脱矿牙本质基质骨诱导作用的研究

因外伤、感染和肿瘤术后造成的牙槽骨损伤,经常需要植入骨或骨替代物.随着种植技术的日渐成熟,骨增量技术在种植修复中的应用越来越广泛,对骨替代材料的研究也越来越多.脱矿牙本质基质因其来源广泛,是近年来研究较多的一种骨诱导材料.本文就脱矿牙本质基质的分类、制备、作用、生物相容性和骨诱导机制作一综述.     

脱矿牙本质基质材料在颌骨骨缺损修复的应用

颌骨缺损会导致颌面部的功能及形态的异常。所以术后的骨缺损修复是必要的。为了避免自体骨移植所带来的二次创伤,寻找优良的骨替代材料是目前的研究热点。牙本质材料因为其易获取,制备简单,成骨效果良好而获得许多关注。并且学者发现脱矿后的牙本质成骨能力更为显著。该文将对脱矿牙本质材料的成骨基质及临床应用作一综述。     

脱矿牙本质基质用于根尖诱导成形术的临床研究

目的　观察同种脱矿牙本质基质(DDM)用于根尖诱导成形术的临床效果。方法　将人牙本质去脂、脱矿粉碎、冻干等处理制备成DDM,作为根尖诱导剂应用于临床,并以氢氧化钙糊剂作为对照,共治疗患牙57颗。分别于术后1年、2年拍X线片及临床检查。结果　根尖诱导成形术后1年,患牙X线片有不同程度的根尖屏障形成,或虽无明显的X线改变但根管内探测有明显阻力,此时更换永久性根管充填材料。术后2年的临床观察发现, DDM组的治愈率为92·86%,略高于氢氧化钙组的91·30%,但无显著性差异。结论　脱矿牙本质基质可作为一种新的根尖诱导剂应用于临床。     

脱矿牙本质基质在骨增量中的研究进展

脱矿牙本质基质(Demineralized Dentin Matrix,DDM)具有良好的骨诱导、骨传导和成骨能力.与异种骨或者同种异体骨充填材料相比较,DDM具有独特的优势:无感染传染病的风险、不需刻意开辟第二术区、无排异反应等.对于本身需要拔除健康牙齿的患者而言,DDM作为骨充填材料更加经济、安全、方便、微创.本文将对DDM的成骨原理、制备方法、最佳使用效果以及在骨移植领域的发展前景作一综述.     

脱矿牙本质基质和脱细胞牙本质基质成骨效果的对比研究

目的 比较骨缺损区植入脱矿牙本质基质和脱细胞牙本质基质的成骨效果。方法 制备脱矿牙本质基质和脱细胞牙本质基质。将24只SPF级SD雄性大鼠随机分为脱矿组（A组）、脱细胞组（B组）、Bio-Oss骨粉组（C组）、空白组（D组）,每组6只大鼠,在麻醉条件下制备双侧股骨骨缺损。A、B、C组大鼠分别在骨缺损区植入脱矿牙本质基质、脱细胞牙本质基质、Bio-Oss骨粉,D组大鼠不植入任何材料。术后4周和8周,每组各随机处死3只大鼠。大体观察骨缺损区愈合情况,血清学检测成骨指标骨形态发生蛋白（BMP）-2及碱性磷酸酶（ALP）浓度,影像学观察骨缺损区高密度灰色区（代表骨愈合）分布情况,组织形态学观察新骨形成情况,计算新骨形成率。结果 术后4周和8周,大体观察见A组成骨能力较其他组活跃,血清学检测A组BMP-2及ALP浓度均高于其他组,差异有统计学意义（P<0.05）。8周时,影像学观察可见A组骨缺损区高密度灰色区分布均匀,组织形态学观察见A组排列规则的骨基质。A组4、8周时的新骨形成率分别为28.51%±0.55%、32.57%±2.28%,均高于其他组,差异有统计学意义（P<0.05）...     

