Number and size spectra of non-myelinated axons of human premolars

The aim of this study was to determine the number and size of apical non-myelinated (C) axons of healthy human premolars. The material was derived from a large collection of specimens prepared for a previous quantitative investigation on the myelinated (A) axons of human premolars. A total of 16 teeth (six maxillary first and five each of mandibular first and second premolars), removed from adolescents for orthodontic reasons, were used. Root discs of about 0.6 mm thickness were prepared at about 2 mm cervical to the root apex and processed for light and electron microscopy. The number of non-myelinated axons was determined by taking a total census of such fibres that could be identified and reconstructed by standardized composite electron micrographs from each root disc. The measurement of axons was done on a statistically representative sample of axons (n=1810) using an electronic image processing unit. The 16 teeth had an average of 2000 ± 1023 non-myelinated axons at the juxta-apical level (range 534–3912). The average diameter of the non-myelinated axons was found to be 0.5 ± 0.4 m (range 0.05–2.4 m).     

Immunocytochemical localization of aromaticl-amino acid decarboxylase and catechol-O-methyltransferase in blood vessel wall of the human dental pulp

Relatively large amounts of DOPA as compared with the concentration of norepinephrine are found in human dental pulp. AADC and COMT are localized in blood vessel walls of human dental pulp. This localization suggests a functional relationship between COMT and AADC with regard to the metabolism of DOPA.     

人龋病牙髓中神经肽与抗原呈递细胞的动态研究

目的 :研究人龋病牙髓中降钙素基因相关肽 (Calicitoningene -relatedpeptide,CGRP)和树突状细胞(Dendriticcells,DC)、P物质 (SubstanceP,SP)和血管内皮细胞(Endothelialcells,EC)之间的空间变化特点 ,以探明牙髓病理状态下神经免疫间的相互作用。方法:采用免疫组化法观察龋病不同阶段牙髓中上述物质的变化 ,并对前、后两种物质分别进行双标免疫组化染色。结果:(1)4个指标的数量在不同组间比较差别有统计学意义 (P<0.05)。 (2)双标染色显示 :龋病牙髓中神经肽与抗原呈递细胞共聚集在龋坏相应冠髓的造牙本质细胞层下 ,CGRP接触或包绕树突状细胞 ;而SP随龋坏深入逐渐接近血管并与管壁接触。结论:龋源性刺激引起牙髓中CGRP、SP、DC、EC的局部相互作用加强共同调节牙髓免疫反应     

硬树脂模配戴法对外伤年轻恒牙辅助护髓治疗的有效性研究

目的:研究配戴硬树脂模对外伤年轻恒牙护髓治疗的有效性。方法:对62例外伤致牙体缺损牙髓活力状态敏感的年轻恒牙,随机采用硬树脂模配戴辅助护髓(实验组)和传统方法脱敏治疗(对照组),6个月后检测牙髓活力情况。结果:两种治疗方法经卡方检验分析表明,实验组与对照组存在明显差异(P<0.05)。硬树脂模配戴法临床护髓效果明显优于传统方法。结论:硬树脂模配戴法能显著提高临床护髓成功率,可以在临床推广使用。     

大鼠实验性牙齿移动过程中骨形成蛋白2的表达和意义

目的探讨骨形成蛋白(BMP)超家族的成员BMP-2在大鼠正畸牙齿移动过程中牙周组织的分布和表达。方法用链霉亲和素生物素复合物(SABC)免疫组织化学法,检测实验性大鼠正畸牙齿移动过程中牙周组织BMP-2的表达。结果BMP-2在正畸牙齿加力各个时期存在特异的分布模式。正常牙周组织中主要分布于牙周膜,加力后张力区染色深,压力区为阴性。结论BMP-2参与了大鼠正畸牙齿移动骨改建过程,起非常重要的作用。     

自体牙移植预后的影响因素

自体牙移植是将自体牙在体内异位移植来修复牙列缺损的一种方法。尽管自体牙移植适用范围不广且预后受到很多因素的影响,但许多研究证实,自体牙移植可作为一种修复牙列缺损的理想选择。本文就自体牙移植预后的影响因素进行综述。     

淋巴增强因子-1在口腔医学中的研究进展

淋巴增强因子-1是Wnt信号路径的重要组成成分,在由上皮和间充质的相互作用而产生的器官如牙的发育中发挥着重要的调节作用。下面就其在调控牙发育、维持牙上皮细胞活性、抑制成骨细胞的终极分化和在口腔恶性肿瘤的发生发展中的作用作一综述。     

Dental anomalies in cleft lip and palate: A case–control comparison of total and outside the cleft prevalence

This study’s objective was to compare the total and outside the cleft prevalence of dental anomalies (DA) between patients with cleft lip and palate (CLP) and a control group. This retrospective cross-sectional study was done under a case–control design. The case group consisted of 192 non-syndromic patients with complete CLP, while the control group included 411 patients. All subjects had orthopantomography, intra, and extraoral photographs. The prevalence of dental agenesis, supernumerary teeth, impacted teeth, dental transposition, and microdontia were compared using a chi-squared test (P < .05). Next, a second test was made, but only the anomalies outside the cleft were considered for this study. Total prevalence was 89.1% for cases, and 20.9% for controls (P < .01). The prevalence of each DA was significantly higher for the case group. In the analysis of DAs outside the cleft, the total prevalence was still significantly associated (P < .01); however, only dental agenesis was statistically significant (P < .01). Further analysis found that a high rate of upper premolar absence (P < .01) could explain this event. Patients with CLP have a higher prevalence of DAs compared to controls. After considering only the DAs outside the cleft, the total prevalence remains significantly higher. However, this phenomenon is explained mainly by the elevated prevalence of upper premolars’ agenesis. This study’s results suggest that environmental factors are behind the high prevalence of DAs in subjects with CLP.     

根管长度电测仪在老年人根管治疗中的临床应用

目的初步探讨RootZX根管长度电测仪测定老年人根管工作长度的准确性及不同根髓状态对其测量准确性的影响。方法选择老年患者需作根管治疗的患牙204颗,根管373个,随机分为电测法组和手感法组,分别测定根管的工作长度后预备根管,X线片试尖测定牙齿的长度,比较电测法组和手感法组测定根管工作长度的准确率。以及不同根髓状态对电测法测定根管工作长度准确率的影响。结果电测法组、手感法组准确率分别为93.75%、67.96%。经χ2检验,两组间有显著性差异。电测法中活髓根管准确率为93.81%,死髓根管的准确率为93.68%。经χ2检验,两组准确率无显著性差异。结论RootZX测量老年人根管工作长度的准确率明显高于手感法,其准确性不受根髓状态的影响。     

铸造桩表面喷砂处理对牙根抗折性能影响的体外实验研究

目的：研究铸造桩表面喷砂处理对牙根抗折性能的影响。方法：20颗近期拔除的单根第一前磨牙,根管治疗后于釉牙骨质界冠方1.5mm截冠,随机分为2组,铸造桩核及金属全冠修复。实验组铸造桩粘固前表面喷砂处理,对照组不作处理。试件包埋于丙烯酸树脂块中,在电子万能实验机上进行测试。结果：对照组牙根折裂强度为2.773±0.357kN,实验组牙根折裂强度为3.113±0.357kN,2组间差异具有统计学意义（P〈0.05）。结论：对铸造金属桩表面进行喷砂处理,可以提高桩核冠修复后牙根的抗折强度。