[Effects of lyophilized on the biological activities of lentiviral vector of bone morphogenetic protein 2].

Purpose: To investigate the influence of lyophilization on the biological activity of recombinant lentiviral vectors of bone morphogenetic protein 2(BMP-2).

Methods: Recombinant lenti-BMP-2 was constructed. lenti-BMP-2 was transfected with rat bone marrow stromal cells (BMSCs) by multiplicity infection (MOI) of 10, 25, 50, 100, 200.

[Study of the mandibular growth phases and quantities in Shanghai adolescents].

Purpose: To study the growth phases and quantities of mandible in Shanghai adolescents.

Methods: The samples included 480 Shanghai adolescents from 8-20 years of age, 240 were male and 240 were female. Both male and female groups were divided into 6 consecutive developmental periods according to cervical vertebral maturation stages.

[Initial evolution research for design and process accuracy of one type of domestic computer aided design soft and computer aided manufacture].

Objective: To evaluate the design and manufacture accuracy of a domestic computer aided design (CAD) and computer aided manufacture (CAM) system, and to compare it with similar foreign products.

Methods: Thirty models of posterior-teeth-single-crown preparations were collected, and STL data of these preparations was collected by Denmark 3Shape scanner. Three copings were made for each preparation, the one designed and manufactured using commercial CAD/CAM system (3Shape CAD software and Wieland T1 CAM equipment) was assigned into control group T0, the one designed and manufactured using domestic CAD software (developed by Peking University School and Hospital of Stomatology and Nanjing University of Aeronautics and Astronautics) and Wieland T1 CAM equipment was assigned into experimental group TCAD for design accuracy evaluation, and the one designed and manufactured using 3Shape CAD software and domestic CAM equipment (developed by Peking University School and Hospital of Stomatology, Tsinghua University and ShanDong XinHua Incorporated Company of medical apparatus and instruments) was assigned into experimental group TCAM for manufacture accuracy evaluation.

[Preliminary evaluation of clinical effect of computer aided design and computer aided manufacture zirconia crown].

Objective: To evaluate clinical effects of computer aided design and computer aided manufacturing (CAD/CAM) milled zirconia crown in three aspects: aesthetic, contact wear and fracture.

Methods: Sixty patients were divided into two groups.In one group, 35 full contour CAD/CAM zirconia crown were made on molars of 30 patients.

Accuracy evaluation of a new three-dimensional reproduction method of edentulous dental casts, and wax occlusion rims with jaw relation.

The article introduces a new method for three-dimensional reproduction of edentulous dental casts, and wax occlusion rims with jaw relation by using a commercial high-speed line laser scanner and reverse engineering software and evaluates the method's accuracy in vitro. The method comprises three main steps: (i) acquisition of the three-dimensional stereolithography data of maxillary and mandibular edentulous dental casts and wax occlusion rims; (ii) acquisition of the three-dimensional stereolithography data of jaw relations; and (iii) registration of these data with the reverse engineering software and completing reconstruction. To evaluate the accuracy of this method, dental casts and wax occlusion rims of 10 edentulous patients were used.

[Femtosecond pulsed laser ablation of dental hard tissues with numerical control: a roughness and morphology study].

Objective: To establish the femtosecond laser experimental platform in vitro for numerical controlled cavity preparation, and to evaluate the roughness quantitatively and observe the microscopic morphology of the cutting surface.

Methods: Enamel and dentin planes were prepared on human third molars. A universal motion controller was used to control the samples to do rectangle wave motion perpendicular to the incident direction of the laser at focus.

[A computer aided design approach of all-ceramics abutment for maxilla central incisor].

Objective: To establish the computer aided design (CAD) software platform of individualized abutment for the maxilla central incisor.

Methods: Three-dimentional data of the incisor was collected by scanning and geometric transformation. Data mainly included the occlusal part of the healing abutment, the location carinae of the bedpiece, the occlusal 1/3 part of the artificial gingiva's inner surface, and so on.

[Computer aided design and rapid manufacturing of removable partial denture frameworks].

