The aim was to obtain bone repair materials with sustained release of minocycline and evaluate the effect in periodontal bone defect repair. Two complex material, hydroxyapatite/chitosan (HA/CS) and minocycline-hydroxyapatite/chitosan (Mino-HA/CS), were prepared by the co-precipitation method. The physical and chemical property, cytotoxicity, release of minocycline and the bacteriostasis examination of the materials were evaluated, they were applied to the rabbit model of mandible bone defect to evaluate their effects on the regeneration of periodontal bone defect. After minocycline was added to HA/CS, the setting time of the material was prolonged, the compressive strength was reduced and the pore size and porosity were increased significantly. The pH value did not change obviously and stayed in the neutral range. Mino-HA/CS could promote the growth of osteoblasts effectively compared with control medium. In vivo, Mino-HA/CS material showed better effect of promoting periodontal bone formation.

Objective: To evaluate the curative effect of blue shark skin collagen composite gel on oral mucosal ulcer using the rat oral ulcers model stimulated by glacial acetic acid. Methods: Collagen from blue shark skin was isolated and physiochemically characterized by FTIR, SDS-PAGE and scanning electron microscopy (SEM). Seventy standard male rats were divided into seven groups. The surface and the area of the ulcer were observed and calculated daily. After 12 days of administration, rats in the model group and the control group were killed and the ulcer and surrounding tissues were cut to pieces about one mm 3 size. The specimens were stained with 10% formalin solution, paraffinembedded sections, HE staining and light microscope were used to observe the histopathological changes in ulcer tissues. Results: The high-dose group had the fastest ulcer healing effects after 12 days of treatment with blue shark skin collagen composite gel. The composite gel was found to significantly accelerate the healing of oral ulcers in a dose-dependent manner. Conclusion: The blue shark skin collagen composite gel in this study may be a good biomedical material candidate for the treatment of oral ulcers in the near future. Potential of other marine fish skin collagen comples on healing oral ulcers should be also considered.

It is of great interest to develop implantable biomaterial with controlled BMP-2 release. This study aimed to construct a composite (BMP-2/PLGA-NP/RADA) containing periodontal ligament stem cells (PDLSCs), rhBMP-2-loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles (BMP-2/PLGANP), and self-assembling RADA-16 peptide hydrogel and characterize its osteogenic capacity. PLGA nanoparticles were produced by double-emulsionmethod, which were then incorporated into RADA16 peptide hydrogel with or without PDLSCs. The time course of rhBMP-2 release was measured by ELISA after incubating BMP-2/PLGA-NP and BMP-2/PLGA-NP/RADA in PBS. The osteoinductivity of BMP-2/PLGA-NP and BMP-2/PLGA-NP/RADA in vitro was analyzed by measuring alkaline phosphotase activity and ossification. The in vivo osteogenesis of BMP-2/PLGA-NP/RADA composite was examined by HE and Alizarin Red staining as well as the expression of ALP and OCN genes. The incorporation of PDLSCs and BMP-2/PLGA-NP did not change the appearance of RADA hydrogel whereas BMP-2/PLGA-NP/RADA improved rhBMP-2 release pattern and enhanced osteoinductive ability compared to BMP-2/PLGA-NP. Implantation of BMP-2/PLGA-NP/RADA composite resulted in significant osteogenesis in 4 weeks. These results indicated that stem cells, rhBMP-2loaded PLGA microparticles, and RADA-16 hydrogel composite would be a promising biomaterial for bone repair and regeneration.

Bone morphogenetic protein-9 (BMP9) shows great osteoinductive potential in bone regeneration. Periodontal ligament stem cells (PDLSCs) with multi-differentiation capability and low immunogenicity are increasingly used as seed cells for periodontal regenerative therapies. In the present study, we investigated the potent osteogenic activity of BMP9 on human PDLSCs (hPDLSCs), in which the c-Jun N-terminal kinase (JNK) pathway is possibly involved. Our results showed that JNK inhibition by the specific inhibitor SP600125 or adenovirus expressing small interfering RNA (siRNA) targeting JNK (AdR-si-JNK) significantly decreased BMP9-induced gene and protein expression of early and late osteogenic markers, such as runt-related transcription factor 2 (Runx2), alkaline phosphatase (ALP), osteopontin (OPN), and osteocalcin (OCN), in hPDLSCs. We also confirmed the in-vivo positive effect of JNKs on ectopic bone formation induced by hPDLSCs injected into the musculature of athymic nude mice and BMP9 ex vivo gene delivery. For the cellular mechanism, we found that BMP9 activated the phosphorylation of JNKs and Smad2/3, and that JNKs may engage in cross-talk with the Smad2/3 pathway in BMP9-mediated osteogenesis.

