优化牙釉质辐射剂量重建方法中的电子顺磁共振谱拟合程序

目的优化牙釉质电子顺磁共振（EPR）谱拟合程序。方法将牙釉质EPR谱拟合程序中的RIS-BGS偏移量设置为定参,取优化值;增加手动拟合功能,可以将参数初始值直接代入高斯模型得到拟合谱。结果将牙釉质EPR谱拟合程序中RIS-BGS偏移量设置为定参后,其优化值为0．529,减少了变参数量;采用手动拟合功能有助于调整参数初始值;在自动拟合程序对于个别样品谱不能给出正确结果情况时,仍然可以通过手动拟合来得到一个近似的拟合结果。结论优化了EPR谱拟合程序的应用过程。     

脑瘫儿童乳牙釉质发育缺陷的临床表现分析

目的:探讨脑瘫儿童乳牙釉质发育缺陷的临床表现特点及可能的发生机制。方法:选择150例脑瘫患儿,检查乳牙釉质发育缺陷的状况,结合胎儿期、围产期、出生后病史,研究釉质发育缺陷的临床表现及可能的发生机制。结果:脑瘫儿童中,乳牙釉质发育缺陷的患病率明显高于正常儿童,男女性别间差异无显著性。缺陷多发生在切牙及第一磨牙,且基本对称发生。釉质发育不全发生最多。结论:脑瘫儿童乳牙的釉质发育缺陷的敏感时期为妊娠的后6个月到出生后1年,其患病率明显高于正常儿童。     

两种釉质粘接剂粘接效果比较及粘接操作中的护理配合

目的探讨3M自凝釉质粘接剂与京津釉质粘接剂的临床操作及粘接效果的异同。方法挑选12～14岁正畸患者40例,男19例,女21例,按就诊先后顺序随机分成两组:3M组和京津组,在同一护士配合下由同一位医师完成所有患者上半口托槽的粘接,分别记录各患者的粘接时间及1个月后的托槽脱落情况并进行统计学分析。结果3M组临床操作时间为(10.42±1.24)min,明显短于京津组的(12.05±0.89)min,统计学分析有显著性差异;但两组的托槽脱落率分别为3.8%和3.4%,差异无统计学意义。结论在充分注意牙面清洁和隔湿、获得患者和家长配合的前提下,3M自凝釉质粘接剂与京津釉质粘接剂的短期粘接效果无明显差异。良好的护理配合是获得良好粘接效果的关键因素之一。     

Varnish XT和ICON渗透树脂对釉质龋白斑微硬度的影响

背景：早期龋的治疗方法中,可以采用氟化物对龋白斑进行再矿化处理。长效释氟玻璃离子保护膜（Varnish XT）和ICON渗透树脂是两种新型的材料,Varnish XT是一种新型的树脂加强型玻璃离子,可以作为再矿化材料的新选择。ICON渗透树脂是一种流动性较好的高渗透系数树脂,借助毛细作用渗入到脱矿釉质的微孔中,利用低黏性的渗透树脂取代由于脱矿而丧失的硬组织并占据微孔的空间,填补釉质脱矿区并阻止病损的进一步发展。目的：观察Varnish XT和ICON渗透树脂两种微创治疗材料对釉质龋白斑微硬度的影响。方法：选择牛门齿100颗,将唇面向下作为观察面,环氧树脂包埋,打磨。暴露至少6 mm×10 mm的釉质牙面,由切端至颈部依次分A,B,C,D,E 5个区,E区用抗酸指甲油封闭。分别采用人工龋脱矿液后,A区不做处理,B区经Varnish XT处理,C区经ICON渗透树脂处理,D区经氟化物处理后,用韦氏硬度仪测量表面显微硬度值。结果与结论：脱矿样本经处理后A,B,C,D区的表面显微硬度值较E区均明显降低（P 〈0.05）, B,C,D区样本表面显微硬度值均较A区升高,且表面显微硬度值C区〉B区、D区（P 〈0.05）;B区的表面显微硬度值与D区相比,差异无显著性意义（P 〉0.05）。说明ICON渗透树脂、Varnish XT和氟化物对龋白斑的微硬度都有明显的改善,ICON渗透树脂的改善较Varnish XT和氟化物明显,Varnish XT和氟化物之间无明显差异。     

