Objective：To evaluate the expression of human osteoprotegerin (hOPG) in periodontal ligament cells (PDLCs) of Beagle dog in order to prepare seed cells with high expression of hOPG gene for periodontal tissue regeneration experiment in later stage. Methods：PDLCs of Beagle dogs were isolated and cultured. Then, adenovirus vector carrying hOPG gene was structured in vitro and transfected into canine PDLCs. Expression of hOPG was observed by flow cytometry, real-time RT-PCR, ELISA and Western Blot. Results：Recombinant adenovirus Ad5-hOPG-EGFP was successfully transfected PDLCs of Beagle dogs. More than 80 per cent of transfected cells positively expressing the green fluorescene protein could be observed under fluorescence microscope and detected by flow cytometry. Effective expression of hOPG was also observed by real-time RT-PCR, ELISA and Western Blot, which proved the successful transfect hOPG into canine PDLCs. Conclusions：hOPG was successfully expressed in PDLCs of Beagle dog which were infected by recombinant adenoviral vector Ad5-hOPG-EGFP.

Objective：To prepare a novel poly (lactic-co-glycolic acid) (PLGA) microcapsule scaffold for bone tissue engineering, characterize the scaffold, and detect its influence on the proliferation and adhesion of osteoblasts. Methods：PLGA was used to prepare microcapsules by double emulsion method. After analyzing the size distribution of PLGA microcapsules by the Malvern Mastersizer 2000, we sieved the microspheres into different sizes. Then we used ethylene chloride vapor to make the random packing of PLGA microcapsules with appropriate size combined. Further sintering helped us to create a three-dimensional microcapsule scaffold. The structure of microcapsule scaffolds were examined by scanning electron microscopy.Osteoblast cell line MC3T3-E1 was chosen to seed on the scaffold, and its adhesive status was observed by SEM. CCK-8 kit was used to analyze the cell proliferation of the group with scaffolds, and to compare with the group without scaffolds. Results：SEM showed that PLGA scaffolds has porous structure, with a certain pore size distribution and porosity. The in vitro study demonstrated that excellent cellular attachment throughout the microcapsule scaffolds. The results of CCK-8 demonstrated the cell viability of cells cultured on PLGA microcapsule scaffolds was higher than the control group after 9 days. Conclusions：From the above results we can conclude that the microcapsule-based scaffold has certain porosity and internal connectivity, which contributes to cell adhesion and proliferation. That means it may be promising as polymeric substitutes for bone repair.

Objective To investigate and measure anterior mandibular jaw bone for clinical application using cone beam computed tomography (CBCT). Methods Fifty Han-Chinese adults were selected in this study between Jan. 2011 and Jan. 2013. All CBCT of the 50 adults were reconstructed to evaluate and measure shape, bucca-lingual width and mesial and distal distance at alveolar crest of anterior region of mandible. Result Buccal shape of anterior mandible was concave in all cases and the most concave point was located on the upper and middle one third of mandible mostly. Shape of lingual was diversified, and convex took a high percentage. For the bucca-lingual width, middle and lower margin of anterior mandibular jaw bone were wider than that of alveolar crest and apex of tooth. Mesial and distal distance at alveolar crest of anterior mandible were between 4.46mm and 6.94 mm, canine had maximum distance, lateral incisor had the second and central incisor had minimum distance. Conclusion When implanting in mandibular anterior alveolar, especially single central incisor or lateral incisor missing, implant may not achieve enough space and adjacent teeth were easy to be affected. Take care of shape of mandible to avoid buccal and lingual penetrating when doing implant surgery in anterior mandible. It was suggested that CBCT should be a routine examination before implant surgery.