牙本质基质颗粒大小及脱矿条件对其性能的影响

目的 观察牙本质基质制备粒度与脱矿程度对其性能的影响。方法 选取成年家兔的上颌门牙随机分为2组，A组：采用稀盐酸（HCL）溶液（浓度1 mol/L）脱矿45 min，干燥后制备成3种不同粒径（400μm以下、400-800μm、800-1200μm）的脱矿牙本质基质材料（Demineralized dentin matrix，DDM），进行扫描电镜及静态接触角检测；B组：采用3种不同浓度（1 mol/L、0.5 mol/L和0.25 mol/L）的HCL溶液脱矿45 min，干燥后制备成粒径400μm以下的牙本质基质材料，分别进行红外光谱检测及电子能谱仪钙元素测定。结果 扫描电镜显示粒径400μm以下的DDM材料呈片状，随机观察牙本质小管充分暴露。A组3种DDM材料的静态接触角由粒径从小到大分别为6.0°、67.0°和96.7°。B组红外光谱检测显示：随着HCL溶液浓度增大，DDM材料中以羟基磷灰石为代表的无机物含量随之降低（P<0.05），但胶原的含量受影响较小；钙元素测定显示：在一定范围内随着脱矿程度增加，样品钙含量呈现梯度式降低（P<0.05）。结论 粒径较小的DDM材料牙本质小管暴露更充分，且具有更优的亲水性，脱矿程度的增加会降低DDM材料中无机物的含量，但对胶原含量影响较小。     

脱矿牙本质基质和丝素蛋白复合生物膜的初步构建

目的:以脱矿牙本质基质(DDM)、丝素蛋白(SF)构建多孔、成骨诱导性生物膜.方法:-60℃冻干条件下,DDM与6％SF(m/v)交联构建生物膜,测定膜的结合、孔径、压缩强度,膜对大鼠骨髓基质干细胞的增殖、植入SD大鼠骨缺损区后的成骨指标.结果:生物膜各成份以共价键结合、孔径53～213 μm、压缩强度50～114KP...     

脱矿牙本质基质在骨增量领域中的研究进展

牙周病、外伤等口腔疾病在导致牙缺失的同时也常导致牙槽骨缺损,以至影响后期临床修复。近年来,引导性骨再生等骨增量技术成为解决该问题的重要手段。脱矿牙本质基质(demineralized dentin matrix, DDM)中富含成骨相关因子,使其具有良好的骨诱导和骨传导能力,被认为是一种很有前景的生物材料。同时,它具有来源广泛,不需要开辟第二术区等优点。DDM中无机成分以羟基磷灰石为主,可结合成骨相关因子作用于骨缺损处,在作为药物载体支架方面具有优势。本文将针对DDM结构、生物学性能及未来展望进行一综述。     

脱矿牙本质基质材料对大鼠颅骨缺损修复的研究

目的：探讨生物相容性较好的脱矿牙本质基质材料对大鼠颅骨缺损的修复效果。方法：①拔除健康大鼠上下前牙,脱矿,脱脂,粉碎后提取脱矿牙本质基质粉末,后与熟石膏以重量2：1比例混合。②大鼠头盖骨正中建立直径约8mm的圆形骨缺损,实验组：在缺损区植入脱矿牙本质基质粉末与熟石膏复合物,用生理盐水调和。对照组：无修复治疗。术后4周和8周分组处死取标本,进行大体标本, X线和组织学HE染色光镜下观察。结果：脱矿牙本质基质粉末与熟石膏具有良好的组织相容性和骨引导性,并与新骨紧密结合,熟石膏可以较好的抑制脱矿牙本质基质牙粉末颗粒离散。结论：脱矿牙本质基质粉末与熟石膏复合骨材料对大鼠颅骨缺损有良好的修复作用,可促进新骨形成,缩短骨缺损修复时间。     

脱矿牙本质基质骨诱导性及对相关细胞鉴定的实验研究

目的 探讨脱矿牙本质基质（DDM）诱导成骨机制的细胞理论框架和成骨方式。方法 在24只新西兰大耳白兔双侧竖脊肌区制备4个肌袋位点,随机选取3个位点为实验位点,植入DDM,另一位点为对照位点,不植入任何材料。术后1、2、3、4、8、12、16和20周处死动物,制作组织标本,应用苏木精-伊红（HE）染色、抗酒石酸酸性磷酸酶（TRAP）染色和免疫组织化学染色对间充质干细胞、成骨细胞、软骨细胞及破骨细胞进行鉴定分析。结果 HE染色显示：3周时,实验组可见软骨样基质、骨样基质和成骨样细胞。免疫组化染色显示：各时间点CD44、碱性磷酸酶（ALP）和Ⅱ型胶原表达有统计学意义（P<0.05）。结论 DDM具有良好骨诱导性和组织相容性,其诱导成骨的主要方式可能为软骨内成骨。     

