牙本质粘结剂对人牙髓细胞毒性的体外研究

目的：评价全酸蚀牙本质粘结剂和自酸蚀牙本质粘结剂对人牙髓细胞的毒性作用.方法：用人牙髓细胞为实验细胞,采用MTT比色分析法,对4 种牙本质粘结剂（Prime ＆ Bond NT,Single Bond,Xeno Ⅲ,iBond）进行体外细胞毒性研究.结果：不同浓度的粘结剂稀释液均可使人牙髓细胞的形态有所改变.4 种牙本质粘结剂的细胞毒性有显著性差异,且作用时间和浓度的改变对其细胞毒性有影响.全酸蚀粘结剂比自酸蚀粘结剂的细胞毒性强.结论：4 种牙本质粘结剂在体外对人牙髓细胞均有一定程度的细胞毒性,其中Single Bond的毒性较强,临床使用粘结剂时应合理选择粘结剂和掌握固化时间.     

可乐丽菲露AP-X复合树脂对人牙髓细胞毒性的研究

目的 通过细胞毒性试验，探讨可乐丽菲露AP-X复合树脂及其SEBOND粘接系统在临床上用于活髓牙窝洞直接修复术的安全性。方法选用年轻健康人新鲜离体牙髓，以组织块培养法及酶消化法进行原代培养。同时制备各材料样品，浸入DMEM培养基制取材料浸渍液。分别将各材料的浸渍液与第五代人牙髓细胞共同培养，以MTT法评价材料的细胞毒性。结果可乐丽菲露AP-X复合树脂的细胞毒性小于双组份玻璃离子水门汀Vitremer及复合树脂Z100，其差别具有统计学意义，与复合体F2000的细胞毒性无统计学意义的差别。可乐丽菲露的细胞毒性小于复合体F2000和复合树脂Z100对应粘接剂，且其差别具有统计学意义（P〈0．05）。结论可乐丽菲露AP-X复合树脂及其粘接剂的细胞毒性小于临床上现在常用的其他牙色类材料。     

Cytotoxicity of dentine-bonding agents on human pulp cells in vitro

AIM: To investigate the cytotoxicity of five different dentine-bonding agents on human pulp cells in vitro. METHODOLOGY: Set specimens from Clearfil SE Bond (CB), Heliobond (HB), Prime & Bond NT (PB), Single Bond (SB), and Syntac Single Component (SC) were eluted with culture medium for 2 and 5 days. Cytotoxicity was judged using tetrazolium bromide reduction assay on human primary pulp cells. RESULTS: Elutes from five dentine-bonding agents were cytotoxic to primary human pulp cells (P < 0.05). CB was the least toxic sealer amongst the chemicals tested. The cytotoxic response decreased in an order of SB > PB > SC > HB > CB. CONCLUSIONS: The influence of the cytotoxicity depended on the materials tested. Dentine-bonding agents have significant potential for pulpal toxicity.     

三种牙本质黏结剂对人牙髓细胞的细胞毒性

目的：比较不同固化时间下3种牙本质黏结剂（Dentin bonding agents，DBA）对牙髓细胞的细胞毒性，指导临床上合理选择黏结剂和掌握固化时间。方法：组织块培养法进行人牙髓细胞原代培养，并以免疫组织化学染色法鉴定。采用MTT比色分析法来评价3种DBA（Prime＆BondNT，Pb；XenoⅢ，Xe；AdheSE，Ad）的细胞毒性。结果：经ANOVA和Dunnett—t检验，与对照组相比，固化10s和40s的3种牙本质黏结剂对牙髓细胞均有毒性（P〈0．001），与浸渍液作用24h后一些牙髓细胞变圆、皱缩、失去细胞突起。固化10s的3种DBA中Ad对细胞毒性最大，Pb毒性最小；固化40s的3种DBA中Xe毒性最大，Pb毒性最小。与固化10相比，Xe和Ad固化40s可以减轻对牙髓细胞的毒性，经student—t检验，P〈0．01。结论：3种牙本质黏结剂对体外培养牙髓细胞均有一定毒性，延长固化时间可以减轻对牙髓细胞的毒性。     