不同邻面去釉厚度对釉质再矿化影响的体外研究

目的通过离体牙的体外实验,比较不同邻面去釉厚度对釉质再矿化效果的影响。方法收集正畸减数拔除的双尖牙50颗,以邻面去釉机分别对每一牙行近远中邻面去釉,并将牙体正中劈开后共100例样本,分为两组:人工唾液对照组(对照组)和氟化泡沫(含氟6‰)处理组实验组。每组中根据去釉量的不同(0.1mm,0.2mm,0.3mm,0.4mm,0.5mm)再分为五个亚组,每亚组10个样本。实验组在邻面去釉后经氟化泡沫处理3次,处理间隔为4周。应用显微硬度仪测量每一样本处理前后去釉面的显微硬度值,应用SPSS19.0进行统计学检验。结果 (1)各组在邻面去釉后、再矿化处理前,显微硬度均值的差异均无统计学意义。(2)两组在再矿化处理后,任一区组内,不同去釉量对牙釉质的显微硬度值影响仍无统计学意义。在区组间,即相同的去釉厚度不同的氟处理,均有统计学差异(均P<0.0001)。结论牙冠邻面去釉厚度在0.1～0.5mm时,对去釉后牙釉质的再矿化效果没有影响。邻面去釉后的氟化处理对釉质的再矿化具有良好的促进作用。     

釉基质蛋白预防鼠再植牙根吸收作用的磨片观察

目的探索釉基质蛋白对再植牙根吸收的预防作用,解决牙再植后根吸收并最终导致牙齿脱落现象。方法通过随机、对照、双盲法等流行病学方法,将釉基质蛋白应用于SD大鼠再植牙的根面和牙槽窝中,在2和4周时间点取标本制成牙根磨片,观察牙根面的吸收情况并对结果进行统计学分析。结果第1,2组(腹壁异位移植)牙根面吸收情况,2周实验组与2周对照组比较χ2=2.051,P>0.05,2周实验组与4周对照组比较χ2=4.021,P<0.05,2周实验组与4周对照组比较χ2=4.211,P<0.05,4周实验组与4周对照组比较χ2=7.853,P<0.05;第3,4组(干燥30min再植)牙根面吸收情况,2周实验组与2周对照组比较χ2=2.222,P>0.05,4周实验组与4周对照组比较χ2=4.013,P<0.05,2周实验组与4周对照组比较χ2=3.130,P>0.05,4周实验组与4周对照组比较χ2=5.230,P<0.05;第5,6组(去牙周膜再植)牙根面吸收情况,2周实验组与2周对照组比较χ2=2.296,P>0.05,4周实验组与4周对照组比较χ2=5.698,P<0.05,2周实验组与4周对照组比较χ2=1.569,P>0.05,4周实验组与4周对照组比较χ2=4.528,P<0.05。结论釉基质蛋白能有效降低再植牙根吸收的发生率。     

恒牙牙体硬组织钙磷成分的检测：分光光度法与EDTA 滴定法

背景：目前酸蚀与黏结技术已经广泛应用于口腔临床,有资料表明年轻恒牙与成年恒牙的牙体硬组织中的主要无机元素钙和磷的含量有一定的差异。目的：通过分光光度法与EDTA 滴定法测量年轻恒牙与成年恒牙的牙釉质与牙本质中主要无机元素（钙、磷）的含量。方法：年轻恒牙与成年恒牙离体牙各20 颗,用生石膏和水混合,待近干时,将牙齿垂直铸于其中,使牙面暴露。用syj-200 精密切割机将模型切割成切片,然后将切片放入浓硝酸中,通过加热器使之溶解,然后制备成标准溶液,最后采用分光光度法与滴定法分别测量两者硬组织的钙和磷的浓度。结果与结论：结果证实,年轻恒牙的牙体硬组织钙磷含量和钙/磷比值小于成年恒牙（P 〈 0.05）,说明有机物含量较成年恒牙多;矿化程度低于成年恒牙（P 〈 0.05）,相对于成年恒牙更加耐酸,临床操作可适当延长对年轻恒牙的酸蚀时间,以达到更佳的酸蚀效果。     

Fundamental Interactions of Laserswith Dental Hard Tissues

In order to choose the laser conditions that will be best suited for a particular application in dentistry, knowledge of the fundamental interactions of lasers with the tissues is necessary. Lasers interactions with tissue are complicated and no single parameter alone will determine how the laser affects the tissue. Dental hard tissue applications include ablation of carious lesions, cavity preparation for restoration, caries detection, endodontic surgery, and the potential for caries preventive therapy. The parameters of prime concern in understanding desirable or undesirable tissue effects are wavelength, pulse duration, absorption properties, scattering, energy, fluence (energy/surface area), power density, repetition rate, number of pulses, pulse duration and pulse shape. A range of laser parameters has been found with which dental enamel can be treated to make it resistant to subsequent dissolution by acid during dental caries. Our studies have demonstrated that treatment of enamel by specific pulsed carbon dioxide laser irradiation can markedly inhibit subsequent caries progression. During irradiation, heat causes carbonate loss from the carbonated hydroxyapatite mineral, converting it into a low solubility hydroxyapatite-like calcium phosphate. By carefully choosing the parameters it is possible to produce a laser that can selectively remove carious tissue, leading to a conservative cavity preparation, and also providing protection against later caries challenges.     

