牙髓成纤维细胞传代培养与冻存复苏后生长情况比较

目的：比较牙髓成纤维细胞在体外传代培养及冻存复苏后细胞生长情况的差异,探讨其应用价值。方法：采用组织块培养法对牙髓组织标本进行体外成纤维细胞的原代及传代培养,观察成纤维细胞形态及生物学特性,选取第4代处于对数生长期的细胞梯度降温后置入液氮中（196℃）保存3个月,比较经传代培养细胞与复苏后成纤维细胞的生长情况,用MTT法分别绘制细胞生长曲线,比较细胞生长情况。结果：经冻存保存3个月后牙髓细胞复苏率超过80%,而细胞形态未见明显的改变。复苏后细胞生长较对照组慢,进入对数生长期的时间较对照组略长。但两者生长曲线基本一致。结论：牙髓成纤维细胞传代培养与冷冻复苏后形态及生长特性基本相同,冻存的成纤维细胞可以成功的复苏。     

冷光牙齿漂白技术对活髓牙牙髓影响的病理观察

目的 探讨冷光牙齿漂白技术对活髓牙牙髓的影响.方法 选择因正畸需要拔除的40颗活髓牙,对照组(10颗)不做任何处理拔除,其余30颗牙采用冷光漂白后分别即刻拔除(15颗)和漂白7 d后拔除(15颗).40颗牙齿均制作病理切片,镜下观察牙髓组织形态.结果 所有活髓牙漂白前后均未发现有任何临床症状.漂白后即刻拔除组、7 d后拔除组以及对照组在镜下均表现为正常的牙髓组织结构,与对照组相比漂白后即刻拔除组及7 d后拔除组牙髓组织均无明显改变.结论 冷光牙齿漂白技术对活髓牙牙髓无明显不良影响,是一项安全可靠的漂白技术.     

活髓牙与去髓牙的牙体脆性比较研究

150颗离体牙中,正常活伪髓牙50颗。离体干燥牙50颗,去髓牙50颗。将其制成含牙釉质和牙本质的牙体硬组织标本,置于电子万能试验机下测定抗压强度和抗剪切强度。结果表明,三组标本之间,平均抗压强度和抗剪切强度差别无显著性。     

Beyond冷光牙齿漂白技术对人牙髓影响的组织病理学研究

目的 探讨Beyond冷光牙齿漂白技术对牙髓的影响.方法 选择因正畸要拔除的40颗活髓牙,对照组(10颗)不做任何处理拔除,其余30颗采用Beyond冷光漂白后分别即刻拔除(15颗)和漂白七天后拔除(15颗).40颗牙齿均制作病理切片,镜下观察牙髓组织形态.结果 所有活髓牙漂白前后均未发现有任何临床症状.漂白后即刻拔除组、七天后拔除组以及对照组在镜下均表现为正常的牙髓组织结构,漂白组较对照组牙髓组织无明显改变.结论 Beyond冷光牙齿漂白技术对活髓牙牙髓无明显不良影响,是一项安全可靠的漂白技术.     

活髓牙与去髓牙的牙体脆性比较研究

１５０颗离体牙中，正常活髓牙５０颗。离体干燥牙５０颗，去髓牙５０颗，将其制成含牙釉质和牙本质的牙体硬组织标本，轩于电子万能试验机下测定抗压强度和抗剪切强度。结果表明，三组标本之间，平均抗压强度和抗剪切强度差别无显著性。     

离体牙储存方式对牙本质黏结剂微拉伸强度的影响

目的：对比研究不同的离体牙储存方法和时间对牙本质黏结剂Single Bond微拉伸强度的影响。方法：选用30颗因正畸拔除的第一前磨牙,随机分为5组。拔除后立即分别放人4℃的0．02％麝香草酚水溶液、10％甲醛溶液、1％氯胺溶液、蒸馏水中储存,以及用湿纱布包裹-20℃冰箱中储存。分别在储存的第10天、90天取出,在牙冠殆面表层牙本质上使用牙本质黏结剂Single Bond,复合树脂Z250黏结修复,测定牙本质黏结剂的微拉伸强度值。选用新鲜拔除的前磨牙作为对照组。用体视显微镜和扫描电子显微镜观察微拉伸强度测试样本的断裂类型。用SPSS11．5软件对牙本质黏结剂的微拉伸强度值做双因素方差分析。结果：不同的储存方法对牙本质黏结剂微拉伸强度有显著影响(P=0．01),与新鲜拔除的牙比较,蒸馏水中4℃储存(P=0．024)和0．02％麝香草酚水溶液4℃储存(P=0．008)的离体牙的微拉伸强度显著降低;不同的储存时间对牙本质黏结剂的微拉伸强度影响无统计学差异(P=0．279)。所有微拉伸强度测试样本的断裂均发生在黏结界面。结论：离体牙储存方法对牙本质黏结剂Single Bond的黏结强度有重要影响,建议使用离体牙评价牙本质黏结剂的黏结强度时,选用新鲜拔除的牙、-20℃冷冻的牙或1％氯胺溶液4℃储存的牙,以减小不必要的实验误差。     