Cytotoxicity of three dentin bonding agents on human dental pulp cells

OBJECTIVES: Dentin bonding agents (DBA) have been widely used in operative restoration to prevent leakage and promote bonding strength in the resin-dentin interface. However, DBA may exert potentially harmful effects to the dental pulp. In the present study, differential cytotoxicity of three DBA (Syntac Sprint, SP; Prime and Bond 2.1, PB; and Single Bond, SB) on the pulp cells was tested. METHODS: Three DBA were diluted with the culture medium by a ratio of 1:1000, 1:2000 and 1:4000 (v/v). Pulp cells (5 x 10(4) cells/well) were then exposed to culture medium containing different diluents of three DBA for 12, 24h and 3 days. Cytotoxicity was measured with a modified 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assay. RESULTS: A 12h experiment revealed that SP was the strongest cytotoxic agent, followed sequentially by SB and PB. Exposure of pulp cells to 1:4000 (v/v) dilution of SP, PB and SB for 24h reduced the cell number by 23, 6 and 45%, respectively. A 1:2000 (v/v) of DBA diluents reduced the cell number for 32, 13 and 65%, respectively, by SP, PB and SB. Dilution of DBA by 1000-fold of culture medium further enhanced the cytotoxic response. Cell number decreased by 89, 65 and 72%, respectively, by SP, PB and SB. Similar to the 12h-cytotoxicity data, SB is more toxic at high dilution condition, whereas, at low dilution condition, SP is the most toxic agent to pulp cells. Similar cytotoxicity was noted when pulp cells were exposed to DBA for 3 days. Toxicity of DBA was concomitant with marked retraction and rounding of dental pulp cells. SIGNIFICANCE: These results indicate that DBA exerts potential harmful effects to the pulp. Differential toxic effects of DBA on the pulp cells should be considered during selection of a suitable DBA for operative restoration.     

Cytotoxicity of dental filling materials in primary cultured cells derived from human dental pulp (in vitro)

Primary cultured cells derived from human pulp tissue were used for examining the cytotoxicity of nine commercial filling materials used in restoration and root canal procedures. Cell growth was evaluated by photo pattern analysis, cell nuclei counting, and neutral red uptake. L-strain cells were also used for comparison. Primary cultured cells from either the coronary or radicular part of the pulp tissue were less sensitive to the tested materials, than were L-cells. As for sensitivities over time following mixing of the materials, the cytotoxicity of the three restorative materials was immediately moderate but disappeared 24 hours after mixing. The other six root canal filling materials yielded similar moderate to high cytotoxic levels immediately after mixing and the effects continued. The order of cytotoxicity was: Diaket and Calvital (highest); Pulp canal sealer, AH-26, and Canals (high); and then Kloroperka and three restorative materials (moderate). The differences in cellular reactions between primary and strain cells was considered to be due to cell origin, i.e. diploid or heteroploid. The importance of using primary cultured cells from designated target tissues when evaluating various materials in vitro was discussed.     

四种修复粘接材料的体外细胞毒性研究

目的 比较4种修复粘接材料—聚羧酸锌水门汀、玻璃离子水门汀( FujiI)、树脂改性玻璃离子水门汀( RelyXTM Luting)、树脂类粘接剂(Super-Bond C&B)对人牙髓细胞的生物学作用.方法 原代培养人牙髓细胞,同时制备各材料样品,浸入α-MEM培养基制取材料浸提液.分别将各材料的浸提液与第4代人牙髓...     

Freshly-mixed and setting calcium-silicate cements stimulate human dental pulp cells

Objectives

To evaluate the effect of the eluates from 3 freshly-mixed and setting hydraulic calcium-silicate cements (hCSCs) on human dental pulp cells (HDPCs) and to examine the effect of a newly developed hCSC containing phosphopullulan (PPL) on HDPCs.

