Biomedical subjects

Pei-jun Lü

Publications and source records attributed to Pei-jun Lü.

5 recordsLinked to original sources

PubMed2006

[Computer aided design for fixed partial denture framework based on reverse engineering technology].

OBJECTIVE: To explore a computer aided design (CAD) route for the framework of domestic fixed partial denture (FPD) and confirm the suitable method of 3-D CAD. METHODS: The working area of a dentition model was scanned with a 3-D mechanical scanner. Using the reverse engineering (RE) software, margin and border curves were extracted and several reference curves were created to ensure the dimension and location of pontic framework that was taken from the standard database. The shoulder parts of the retainers were created after axial surfaces constructed. The connecting areas, axial line and curving surface of the framework connector were finally created. RESULTS: The framework of a three-unit FPD was designed with RE technology, which showed smooth surfaces and continuous contours. CONCLUSIONS: The design route is practical. The result of this study is significant in theory and practice, which will provide a reference for establishing the computer aided design/computer aided manufacture (CAD/CAM) system of domestic FPD.

Computer-Aided Design↗

PubMed2006

[Computer aided design and computer aided manufacture of sacrificial pattern of removable partial denture framework].

OBJECTIVE: To introduce a method applied in computer aided design and computer aided manufacture (CAD-CAM) of removable partial denture framework for rehabilitating edentulous arch of Kennedy Class II and found a basis for this project. METHODS: Point cloud data of dental stone model was obtained by laser scanning. The following processes were made: drawing framework outline on the reconstructed triangle mesh model, picking up and processing its inner side data as the data of tissue surface, shelling it for 3-D model of framework, and transferring the data to rapid prototyping equipment for manufacture. RESULTS: 3-D model of the removable partial denture framework was preliminarily accomplished. The resin framework used as a sacrificial pattern was manufactured with the rapid prototyping equipment. The fit between resin framework and plaster model was good. CONCLUSIONS: This method, as an integrated procedure including data acquisition, 3-D computer modeling and fabrication by rapid prototyping, is feasible to implement CAD-CAM of removable partial denture framework.

Computer-Aided Design↗

PubMed2006

[The measurement of cutting forces in full crown preparation with three-dimensional transducer unit].

OBJECTIVE: To measure the cutting forces applied by clinicians during preparing full crown and to provide basic data for the training of dentistry in a virtual reality. METHODS: Each of six prosthodontists and six dental students prepared three extracted maxillary premolars. The cutting forces were measured with a three-dimensional transducer unit. Differences in cutting time and forces between groups were analyzed with independent-samples t-test. RESULTS: The cutting forces varied in the range from 0.10 N to 4.90 N. The average cutting force (1.71 N) of four axial surfaces was higher than that (0.45 N) of occlusal surface (including functional cusp inclines) (P < 0.01). The cutting time by prosthodontists was shorter than that by the students (P < 0.05). Moreover, the vertical component of the cutting force was higher than the horizontal one (P < 0.01). CONCLUSIONS: The magnitude of cutting forces could be greatly influenced by the motion direction and tendency of the handpiece. The data on cutting forces might serve as the foundation of cutting simulation algorithm for training in a virtual reality.

Adolescent↗

PubMed2006

[Application of functionally generated path technique in computer-aided-design modeling of occlusal surface of full crown].

OBJECTIVE: To apply the functionally generated path (FGP) technique for modeling the occlusal surface of a computer-aided-design (CAD) posterior full crown to obtain anatomic morphology. METHODS: A patient with defected left mandibular first molar was employed. After tooth preparation and impression making, the gypsum working cast and die were scanned with a digitized mechanical scanner and the surface data was acquired. The interocclusal records at intercuspal position (ICP) and FGP were made in the patient's mouth. These records were placed on the working cast and their surfaces were scanned. In the process of the computer-aided designing full crown, the cusps and fossae of the occlusal surfaces were accurately modified according to the digitized information of ICP and FGP interocclusal records. RESULTS: A full crown was designed and the occlusal morphology of the restoration was adapted to dynamic occlusion as well as static occlusion. CONCLUSIONS: The FGP technique was practical for the CAD of full crown and could avoid potential occlusal interferences with opposing teeth during function.

Adult↗

PubMed2005

[The inlay computer aided design based on reverse engineering technology].

OBJECTIVE: This study was to explore a CAD method for constructing occlusal and proximal surfaces of inlays using reverse engineering (RE) software and to develop a CAD software for the inlay fabrication. METHODS: The dentition model of a volunteer with individual normal occlusion was scanned with a 3D mechanical scanner. The scanned objects were prepared teeth with G. V. Black class I, class II and class VI (MOD) cavities, neighbor teeth, intercuspal position (ICP) record, and functional bite record (or functional generate path, FGP). Inlays were constructed based on RE technology using the database of Chinese normal teeth. RESULTS: The technique guideline of inlay CAD was developed based on RE softwares. Inlays designed with CAD technique showed smooth and continuous contours. The occlusal and proximal contacts of inlay met physiologic demands. CONCLUSIONS: It is a feasible method to develop a CAD software for inlay fabrication based on RE software.

Adult↗