[Emission Characteristics and Environmental Impact of VOCs from Chemically Synthesized Pharmaceuticals in Shandong Province].

Three typical chemical synthesis pharmaceutical enterprises in Shandong Province were selected as the research object, 61 volatile organic compounds （VOCs） in different emission processes were monitored, the VOCs source profile of each enterprise was established, the impact of VOCs on ozone formation potential was evaluated, and the VOCs emission factor of localized synthetic pharmaceutical enterprises was constructed. The results showed that： The average （TVOCs） of the organized emissions of the three pharmaceutical enterprises varied from 6 055.46 to 10 700.

Scanning Accuracy of 10 Intraoral Scanners for Single-crown and Three-unit Fixed Denture Preparations: An In Vitro Study.

Objective: To evaluate the accuracy of 10 intraoral scanners for single-crown and three-unit preparation models.

Methods: A maxillary partially edentulous model was fabricated. A dental cast scanner was used to obtain standard tessellation language (STL) data.

Comparative Study of Temporomandibular Articular Fossa Bone Surface and the Envelope Surface of the Condyle Movement.

Objective: To investigate the differences between temporomandibular articular fossa bone surface and the envelope surface of the mandibular condyle movement.

Methods: Thirty-four healthy adults underwent skull base and mandible scans using CBCT and performed mandibular border movement using the mandibular movement recording system. Landmarks of the fossa and tubercle were indicated and distance and angle parameters were measured on the 3D models reconstructed from the CBCT.

Clinical application and research progress of digital complete denture.

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.

Accuracy of Intraoral Scanning of Edentulous Jaws with and without Resin Markers.

Objective: To evaluate the accuracy of digital models obtained from intraoral scanning of edentulous maxilla and mandible models with and without resin markers. Methods: A pair of standard edentulous models were scanned using a laboratory scanner and saved as reference models. The edentulous models were fixed onto a phantom head and scanned with an intraoral scanner (IOS) five times each.

Accuracy of root-end resection using a digital guide in endodontic surgery: An study.

Background/purpose: It is difficult to achieve accurate root-end resection clinically. This study was conducted to evaluate the operation accuracy of a digital endodontic surgical guide.

Materials And Methods: 56 extracted maxillary anterior teeth were prepared for endodontic surgical models.

Three-dimensional mandibular motion trajectory-tracking system based on BP neural network.

The aim of this study was to develop a prototype three-dimensional optical motion capture system based on binocular stereo vision, Back-propagation (BP) Neural Network and 3D compen-sation method for accurate and real-time recording of mandibular movement. A specialized 3D method of compensation to eliminate the involuntary vibration motions by human heart beating and respiration. A kind of binocular visual 3D measurement method based on projection line and a calibration method based on BP neural network is proposed to solve the problem of the high complexity of camera calibration process and the low accuracy of 3D measurement.

3D Evaluation of Accuracy of Tooth Preparation for Laminate Veneers Assisted by Rigid Constraint Guides Printed by Selective Laser Melting.

Objective: To design and fabricate 3D-printed rigid constraint guides for the tooth preparation for laminate veneers and to evaluate the accuracy of guide-assisted preparation.

Methods: Twenty maxillary right central incisor resin artificial teeth were randomly divided into two equal groups and prepared for laminate veneers. Tooth preparations were performed, assisted by guides in the test group and by depth gauge burs in the control group, and both were finished by freehand operation.

Osteogenic Differentiation of Three-Dimensional Bioprinted Constructs Consisting of Human Adipose-Derived Stem Cells In Vitro and In Vivo.

Here, we aimed to investigate osteogenic differentiation of human adipose-derived stem cells (hASCs) in three-dimensional (3D) bioprinted tissue constructs in vitro and in vivo. A 3D Bio-plotter dispensing system was used for building 3D constructs. Cell viability was determined using live/dead cell staining.

[Osteogenesis of human adipose-derived mesenchymal stem cells-biomaterial mixture in vivo after 3D bio-printing].

Objective: To construct human adipose-derived mesenchymal stem cells (hASCs)-biomaterial mixture 3D bio-printing body and detect its osteogenesis in vivo, and to establish a guideline of osteogenesis in vivo by use of 3D bio-printing technology preliminarily.

Methods: P4 hASCs were used as seed cells, whose osteogenic potential in vitro was tested by alkaline phosphatase (ALP) staining and alizarin red staining after 14 d of osteogenic induction. The cells were added into 20 g/L sodium alginate and 80 g/L gelatin mixture (cell density was 1 × 10(6)/mL), and the cell-sodium alginate-gelatin mixture was printed by Bioplotter 3D bio-printer (Envision company, Germany), in which the cells'survival rate was detected by live- dead cell double fluorescence staining.