4种牙体修复材料对人牙髓细胞毒性的实验研究

目的：比较4种牙体修复材料--Dyract AP、Ceram X、Quixfil U及Surefil复合树脂对人牙髓细胞的生物学作用.方法：制备4种牙体修复材料的细胞培养基（DMEM）浸出液,采用四唑盐MTT比色分析法测定材料对人牙髓细胞生长的影响;通过扫描电镜观察人牙髓细胞在不同材料表面的生长情况.结果：人牙髓细胞在4种复合树脂浸出液作用下,细胞相对增值率（RGR）与对照组相比均有显著性差异（P＜0.05）,其中Surefil的RGR与其他3种材料相比有显著性差异（P＜0.05）,而Ceram X、Quixfil U、Dyract AP 3种材料之间RGR无显著性差异（P＞0.05）;扫描电镜观察到人牙髓细胞在4种材料表面均可贴附,且生长良好.结论：4种牙体修复材料均对牙髓细胞的生长无不良影响,具有良好的生物相容性.     

复合树指单体对人牙髓细胞毒性的研究

目的：评价复合树脂单体对人牙髓的毒性作用,探讨不同细胞系对检测敏感性的影响。方法：选用人牙髓细胞（ＬＳＣ）为实验细胞,以Ｌ－９２９小鼠成纤维细胞作为对照细胞系,采用ＭＴＴ比色分析法,对两种牙科用复合树脂单体（ＴＥＧＤＭＡ和ＵＤＭＡ）进行体外细胞毒性研究。结果：在低于ＩＣ５０的各浓度组中,ＬＳＣ细胞的生存率高于Ｌ－９２９细胞;ＭＴＴ比色法作为一种能定量检测牙科材料细胞毒性的有效方法,实验时应注重考虑     

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。     

Cytotoxicity of a trial resin composite liner containing TiK2F6 on rat dental pulp cells

The aim of this study was to assess the toxicological responses of a resin composite containing TiK2F6 and NaF in rat dental pulp cells. Trial resin composite liners were made, containing 3 wt% fluorides (TiK2F6 or NaF). These specimens were immersed in 5 ml of cell culture medium supplemented at 37 degrees C for 24 hours. The eluates were used for the experiments. We judged the cytotoxicity of the samples by the cell viability. The original elute solution was serially diluted and then the medium was exchanged for the dilute medium. The cell viability at 1, 2 or 5 days after commencement of re-culturing was calculated. The viability of cells in the eluate from the resin composite liners containing TiK2F6 and NaF decreased with time. The cytotoxicity of TiK2F6 was weaker than that of NaF at all times.     

Cytotoxicity of fluoride on human pulp cell cultures in vitro

OBJECTIVES: Numerous studies have revealed that conventional glass-ionomer cements might release fluoride into an aqueous environment. The objective of this study was to examine the effects of fluoride on human pulp cells in vitro. STUDY DESIGN: H33258 fluorescence, cell proliferation, protein synthesis, and mitochondrial activity assay were used to investigate the pathobiological effects of fluoride on cultured human pulp cells. RESULTS: Fluoride was found to be a cytotoxic agent to cultured human pulp cells by inhibiting cell growth, proliferation, mitochondrial activity, and protein synthesis. CONCLUSIONS: Fluoride release has significant potential for pulpal toxicity.     

Thermo-setting glass ionomer cements promote variable biological responses of human dental pulp stem cells

Objective

To evaluate the in vitro cytotoxicity of Equia Forte (GC, Tokyo, Japan) and Ionostar Molar (Voco, Cuxhaven, Germany) on human dental pulp stem cells (hDPSCs).

