SOD盖髓术后牙髓组织免疫组化染色的观察

目的：探讨ＳＯＤ作为盖髓剂促进牙髓修复的作用机理。方法：应用ＢＭＰ－ＡＢＣ法对盖髓后获得成功的标本进行免疫组化染色。结果：空白组、正常对照组标本ＢＭＰ染色结果为阴性；ＳＯＤ盖髓后有牙本质桥、牙本质瘤形成的标本，ＢＭＰ染色均呈不同程度的阳性反应，显微镜下观察为黄褐色颗粒。主要分布在牙本质桥下成牙本质细胞、牙髓细胞浆中和牙髓组织。结果：ＳＯＤ用于盖髓促进牙髓组织修复、牙本质桥形成与ＢＭＰ作用有关，ＳＯＤ一方面抑制炎症反应，改善局部微环境，为组织自身修复创造条件；另一方面则刺激牙髓组织增生、诱导牙髓细胞合成分泌ＢＭＰ。     

242颗牙本质折断恒牙牙髓预后及影响因素的回顾性分析

目的 分析牙本质折断恒牙的牙髓预后及其影响因素。方法 对行间接盖髓治疗且复诊时间大于2年的牙本质折断病例进行回顾分析,记录牙髓预后情况,回归分析影响牙髓预后的危险因素。结果 收集到牙本质折断病例205例,涉及患牙242颗。242颗患牙中,78颗（32.2%）发生了牙髓坏死,3颗（1.2%）发生了牙髓钙化。牙本质折断后行间接盖髓术的成功率为67.8%。复诊期间177颗年轻恒牙中141颗根尖孔闭合。冠折近髓程度与牙髓坏死率有相关性（P=0.001）。结论 牙本质折断恒牙行间接盖髓术的预后较好,冠折近髓程度是判断牙髓预后的重要指征。     

Is a calcium hydroxide liner necessary in the treatment of deep caries lesions? A systematic review and meta‐analysis

The aim of this systematic review and meta‐analysis was to evaluate whether the use of calcium hydroxide (CH) liner improves the clinical success in the treatment of deep caries lesions of primary and permanent teeth. The review was reported in accordance with the PRISMA Statement. Only studies that evaluated deep carious lesions treated with and without a CH liner were included. The required outcomes had to be obtained by clinical, radiographic or laboratory evaluations. Statistical analyses were performed with the RevMan 5.2 program (The Cochrane Collaboration, Copenhagen, Denmark) for randomized clinical trials with at least 12 months of follow‐up, using fixed‐effect models at a significance level of P < 0.05. The literature search was performed in eight databases: PubMed (MEDLINE), Lilacs, IBECS, BBO, Web of Science, Scopus, SciELO and The Cochrane Library. A total of 17 studies were included (15 in primary teeth, two in permanent teeth). The overall risk difference for CH versus adhesive system in primary teeth was 0.06 [95% CI ?0.01 to 0.13], and the overall risk difference for CH versus GIC was 0.10 [95% CI ?0.01 to 0.22], with no significant differences between materials. CH liner did not influence the clinical success of treatment for deep caries lesions of primary or permanent teeth. Although the present analysis demonstrated that use of CH liner in deep caries lesions was unnecessary, the evidence was of moderate to very low quality; thus, further well‐designed, randomized and controlled clinical trials are necessary to provide stronger recommendations.     

Dentinogenic Responses after Direct Pulp Capping of Miniature Swine Teeth with Biodentine

Introduction

The aim of this study was to evaluate pulpal responses after experimental direct pulp capping of mechanically exposed teeth with a new calcium silicate–based dentin replacement material.

Methods

Thirty-four anterior and posterior teeth of 3 miniature swine were used. Class V or I cavities were prepared on the buccal or occlusal surfaces, respectively. Pulpal exposures were further performed using a round carbide bur 0.8 mm in diameter. Exposures were treated with white MTA Angelus (Angelus, Londrina, PR, Brazil) or Biodentine (Septodont, Saint Maur des Fosses, France), and the cavities were further restored with Biodentine. The pulpal tissue responses were histologically assessed at postoperative periods of 3 and 8 weeks. Data were statistically analyzed using the Kruskal Wallis and the Mann-Whitney U tests.

Results

Inflammatory infiltration or pulp tissue necrosis was not found in any of the specimens. All teeth showed mineralized matrix formation in the form of a complete hard tissue bridge composed of osteodentin or osteodentin followed by a discontinuous or continuous reparative dentin zone. A significantly higher thickness of the hard tissue bridge was found in the group of teeth treated with Biodentine at both 3 and 8 weeks. A number of teeth, which were under root development at the onset of the experimental procedures, exhibited ectopic pulp calcification.

Conclusions

The application of both calcium silicate–based materials in direct contact with the mechanically exposed pulp of healthy miniature swine teeth led to pulp repair with complete hard tissue bridge formation. The thickness of hard tissue bridges was significantly higher after pulp capping with Biodentine.     

