spinal diseases using various modern technology, materials and equipment .How to repair or preserve the anatomical structure and function of spine to the maximum extent while treating spinal diseases is an important content of spinal bionic therapy.Firstly, the use of movable spinal implants not only preserves the spinal mobility function to a certain extent, reduces the degeneration of adjacent segments, but also reduces the incidence of internal fixation fracture and improves the long-term efficacy.Secondly, with the help of the development of three dimensional printing technology, personalized artificial prostheses can be made to fill the spinal structure with complex defects, and biological scaffolds and functional prostheses with anti-tumor drugs can not only realize the biomimetic and functional spine anatomy, but also become a multiplier of the efficacy of anti-tumor drugs.Thirdly, in the design and manufacture of spinal orthopaedic braces, computer aided design and manufacturing technology can make spinal orthopaedic braces more comfortable with better orthopaedic effect and ergonomic characteristics.How to apply bionics concepts and relate technologies to spinal surgery have not been determined yet, and no relevant diagnosis and treatment guidelines have been formulated.It is foreseeable that with the continuous development of medical technology, the content of spinal bionic therapy will be gradually enriched and improved, and become a powerful measure to overcome difficulties in the diagnosis and treatment of spinal surgery diseases.
Bionics
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Computer-Aided Design
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Humans
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Printing, Three-Dimensional
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Prostheses and Implants
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Spine/surgery*
10.Application and research progress of digital virtual simulated design in dental esthetic rehabilitation.
Si Wei WANG ; Jia Hui YE ; Yun Song LIU ; Yu Chun SUN ; Hong Qiang YE ; Yong Sheng ZHOU
Chinese Journal of Stomatology 2022;57(1):101-106
In dental esthetic rehabilitation, patients pay great attention to the rehabilitative esthetic effect before teeth preparation, and this is also an important content of doctor-patient communication. Along with the development and combined application of intraoral scan, three-dimensional (3D) face scan, digital design, numerical control machining and 3D printing technology, digital technology is gradually applied to the virtual simulated design before irreversible operation in dental esthetic rehabilitation. Digital technology can be used in dentistry to simulate the esthetic outcome in advance, to assist communication among the dentists, patients and dental technicians, and to realize satisfactory outcome in the final restorations precisely, which, as a result, increases the clinical satisfaction. This review focuses on the application of digital virtual simulated design technology in dental esthetic rehabilitation, analyzes the current research development, deficiency and future prospects, so as to provide guidance for clinical diagnosis and treatment.
Computer-Aided Design
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Esthetics, Dental
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Face
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Humans
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Printing, Three-Dimensional
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Tooth Preparation