The effect of Emdogain on ectopic bone formation in tubes of rat demineralized dentin matrix

BACKGROUND: Emdogain (EMD) is made from enamel matrix proteins (EMPs) from the tooth germ of swine and propylene glycol alginate (PGA) as a matrix. The function of EMD is known to differentiate cells of the dental follicle into cementoblasts. However, little is known about the effect of EMD on mesenchymal cells in other tissue. OBJECTIVE: The purpose of this study was to investigate whether EMD has the ability to induce hard tissue when applied with or without demineralized dentin matrix. METHODS: Half of the dentin tubes prepared from rat incisors were demineralized by treatment with 0.6 N hydrochloric acid for 3 h. EMD or PGA was injected into the demineralized or non-demineralized dentin tubes, which were then transplanted into rectus abdominis muscles. Untreated dentin tubes were also transplanted as a control. Animals were killed at 7, 14 and 21 days after the implantation. RESULTS: Non-demineralized dentin tubes with or without EMD or PGA did not form any hard tissue. In the demineralized group, chondrogenesis in the PGA groups occurred earlier than in the EMD groups. The expression of vascular endothelial growth factor (VEGF) mRNA in the demineralized group with PGA at day 14 was the highest. The expression of osteopontin and osteocalcin mRNAs was higher in all groups at 21 days compared with 7 or 14 days. CONCLUSION: These results suggest that neither EMD nor PGA has the ability to induce hard tissue and that EMPs contained within EMD might aggregate on the dentin surface and inhibit the effect of the demineralized dentin matrix.     

Clinical application of autogenous partially demineralized dentin matrix prepared immediately after extraction for alveolar bone regeneration in implant dentistry: a pilot study

The aim of this study was to examine the efficacy and safety of autogenous partially demineralized dentin matrix (APDDM) prepared onsite, for clinical application in bone regeneration procedures related to implant dentistry, including socket preservation, alveolar ridge augmentation, and maxillary sinus floor augmentation. In this study, 16 patients underwent dental implant placement using APDDM transplantation. There were no systemic or local complications (including surgical site infection) in any of the cases, and oral rehabilitation using dental implants was successful in all cases for at least 2 years after attachment of the suprastructure. This report describes the clinical application of APDDM prepared immediately after tooth extraction to bone augmentation, taking advantage of the relatively short preparation time due to partial demineralization. APDDM, as introduced in this study, is an efficient, safe, and reasonable bone substitute. Consequently, this material has the potential to become one of the options as a bone substitute in implant dentistry.     

Denaturation of demineralized bone matrix significantly reduces bone formation by guided tissue regeneration

AIM: To examine in a discriminating capsule model whether denaturation of demineralized bone matrix (DBM) by heating may influence bone formation. MATERIALS AND METHODS: DBM was produced from the long bones of rats. Half the portion of DBM was denatured by heating in distilled water for 20 min at temperatures between 70 degrees C and 90 degrees C. Prior to the study, the destruction of the osteoinductive properties of the DBM was confirmed in three rats following intramuscular implantation. Thirty, 4-month-old, male albino rats of the Wistar strain were used in the study. Following surgical exposure of the mandibular ramus, a hemispherical Teflon capsule (internal diameter = 5.0 mm) was placed, with its open part facing the lateral aspect of the ramus. On one side (test side), the capsule was loosely packed with denatured DBM, while on the contralateral side, serving as control, the capsule was loosely packed with the same amount of non-denatured DBM. After healing periods of 30, 60, and 120 days, groups of 10 animals were killed and 40-70 microm thick undecalcified sections of the capsules were produced. Three sections from each specimen, representing the mid-portion of the capsule, were subjected to histological analysis and computer-assisted planimetric measurements. RESULTS: Increasing amounts of newly formed bone were observed in both test and control capsules during the experimental period. At 4 months, the new bone formed in the control capsules occupied 46.7% of the cross-sectional area of the capsules, while it was only 19.1% in the test capsules (P<0.05). CONCLUSION: Denaturation of DBM by heating significantly reduces bone formation by guided tissue regeneration.     

