目的:探讨miR-30d拮抗剂(antagomir-30d)正性调控大鼠骨髓基质干细胞(BMSCs)的成骨分化作用并确认转染的最佳浓度.方法:BMSCs培养并分组,分为不同浓度的antagomir-30d(antagomir-30d组)、阴性对照(NC组)和未做转染的BMSCs(空白组);将不同浓度的antagomir-30d及其NC转染至BMSCs后进行成骨诱导.通过RT-PCR技术进行比较,测定成骨基因碱性磷酸酶(ALP)、骨钙素(OC)、Runt相关转录因子2(RUNX2)的mRNA的表达情况,并确定最佳转染浓度及其转染效率.通过ALP染色验证antagomir-30d对成骨分化的调控作用.结果:RT-PCR结果表明,antagomir-30d体外可以促进BMSCs的成骨分化.不同浓度antagomir-30d组的成骨基因表达量随浓度变化而改变,当antagomir-30d转染浓度为150 nmol/L时,ALP、OC、RUNX2的mRNA水平均显著高于空白组和NC组(P<0.05).Antagomir-30d的转染最佳浓度为150 nmol/L,此时ALP染色结果显示其活性最高,成骨分化作用好.结论:Antagomir-30d体外正性调控BMSCs的成骨分化,其转染至BMSCs的最佳浓度为150 nmol/L.

Objective: To assess the initial effects of platelet-rich fibrin (PRF) in conjunction with bone marrow aspirate concentrate (BMAC) on reconstruction of bone defect. Methods: Four bone defects of 5-mm in diameter were performed in the calvaria of 6 rabbits. These defects were randomly filled with blood clot (group A), autogenous bone (group B), PRF and BMAC (group C). Meanwhile, PRF was collected for histological observa-tion. Animals were sacrificed 6 weeks later, and bone samples were harvested for histological observation and statistical analysis. Results: PRF was milk white fibrin glue with elasticity and toughness. The loose and porous three dimensional network structure and white blood cells at the bottom of PRF could be seen in the histological sections. The percentage of new bone formed in each group was 7.64%±1.02% (group A), 12.94%±0.81% (group B), 37.19%±1.26% (group C), respectively. Group C showed a statistically greater amount of new bone formation compared with group A and group B (P<0.05). Conclusion: PRF mixed with BMAC couldaccelerate the regen-eration of new bone to repair the rabbit calvarial defect.

Objective: To investigate the application effect of piezosurgery in transcrestal maxillary sinus augmentation (TMSA).Methods: Fifty-two patients need TMSA instomatology of Wenzhou Medical Univer-sity were randomly divided into two groups: the experimental group and the control group. The piezosurgery was used in the experimental group for TMSA and the Summers’ technology was used in the control group for TMSA. The feeling of treatment was analyzed by visual analog scale (VAS), and then the differences in the perforation rate of maxillary sinus membrane and the height of lifting were analyzed with SPSS17.0 software. Results:A signiifcant lower VAS score was found in the experimental group, compared with the control group (P<0.05). Meanwhile, the perforation rate of maxillary sinus membrane of experimental group was lower than that of the control group (P<0.05). However, the difference of the height of lifting in the two groups was not sig-niifcant (P>0.05).Conclusion: The application of pizeosurgery is safe and reliable in TMSA. Compared with the Summers’ technology, the pizeosurgery can reduce discomfort feeling, and improve the treatment experience of patients.

This study investigated the effects of process parameters and material characteristics in glass infiltration of gelcast zirconia-toughened alumina (ZTA) ceramics for dental applications. Nine types of lanthanum-based silicate glasses with different concentrations of La2O3, B2O3, and Li2O were prepared and characterized on the basis of their melting temperature, crystal structure, and thermal characteristics. These glasses were infiltrated into a ZTA matrix that was semi-sintered at 1200°C to obtain a ceramic material with low shrinkage and high strength. The performance of the glass-infiltrated ceramic samples obtained with various glasses for various infiltration durations and temperatures was evaluated on the basis of the linear shrinkage rate, three-point bending strength, fracture morphology, and elemental composition. From the results, the infiltration temperature was identified as 1150°C, and the optimum glass composition was 30%La2O3–15%Al2O3–15%B2O3–15%SiO2–5%Li2O by mass. The glass-infiltrated gelcast ZTA ceramic has a strength of 291.24±27.94MPa with a shrinkage of 1.8548±0.2663%. These findings could provide a basis for further development of gelcast dental ceramics, which will make all-ceramic oral restoration less reliant on special equipment and materials.

Objective: To investigate the effects of process parameters in curing polymerization and vacuum drying process of gelcast zirconia-toughened alumina(ZTA) ceramics,and the gel-casting route was optimized for dental all-ceramic restoration applications.Methods: The ZTA composite gel system was prepared by gelcasting.①Samples were prepared respectively under different polymerizing temperature.Change of relative surface hardness on solidifying course was measured.The strength and shrinkage of ceramic green bodies were tested before and after sintering.②On the basis of previous studies,all the samples were dried under different allocation of temperature and vacuum degree.Their relative moisture content at each time point was characterized,and ceramic performance was estimated by means of three-point bending strength,linear shrinkage rate while sintered.Results: ①The temperature area between 40 ℃ to 70 ℃ could improve the gel reaction rate,while ceramic performance degraded at the temperature of 80 ℃.②Vacuum with warming environment could shorten gel ceramic drying time vastly,however,unbalanced proportion of temperature and vacuum degree may lead to tremendous damage of ceramics.Conclusion: ZTA gel system requires only 20 min for fully curing reaction at 50～60 ℃.In condition of 70～80 ℃ heating and 0.08～0.09 MPa of vacuum degree,wet ceramic matrix were completely dried within 2.5 h.Furthermore,the specimen showed a unbroken surface,with little defect and deformation in structure.This technological process has the promising for dental all-ceramic applications and may merit further research.