极固宁TM对活髓基牙牙髓组织影响研究

目的 研究极固宁TM对金属烤瓷全冠活髓基牙牙体预备后1、2周牙髓组织形态学的影响。方法 选择2012年1月至2013年8月在福建医科大学附属口腔医院就诊患者15例,因正畸治疗需要而计划拔除40颗前磨牙（同一患者的同颌同名牙20对）,将每对同颌同名牙随机分为对照组和试验组。对照组：金属烤瓷全冠牙体预备后直接用氧化锌丁香油水门汀黏固暂时冠;试验组：在牙预备体上涂布极固宁TM后用氧化锌丁香油水门汀黏固暂时冠。分别于牙体预备后1、2周局麻下拔除同颌同名研究牙。常规组织病理切片,HE染色,显微镜下观察评价牙髓组织反应并测量颊侧髓角的剩余牙本质厚度。结果 金属烤瓷全冠牙体预备后1、2周时,试验组与对照组的牙预备体颊侧髓角的剩余牙本质厚度差异均无统计学意义（P > 0.05）。活髓基牙全冠牙体预备后1周,对照组的牙髓组织炎症反应比试验组严重（P < 0.05）;而牙体预备后2周,对照组与试验组的牙髓组织反应差异无统计学意义（P > 0.05）。不论是金属烤瓷全冠牙体预备后1周或2周,所有样本均未见第三期牙本质的形成。 结论 极固宁TM在金属烤瓷全冠牙体预备后1周时可降低活髓基牙牙髓组织的炎症反应。     

根面过敏牙髓中P物质分布的免疫组化研究

目的：研究神经肽SP在根面过敏发病中的意义。方法：15只因牙周病拔除的离3体牙，另取整畸拔除牙5只。按ABC法行免疫组织化学染色。结果：在各标本牙髓中均可见SP阳性神经纤维的存在。在正常和根面过敏患牙在成牙本质细胞层下形成神经丛。SP阳性神经在牙髓毛细管周围，少数纤维穿过本质细胞层进入前期牙本质和牙本质小管。结论：通过对严重牙周病根面过敏牙牙髓神经肽P物质的分布观察，提示神经肽在其发病中起重要作用。     

全冠修复牙体预备后牙髓的组织学研究

全冠修复过程中保护牙髓组织的健康是影响修复成功的重要因素之一,通过组织切片,观察４０颗因正畸需要拔除的健康活髓牙,经全冠牙体预备后即时和截暂冠后１,２周的牙髓组织学反应。结果表明：在水雾冷却情况下采用涡轮机进行金瓷全冠牙体预备,牙髓组织改变主要是成牙本质细胞层的乱及局部的出血,充血,备牙后立即给予氧化锌丁香占固剂固暂冠修复,２周后牙髓组织逐渐恢复正常。     

人牙髓细胞在离体牙髓腔内向成牙本质细胞样细胞分化的研究

目的观察人牙髓细胞在离体牙髓腔内向成牙本质细胞样细胞分化的潜能。方法将原代培养的人牙髓细胞接种至处理过的离体牙髓腔内,2周后固定、脱钙、包埋、切片、染色,显微镜下观察其生长及分化情况。结果牙髓细胞在牙本质表面生长良好,部分细胞伸出胞质突伸入牙本质小管中,表现出成牙本质细胞样细胞的形态。结论牙本质可以诱导牙髓细胞向成牙本质细胞样细胞分化,可为组织工程化牙髓的研制提供实验依据。     

碱性成纤维因子用于犬牙盖髓剂的实验研究

目的探讨碱性成纤维因子(bFGF)对犬牙髓损伤修复的影响。方法选取健康英国小猎兔犬牙齿64颗,分为bFGF盖髓组、Dycal盖髓组及ZOE盖髓组。进行直接盖髓术,观察术后14天和28天修复性牙本质形成及牙髓组织学变化。免疫组化检测骨形成蛋白表达情况。结果术后14天:实验组及阳性对照组有纤维性基质形成,无牙本质桥形成;术后28天:实验组及阳性对照组有骨样牙本质桥、管状牙本质形成,阴性对照组无牙本质桥形成。结论bFGF在体内能够有效诱导牙髓细胞分化,形成修复性牙本质。     

