Induction of dental pulp fibroblast matrix metalloproteinase-1 and tissue inhibitor of metalloproteinase-1 gene expression by interleukin-1alpha and tumor necrosis factor-alpha through a prostaglandin-dependent pathway

Matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinase-1 (TIMP-1) are involved in the degradation of extracellular matrix in many inflammatory diseases. Little is known regarding the expression of these mediators in dental pulp fibroblasts. The effects of proinflammatory cytokines (interleukin (IL)-1alpha and tumor necrosis factor-alpha (TNF-alpha)) and prostaglandin E2 (PGE2) on pulp fibroblast MMP-1 and TIMP-1 gene expression were investigated. Northern hybridization showed that IL-1alpha and TNF-alpha induced significant MMP-1 gene expression, with only little effect on TIMP-1 gene. Exogenous PGE2, however, upregulated TIMP-1 mRNA synthesis but not MMP-1. Concomitant addition of IL-1alpha and PGE2 or TNF-alpha and PGE2 suppressed MMP-1 mRNA production, compared with the groups treated with IL-1alpha or TNF-alpha alone. In contrast, PGE2 enhanced the upregulatory effects of TIMP-1 mRNA by IL-1alpha or TNF-alpha. Furthermore, cytokine stimulation of MMP-1 and TIMP-1 gene expressions can be enhanced or blocked by indomethacin, respectively, and reversed by exogenous PGE2. These results suggested that cytokine-stimulated MMP-1 and TIMP-1 gene expression in dental pulp fibroblasts was mediated, at least in part, by a prostaglandin-dependent pathway. The differential regulation of IL-1alpha or TNF-alpha-induced MMP-1 and TIMP-1 mRNA synthesis, as well as the direct upregulation of TIMP-1 gene expression by PGE2, also implied that prostaglandin may serve as a protective mechanism from excessive tissue breakdown during pulpitis.     

用Western Blot和原位杂交法研究Shh在小鼠牙胚钟状晚期的表达

目的 从形态学和半定量分析两方面研究Shh(Sonic Hedghog)基因在小鼠牙胚钟状晚期的表达，探讨Shh在牙胚钟状晚期的生物学作用。方法 取出生后1、2、3、5和7d(P1,P2,P3,P5,P7)的Bal b/c纯系小鼠牙胚，用Western印迹方法检测Shh的表达量；原位杂交检测Shh在出生后1d和3d天乳鼠牙胚中的表达部位与强度。结果 钟状晚期Shh特异表达于成釉细胞层，其强度随出生天数增加而减弱；随着成釉细胞发育成熟，44500Shh表达量逐渐降低，P1的吸光光度值为P7的5.5倍，P1，P2与P3可检测出活性Shh-N片段。结论 Shh在钟状晚期特异地表达于成釉细胞层，其表达量与成釉细胞的功能状态有关。     

新型舌侧磨牙远移器的研制和临床应用

目的 :研制新型舌侧磨牙远移器并运用于临床远移上颌磨牙。方法 :下颌牙弓排列较好的牙性安氏Ⅱ类错牙合病例 2 3例 ,平均年龄 12 .6岁 ,应用我科与杭州西湖生物材料研究所研制的舌侧磨牙远移器 ,采用 15 0 g力远移上颌第一磨牙 ,用头影测量分析上颌磨牙的远移效果。结果 :经过 3 -6个月 ,上颌磨牙平均整体远移 5 .8mm ,前牙覆牙合减少 2 .9mm ,覆盖增加 3 .4mm。远移完成后用Nance腭托将纠正后的安氏I类咬合关系保持 3个月。结论 :舌侧磨牙远移器可以在较少的支抗丧失情况下有效的远中移动上颌磨牙。该装置临床组装容易 ,可减少椅旁操作时间 ,患者易于接受。     

44例老年患者慢性根尖周炎伴皮瘘牙的治疗

自1992年以来,共诊治慢性根尖周炎致颌面部皮瘘的老年患者59例,其中15例因病源牙无保留价值,采取拔牙法而治愈皮瘘.其余44例的病源牙进行了保存治疗,经临床观察,疗效满意,报道如下. 临床资料:44例,男性27例,女性17例;年龄60～76岁,平均65.2岁.病程最短3个月,最长3年;本组病例颌骨均未发现伴有慢性骨髓炎.皮瘘发生的部位与牙位见附表.     