Objective The feasibility of dental zirconia toughened alumina all-ceramic restoration material manufactured by the combination of gel-casting technology and glass infiltration was investigated in the present study.Methods ① Zirconia-toughened alumina(ZTA) ceramic matrixes were prepared by gel-casting technology,and were semi-sintered at 1 150 ℃,1 200 ℃,1 250 ℃ respectively.In addition,one more group of samples were manufactured by means of dry-pressing molding,and were sintered at 1 200℃.Their performance was tested by linear shrinkage rate test and pore size distribution detection.②The four groups of ceramics were infiltrated for 20 mins with specific glass,which was optimized on the basis of Tyszblat patent.Furthermore,gel group of samples sintered at 1 200 ℃ were infiltrated for 20 min,40 min,60 min respectively.Then the infiltration depths were measured.Results ①The infiltration depth of samples showed lower value after semi-sintered at 1 250 ℃,while 1 150 ℃ sintered group showed a distinct deformation.The porosity and pore sizes of dry-pressing molding group,however,were apparently less than those of the other three gel-casting groups.②With growth of infiltration time,the infiltration depths increased,while infiltration transitional surfaces got rough as a result.Besides,the infiltration time was in proportion to square of infiltration depth.Conclusions The ZTA ceramics formed by gel-casting technology can well infiltrate into glass,suggesting its potential prospect in clinical application.

PURPOSE:The influence of La2O3 and Li2O on glass powder was studied in this paper, which is to infiltrate ZTA all-ceramic dental material formed by gel-casting. The performance of different component was analyzed to optimize glass formula.METHODS:Six groups of glass powder were designed and prepared by conventional melt-quenching method. ZTA ceramic blocks were covered with glass paste, which were formed by gel-casting and sintered in 1200 degrees centigrade, then infiltrated in 1150 degrees centigrade for twice to make glass/ZTA ceramic composites. By detecting differential thermal analysis and melting range of infiltration glass power, as well as flexural strength, linear shrinkage, SEM and EDS of glass/ZTA ceramic composites, the optimized glass group was determined out. Statistical analysis was performed using SPSS 13.0 software package by means of paired t test or one way ANOVA.RESULTS:The bending strength of group Li1 was (291.2±27.9) MPa, significantly higher than group Li2 and group La2(P<0.05), and linear shrinkage of group Li1 was only(1.85±0.27)%. SEM and EDS showed glass of group Li1 can lubricate ZTA ceramics well, their structure was compact and had a few small pores. Intergranular fracture existed on cross surface as well as transgranular fracture.CONCLUSIONS:The results showed that Li1(30%La2O3-15%Al2O3-15%SiO2-15%B2O3-5%Li2O) glass infiltrated ZTA ceramic composite had the best capability. Glass/ZTA composite material can be prepared by gel-casting and infiltrating way, and this process is simple and economically suitable for general dental laboratory.

OBJECTIVE:To investigate the efficacy of a new collagen-hydroxyapatite (COL-HA) composite membrane on bone regeneration of SD rat cranial defects.METHODS:Four defects were produced in the calvaria of 24 SD rats. The animals were divided into four groups: Empty defects without membrane (group 1); defects covered by COL-HA single-layer dense membranes (group 2); defects covered by COL-HA double-layer membranes (group 3); defects covered by Bio-Gide membranes (group 4). At 2, 4, 8 and 12 weeks after surgery, 6 rats were sacrificed and the following parameters were analyzed: Macroscopic observation, X-ray examination, descriptive histology, regenerate bone quantitative histology. Statistical analysis consisted of generalized linear models/factorial design analysis of variance and LSD-t test was performed.RESULTS:Since two weeks after surgery, there were a small amount of bone regenerated in three groups except group 1. At 12 weeks after surgery, the opaque sclerous tissues filled with the defects in three groups, and residual membrane fragments still could be found. X-ray pictures showed the density of regenerate bone in group 3 and group 4 was closed to the original bone and greater than that of group 2. Quantitative analysis of regenerate bone showed that in initial stage, group 4 had more bone regeneration than the other groups (P < 0.05), and at 12 weeks after surgery the differences between group 4 and group 2/group 3 had no statistically significant.CONCLUSION:The COL-HA composite membranes can guide bone regeneration of rat cranial defects. The efficacy of bone regeneration of COL-HA double-layer membrane is superior to COL-HA single-layer dense membrane, because its property is more propitious to the adherence and proliferation of osteoblasts.

目的采用凝胶注模成型技术结合涂塑技术制备VitaIn-ceram氧化铝渗透陶瓷,探讨该技术对玻璃渗透复合铝瓷性能和渗透速率的影响。方法根据不同的氧化铝坯体制备工艺分别制备以下3组试件:A组采用凝胶注模成型坯体,B组在采用Vita涂塑技术制备铝浆时添加AM和MBAM使浆料原位聚合成坯体,C组采用Vita产商推荐操作制备坯体。对3组坯体进行半烧结,渗透,形成玻璃复合铝瓷,研究氧化铝基体的凝胶注模成型、渗透和玻璃复合铝瓷的性能。结果 3组氧化铝试件烧结后和渗透后的线收缩率小,均小于0.11%;凝胶注模成型技术可提高玻璃渗透复合氧化铝的渗透速率;渗透后A组和B组强度分别达383MPa和384Mpa,满足临床上全瓷冠内核材料的强度要求。结论凝胶注模成型技术可提高玻璃渗透复合氧化铝的渗透速率。凝胶注模成型工艺适用于制备全瓷冠基底冠。