修复性牙本质形成的机理与调控

修复性牙本质的形成是牙体组织重要的保护性防御行为,在牙体组织遭受龋损、外伤、严重磨耗等损伤时,对于保护牙髓的活性和功能具有重要意义。修复性牙本质形成的机制较为复杂,有多种细胞参与,并受各类因子调控。本文就修复性牙本质的形成机制及其促进因素作一综述。     

Effect of dental materials calcium hydroxide-containing cement, mineral trioxide aggregate, and enamel matrix derivative on proliferation and differentiation of human tooth germ stem cells

Introduction

Biocompatibility of pulp capping materials is important for successful use in dentistry. These materials should be nontoxic and permissive for proliferation and induction of odontogenic differentiation of pulp cells. The aim of our study was to evaluate the effects of enamel matrix derivative (EMD), mineral trioxide aggregate (MTA), and calcium hydroxide-containing cement (DYCAL) on proliferation and odontogenic differentiation of human tooth germ stem cells (hTGSCs) in which cells belonging to both pulp tissue and dental follicle exist.

Methods

The 96-well plates, 24-well plates, and special chamber slides were coated with biomaterials for cell proliferation, differentiation, and scanning electron microscopy analysis. Odontogenic differentiation of hTGSCs was evaluated by analyzing mRNA expression of dentin sialophosphoprotein (DSPP) by real-time polymerase chain reaction expression analysis, measurement of alkaline phosphatase activity, and visualization of calcium depositions by von Kossa staining.

Results

Our results demonstrate that EMD is the best material in terms of inducing differentiation and proliferation of hTGSCs. DYCAL was found to be toxic to hTGSCs; however, EMD-coated DYCAL showed less toxicity. EMD-coated MTA was not efficient at inducing proliferation and differentiation.

Conclusions

Pulp capping materials come in direct contact with dental pulp cells; thus, they require comprehensive evaluation of interactions between cells and biomaterials. Therefore, we cultured hTGSCs, capable of odontogenic differentiation, on pulp capping materials directly. Our results suggest that combination of capping materials with EMD would increase the quality of capping by increasing biocompatibility of capping materials.     

天然型网孔羟基磷灰石复合BMP基因质粒直接盖髓的实验研究

目的观察以质粒为BMP基因转移载体以羟基磷灰石为支架的缓释系统(HAP-BMPcDNA)促进修复性牙本质形成的情况。方法将编码骨形成蛋白的cDNA克隆至真核表达质粒,然后将其与网孔羟基磷灰石复合导植到狗牙露髓处,同时用BMP组和氢氧化钙组做实验对照,进行组织学观察。结果HAP-BMPcDNA组可有效促进修复性牙本质的形成,效果明显优于BMP组和氢氧化钙组。结论质粒为BMP基因转移载体羟基磷灰石为支架的缓释系统(HAP-BMPcDNA)作用于促进修复性牙本质(reparative dentinogenesis.RD)形成的方法,不仅可有效增强牙齿露髓时RD的形成、克服在露髓处单纯放置BMP不能为成牙本质细胞样细胞提供足够刺激的不足;而且还可避免因用重组病毒作为载体可能诱发牙髓组织免疫损伤的发生。     

根管治疗期急症的相关因素分析

目的探讨根管治疗期间急症发生的相关因素。方法对208例根管治疗病例进行临床观察,分析急症发生的相关因素。结果根管治疗期间急症发生率为11.1%,其中扩大针超出根尖孔、充填质量、无瘘管型尖周炎等相关因素影响下根管治疗急症发生率较高。结论根管治疗期间急症发生较为密切的因素有术者操作水平、根管病变情况等。     

丹参多酚酸盐对持续性＋Gz 环境下大鼠牙髓的影响

目的：探讨丹参多酚酸盐（DSSM）对高正加速度（＋Gz）重复作用下的大鼠磨牙牙髓的作用。方法：27只 SD 雄性大鼠用随机区组法分为9组,每组3只。阳性对照组和药物组分别在＋5 Gz、＋10 Gz 的条件下共离心30 s,每天重复5次,间隔以＋1Gz 持续60 s,4 d /周,共3周。实验期间药物组于每次离心前30 min 按剂量腹腔注射 DSSM溶液（低、中、高给药剂量分别为2、6、18 mg/kg）,阴性及阳性对照组注射等体积生理盐水。实验结束后,光镜下观察各组大鼠牙髓组织形态学变化情况,并采用 Real time qPCR 方法测定大鼠磨牙牙髓中热休克蛋白（HSP70）mRNA 相对含量表达的情况。结果：＋5 Gz 和＋10 Gz阳性对照组大鼠活动程度降低,磨牙牙髓中出现空泡性变,组间差异不明显。HSP70 mRNA 的相对含量比阴性对照组高（P ＜0．05）。药物组中 HSP70 mRNA 的相对表达量较各自阳性对照组降低,＋10 Gz 高剂量组有统计学意义（P ＜0．05）。结论：＋Gz可引起牙髓损伤,＋Gz 值的增加与 HSP70 mRNA 相对表达量增加相关,DSSM可能对牙髓有保护作用。