Biomedical subjects

Cheng-tao Wang

Publications and source records attributed to Cheng-tao Wang.

13 recordsLinked to original sources

PubMed2006

[Stress analyses and comparison of the Kennedy III dentition defect restored with removable partial denture].

PURPOSE: To investigate the stress distribution of the abutment and oral mucosa in Kennedy III, restored with removable partial dentures, either unilateral or bilateral designed. METHODS: Five FEA models were established for the partial edentulous and RPDs, which were divided into group A and group B. According to the denture design, bilateral (B) or unilateral (A) designed. The 3-D finite element analyses were proceeded and calculated with the help of the software ANSYS. Paired t test was used for statistical analysis using SAS 6.2 software package. RESULTS: The maximum stress appeared near the cervical mesial area of the first bicuspid and the second molar. There was no significant difference between the two groups in the stress distribution of the abutment and oral mucosa (P>0.05). CONCLUSION: In regard to the stress of the abutments, unilateral designs have no excess stress formed when RPD was used to restore Kennedy III dentition defect.

Bicuspid↗

PubMed2006

[Establishing three-dimensional reconstruction and measuring system for complete denture occlusion].

PURPOSE: This study was designed to investigate the digital method of locating and reconstructing the occlusal relationship between the upper and lower full dentures. METHODS: The artificial teeth occlusal surfaces of ten complete dentures were scanned by non-contact laser scanner and were reconstructed by three-dimensional technique. With placements of 6 standard steel ball, the three-dimensional position relationship of upper and lower full dentures were studied and reconstructed in centric occlusal position. RESULTS: The three-dimensional reconstruction and measuring system of complete denture occlusion was preliminarily established in this study. CONCLUSIONS: This study focused on exploiting a new system to quantitatively reconstruct the occlusal relationship of complete denture in centric occlusion. And the study may set a methodological foundation of further three-dimensional research for complete denture occlusion.

Dental Occlusion↗

PubMed2005

[A primary construction of the 3D finite element model for fixed edgewise appliance].

PURPOSE: To construct a three-dimensional finite element model (3D-FEM) of the fixed appliance for mechanical analysis. METHODS: The figures of the brackets and the edgewise wire were constructed at the platform of powerSHAPE3040, based on a male's figures of mandibular dentition and alveolar bone. First, the bracket slot center plane (H plane) was lined, which was 4.3mm under the mesial buccal cusp of the 2nd molar and parallel to the XY plane. The point that each tooth's axis of buccal surface (line A) crossed the H plane was at the bracket's center (point O). Second, on the basis of H plane, line A, and point O, 0.018 inchx0.025 inch brackets were constructed on the teeth. All the slots were on the H plane.Then, according to the brackets' slots, plane f was gotten, which went through every slot smoothly and was perpendicular to the XY plane. At the base of slots' basal wall and gingival wall, the 0.016 inchx0.022 inch wire was constructed on the plane f. The figures of edgewise wire, teeth, alveolar bone, and brackets were transferred to ANSYS5.5 system in the IGES format. The teeth, periodontal membrane (PDM), alveolar bone, and brackets were broken down to 4-node tetrahedron element. The 10-node tetrahedron element was chosen to make the model of edgewise wire. RESULTS: The 3D-FEM of the brackets with teeth, PDM, alveolar, and the edgewise wire about the mandible were obtained. This kind of bracket was torqued slot bracket, which is similar to the preadjusted appliance. The edgewise wire was not as same as catenary curve or parabola completely. There were inset and offset on the wire following the dentition model. When the plain edgewise wire was inserted in the brackets, there was no force between the wire and brackets. If the wire was deformed as designed, the action could be analyzed. CONCLUSION: 3D mechanical analysis about the fixed appliance could be done on the model.

Finite Element Analysis↗

PubMed2004

[Stress analysis of the mandible by 3D FEA in normal human being under three loading conditions].

PURPOSE: The condition and character of stress distribution in the mandibular in normal human being during centric, protrusive, laterotrusive occlusion were analysed. METHODS: The three-dimensional finite element model of the mandibular was developed by helica CT scanning and CAD/CAM software, and three-dimensional finite element stress analysis was done by ANSYS software. RESULT: Three-dimensional finite element model of the mandibular was generated. Under these three occlusal conditions, the stress of various regions in the mandible were distributed unequally, and the stress feature was different;while the stress of corresponding region in bilateral mandibular was in symmetric distribution. The stress value of condyle neck, the posterior surface of coronoid process and mandibular angle were high. CONCLUSION: The material properties of mandible were closely correlated to the value of stress. Stress distribution were similar according to the three different loading patterns, but had different effects on TMJ joint. The concentrated areas of stress were in the condyle neck, the posterior surface of coronoid process and mandibular angle.

Finite Element Analysis↗

PubMed2004

[The establishment of 3D-FE model libraries for the elements of the RPD].

PURPOSE: To establish the 3D-FE model libraries for the elements of the RPD. METHODS: Based on the 3D geometric model libraries of the RPD and normal stomatognathic system, using the software, such as Powershape,Pro/E and Ansys5.5, transformed data, trimmed models, or rebuilt it, established many kinds of FE model elements, then combine these elements in the whole model, connected and trimmed, at last created several kinds of FE model libraries. RESULTS: This study established eight kinds of FE model libraries, including the occlusal rests, clasps, bases, artificial teeth, and connectors, etc, nearly two hundreds FE model elements. CONCLUSION: The established models have a satisfied geometric configuration; these elements combined well in the whole model, and can be easily call-in and edit.