New observations of the hierarchical structure of human enamel, from nanoscale to microscale

Microstructure in terms of hierarchical assembly exists widely in mineralized biomaterials, fulfilling an important role in setting up their outstanding properties. The purpose of this study was to investigate the hierarchical assembly of enamel structure and functions, which are related to the unique characteristics of enamel. Human enamel taken from mature third molars was explored using scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM) and atomic force microscopy (AFM). Integrating the microscopic observations revealed the high complexity of the well-organized enamel structure in terms of hierarchical assembly. Based on these observations, seven hierarchical levels of the microstructure were proposed and described, using a scheme representing a complete spectrum of the organization in detail, covering a range from microscale to nanoscale: hydroxyapatite crystals (Level 1) at first form mineral nanofibrils (Level 2); the nanofibrils always align lengthways, aggregating into fibrils (Level 3) and further thicker fibres (Level 4); prism/interprism continua (Level 5) are then composed of them. At the microscale, prisms assemble into prism bands (Level 6), which present different arrangements across the thickness of the enamel layer (Level 7). Analysis of the enamel and bone hierarchical structure suggests similarities of scale distribution at each level. This study also aimed to understand further the structural-mechanical relations at each hierarchical level.     

CBCT评价下颌第一恒磨牙牙冠硬组织厚度增龄性变化

目的 利用锥形束CT(CBCT)测量下颌第一恒磨牙牙冠硬组织厚度的增龄性变化。方法 收集本院645例患者的下颌第一恒磨牙CBCT资料,分为6~15岁、>15~25岁、>25~35岁、>35~45岁、>45~55岁、>55~65岁、>65~82岁7个年龄段,测量牙釉质、牙本质、髓腔高度、髓底、近中髓角上方牙冠硬组织、远中髓角上方牙冠硬组织的厚度。结果 各年龄段的远中髓角上方牙冠硬组织厚度的变化差异无统计学意义(P>0.05),其余牙冠硬组织厚度的增龄性变化差异均有统计学意义(P均<0.05)。结论 下颌第一恒磨牙牙冠硬组织的牙釉质厚度、牙本质厚度、髓腔高度、髓底厚度和近中髓角上方牙冠硬组织厚度存在明显的增龄性变化,在远中髓角上方牙冠硬组织厚度无明显的增龄性变化。     

The effect of enamel matrix derivative (Emdogain®) on gene expression profiles of human primary alveolar bone cells

Emdogain® is frequently used in regenerative periodontal treatment. Understanding its effect on gene expression of bone cells would enable new products and pathways promoting bone formation to be established. The aim of the study was to analyse the effect of Emdogain® on expression profiles of human‐derived bone cells with the help of the micro‐array, and subsequent validation. Bone was harvested from non‐smoking patients during dental implant surgery. After outgrowth, cells were cultured until subconfluence, treated for 24 h with either Emdogain® (100 µg/ml) or control medium, and subsequently RNA was isolated and micro‐array was performed. The most important genes demonstrated by micro‐array data were confirmed by qPCR and ELISA tests. Emdogain tipped the balance between genes expressed for bone formation and bone resorption towards a more anabolic effect, by interaction of the PGE₂ pathway and inhibition of IL‐7 production. In addition the results of the present study indicate that Emdogain possibly has an effect on gene expression for extracellular matrix formation of human bone cells, in particular on bone matrix formation and on proliferation and differentiation. With the micro‐array and the subsequent validation, the genes possibly involved in Emdogain action on bone cells were identified. These results can contribute to establishing new products and pathways promoting bone formation. Copyright © 2012 John Wiley & Sons, Ltd.     