深冷冻保存对离体牙牙周膜细胞活性影响的研究

目的：探讨应用不同降温方法和不同冷冻保护液的深冷冻保存技术,对人离体牙牙周膜细胞活性的影响。方法：收集新鲜拔除的人第一或第二前磨牙25颗随机分为5组;其中4组使用含海藻糖或不含海藻糖的冷冻保护液,分别应用程序降温或快速降温至－196℃,冷冻保存一周;一组新鲜拔除牙齿为对照组。分别刮取牙根面中1／3的牙周膜组织,消化法收集细胞,台盼蓝染色,高倍镜下计数活细胞数,并计算细胞存活率。结果：不同降温方法不同冷冻保护液深冷冻保存与对照组相比,牙周膜细胞存活率无明显差异。其中,使用含海藻糖的冷冻保护液程序降温的方法牙周膜细胞存活率最高。结论：应用深冷冻技术保存牙齿,牙周膜细胞的活性无明显变化,其中使用含海藻糖的冷冻保护液程序降温的方法对牙周膜细胞的活性影响最小。     

Effects of cryopreservation on the characteristics of dental pulp stem cells of intact deciduous teeth

Objectives

The aim of this study was to isolate and cultivate cells from the pulp of 7-day-cryopreserved intact deciduous human teeth and evaluate the effect of cryopreservation on dental pulp stem cell (DPSC) characteristics.

Design

Twenty-six deciduous teeth were collected and allocated in two groups: immediate cell isolation (non-cryopreserved group) and intact cryopreserved (cryopreserved group). The teeth were cryopreserved in dimethylsulfoxide solution and recovered after 7 days. The success rate of isolation, proliferation, surface markers (CD14, CD29, CD34, CD45, CD73, CD90, and HLA-DR), differentiation capacity, and morphology were evaluated.

Results

Isolation success rate was 61% and 30% for the non-cryopreserved and cryopreserved groups, respectively. There were no statistical differences between the groups for the tested surface markers. The cells in both groups were capable of differentiating into three mesenchymal lineages. No statistical differences between the groups were observed through the time course proliferation assay (0, 1, 3, 5, and 7 days); however, the mean time between isolation and the fifth passage was shorter for the non-cryopreserved group (p = 0.035). The morphology of the cells was considered altered in the cryopreserved group.

Conclusion

DPSCs were obtained from cryopreserved intact deciduous teeth without changes in the immunophenotypical characteristics and differentiation ability; however, lower culture rates, proliferation potential, and morphological alterations were observed in relation to the control group.     

Human dental pulp stem cells derived from different cryopreservation methods of human dental pulp tissues of diseased teeth

J Oral Pathol Med (2011) 40 : 793–800 Background: Successful isolation of human dental pulp stem cells (hDPSCs) has been documented at least 120 h after tooth extraction. Viable hDPSCs have been isolated chiefly from cryopreserved healthy molar teeth and their undigested dental pulp tissue. Isolation of hDPSCs from diseased but vital teeth after cryopreservation has not been reported. This study aimed to isolate hDPSCs from cryopreserved diseased but vital teeth of various tooth types. Materials: Fifty tooth samples were divided into group A (n = 20) – freshly derived dental pulp tissues, group B (n = 20) – liquid nitrogen (liq N₂)‐stored dental pulp tissues and group C (n = 10) – liq N₂‐stored intact teeth. Methods and results: The success rate for hDPSCs isolation was 100% for groups A and B and only 20% for group C. hDPSCs from all groups demonstrated self‐renewal properties and similar multipotent potential characteristics of adipogenic, chondrogenic and osteogenic differentiation. In addition, hDPSCs showed high expression of bone‐marrow mesenchymal stem‐cell markers (CD29, CD90 and CD105) and very low expression of specific hematopoietic cells markers (CD14, CD34 and CD45). Conclusion: Our results indicate that hDPSCs isolated from diseased but vital teeth of various tooth types can be stored in liq N₂ for future usage.     