Denture, Partial, Removable↗

PubMed2004

[The establishment of 3D-FE model libraries for the elements of FPD].

PURPOSE: To establish the 3D-FE model libraries for the elements of the FPD. METHODS: Based on the 3-D geometric model libraries of the normal stomatognathic system, using the software, such as Powershape,Pro/E and Ansys5.5, the models of abutments,retainers and pontics were created according to the models of natural crowns. The models of connectors were established according to the sutures between the crowns. RESULTS: This study has established the FE model libraries for the elements of the FPD, including the retainers,pontics,and connectors, three kinds of libraries and 82 elements in all. CONCLUSION: The established models have a satisfied geometric configuration; the analysis models can be easily established and edited.

Denture, Partial, Fixed↗

PubMed2004

[Multi-objectives optimization on life cycle pollutants emission of cassava-based ethanol blended gasoline fuels].

An optimization model on life cycle pollutants emission of cassava-based ethanol blended gasoline fuels, including single and multi-objectives, was carried out in this paper. And, the single and multi-objectives optimization of cassava-based ethanol blended gasoline fuels were done, using the life cycle CO, NOx, PM, HC, SOx, CO2 emissions as objectives. Moreover, sensitivity analysis of design variables was done. The multi-objectives results shown that the blend ratio between cassava-based ethanol and gasoline was 63%. Compare with the initial value, multi-objective optimization of cassava-based ethanol blended gasoline fuels achieved a little more life cycle CO, NOx and PM emissions, about 1%, 15% and 19% respectively, and reduced life cycle HC, SOx and CO2 emissions, 8%, 50%, and 21% respectively.

Air Pollutants↗

PubMed2003

[Using laser scanning to 3-D reconstruct an ear model].

OBJECTIVE: The purpose of the study was to get the ear data from a laser scanning so that a. STL file can be promoted though which a 3-d ear reconstruction can be held. METHODS: A laser scanning manufactured by France was used to get the data of an auricular model, then the data was turned into a. STL file so that a 3-d image of ear was got. RESULTS: The result shows that a 3-d ear reconstructed image can be got quickly and precisely. The digital image shows that the dimension, shape and long axis of the ear is really similar to the ear model. CONCLUSIONS: This study suggests that laser scanning is helpful and effective to get the data of ear. Through this method, it makes it possible to be ready for the technique of rapid prototyping and provide a new, convenient, effective and safe method to auricular prosthesis.

Ear, External↗

PubMed2003

[Spectral analysis of electromyography of low back muscle fatigue induced by simulated driving].

OBJECTIVE: To evaluate the effects of different vibration frequency on the back muscle fatigue during simulated driving. METHODS: Thirty-six subjects performed three simulated driving experiments under three vertical vibration frequencies which were 1.8, 4.0, 6.0 Hz respectively and the driving time was 90 minutes. At the same time the electromyography of low back was recorded. RESULTS: The median frequencies calculated from the power spectrum were decreased exponentially under three vertical vibration frequencies, especially under 4.0 Hz vibration frequency. CONCLUSION: The 4.0 Hz vibration frequency has the most important effect on the back muscle fatigue under simulated driving condition.

Adult↗

PubMed2002

[The establishment of 3D geometry model element for dentition defect restoration].

OBJECTIVE: To establish the library including all elements for the restoration of removable partial dentition defect. METHODS: To design and reconstruct every element that could be used to build up 3D geometry stimulation for any kind of restoration. The restoration made up of elements could be edited and changed easily for proper dentition defect. And the different restoration for the same defect can be got easily. RESULTS: Established the library of all elements for restoration of removable partial dentition defect. CONCLUSION: Established the elements library. It avoided the much work repeated and improved efficiency.The elements were the important base works for the further research on dentition defect restoration and instruction system.

English Abstract↗

PubMed2002

[The application of 3D geometric modular element for the removable partial denture].

OBJECTIVE: To discuss the application way for element library of dentition and the removable partial denture. METHODS: With the help of some software, such as PRO/E, POWERSHAPE, etc, design the content and structure of the element libraries reasonably, and discussed the efficiency way of usage. RESULTS: We can use the element libraries by the way of "import-edit",and the way of "element group". CONCLUSION: The structure of the element libraries is reasonable and can run effectively.

English Abstract↗

PubMed2002

[Development of the editable software for dentition defect and dentures].

OBJECTIVE: Discussed how to develop a software for prosthodontics teaching with the models and element libraries of the dentition and dentures. METHODS: Selected the typical Kennedy's types and prostheses, used the kinds of model and libraries, by the way of the image manipulation, we established an applied software. RESULTS: We established an useful software for the prosthodontics teaching. CONCLUSION: The software we developed is effective and editable.

English Abstract↗

PubMed2002

[The basic research on fabricating an ear model by means of rapid prototyping (FDM)].

OBJECTIVE: The purpose of the study was to reconstruct a 3-D auricular model. METHODS: Laser scanning was used to get the data of an auricular model, Fused Deposition Manufacturing (one of rapid prototyping technique) was chosen to fabricate an ear cast. The differences between the two models were compared. RESULTS: The result showed that the reconstructed model was precise. CONCLUSION: This study suggests that the technique of rapid prototyping is precise, convenient, effective and safe to auricular prosthesis.

English Abstract↗