[Short-term effect of CaCl₂on human adipose-derived mesenchymal stem cells proliferation and osteogenic differentiation].

Objective: To examine the effect of CaCl₂, a sodium alginate crosslinker, to stimulate cells for a short time period on human adipose-derived mesenchymal stem cells (hASCs) proliferation and osteogenic differentiation ability, and to determine the appropriate concentration of CaCl₂for post three-dimensional biological experiments.

Methods: hASCs stimulated with or without CaCl₂at various concentrations were seeded and cultured in control medium and osteogenic medium, respectively. The cell counting kit-8 (CCK8) was used to estimate the cell proliferation level of each group.

[Application of patient-participated digital design in esthetic rehabilitation of anterior teeth].

Objective: To explore a new method of patient-involved digital design, esthetic outcome prediction and fabrication for the esthetic rehabilitation of anterior teeth, and to provide an alternative choice for the restoration of anterior teeth.

Methods: In this study, 32 patients with esthetic problems in their anterior teeth were included and divided into two groups randomly: the experimental group (16 patients) and control group (16 patients). In the experimental group, the dentition and facial images were obtained by intra-oral scanning and Three-dimensional (3D) facial scanning and then calibrated.

[Quantitative assessment on artifacts of dental restorative materials in cone beam computed tomography].

Objective: To quantitatively evaluate the artifacts appearance of eight kinds of common dental restorative materials, such as zirconia.

Methods: For the full-crown tooth preparation of mandibular first molar, eight kinds of full-crowns, such as zirconia all-ceramic crown, glass ceramic crown, ceramage crown, Au-Pt based porcelain-fused-metal (PFM) crown, Pure Titanium PFM crown, Co-Cr PFM crown, Ni-Cr PFM crown, and Au-Pd metal crown were fabricated. And natural teeth in vitro were used as controls.

[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.

[Effects of fluence and scanning velocity on the ablation efficiency of dentin and enamel by femtosecond laser].

Objective: To measure the effect of laser fluence and scanning velocity on ablation efficiency of enamel and dentin.

Methods: Two extracted human incisors and two molars were cut transversely along the axial plane with a diamond saw to obtain dentin and enamel slices with thickness of about 1 mm. Samples were fixed on a motorized translation stage, the linear reciprocating movement in the plane perpendicular to the direction of laser incident was programmed by the controller, and the laser focused on the tooth surface, then 36 ablation lines on enamel and 48 ablation lines on dentin were produced.

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.

[Accuracy of different registration methods for laser-scanned dental cast data and maxillofacial cone-bean CT data].

Objective: To evaluate the accuracy of four dominant methods of three-dimensional multisource data registration.

Methods: Laser-scanned dental model and maxillofacial cone-bean CT rebuilt model were collected for one orthodontic patient before treatment. Registration process was done based on locating spheres' center, anatomic landmarks, partial characteristic region and global data separately.

[Influence of intra-pulpal temperature when using femtosecond laser in specific parameters to prepare cavities in tooth enamel: an in vitro study].

Objective: To take the Real-time measurement of the intra-pulpal temperature (IPT) when using femtosecond laser in specific parameters to prepare cavities in tooth enamel in vitro, and to preliminarily evaluate the effect of air cooling.

Methods: All pulp champers of extracted human teeth (premolars and molars) were exposed by roots amputated and pulp scraped out. All chambers were tightly filled with copper powder, and thermocouple was inserted into the center of the powder stack.

[Quantitative evaluation for the accuracy of dental model three-dimensional scanner].

Objective: To establish a method to evaluate dental model three-dimensional scanner quantitatively, and to evaluate the accuracy which is a core indicator of 3Shape D700 scanner.

Methods: A standard geometric model similar to the dental arch was designed by three-dimensional reverse software and processed by high precision CNC (computer numerical control) processing technology. Core indicators of dental model three-dimensional scanner including single scanning accuracy, space consistency and rescan accuracy were evaluated.

[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.

[Digital inlaid design based on anatomical characteristics and preliminary implementation of its program].

Objective: To explore the technical guideline of inlays computer aided design (CAD) for further development, to test the feasibility of processing for the design results of the technical guideline, and to assist co-operation with automatic inlay CAD software development.

Methods: On the basis of point cloud data of right mandibular first molar of standard crown, we established the coordinate system,the landmarks and lines and the characteristic curves. A dental cast of right mandibular first molar MOD-inlay of an individual normal occlusion was scanned.

[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.