内分泌因素影响牙槽骨修复的动物实验研究

目的：明确内分泌因素对牙槽骨修复过程中碱性磷酸酶（ＡＬＰ）和酸性磷酸酶（ＡＣＰ）活性的影响,并探讨牙槽骨吸收修复机制。方法：２４只狗的牙槽骨二壁骨袋模型,随机分成４组,采用组织学检查,酶组织化学和全自动图像分析等技术定量分析去除卵巢,诱发实验性糖尿病及提高甲状腺素水平情况下,骨缺损修复过程中ＡＬＰ和ＡＣＰ活性变化。结果：甲状腺素组除６个月组ＡＣＰ活性较高外,ＡＬＰ与ＡＣＰ活性较对照组低,有统计学差     

内分泌代谢因素对狗牙槽骨缺损修复影响的超微结构研究

目的在超微结构水平阐明内分泌因素对骨缺损修复的影响。方法采用狗牙槽骨二壁骨缺损模型，观察在切除卵巢，诱发糖尿病及提高甲状腺素水平情况下牙槽骨修复过程中的超微结构变化。结果去除卵巢组新骨形成明显较同期正常对照组慢；诱发糖尿病组骨质明显稀疏，可见胶原破坏和退变细胞；甲状腺素组可见骨质形成减少，6个月时尤为明显，大部分骨缺损部位被纤维缔组织所代替。结论证实牙槽骨修复确受全身内分泌因素调控。     

收集骨修复种植体周围骨缺损的效果评价

目的:测量aspeo12000骨收集器在牙种植术中收集的骨量,观察收集骨的组织学特点、成骨活性及即刻移植修复种植体周围骨缺损的临床效果。方法:分2组进行。第1组,15例健康牙种植患者,应用aspeo12000骨收集器收集18颗ITI种植窝制备时钻出的骨屑,测量收集骨的体积,并用t检验比较不同性别、不同部位之间是否存在差别;每一样本脱钙后常规包埋、HE染色,光镜下观察其形态结构,计算骨组织面积所占的比例。第2组:11例患者,植入16颗种植体时发生12处骨缺损,所有缺损应用收集骨即刻移植或收集骨与Bio-oss混合移植。结果:健康牙种植患者收集骨量在不同性别、不同部位之间无显著差异,制备1个种植体窝平均可获得0.93倍体积的“湿骨”。光镜下收集骨以骨组织为主,其面积约占94.2%。牙种植术后3～6个月,原缺损处局部形态饱满,二期手术时见缺损处已覆盖成熟骨质,移植骨成活良好。结论:应用骨收集器获得的收集骨即刻移植修复种植体周围小的骨缺损,是一种简单实用的方法。     

MTA修复犬牙髓室底穿孔的组织学评价

目的 用MTA、Dycal、GIC即时修复不同大小髓室底穿孔，从组织学角度评价三种材料对牙周组织的炎症反应和硬组织形成的影响。方法 选择3条成年杂种犬的42颗后牙，用随机法先将一侧牙分为小穿孔组，另一侧牙分为大穿孔组；每侧再分为三个亚组，分别用MTA、Dycal、GIC修复。4个月后处死动物，标本经处理，光学显微镜下观察材料下方牙周组织的炎症细胞及其程度、上皮增生以及硬组织形成情况。结果 MTA组的14例中5例无炎症反应，其余9例仅有轻度至中度的炎症反应，4例有牙骨质形成，周围可见成牙骨质细胞；Dycal组材料下方均引起牙周组织中度或重度的炎症反应，2例小穿孔处有不规则的钙化物沉积，同时伴有大量炎症细胞，上皮增生多见(6／14)；GIC组除1例大穿孔标本有少量散在的炎症细胞及纤维组织包绕，其余标本均可见中度或重度的炎症反应，有的伴有上皮增生(4／14)。上皮增生与穿孔大小有一定关系。结论 MTA用于即时修复犬牙髓室底穿孔，能诱导硬组织形成，对组织的刺激小，效果优于GIC和Dycal。     