Biological response to lyophilized demineralized dentin matrix implanted in the subcutaneous tissues of rats

AimLyophilized demineralized dentin matrix (LDDM) consists of a type 1 collagen complex matrix containing growth factors and no mineral crystals. Although the efficacy of LDDM for bone grafting is well known, there is limited evidence on the biological response to human lyophilized DDM. Therefore, the aim of this study was to evaluate the biological response of subcutaneous tissues in rats to powdered LDDM, mineral trioxide aggregate (MTA), and Biodentine implanted using polyethylene tubes.MethodsForty Wistar rats were divided into four groups (n = 10 each) depending on the experimental time intervals and were placed in polyethylene tubes containing LDDM, MTA, biodentine, and one empty control. After 3, 7, 15, and 30 observation days, the animals were sacrificed and quantitative and qualitative analysis of the subcutaneous tissue samples was carried out. The intensity of the inflammatory response was scored from 0 (no response) to 3 (severe response), and the data were statistically analyzed using ANOVA and Bonferroni tests (p < 0.05).ResultsAll groups exhibited moderate inflammation after 3 and 7 days of observation, with presence of inflammatory infiltrate predominantly consisting of macrophages and angioblastic proliferation being observed. After 15 observation days, the control group exhibited mild inflammation and a predominance of fibroblasts, and this differed significantly from the remaining cement groups that exhibited moderate inflammation. After 30 days of observation, all groups exhibited a mild inflammatory response, predominance of fibroblasts, and a greater amount of collagen fibers.ConclusionWithin the limitations of this study, it can be concluded that LDDM exhibited an acceptable biological response similar to MTA and Biodentine in the subcutaneous tissues of rats.     

烟草烟雾对大鼠牙槽骨内牙本质基质蛋白1C 末端表达的影响

目的 观察烟草烟雾对大鼠牙槽骨内牙本质基质蛋白（DMP）1 C末端表达的影响。方法 建立试验大鼠吸入烟草烟雾模型,免疫组织化学法检测DMP1 C 末端在大鼠牙槽骨内的表达。结果 阳性对照组：DMP1 C末端深棕黄色连续线形表达于固有牙槽骨的钙化前缘,形成明显的矿化条带;棕黄色颗粒状密布于骨细胞周围,浅棕黄色颗粒状散布于矿化区域;上述表达由牙槽嵴顶至根尖方向逐渐上调。试验组：DMP1 C 末端表达部位同对照组,表达强度下调且随试验时间的延长下调加重。结论 吸入烟草烟雾可下调大鼠牙槽骨内DMP1C 末端的表达;在试验周期内,DMP1 C 末端的表达下调呈时间依赖性。     

Porcine dentin matrix protein 1: gene structure, cDNA sequence, and expression in teeth

Dentin matrix protein 1 (DMP1) is an acidic non-collagenous protein that is necessary for the proper biomineralization of bone, cartilage, cementum, dentin, and enamel. Dentin matrix protein 1 is highly phosphorylated and potentially glycosylated, but there is no experimental data identifying which specific amino acids are modified. For the purpose of facilitating the characterization of DMP1 from pig, which has the advantage of large developing teeth for obtaining protein in quantity and extensive structural information concerning other tooth matrix proteins, we characterized the porcine DMP1 cDNA and gene structure, raised anti-peptide immunoglobulins that are specific for porcine DMP1, and detected DMP1 protein in porcine tooth extracts and histological sections. Porcine DMP1 has 510 amino acids, including a 16-amino acid signal peptide. The deduced molecular weight of the secreted, unmodified protein is 53.5 kDa. The protein has 93 serines and 12 threonines in the appropriate context for phosphorylation, and four asparagines in a context suitable for glycosylation. Dentin matrix protein 1 protein bands with apparent molecular weights between 30 and 45 kDa were observed in partially purified dentin extracts. In developing teeth, immunohistochemistry localized DMP1 in odontoblasts and the dentinal tubules of mineralized dentin and in ameloblasts, but not in the enamel matrix.