牙髓干细胞向成牙本质样细胞分化过程中基因表达研究

目的：分离培养来源于人成体牙髓组织的干细胞(dental pulp stem cells，DPSC)，分析研究其在未分化状态及在矿化诱导液中基因表型的变化：方法：采用胶原酶消化法获得人牙髓组织的单细胞悬液，14 d后挑取细胞克隆，分别在普通培养基和矿化诱导培养基中进行培养，利用RT-PCR，图像分析检测细胞基因表型变化。结果。未诱导的DPSC不表达牙本质特异性蛋白(dentin phosphprotein,DSPP)及骨涎蛋白(Bone sialoprotein，BSP)，表达部分成骨(osteocalcin,OCN alkaline phsphatase,ALP)相关表型，低表达转录因子核心结合因子(Cbfa-1)；与末诱导的DPSCs相比较，在成骨诱导中DPSCs表达DSPP和BSP，骨相关基因表达也相应上调。结论：DPsCs在矿化诱导液的作用下向成牙本质样细胞分化，其过程有可能是通过谱系特异表犁的表达或表达上调实现的。     

Solubility study of phytochemical cross-linking agents on dentin stiffness

Objectives

The effects of interactions between cross-linking proanthocyanidins (PA) in polar solvents and type-I collagen of demineralized dentin were investigated.

Methods

Three PA-rich extracts, two from grape seed (GSEP and GSES) and one from cocoa (COE), were dissolved (water, ethanol:water and acetone:water) and analyzed for their ability to increase the modulus of elasticity of demineralized dentin. Sound dentin beams (0.5 mm × 1.7 mm × 7 mm) were fully demineralized and divided into 12 groups according to the type of cross-linking agent and solvents used. Specimens were immersed in the respective solutions and tested at baseline, 10, 30, 60, 120 and 240 min.

Results

The elastic modulus (EM) of dentin was significantly increased by the PA treatment regardless of time (p < 0.05 for all times). The extracts showed different solubility in different solvents. GSEP showed the highest increase in EM when diluted in distilled water and acetone at all exposure times. Both GSEs showed superior results when diluted in distilled water and after 4 h of treatment, while COE produced strongest enhancement when dissolved in ethanol:water.

Conclusions

The results indicates that herbal extraction process and other pharmacognostic parameters have an important influence on extract solubility as well as constitution and, consequently, on the PA–dentin matrix interaction.     

IL—1,IL—6,TNF对人TMJ滑膜细胞蛋白合成的影响

目的：研究人ＴＭＪ滑膜细胞（ＳＭＣ）蛋白质合成能力，与其它组织细胞的差异，及细胞因子对这方面的影响。方法：采用体外培养的ＳＭＣ、ＴＧＣ、ＮＭＣ３种细胞及无血清培养液，应用紫外分光光度仪在２８０ｎｍ波长处，对培养上清中的蛋白含量进行测定，并与加用ＩＬ－１、ＩＬ－６、ＴＮＦ后蛋白质合成的量进行对比观察。结果：正常状态下，ＴＧＣ蛋白合成量最高，ＯＤ值达０．１４，而ＳＭＣ最低，为０．０７９。在加用细胞因子作用４８ｈ后，ＳＭＣ蛋白含量达到０．１１７，提高３０％，而ＴＧＣ、ＮＭＣ却下降１０％～３０％。结论：正常状态下ＳＭＣ合成蛋白质成份较其它细胞少，而细胞因子可刺激ＳＭＣ蛋白质合成增加，这些蛋白成份中可能具有影响关节炎症的物质。     

Bonding properties of universal adhesives to root canals prepared with different rotary instruments

Statement of problem

Preparation of coronal dentin by using a diamond rotary instrument usually results in higher bond strength values than preparation with tungsten carbide burs, but information is lacking about the influence of rotary instruments on root canals before the bonding of fiber posts.

半负荷状态下即刻和延期植入种植体的实验研究

选择3种不同种植体采用即刻和延期两种方式植入5只狗的下颌前磨牙及第一磨牙区内,呈半负荷状态,分别于术后 2.4.6.8.12.24周取出标本作X线.LM SEM观察,结果显示:3个月时所有种植体均已达到完善骨整合,成骨量和骨小梁排列方向与(牙合)力负荷一致,且在同一机体上,骨整合无显著性差异,不同种值体之间8周时骨整合己无差异.     

螺旋型牙种植体下颌磨牙区种植的尝试

磨牙区种植对种植义齿修复，特别是下颌总义齿的稳固和Ｈｅ力均匀分布非常重要。但是，由于下颌管走行于下颌骨体中间，盲目种植会损伤下齿槽神经和血管。作者采取Ｘ线测量，根据所测下颌管上壁至牙槽嵴顶的距离，选用一定长度的固位钉作种植；和对骨吸收严重者由下颌管上方去除舌侧骨板，解剖游离该神经血管束将其避开，选长钉植入，可抵达下颌下缘皮质骨，解决了此类病人磨牙种植的难题。作者对磨牙区种植的适应证、手术方法及可能     

骨性Ⅲ类错的早期矫治

骨性Ⅲ类错是临床较常见的错畸形,其早期治疗一直是临床的难题之一。多数学者认为,临床上若早期开始治疗,大多数轻中度骨性Ⅲ类错畸形能得到明显的临床改善或治疗成功。文献报道约25%的患者需正颌手术治疗,因此,大部分骨性Ⅲ类错的早期治疗是必需的。学者对此进行了大量的研究以及临床探索,本文就国内外关于骨性Ⅲ类错的治疗时机、治疗方法以及适应证的选择作一综述。     

Nance弓的支抗与支抗消耗分析

目的：评价不同状态时Nance弓的支抗强弱和支抗消耗。方法：43例分成J钩、Nance弓及J钩和Nance弓联合支抗3组，分别测量矢状向和水平向的支抗消耗并进行统计分析。结果：3种支抗时第一磨牙均有显著性前移(P＜0．001)，三者相互之间有显著性差异(P＜0．01或P＜0．05)，Nance弓水平支抗稳定(P＞0．05)。结论：Nance弓是一种简单有效的支抗装置，具有三维支抗作用，支抗消耗可通过与其它支抗联合或改变牵引方式来调节。