天然煅烧骨修复材料（骼瑞）修复动物骨缺损的有效性研究

目的:观察煅烧牛骨(骼瑞)修复动物骨缺损的有效性。方法:分别建立犬牙槽骨缺损修复模型、SD大鼠和新西兰白兔颅骨极限缺损模型,对照组骨缺损不植入修复材料,实验组骨缺损中植入骼瑞,每个组取材6只动物。术后用HE染色、Micro CT、Masson三色染色等方法观察缺损修复效果。结果:犬牙槽骨缺损修复8周后牙槽骨缺损修复良好。兔的颅骨修复实验中,实验组术后6周,煅烧骨颗粒周围有大量新骨形成。术后12周,骨缺损区新骨部分连接成片,已改建成板层骨,煅烧骨颗粒大多被新生骨包围。术后24周,新生骨成熟度进一步提高。SD大鼠颅骨缺损修复实验,术后8周,实验组骨缺损区域愈合,且填充修复区域的骨密度几乎接近于正常骨的骨密度。3种动物实验中,实验组骨缺损修复均优于对照组。结论:骼瑞材料对于骨缺损修复具有显著的促进作用。     

无机诱导因子复合性支架材料修复骨缺损的组织学观察

目的:应用无机诱导因子复合性支架材料修复山羊的下颌骨角部大型箱状缺损,研究该材料的成骨性能,探讨其在骨组织工程中的应用价值。方法:山羊15只,按4、8、12周3个时间点分为3组,于双侧下颌角手术制备30mm×25mm×10mm的大型箱状缺损,采用自身配对设计,左侧置入支架材料(A组),右侧空白对照(B组)。术后4、8、12周分别处死动物,取缺损修复区和材料—骨界面标本,观察组织动态学。结果:!4～12周A组有进行性成骨、钙化、骨髓形成的过程,而B组骨缺损内为未充满的纤维结缔组织,下缘有不成熟的软骨细胞附着。结论:支架材料有相当良好的生物活性;修复骨缺损显示优良的修复效果;具有临床应用的可行性。     

小牛皮胶原对新骨形成影响的定量组织学研究

将小牛皮胶原植入10只成年狗颌骨内，在不同时段取标本进行组织学光镜检测和定量分析。结果显示，此材料组织相容性良好，不影响新骨形成，材料与骨组织间无纤维被囊形成，与新骨直接结合，材料最后在机体内大部分降解，为宿主新生骨组织替代，表明小牛皮胶原是一种良好的组织修复材料。     

全身因素对牙髓根尖周病的影响

牙髓根尖周病是一种主要由细菌感染引起的、机体免疫系统参与的疾病。全身因素对牙髓根尖周病的发生、发展和预后有着重要的影响。本文从全身因素如激素失调、病毒感染、维生素缺乏、蛋白质缺乏及其他疾病对牙髓根尖周病的影响作一综述。     

胶原/纳米磷酸三钙复合人工骨修复骨缺损的实验研究

目的 观察胶原（Collagen,简称Co)／纳米磷酸三钙（Nano-Tricalcium Phosphate,简称N－TCP）复合人工骨的生物相容性，Co/N-TCP植入骨缺损区促进骨创愈合的能力。方法 家兔24只，颅骨制成直径8.0mm圆形穿通型缺损，左侧植入Co/N-TCP复合人工骨作为实验组，右侧植入非纳米Co/TCP人工骨作为对照组；于2，4，8，12周后处死各组动物取材，行肉眼，组织学方法观察。结果 两组材料除早期（2周内）轻微炎性2细胞浸润外，其余各时间点均未见异物巨细胞反应，4－8周骨新生活跃，有骨岛形成，12周时可见骨性连接。结论 Co/N-TCP复合人工骨具有良好的生物相容性及骨引导活性，能促进骨缺损的早期修复，是一种颇有潜力的骨缺损修复材料。     

Bio-oss结合Bio-gide修复牙种植体周围骨缺损的组织学研究

目的：通过制作带有种植体的硬组织磨片,评价无机牛骨(deproteinized natural bovine mineral,Bio-oss)结合可吸收性胶原膜(bioresorbable collagen mambrane,Bio-gide)在牙种植体周围骨缺损中的引导骨再生作用及效果。方法：在免股骨植入羟基磷灰石涂层BLB种植体,并在其外侧壁制造标准骨缺损,A组在骨缺损处植入Bio-oss颗粒并在其表面覆盖Bio-gidt,膜,B组作为空白对照,分别于术后1、2、4、6个月取样品,通过带种植体的硬组织切片进行骨组织形态学分析。结果：术后1个月Bio-oss颗粒表面有新骨形成,随时间延长Bio-oss发生降解吸收,新生骨量增加,并与种植体表面形成骨性结合。结论：可吸收性胶原膜Bio-gide结合Bio-oss应用于牙种植体周围骨缺损中,可以引导骨组织再生,重建缺损的骨组织,新生骨与种植体形成骨性结合。     

