This paper introduces what signals are actually transmitted in every procedure of the start-up process of Mx8000 Exp double-slice spiral CT and what relevant parts are acted.Some troubles related to start-up process is briefly presented.

Objective: To investigate the bone healing of rigid internal fixatio n(RIF) during Le Fort I Osteotomy.Methods: We regarded rabbits as study objects and evaluated the form of bone healing by bone histomorphometry.Results:There was significant difference in the degree of the new bone formation between groups,and the degrees in group A were much higher than that in group B at any stages .Conclusion:The use of RIF in orthognathic surgery can speed the bone healing.`

BACKGROUND:Studies have found that combination of two of chitosan (CS), nano-hydroxyapatite (nHA) and poly(lactide-co-glycolide) (PLGA) can improve the mechanical properties and biocompatibility of the composite stent in certain extent as wel as improve osteogenic differentiation of the cels, but there is a certain distance from the ideal bone tissue engineering scaffolds.
OBJECTIVE:To study biocompatibility and osteoinductive activity of nHA/CS/PLGA scaffolds with different proportions in vitro.
METHODS: nHA/CS/PLGA scaffolds were prepared at mass ratio of 10:10:80, 10:20:70, 20:10:70 respectively by particle leaching method. And human bone marrow stem cels (hBMSCs) were co-cultured with these scaffolds in vitro. Adhesion, proliferation, and osteoinductive activity of these scaffolds were examined qualitatively and quantitatively by growth curve of hBMSCs on scaffolds. Gene expression of alkaline phosphatase activity and osteocalcin was detected by RT-PCR.
RESULTS AND CONCLUSION: hBMSCs could be attached, proliferated, and osteoinduced better on the nHA/CS/PLGA scaffold with the mass ratio of 20:10:70, compared to the other two groups of scaffolds. The differences were significant statisticaly (P< 0.05). Alkaline phosphatase and osteocalcin expressions were respectively higher in the scaffold with the mass ratio of 20:10:70 after 9-27 days of co-culture and 15-27 days of co-culture, in comparison with the other two groups of scaffolds. These findings indicate that the nHA/CS/PLGA scaffolds with the mass ratio of 20:10:70 demonstrated preferable biocompatibility and osteogenic inductivity, which is expected to be a promising scaffold material for bone tissue engineering.

It is a digital age today.Exposed to all kinds of digital products in many fields.Certainly,implant dentistry is not exception.Digitalization could improve the outcomes and could decrease the complications of implant dentistry.This paper introduces the concepts,definitions,advantages,disadvantages,limitations and errors of digital implant dentistry.

BACKGROUND: Mis Seven implant has become more and more popular in oral implant restoration, and the clinical application in dentate-deficient patients remains to be studied. OBJECTIVE: To explore the short-term effects of the Mis Seven implant system on fixed restorations in dentition loss. METHODS: Nineteen patients undergoing fixed dental prostheses with the Mis Seven system due to dentition loss at the Department of Implants of the Stomatological Hospital of Guangzhou Medical University between April 2015 and December 2017 were included. Three patients had missing maxillary and maxillary dentition and unilateral maxillary teeth. Six patients were loss of maxillary dentition, and there were 10 cases of unilateral mandibular dentition missing. The total dental implants were 134. All cases were implanted and fixed for one stage. Clinical examination, alveolar bone and inter-implant image performance and post-load repair effect at 6, 12 and 24 months of follow-up were used as evaluation indicators. RESULTS AND CONCLUSION: (1) In 134 implants, failure was in 2 cases due to surrounding tissue infection. The success rate of before implant restoration was 98.51％, and the success rate after repair was 100％. (2) The stability of dentition of 19 patients was good, showing good occlusion. No mechanical complications or biological complications occurred. The stability of the restoration was 100％. (3) The vertical absorption of bone tissue around all implants was less than 0.2 mm at 6, 12, 24 months after repair, suggesting that the implant has no obvious edge bone resorption. The gingival tissues around all implants were healthy, and no unhealed inflammation or hyperkeratosis appeared. (4) These results imply that the Mis Seven system in the dentition defect fixation exhibits good short-term clinical results.

Objective: To clone mouse rod opsin promoter (ROP) and establish transgenic mice harboring mouse rod opsin promoter and enhanced green fluorescent protein(mROP-EGFP) fusion gene. Methods: Mouse ROP was cloned from C57BL/6 mouse genomic DNA by polymerase chain reaction (PCR). Expression vector of mROP-EGFP fusion gene were constructed by recombination DNA technique. It was identified by restriction endonucleases digestion and confirmed by DNA sequencing. After Not I restriction endonuclease digestion, the coding elements were microinjected into male pronuclei of mice zygotes to generate transgenic mice. The pups were evaluated by PCR at genomic DNA level and mated with normal mouse. Expression of GFP in retina of transgenic mice was detected by fluorescent microscope. Results: 2. 1 kb mouse rod opsin promoter fragment was amplified from mice genome DNA. Expression vector pmROP-EGFP was constructed successfully. Following microinjection of coding sequence of pmROP-EGFP, 3 pups were verified to integrate the mROP-EGFP fusion gene in their genomic DNA by PCR assay, named C57-TgN (mROP-EGFP )SMMU21, C57-TgN (mROP-EGFP)SM-MU26 and C57-TgN(mROP-EGFP) SMMU27. They could express GFP in retina. Conclusion: 2. 1 kb mouse rod opsin promoter is cloned and expression vector pmROP-EGFP is constructed. mROP-EGFP fusion gene transgenic mice are established, which harboring mROP-EGFP gene and expressing GFP in their retina. This is valuable for studying the development of brain and retina, pathogenesis of retina disorder and retina transplanting.