Formation of odontoblast-like cells from cultured human dental pulp cells on dentin in vitro

Recent characterization of human dental pulp stem cells has shed new light on the understanding of the odontoblastic lineage. The purpose of the study was to characterize human adult dental pulp cells isolated and cultured in vitro and to examine the cell differentiation potential grown on dentin. We observed that some pulp cells isolated with an enzyme-digestion approach proliferated at a similar rate as the immortal cell line NIH 3T3. Population doubling time (PDt) for pulp cells at passage 3 was 22.6 +/- 0.5 hours and for NIH 3T3 was 23.1 +/- 2.3 hours. The pulp cells formed mineral nodules stimulated with dexamethasone or dexamethasone plus 1,25-dihydroxyvitamin D3. Pulp cells, after being seeded onto mechanically and chemically treated dentin surface, appeared to establish an odontoblast-like morphology with a cytoplasmic process extending into a dentinal tubule revealed by scanning electron microscopy analysis. Our data demonstrated the formation of cells with odontoblastic morphologies on existing dentin, suggesting that isolated human pulp stem cells may differentiate into odontoblasts on dentin in vitro.     

人牙髓细胞与牙周韧带细胞多向分化能力的比较

目的 比较人牙髓细胞(dental pulp cells,DPC)和牙周韧带细胞(periodontal ligamentcells,PDLC)的多向分化能力,揭示其干细胞成分特征,为开展干细胞介导的生物牙根再生奠定实验基础.方法 酶消化法分离培养人DPC和PDLC,流式细胞术检测STRO-1的表达.诱导细胞成牙本质及成骨分化、成脂分化和成软骨分化,von Kossa染色、抗骨钙素(osteocalcin,OCN)和牙本质涎蛋白(dentin sialoprotein,DSP)免疫组化染色、油红O染色、阿新蓝染色、抗Ⅱ型胶原免疫组化染色以及实时荧光定量反转录聚合酶链反应(RT-PCR)等检测DPC和PDLC的多向分化.结果 DPC和PDLC体外呈克隆样生长,STRO-1阳性率分别是(16.5%±4.2%)和(11.6%±1.1%).100%的DPC和83.3%的PDLC样本可多向分化.细胞诱导分化后,OCN、牙本质涎磷蛋白(dentinsialophosphoprotein,DSPP)、过氧化物酶体激活物增生受体2(peroxisomal proliferator activated receptorgamma 2,PPARγ2)、脂蛋白脂酶(lipoprotein lipase,LPL)和Ⅱ型胶原mRNA表达上调,与诱导前相比差异均有统计学意义(P<0.001),DPC和PDLC间OCN和PPARγ2基因上调倍数的差异有统计学意义(P<0.001).结论 人DPC和PDLC的间充质干细胞比例和多向分化能力相似.     

Cytotoxicity of four categories of dental cements

ObjectivesAssessment of dental material biocompatibility is gaining increasing importance for both patients and dentists. Dental cements may be in contact with oral soft tissues for prolonged periods of time and play an important role in prosthetic rehabilitation. The aim of the present study was to evaluate eight dental cements using a standardized L929-fibroblast cell culture test.MethodsFor each material, fresh specimens (added to the cultures immediately after preparation) and specimens preincubated for 7 days in cell culture medium were prepared according to the manufacturers’ recommendations. After exposure to test specimens, cell numbers were compared to glass controls. The main outcome was a two-sided 95% confidence interval for the mean value of the standardized cell number for each substance investigated.ResultsFresh specimens of all tested cements showed significant cytotoxicity, which diminished after 7 days preincubation. Cytotoxicity of fresh adhesive and self-adhesive resin cements was lower when specimens were dual-cured compared to self-cured. A rank order of cytotoxicity was established based on mean values: Nexus 2 (dual-cured) showed least cytotoxicity, followed by Variolink II (dual-cured), Nexus 2 (self-cured), Harvard, RelyxUnicem (dual-cured), Panavia 21, Fujicem, Durelon, Variolink II (self-cured), RelyxUnicem (self-cured), Maxcem (dual-cured) and Maxcem (self-cured). When bondings were added to Nexus 2 or Variolink II specimens, a slight increase in cytotoxicity was observed.SignificanceAdhesive resin cements showed less cytotoxicity than self-adhesive and chemically setting cements. Bonding only slightly influenced cytotoxicity of the adhesive resin cements. Dual-cured specimens of adhesive and self-adhesive resin cements showed significantly less toxicity than self-cured specimens.