Accuracy of Conventional Periapical Radiography in Diagnosing Furcation Repair after Perforation Treatment

IntroductionPeriapical radiography (PR) is a diagnostic tool to be used by professionals in clinical practice. The method presents limitations, and doubts still exist about its value to evaluate furcation perforation and the reparative process of hard or soft tissues after treatment. Thus, the aim of this study was to evaluate the accuracy of PR as a diagnostic method to detect both resorption of the furcation area after induced experimental perforation and repair after perforation treatment using histopathological findings as a gold standard.MethodsThirty teeth of beagle dogs with furcation perforation were filled with Biodentine (Septodont, Saint-Maur-des-Fossés, France), ProRoot White mineral trioxide aggregate (Dentsply Tulsa Dental Specialties, Tulsa, OK), or gutta-percha and examined using PR and histology. Sensitivity, specificity, predictive values, and accuracy were calculated.ResultsPR detected repair and reabsorption of furcation perforation in 55% and 48% of the teeth, respectively. Histologic analysis showed furcation perforation in 66% and 21% of the teeth, respectively. Sensitivity and specificity of PR for the detection of repair were 0.84 and 1, respectively, whereas for resorption detection, the values were 0.43 and 0.65, respectively. Diagnostic accuracy for PR was 0.89 and 0.72 for repair and resorption of furcation perforation, respectively. PR showed more accurate diagnostic (true positives + true negatives/total) in repair detection compared with resorption of furcation perforation.ConclusionsWe conclude that PR is not adequate in detecting resorption progress after the treatment of furcation perforation, and we encourage the use of digital imaging when suspicious of a possible unsuccessful result after furcation perforation treatment.     

Applicability of an image analysis system in alveolar bone loss measurement

Clinical and epidemiological studies in the field of periodontics and endodontics often utilize radiographs to monitor or measure the changes in bone structure and density. Periodontal bone loss or gain can be quantified on a radiograph by measurement of the distance between the bottom of the bony pocket and the apical contour of the involved tooth. The objective of this investigation was to study the accuracy of an image analysis system (IAS) to measure changes in height of the interproximal crest on radiographs. Artificial bone lesions were introduced in a dissectioned part of a human mandible. The distances between crest and apices were measured with a micrometer (MM). Radiographs were produced with horizontal and vertical deviations of 10 degrees. The radiographs were digitized and processed by computer. The landmarks in the digital image were enhanced mathematically and by histogram-based thresholding. The depth of the introduced defect was increased 6 times, followed by the measurement procedure. The IAS produced measurements of crown-apex distances with an accuracy of 0.066 to 0.358 mm. Repeated crest height measurements were recorded with an accuracy of 0.112 to 0.184 mm. Both the histogram-based binarization and the ellipse-fitting type of contour detection could be applied precisely. Misangulation errors during radiographic exposure of 10 horizontal or vertical did not statistically significant influence the IAS-measurements. The IAS can be applied in clinical trials and follow-up studies.     

Clinical and Histological Evaluation of Tissue Healing in Beveled or Perpendicular Vertical Releasing Incision

ObjectivesThe aim of this investigation was to evaluate the clinical and histological differences in wound healing between beveled and perpendicular vertical releasing incisions in dogs.Material and MethodsFour male mongrel dogs were used in this investigation. In each quadrant, a vertical releasing incision was made on either the mesial or the distal aspect of the cuspid teeth of each animal all on the same day. The sites were randomly selected to either receive a beveled incision or a perpendicular incision. A sulcular muco-periosteal flap was raised, reapproximated, and then sutured using 3-0 Vicryl. The animals were evaluated daily for the first week, and then at different time intervals during this investigation. One animal was killed at each time interval of 9, 14, 21, and 28 days after surgery. One animal was killed at each time interval, and a bone block consisting of the cuspid teeth and their surrounding bone and soft tissues was harvested, formalin fixed, and paraffin embedded. Samples were sectioned serially and stained with hematoxylin-eosin. Specimens were evaluated using a microscope with magnification ranging from ×10 to ×400 by a histopathologist. Four indices were used for histologic evaluation.ResultsAt day 9 after surgery, a visible groove was seen in the marginal tissues of both perpendicular and beveled incisions. At day 9, both of the histologic sections showed less organized connective tissue and capillary networks with no significant difference in inflammation. In the 14-day samples, a depression was still present at the perpendicular incision sites, but not in the beveled incision group, where the groove was not visualized at all.In the 21- and 28-day samples, irregular capillary arrangements were seen in the connective tissue of the perpendicular incision groups with completely healed epithelium. There were no statistically significant differences noted histologically between the beveled and perpendicular incision groups noted at 9, 14, 21, or 28 days (P > .05).ConclusionBased on these findings, it appears that clinical and histologic healing of beveled or perpendicular releasing incisions are similar 28 days after surgery.     