生物活性玻璃对早期人工釉质龋的再矿化*

背景:生物活性玻璃具有良好的生物相容性,且具有抑制口腔致龋细菌和牙周相关细菌及抗牙本质过敏的作用.目的:评价生物活性玻璃促进早期人工釉质龋再矿化的作用.方法:将新鲜拔除的30颗牛切牙制成人工龋模型,将标本在37℃人工脱矿液内脱矿72 h,用扫描电镜观察脱矿后釉质表面的平滑情况,用显微硬度仪测量脱矿后釉质的显微硬度.然后随机分为3组,每组10个.采用pH循环法模拟人口腔环境,将3组标本分别浸泡在生物活性玻璃溶液、氟化钠溶液及人工唾液内,3次/d,10 min/次,循环浸泡20 d,扫描电镜检测标本脱矿及再矿化情况,用显微硬度计检查牙釉质显微硬度.结果与结论:浸泡在生物活性玻璃溶液中的牙釉质表面较浸泡在其他两溶液中的牙釉质表面光滑平整,无空隙存在;浸泡在生物活性玻璃溶液中的牙釉质表面显微硬度高于浸泡在其他两溶液中的牙釉质表面显微硬度(P <0.05).说明生物活性玻璃在体外实验中能促进早期釉质龋的再矿化.     

Enamel matrix derivative inhibits proteoglycan production and articular cartilage repair,delays the restoration of the subchondral bone and induces changes of the synovial membrane in a lapine osteochondral defect model in vivo

Improving the structural qualities of the new tissue that fills osteochondral defects is critical to enhance articular cartilage repair. Enamel matrix derivative (EMD) modulates chondrocyte proliferation and differentiation. In the present study, we assessed the effect of EMD on early chondrogenesis and bone repair in an osteochondral defect model in vivo. Standardized osteochondral defects were established in the trochlear groove of rabbits. EMD or the carrier substance without EMD activity was applied to the blood clot that was forming within the defect. After 3 weeks in vivo, the quality of articular cartilage repair was evaluated using a semiquantitative scoring system and biochemical assays for proteoglycan and DNA contents. The extent of formation of the subchondral bone within the original osteochondral defect was measured. Application of EMD resulted in an inferior histological articular cartilage repair. The total proteoglycan content of the repair tissue as well as the proteoglycan production standardized to the cell proliferative activities within the defects were reduced following treatment with EMD. Restoration of the subchondral bone within the osteochondral defect was delayed when EMD was applied. Significant changes of the synovial membrane were present, reflected in an increased villus thickening and changes in villus architecture. These data suggest that EMD inhibits the early repair of the osteochondral unit in vivo. Copyright © 2012 John Wiley & Sons, Ltd.     

康复新液联合自我效能干预在口腔正畸固定矫正术中的应用

目的探讨康复新液联合自我效能干预在固定矫正术中的应用效果。方法将100例行口腔正畸固定矫正术治疗的患者随机分为观察组和对照组,每组50例。对照组采用牙龈清洁术进行治疗,并进行常规口腔健康教育,观察组加用康复新液治疗,并进行自我效能干预。观察2组菌斑指数(PLI)、牙龈指数(GI)及牙面釉质脱矿程度。结果2组治疗1、3、6、12、18个月后PLI、GI均高于治疗前,但观察组低于对照组,差异有统计学意义(P<0.05);治疗12个月后,2组患者牙面釉质脱矿程度均加重,但观察组轻于对照组,差异有统计学意义(P<0.05)。结论康复新液联合自我效能干预可减少固定矫正术患者菌斑、牙龈红肿及牙釉质脱矿等并发症的发生,具有较好干预效果。     

Effectiveness of a microabrasion technique using 16% HCL with manual application on fluorotic teeth: A series of studies

BACKGROUND Dental fluorosis is caused by excessive fluoride ingestion during tooth formation.As a consequence,there is a higher porosity on the enamel surface,which causes an opaque look.AIM The aim of this study was to identify a dental intervention to improve the smile in patients with tooth fluorosis.Additional aims were to relate the stain size on fluorotic teeth with the effectiveness of stain removal,enamel loss and procedure time using a manual microabrasion technique with 16%hydrochloric acid(HCL).METHODS An experimental study was carried out on 84 fluorotic teeth in 57 adolescent patients,33 females and 24 males,with moderate to severe fluorosis.The means,standard deviations and percentages were analyzed using nonparametric statistics and ArchiCAD 15 software was used for the variables including stain size and effectiveness of stain removal.RESULTS The average enamel loss was 234μm and was significantly related to the procedure time categorized as 1-4 min and 4.01-6 min,resulting in a P>0.000.The microabrasion technique using 16%HCL was effective in 90.6%of patients and was applied manually on superficial stains in moderate and severe fluorosis.Procedure time was less than 6 min and enamel loss was within the acceptable range.CONCLUSION Microabrasion is a first-line treatment;however,the clinician should measure the average enamel loss to ensure that it is within the approximate range of 250μm in order to avoid restorative treatment.     