Periodontal ligament stem cells (PDLSCs) have been confirmed to have self‐renewal capacity and multidifferentiation potential and are good candidates for periodontal tissue regeneration. Pulsed electromagnetic field (PEMF) has been demonstrated to promote osteogenesis in non‐union fractures, partly by regulating mesenchymal stem cells or osteoblast activity. However, there is no report about the osteo‐inductive effect of PEMF stimulation on human PDLSCs (hPDLSCs). Thus, we tested the hypothesis that PEMF biophysical stimulation alone has an influence on the proliferation and osteogenic differentiation of hPDLSCs. To detect the osteo‐inductive potential of bone morphogenetic protein (BMP9), we transfected the STRO‐1+/CD146+ hPDLCSs with BMP9‐expressing recombinant adenoviruses. We examined the proliferation and osteogenic differentiation of hPDLSCs treated with either PEMF (15 Hz, 1 h daily, different intensities), or BMP9, or both stimuli. Cell counting kit‐8 (CCK‐8) assay showed that PEMF of different intensities had no effect on the proliferation of hPDLSCs and did not enhance the proliferative capability of BMP9‐transfected cells. Quantitative real‐time polymerase chain reaction (qRT‐PCR) and Western blotting showed that the combination of both PEMFs (1.8 or 2.4 mT) and BMP9 stimulation had a synergistic effect on early and intermediate osteogenic genes and protein expressions of runt‐related transcription factor 2, alkaline phosphatase, osteopontin, and late mineralized extracellular matrix formation in hPDLSCs. Bioelectromagnetics. 38:63–77, 2017. © 2016 Wiley Periodicals, Inc.

BACKGROUND: Hydroxyapatite/chitosan (HA/CS) complex may act as a drug carrier for drug release, but little is reported about the release amount and antibacterial effect of minocycline-HA/CS (Mino-HA/CS) complex. OBJECTIVE: To investigate the in vitro release and antibacterial property of Mino-HA/CS complex. METHODS: HA/CS and Mino-HA/CS were prepared using co-precipitation method. The surface and cross-section features of the complexes were observed under scanning electron microscopy. The porosities were measured according to Archimedes Principle. The release of minocycline hydrochloride was measured by high performance liquid chromatography with the simulated saliva as drug release media. In vitro antibacterial effect on Porphyromonas gingivalis and Staphylococcus aureus were measured by bacteria-inhibiting ring method. Biological toxicities were evaluated via cel counting kit-8cel proliferation assay. RESULTS AND CONCLUSION: The porosity of Mino-HA/CS was larger than that of HA/CS, with the average porosity of 53.99%. Single-day release amount of Mino-HA/CS could maintain at the level of 0.5-1 μg per day for a long-term. Bacteriostatic rings of Porphyromonas gingivalis and Staphylococcus aureus stil existed clearly after 7 days. Cel proliferation assays showed that Mino-HA/CS extract had the significant effect on promoting cel proliferation. These findings indicate that the Mino-HA/CS sustains the release of minocycline at a relatively stable level within a longer period, shows good inhibitory effect on Porphyromonas gingivalis and Staphylococcus aureus and promotes the proliferation of periodontal ligament cel s.

In this work, a lysostaphin-loaded, control-released, self-setting and injectable porous bone cement with efficient protein delivery was prepared by a novel setting method using hydroxyapatite/chitosan (HA/CS) composite scaffold. The cement samples were made through cementitious reactions by mixing solid powder, a mixture of HA/CS composite particles, lysostaphin, Ca(OH)2, CaCO3 and NaHCO3, with setting liquid containing citric acid, acetic acid, NaH2PO4, CaCl2 and poloxamer. The setting parameters of the cement samples were determined. The results showed that the final setting time was 96.6±5.2 min and the pH value increased from approximately 6.2 to nearly 10 during the setting process and the porosity was 34% at the end. And the microstructure and composition were detected by scanning electron microscopy (SEM), x-ray diffraction and Fourier transform-infrared spectroscopy. For the release behavior of lysostaphin loaded in the cement sample, the in vitro cement extract experiment indicated that about 94.2±10.9% of the loaded protein was released before day 8 and the in vivo Qdot 625 fluorescence tracking experiment showed that the loaded protein released slower than the free one. Then the biocompatibility of the cement samples was evaluated using the methylthiazol tetrazolium assay, SEM and hematoxylin-eosin staining, which suggested good biocompatibility of cement samples with MC 3T3-E1 cells and subcutaneous tissues of mice. Finally the antibacterial activity assay indicated that the loaded lysostaphin had good release ability and strong antibacterial enzymatic activity against methicillin-resistant Staphylococcus aureus. Collectively, all the results suggested that the lysostaphin-loaded self-setting injectable porous bone cement released the protein in a controlled and effective way and the protein activity was well retained during the setting and releasing process. Thus this bone cement can be potentially applied as a combination of artificial bone substitute and controlled-release system for delivery of lysostaphin to treat bone defects and infections.