Objective:To observe the status of the sinus membrane using fiber optic endoscope during the lateral window approach sinus floor elevation to provide a reference for clinicians when evelvating the sinus mucoperiosteum.Methods:Sixty-six patients (72 sides) who underwent maxillary sinus floor elevation in Beijing Ruicheng Stomatology Hospital from September 2016 to December 2019 were selected, including 40 males and 26 females, aged 26-80 years old [(56.2±11.5) years]. And fiber optic endoscopy was used to observe the maxillary mucoperiosteum during the operation.Results:The status of maxillary sinus mucoperiosteal during lateral window approach sinus floor elevation can be divided into four categories: ① Class Ⅰ, complete periosteal, no damage to mucoperiosteum; ②Class Ⅱ, periosteal injury, unexposed laminae propria; ③Class Ⅲ, periosteal Rupture, exposed lamina propria; ④ Class Ⅳ, mucoperiosteum perforation, rupture of periosteum, lamina propria and epithelial layer. A total of 72 operations were performed, including 18 cases of class I, 28 cases of class Ⅱ, 4 cases of class Ⅲ, and 22 cases of class Ⅳ.Conclusions:The status of maxillary sinus mucoperiosteal during lateral window approach sinus floor elevation can be divided into four categories. Fiberoptic endoscopy as a clinical auxiliary examination method can improve the operator′s control of the status of the maxillary sinus membrane and assist the peeling of the mucosa.

Oral implantology has experienced more than half a century of development, the theoretical foundation and clinical technology are becoming more mature. This article elaborates on the establishment of implant timing, implant-related bone augmentation technology, surgical alternatives to bone augmentation technology, implant-related soft tissue augmentation technology, and computer-guided surgery. Provide a reference for a comprehensive understanding of dental implant surgery technology and its new developments.

Objective:To comparatively evaluate the scan time and the accuracy of maxillary full-arch scans using four intraoral scanners (IOS) on conditions of the intraoral head-simulator and the hand-held model, and to evaluate the influence of different scanning conditions on digital scan.Methods:A upper dental arch model with melamine-formaldehyde resin teeth and silica gel gingiva that could be fixed on a head simulator was scanned with an optical scanner (ATOS Core) in order to obtain the standard tessellation language dataset as reference. Intraoral scans were performed on the model fixed on the head simulator by three researchers with four IOS [A: TRIOS 3; B: CS 3600; C: CEREC Omnicam; D: iTero]. For each scanner and each researcher, six scans were performed, to obtain the datasets as the head simulator group. And another six scans with each of the four intraoral scanners were performed by each researcher on the hand-held model to obtain the STL datasets as the hand-held group. The scan time were recorded for each scan. In the Geomagic Wrap software, the digital models were trimmed with only the teeth information retained and supreimposed by best fit alignment function and compared to obtain the root mean square (RMS) values of the discrepancies by three-dimensional compare function. The test datasets of each group were compared with the reference dataset for trueness. The six test scanning datasets with the same scanner of the same researcher were cross compared for precision. Mann Whitney U test was used to statistically analyze the difference values of the scan time, trueness and precision of the same intraoral scanner between head simulator group and hand-held group. Results:Compared to the hand-held group, the scan time of A [142(82) s] and D [119(52) s], which two IOS both with handle, were longer in head simulator group [A: 98(28) s; D: 85(22) s] ( P<0.01). However there were no significant differences between the two groups for scan time of IOS B and C ( P>0.05). For full-arch scan accuracy (trueness and precision), there were no significant differences between the two groups of IOS A and B ( P>0.05), while the trueness of C ( P<0.05) and the precision of D ( P<0.01) were better in head simulator group [C: 112(38) μm; D: 43(13) μm] compared to hand-held group [C: 135(47) μm; D: 53(18) μm]. However, there were no significant differences for the precision of C ( P>0.05) and the trueness of D ( P>0.05). Conclusions:The scan time and the accuracy of full-arch digital scans with different IOS may be effected by the scan conditions. For in vitro study of intraoral scanning, head-simulator can simulate the intraoral environment of the real patient to some extent. Meanwhile, the position of the dentist and the patient, and also the limited intraoral space during intraoral scanning are also simulated.