Change in supporting tissue following loss of a permanent maxillary incisor in children

Alveolar bone resorption is an inevitable consequence of tooth loss and may be detrimental to long-term dental aesthetics and function. The aim of the present study was to quantify the degree of tissue resorption following the loss of a permanent incisor in a young population. The study group comprised 11 boys and five girls who all required the extraction of a permanent maxillary central incisor due to trauma-related sequelae. Mean age at tooth loss was 10.8 years. Upper alginate impressions were taken at regular intervals following tooth loss and were cast in yellow dental stone. Study models were sectioned longitudinally through the mid-point of both the maxillary incisor socket and the contra-lateral incisor to provide a thin plaster section. Digital photographs were acquired of the edentulous (A1) and dentate (A2) surfaces of this section and image analysis software was employed to quantify the surface area of both A1 and A2. At 3 months postextraction, mean A1 was 15.7% less than mean A2. By 6 months mean A1 had further reduced and was 25.3% less than that of the corresponding dentate alveolus. However, at subsequent time intervals following tooth extraction (>6 months), tissue loss appeared to stabilise with an overall reduction in tissue area remaining at 22%. This reduction in supporting tissue area was found to be highly statistically significant (P = 0.002, anova). Furthermore, girls appeared to have an overall greater degree of tissue loss than boys (P = 0.015). Further research is indicated to explore factors influencing the degree of tissue loss following incisor extraction and the benefit of therapeutic interventions in limiting this resorption.     

富血小板血浆及其在口腔颌面骨修复中的应用

1984年,Assoion等发现了人血浆中提取的富血小板血浆（platelet—rich plasma,PRP）中含有多种生长因子,当PRP与氯化钙以及凝血酶混合后,各种生长因子即从血小板中的仪颗粒中释放出来^[1]。这些生长因子包括血小板源性生长因子（platelet—derived growth factor,PDGF）、转化生长因子β（transforming growth factor—β,TGF—β）、     

Evaluation of Biochemical Parameters and Local and Systemic Levels of Osteoactive and B‐Cell Stimulatory Factors in Gestational Diabetes in the Presence or Absence of Gingivitis

Background: Gestational diabetes mellitus (GDM) is defined as varying glucose intolerance, with first onset or recognition in pregnancy. This study evaluates clinical and biochemical parameters in a possible association between GDM and gingivitis. Methods: A total of 167 pregnant females was included in the study. There were 101 females with GDM and 66 females without GDM. Subgroups were created according to the presence or absence of gingival inflammation. Plaque index, bleeding on probing, and probing depth were recorded at four sites per tooth. Serum, saliva, and gingival crevicular fluid (GCF) levels of interleukin (IL)‐6, IL‐8, soluble receptor activator of nuclear factor‐kappa B ligand (sRANKL), osteoprotegerin (OPG), B‐cell activating factor (BAFF), and a proliferation‐inducing ligand (APRIL) were determined by enzyme‐linked immunosorbent assay. Data were analyzed by Kruskal‐Wallis and Mann‐Whitney U tests and Spearman correlation analysis. Results: Age and anthropometric indices were higher in the GDM than non‐GDM group (P <0.0001). Clinical periodontal recordings, serum BAFF, IL‐8, and saliva sRANKL levels were higher in the GDM group (P <0.05). Saliva IL‐6 level was higher in the GDM with gingivitis group than non‐GDM with gingivitis group (P = 0.044). Serum and GCF BAFF (P <0.0001), serum, saliva, and GCF APRIL (P <0.0001; P <0.0001; P = 0.032, respectively), GCF OPG (P = 0.036), and serum and saliva sRANKL (P <0.0001) were higher in the GDM with gingivitis group than GDM without gingivitis group. Conclusions: The inflammatory response seems to be more pronounced in females with GDM. The observed increase in both local and systemic levels of inflammatory cytokines may suggest an interaction between gingivitis and GDM.