Medical education models play an important role in medical education, especially in military medical education. However, there are shortcomings in various existing teaching models of maxillofacial gunshot injuries. To resolve this issue, we integrated a dynamic simulation of image data to create a new, three-dimensional dynamic digital teaching model that was based on our previous completed three-dimensional finite element model of human maxillofacial bone tissue gunshot injuries. This model was applied to teaching practice with good results. The new model has helped us to achieve the teaching objective and improve the teaching efficiency.

住院医师规范培训是医学生毕业后教育的重要组成部分,对于培训临床高层次医师,提高医疗质量极为重要。口腔内科由于其具有较强的实践性,在住院医师的规范法培训中存在诸多难点,本文针对口腔内科住院医师规范化培训,提倡通过明确培训目标、详细制定培训计划、加强培训组织管理、加强专业理论知识与临床基本技能的培训及严格规范考核制度等措施来提高口腔内科住院医师规范化培训质量。

医学教学模型在医学教学中有着重要的地位,在军事医学教学中更是如此.由于目前颌面部战伤的各类教学模型均存在自身的缺陷,如何为军医大学学员讲授颌面部战伤的相关知识成为军事医学教学的难点.我们以前期完成的人颌面部骨组织枪弹伤的三维有限元模型为基础,将其动态模拟的图像资料转化为教学模型,达到教学目的,提高教学效率.

<正> 根管治疗是临床上各种牙髓病及根尖周病的首选治疗方法,可分为根管预备、根管消毒及根管充填3个步骤,其最终目的是用无刺激性的充填材料严密地封闭整个根管系统,断绝根管和根尖周组织的交通,防止再感染。根管充填不完善导致根管治疗的失败率最高,而根管充填的完善与否又直

目的:探讨TNF-A-863与CGRP979基因多态性与重度慢性牙周炎易感性的关系。方法:收集100例重度慢性牙周炎患者和118例健康对照组的颊黏膜拭子并抽提DNA,应用PCR-LDR方法检测TNF-A-863与CGRP979基因型,用计算机软件统计分析患者和对照组间基因型分布的差异。结果:TNF-A-863在重度慢性牙周炎组中TNF-A-863"A/C"杂合子占优势,在健康对照组中TNF-A-863"C/C"纯合子基因型为主,TNF-A-863基因型分布在两组间的差异有统计学意义（P＜0.05）。CGRP979在重度慢性牙周炎患者中"A/G"基因型明显占多数,两组间基因型分布有统计学意义（P＜0.05）。结论:TNF-A-863基因多态性与重度慢性牙周炎有相关性;CGRP979等位基因"A/G"杂合子基因型可能是重度牙周炎的易感因素。

PURPOSE:To evaluate the clinical effect of apicectomy and root canal obturation completed one time under direct vision on chronic periapical periodontitis of anterior teeth.METHODS:34 cases(40 teeth) with RCT failing or larger periodontal lesion, which couldn't be cured depending on RCT only, were chosen for this clinical study. They were randomly divided into two groups with 20 teeth in each group. Root canal obturation was done after apicectomy under direct vision(group A),or apicectomy was done after RCT(group B).The time of filling process, the ratio of postobturation pain, the obturation quality and short-term efficiency of the treatment were assessed. The data were separately subjected to t test, Chi-square test, Mann-Whitney U test with SPSS12.0 software package.RESULTS:The time of filling process in group A was significantly less than group B (P<0.05); No statistically significant difference was found between group A and group B in the ratio of postobturation pain, obturation quality and clinical therapeutic efficiency.CONCLUSIONS:The method of apicectomy and root canal obturation completed one time under direct vision is rapid, simple and effective in treating chronic periapical periodontitis of anterior teeth.The short-term clinical therapeutic efficiency is similar to that of apicectomy done after RCT.