The effect of pulpotomy using CO2 and Nd:YAG lasers on dental pulp tissue

The histological response of the dental pulp after laser irradiation was studied. After pulpotomy was performed in the premolar and molar teeth of dogs, the exposed pulp tissue at the root canal opening was lased using either a CO₂ or Nd:YAG laser. The laser parameters were 2 W, 10 ms, 5 times per second for 1, 2 and 3 s for CO₂ laser and 2 W, 20 pulses per second for 1, 2 and 3 s for the Nd:YAG laser. Observations were made 30 and 45 days after treatment. The results revealed that laser irradiation caused carbonization, necrosis, infiltration of inflammation cells, oedema and haemorrhage in the pulp tissue. Under the conditions of this experiment, there was little histological evidence of repair to the treated pulp with a newly formed dentine barrier, which was in contrast to the control samples treated with a calcium hydroxide-containing cement (Dycal).     

Side population cells expressing ABCG2 in human adult dental pulp tissue

AIM: To investigate the presence of side population (SP) cells by the Hoechst exclusion method in human adult dental pulp tissue. METHODOLOGY: Human adult dental pulp-derived cells were generated from third molar teeth. The cells were stained with Hoechst 33342 and sorted into SP cells or non-SP cells [main population (MP) cells]. Both cell types were compared with cell growth and RT-PCR analyses. RESULTS: SP cells that express ABCG2, Nestin, Notch-1 and alpha-smooth muscle actin were found at frequencies ranging from 0.67% to 1.02%. This SP profile disappeared in the presence of verapamil. These SP cells expressed dentine sialophosphoprotein and dentine matrix protein-1 when cultured in osteogenic medium. CONCLUSION: Human adult dental pulp tissue contains SP cells that differentiate into odontoblast-like cells.     

年轻恒牙牙髓再生性治疗的研究进展

个体患牙髓病或根尖周病后,年轻恒牙牙根的继续生长发育受阻,因此,如何保证患牙根尖的正常形成和继续生长发育对口腔医生而言极具挑战。近年来报道的牙髓再生治疗病例,其利用根管内残余牙髓组织、根尖周或牙周组织中干细胞的再生分化能力,在合适的条件诱导下再生出新的高度血管化并富含结缔组织的活髓,促使牙根继续生长发育,牙根长度增加、根管壁增厚、根尖孔缩窄闭合,而且临床检查和影像学辅助检查的结果均较理想,这具有划时代的意义。牙髓再生基于组织工程学,以达到用新生牙髓组织代替原有病变牙髓组织目的。其包括两种理念：一是牙髓血运重建,诱导根尖部干细胞迁移和分化,在患牙根管内新生出有活力的牙髓样组织,完成牙根继续生长发育;二是运用组织工程技术,将具有增殖分化潜能的干细胞和适宜的生物活性支架物质置入患牙根管内,在一定的生长因子诱导下,产生新的牙本质牙髓复合体（den?tin?pulp complex,DPC）,实现牙髓再生。笔者就这两部分的研究进展作一阐述。     

Alkaline phosphatase activity in dental pulp of orthodontically treated teeth.

INTRODUCTION: The aim of this study was to examine alkaline phosphatase (ALP) activity in the dental pulp of orthodontically treated teeth. METHODS: Sixteen healthy subjects (mean age 17.0 +/-1.6 years) who required extraction of 4 first premolars for orthodontic reasons participated. One maxillary first premolar subjected to orthodontic force was the test tooth. The contralateral first premolar, bracketed but not subjected to mechanical stress, was the control tooth. After a week of treatment, the first premolars were extracted and the dental pulp removed from the teeth. ALP activity was determined spectrophotometrically and the results expressed as units/liter per milligram of pulp tissue [U/(L x mg)]. RESULTS: ALP activity was 89 +/- 26 U/(L x mg) in the test teeth and 142 +/- 33 U/(L x mg) in the control teeth. The difference between the groups was statistically significant (P < .01). CONCLUSIONS: Orthodontic treatment can lead to significant early-phase reduction in ALP activity in human dental pulp tissue.     

半导体激光治疗牙本质过敏症牙髓刺激性反应临床及动物实验研究

目的 :探讨激光治疗牙本质过敏症时 ,牙髓组织的刺激性影响。方法 :临床 3 60颗患牙激光治疗 5次 ,观察牙髓刺激性反应发生率。 2 2颗兔牙激光照射后 ,光镜下观察牙髓组织病理改变。结果 :3 60颗患牙发生牙髓刺激性症状共 3颗 ,0 0 0 8%。 2 2颗兔牙照射后即刻或次日拔除的均有牙髓充血 ,或轻度慢性炎症反应 ,第 3天、第 5天拔除的 ,牙髓组织基本恢复正常。结论 :适量的激光照射可产生牙髓充血。但此反应是极轻微的 ,一般不会产生临床症状 ,可以安全使用。