Objective: To introduce a method of digital modeling and fabricating removable partial denture (RPD) frameworks using self-developed software for RPD design and rapid manufacturing system.

Methods: The three-dimensional data of two partially dentate dental casts were obtained using a three-dimensional crossing section scanner. Self-developed software package for RPD design was used to decide the path of insertion and to design different components of RPD frameworks.

[Electronic surveying of digital partially dentate casts].

Objective: To develop a method of surveying the digitalized partially dentate cast in order to accomplish computer aided design (CAD) of removable partial denture (RPD) frameworks.

Methods: The stone cast of a partially dentate patient was scanned using a three-dimensional laser scanner. Points on the surface of the digitalized cast, termed as a "point cloud", were obtained.

[Three-dimensional computer aided design for individualized post-and-core restoration].

Objective: To develop a method of three-dimensional computer aided design (CAD) of post-and-core restoration.

Methods: Two plaster casts with extracted natural teeth were used in this study. The extracted teeth were prepared and scanned using tomography method to obtain three-dimensional digitalized models.

[The identification of electronic surveying lines on 3-D digital models of dentition defects].

Objectives: To develop a mathematical algorithm and a software package for the process of electronically surveying a scanned point cloud cast. To provide a principal premise to the subsequent computer aided design and computer aided manufacture (CAD/CAM) of removable partial denture framework, and to provide a method to improve quality control in the dental laboratory.

Methods: Point cloud data of a partially edentulous cast, a mandibular Kennedy Class II Modification 2 arch, was captured using an optical scanning system with projective grating and high-resolution digital camera.

[Experimental study on bond strength of machinable composite resin and dentin with three kinds of resin cements].

Objective: To examine the shear and microtensile bond strength between a newly developed dental machinable composite resin (polymethylmetacrylate/nano SiO2-ZrO2, PNSZ) and dentin cemented using three resin luting systems and to select the most suitable one.

Methods: The shear and microtensile bond strength between the machinable composite resin and dentin cemented using three resin luting systems (Group A:RelyX ARC, Group B:Panavia-F,Group C:Variolink II) were tested. The broken specimens were observed with a stereomicroscope (x 50) to compare their failure modes.

[Microstructure and mechanical properties of laser melted rapidly solidified forming pure titanium specimens].

Objective: To compare the microstructure and mechanical properties of pure titanium specimens fabricated using laser melted rapidly solidified forming (LMRSF) and casting, and to provide scientific evidence for the new method of laser rapid forming in prosthodontic field.

Methods: Six pure titanium specimens were fabricated from pure titanium powder using LMRSF technology, and six pure titanium casting specimens were used as the controls. The tensile strength was measured and the microstructures and natural fracture surface of the pure titanium specimens made in two different ways were observed.

[Research progress of dental machinable materials].

The concept of computer-aided design/computer aided manufacturing (CAD/CAM) was first mentioned decades ago in the field of dentistry. The technology to make dental restorations has found wide application recently and developed rapidly in prosthodontics and oral implantology, for it could save patients' time and manpower, have precision on prostheses' edging, etc. Until now there are several commercial CAD/CAM systems on market.

[Research and development of computer aided design and rapid prototyping technology for complete denture].

Objective: To explore a computer aided design (CAD) and rapid prototyping (RP) approach for fabrication of complete denture and to develop relevant programs for implementing it.

Methods: Automatic crossing section scanner was used to scan artificial teeth and 3D graphic database of artificial teeth that could be aligned with parameters was established. A 3D laser scanner was used to scan upper and lower edentulous jaw casts and rims made in clinic.

[Establishment of artificial-tooth three-dimensional coordinates based on dental anatomic concepts].

Objective: To establish a three-dimensional (3-D) descartes coordinates of artificial teeth based on concepts of dental anatomy and to obtain their geometric parameters.

Methods: Using the 3-D reverse engineering software, artificial-tooth coordinates were defined based on their anatomic concepts which included long axis, mesiodistal and buccolingual directions, and occlusal plane. Some geometric parameters, such as mesiodistal and buccolingual dimensions, height and obliquity of dental cusp, were measured.

[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 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.

[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.

[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.