Objective：To investigate the clinic application of computer aided design & computer aided manufacturing ( CAD/CAM) custom abutments and all ceramic crowns and evaluate their esthetic effect in the anterior teeth area according to the assessment criteria Pink Esthetic Score (PES) and White Esthetic Score (WES). Methods：Totally 73 CAD/CAM custom abutments and all ceramic crowns were used in 51 implant-supported prosthesis cases. The esthetic prosthetic effect was evaluated according to the assessment criteria PES and WES. Results：The 3-month-follow-up results of totally 73 CAD/CAM custom abutments and all ceramic crowns of 51 patients: the percentage of the PES scores of 10, 8-9, 6-7 and ≤5 was 9.59%, 71.23%, 17.81%, and 1.37%, respectively; the percentage of the WES scores of 10, 8-9, 6-7 and ≤5 was 39.73%, 60.27%, 0%, and 0%, respectively. The 6-month-follow-up results: the percentage of the PES scores of 10, 8-9, 6-7 and ≤5 was 8.22%, 69.86%, 17.81%, and 4.11%, respectively; the percentage of the WES scores of 10, 8-9, 6-7 and ≤5 was 36.99%, 61.64%, 1.37%, and 0%, respectively. The 1-year-follow-up results: the percentage of the PES scores of 10, 8-9, 6-7 and ≤5 was 5.48%, 68.49%, 20.55%, and 5.48%, respectively; the percentage of the WES scores of 10, 8-9, 6-7 and ≤5 was 31.51%, 64.38%, 4.11%, and 0%, respectively. During the follow-up of 1 to 3 years, there was only one abutment got fractured when the torque control was installed, and one loosened during observation. In all cases, the gingivae were in healthy condition, and no further obvious gingival retreat or periimplantitis occurred. Conclusions：PES and WES are objective, integrated and comparable. CAD/CAM custom abutments and all ceramic crowns have good biocompatibility and chemical stability, and can be more widely used in the anterior teeth area. However, their long term effects need to be confirmed by further follow-up.

Objective: The purpose of this study was to observe the immunohistochemical localization of RANKL(receptor activator for nuclear factor-κB ligand) and OPG(osteoprotegerin) and bone resorption in induced periapical lesions in rats.Methods: 8 -week-old male Wistar rats were use in this study, and those whose one side of their mandibular first molar pulp cavity was exposed to the oral cavity served as the treated group and those of the other side as control. Animals were randomly sacrificed at 1st day, 3rd day, 7th day, 14th day and 21st day after operation. We removed the jaw of rats, took X- ray to observe the apical lesion and sections were prepared for immunohistochemistry to detect RANKL / OPG expression in various stages of periapical tissue. Results: Rats periapical bone lesion area significantly increased from the 3rd day, reaching the peak at 21st day, which was time-dependent. RANKL expression of 3rd day group dramatically increased, reached the peak at 7th day, and began to decrease at 14th day. OPG expression sharply increased at 1st day and smoothly rose after 3rd days until it reached the peak at 21st days. The study found a significant correlation between the expression of RANKL/OPG system and the development of periapical lesions. Conclusions: RANKL / OPG system plays an important regulatory role in periapical inflammatory bone destruction.

[Abstract] Objective To investigate the clinical value of polar coordinate measuring method through analyzing effect of adults skeletal cross-bite malocclution. Methods 18 adults skeletal cross-bite patients (aged 18-23, average 20.8, 9 men, 9 women) were chosen. In these cases,four premolars were extracted. Lateral cephalograms were taken at central occlusion position for all of them befor and after treatment. The system of polar coordinates was established with the Bolton Point (Bo) as the pole, and the Bo-N Line as the polar axis. The polar angles and the polar radiuses of soft and hard tissue marking points of maxilla-mandibular facial region were measured respectively. The measured data were processed by SPSS 17.0 with pair t test. Results All cases were treated successfully. Bo-L1 was decreased significantly by 6.54mm in average (P<0.01), Bo-LL was decreased by 3.51mm and Bo-U1 was increased 2.17mm respectively in average (P<0.05). Conclusions Polar coordinates can be used to accurately describe as a whole the craniofacial features for the skeletal cross-bite patients. Soft and hard tissue profiles were improved significantly after treatment . [Key Words] Extraction therapy ; Skeletal cross-bite;Polar coordinates

Objective：To evaluate the erosive potential of orange juice modified by calcium. Methods：45 permanent teeth were randomly divided into there groups, and were immersed in orange juice, orange juice modified by calcium（0.4g/l, calcium lactate pentahydrate）, and deionized water respectively for 25 hours. A laser fluorescence system was used to make a quantitative record. Results：The experiment showed that the group of orange juice and orange juice modified by calcium showed significant higher laser fluorescence value than the group of deionized water （P<0.05）. Orange juice modified by calcium showed significant lower laser fluorescence value than orange juice group （P<0.05）. Conclusions：Calcium ion could significantly reduce the erosion potential of orange juice.

In order to improve various performance of the orthodontic archwire to satisfy the needs of clinicians, the domestic and foreign scholars try diversified surface treatment technologies for metallic biomaterials to realize the archwire surface modification, hoping to reduce the friction coefficient and reach good corrosion resistance, biocompatibility, and aesthetics as well.In this paper, the development of surface modification techniques for orthodontic archwires are reviewed,also including the research progress in surface modification methods for orthodontic archwires.