不同年龄人牙釉质对龋敏感性研究

采用细菌培养人工龋实验技术比较了青少年牙釉质和老年人牙釉质对龋病的敏感性。结果表明老年人牙釉质比青少年牙釉质薄，但脱矿改变是相似的。因此，可以认为老年人牙釉质与青少年牙釉质对龋病的敏感性无明显的差异。     

Extended bleaching of tetracycline-stained teeth: a 5-year study

Bleaching tetracycline-stained teeth is the most challenging form of tooth lightening. This article reports on 44 subjects who bleached their tetracycline-stained teeth for 6 months using trays with reservoirs overnight in a half-mouth designed study and 2 of 3 different concentrations of carbamide peroxide (10%, 15% or 20%). The subjects were followed for 5 years. The area evaluated was the middle third of the teeth. More than 55% of tooth lightening occurred within 1 month; after 5 years, more than 65% of the maximum tooth whitening remained for all 3 gel concentrations. Tooth whitening can be accomplished with any of the 3 concentrations used.     

带控制阀种植牙手术骨粉收集器的研制及临床应用

目的 介绍自行研制的带控制阀种植牙手术骨粉收集器,并观察其临床应用效果.方法 选取2008年5月至2009年10月38例牙种植患者,应用自制的骨粉收集器收集种植窝制备时产生的骨碎屑,并将其用于修复种植体周围骨缺损,其中开窗式骨缺损29处,唇颊(舌)侧种植体颈部角形缺损23处.结果 所有病例术后均无创口感染及裂开,原缺损处局部形态饱满,牙龈无明显退缩,X线片示种植体与周围牙槽骨形成良好的骨结合.结论 应用自制骨粉收集器收集的骨粉修复种植体周围小型骨缺损效果良好,使用方便,具有良好的应用前景.

Abstract：

Objective To introduce a self-developed bone collector designed by the authors and evaluate its effect in clinical application. Methods A self-developed bone collector was used in 38 patients who underwent the dental implant operation from May 2008 to October 2009. During the operation the bone particles were harvested, which was used for the reconstruction of the bone defects around the implant simultaneously. The defects were fenestrate in 29 regions and triangle in 23 regions on buccal or lingual side of the dental implants. Results All cases had no surgical wound infection and dehiscence 7-10 days after operation. Three to six months after implantation, the X-ray showed that all the dental implants had perfect osseointergration and the alveolar bone were successfully augmented. Conclusions Bone debris harvested by self-developed bone collector could repair small peri-implant bone defects, which is simple to use in clinic.     

受压前颌上颌骨缝组织细胞微观结构变化的观察

目的 :在建立模拟临床双侧上颌前部裂及上颌前颌骨加压的定量研究实验动物模的基础上 ,探索受压骨缝组织的微观结构变化的规律。方法 :12只 3周龄雌性新西兰大耳白兔 ,随机均分为 3组 :空白对照组 ;实验Ⅰ组 ,前颌后推加较小力 ;实验Ⅱ组 ,前颌后推加较大力。分别在术后 3、6、9、12周处死动物 ,取受压迫的前颌上颌骨缝标本 ,切片用于光镜和电镜观察。结果 :在骨缝生长发育的过程中 ,骨缝受一定程度压力后其成骨层的成骨细胞出现损伤 ,并与受力大小成正比。结论 :发育早期骨缝受压会导致该部成骨细胞出现延滞性损伤 ,在一定范围内骨缝基本结构及生长潜力不易被广泛破坏