To establisha parallel typing system based on ligase detection reaction(LDR),and to study the correlation between CGRP and IL-1A gene polymorphism and the susceptibility to severe chronic periodontitis in Chinese Han nationality.METHODS:Buccal swabs were collected from 100 adult patients with severe chronic periodontitis and 118 healthy adults.DNA was extracted from each sample.PCR-LDR technique was used to identify CGRP1210,CGRP+5247,CGRP4218 and IL-1A-889 genotype.The data were analyzed by χ2 test using SHEsis.RESULTS:The results showed a significant difference in the gene type of IL-1A-889,CGRP1210 and CGRP +5247 between patients with severe chronic periodontitis and periodontally healthy controls.CONCLUSION:The parallel typing system based on ligase detection reaction was established for gene polymorphism research.There is a possible role of IL-1A and CGRP gene polymorphisms in the susceptibility to severe chronic periodontitis for some patients.

目的 比较恒磨牙不可复性牙髓炎根管治疗术一次法和失活法的疗效差异.方法 选择门诊接诊的由于深龋引起不可复性牙髓炎的共计169颗患牙,进行根管治疗术.将患牙随机分为二组:对照组使用一次法,试验组采用失活法治疗,比较治疗1周后反应和2年后的疗效.结果 根管治疗一次法在术后1周内出现不适的有7例;失活法术后1周有3例出现不适.2年后复查,根管治疗一次法成功率90.32%,根管治疗失活法成功率94.12%.经统计学处理和分析,P>0.05,一次法和失活法的疗效差异无统计学意义.结论 虽然恒磨牙不可复性牙髓炎根管治疗术一次法与失活法在疗效上差异无统计学意义,但从2年成功率来看,失活法高于一次法.

Objective:To expore the biological features and the proliferation of primary and passaged cells of bone marrow stromal cells(BMSCs) of rabbit cultured in vitro,and we can acquire enough BMSCs to pursue our study on the material's cell histocompatibility with rabbit bone marrow stromal cells.Method:Bone marrow was harvested from rabbit femur bone marrow with flushing method..Adherent cells were selected as BMSCs after the whole marrow was cultured.Trypsin was used to digest and passage.Passaged cells were fed with conditioned medium,and observed under inverted phase contrast microscope every day.Passaged cells were examined by HE staining and histochemistry staining for ALP.Result: The BMSCs of rabbit cultured grew and survived well in vitro.The primary BMSCs were confluent in about two weeks,and passage cells took less than one week to cover the bottle bottom.Observed by HE staining,BMSCs became monocytes,in the spindle or long multiangular shape.Passaged cells showed strong positive staining of Alkaline phosphatase.Conclusion: Since the BMSCs of rabbit cultured can proliferate well and can be induced to differentiate into osteoblasts in vitro,they can be used as test cells to evaluate the cell histocompatibility of bone defect substitution materials.They can also be used as seed cells for bone tissue engineering.

Objective:To compare the root filling results of 2 thermoplasticized gutta-percha filling techniques(Ultrafil 3D and ObturaⅡ) with cold lateral condensation of gutta-percha.Methods: Sixty freshly extracted maxillary mandibular single-rooted teeth were instrumented and randomly divided into 3 groups: Ultrafil 3D,ObturaⅡ and cold lateral condensation groups.The root canal was routinely prepared and the obturation time was recorded.Three days later,10 teeth of each group were randomly stained and the micro effusion length was subsequently measured.The micro-chink between filling materials and the wall of root canal were measured with scanning electron microscope in the other 10 teeth of each group.The data were analyzed using unpaired Student's t-test.Results: The longest obturation time was in cold lateral condensation group,then ObturaⅡ and Ultrafil 3D group in order,with significant difference found between the cold lateral condensation group and the latter 2 groups((P0.01).) The lengths of micro effusion and micro-chink in lateral condensation group were significantly larger than those in the other 2 groups(P0.05);however,there was no significant difference between the 2 injection thermoplasticized gutta-percha technique groups.Conclusion: Under in vitro condition,the 2 injection thermoplasticized gutta-percha techniques have better adaptation to the canal wall,better root filling results,and less obturation time compared with cold lateral condensation.

AIM:To investigate the relationships between the CGRP gene polymorphisms and the susceptibility to severe adult periodontitis in Canton region.METHODS:Buccal swabs were collected from adult patients with severe adult periodontitis and healthy adult controls.DNA was extracted from each sample using Chelex-100 method.CGRP related gene fragments were amplified by the PCR techniques.The amplified gene fragments were sequenced directly.Sequencing data were analyzed with bioinformatics to detect the CGRP related genotype polymorphisms.RESULTS:It was demonstrated that the amplified sequences have great homology with that of the CGRP gene,as compared with the CGRP sequence of GenBank accession number:X15943.Further analysis of the sequences from the periodontitis patient could revealed that there were detectable SNP polymorphism (CGRP+5247 AC) in the CGRP+5247 site.CONCLUSION:There is a SNP existed in the CGRP+5247 allele,which may be one of the makers of susceptibility to severe periodontitis patients in Canton region.