氧化锆及4种全冠修复材料磨耗性能的对比

背景：氧化锆陶瓷是近年来新兴的一种口腔修复材料,因其美观性及生物相容性好而受到患者的欢迎,但目前关于其与对颌天然牙磨耗性能方面的研究较少。目的：观察氧化锆与其他4种临床常用的全冠修复材料与滑石瓷对磨时对其造成的体积损失量,并与天然牙比较,研究氧化锆及另外4种修复材料的磨耗差异。方法：将氧化锆陶瓷,vita陶瓷,金钯合金,镍铬合金,钻铬合金及对照组天然牙釉质作为上试件,分别安装于磨耗机上部夹具中,将滑石瓷作为下试件,分别安装于磨耗机下部夹具中,在人工唾液环境下进行加载磨耗实验,计算上下试件的体积损失量;使用纤维硬度测试仪对上述试件进行硬度测试;扫描电镜下观察试件表面磨耗形态。结果与结论：5种材料所致的滑石瓷体积损失量均大于对照组滑石瓷体积损失量（P〈0．05）;氧化锆陶瓷硬度值最高,自身及对磨滑石瓷体积损失量最大;金钯合金硬度值最小,自身及对磨滑石瓷体积损失量最接近天然牙;5种材料的硬度与其导致的对磨滑石瓷体积损失量呈显著正相关（P〈0．05）。氧化锆及vita陶瓷主要为磨粒磨损,表面沟裂突起样结构明显、磨耗犁沟深、形态不规则,磨耗面可见散在气孔结构。钴铬合金磨耗面相对光滑,表面磨耗犁沟较浅,磨耗面散在金属磨粒;镍铬合金磨耗犁沟深而宽,磨耗面存在大量金属磨粒;金钯合金磨耗犁沟均匀分布,偶见剥脱斑块,斑块内金属磨粒附着。表明氧化锆陶瓷在临床中容易造成对颌天然牙的过度磨耗,永久黏固前应对其进行精细抛光;金钯合金的磨耗性能与天然牙最接近且最优,是较好的后牙区全冠修复材料;口腔修复材料的硬度值不能代表其磨耗性能大小,应综合考虑材料表面的微观结构等因素,采取措施发挥各种材料优势。     

Enamel matrix derivative enhances tissue formation around scaffolds used for tissue engineering of ligaments

The following in vitro translational study investigated whether enamel matrix derivative (EMD), an approved biomimetic treatment for periodontal disease (Emdogain^®) and hard‐to‐heal wounds (Xelma^®), enhanced synovial cell colonization and protein synthesis around a scaffold used clinically for in situ tissue engineering of the torn anterior cruciate ligament (ACL). Synovial cells were enzymatically extracted from bovine synovium and dynamically seeded onto polyethylene terephthalate (PET) scaffolds. The cells were cultured in low‐serum medium (0.5% FBS) for 4 weeks with either a single administration of EMD at the start of the 4 week period or multiple administrations of EMD at regular intervals throughout the 4 weeks. Samples were harvested and evaluated using the Hoechst DNA assay, BCA protein assay, cresolphthalein complexone calcium assay, SDS–PAGE, ELISA and electron microscopy. A significant increase in cell number (DNA) (p < 0.01), protein content (p < 0.01) and TGFβ1 synthesis (p < 0.01) was observed with multiple administrations of EMD. Additionally, SDS–PAGE showed an increase in high molecular weight proteins, characteristic of the fibril‐forming collagens. Electron microscopy supported these findings, showing that scaffolds treated with multiple administrations of EMD were heavily coated with cells and extracellular matrix (ECM) that enveloped the fibres. Multiple administrations of EMD to synovial cell‐seeded scaffolds enhanced the formation of tissue in vitro. Additionally, it was shown that EMD enhanced TGFβ1 synthesis of synovial cells, suggesting a potential mode of action for EMD's capacity to stimulate tissue regeneration. Copyright © 2009 John Wiley & Sons, Ltd.     

渗透性树脂与氟漆治疗正畸后白垩斑的疗效比较

背景：牙釉质脱矿所引起的白垩斑是正畸治疗后常见的不良反应之一。近年来，渗透性树脂在对正畸后白垩斑的治疗中取得了很好的效果。但是渗透性树脂与常规治疗方法氟漆对正畸后白垩斑的疗效有何差别尚未见报道。目的：比较渗透性树脂与氟漆治疗正畸后白垩斑的疗效。方法：选取29例正畸结束后白垩斑患者，共70颗病患牙，分别采取渗透性树脂和氟漆治疗；收集患者白垩斑治疗前以及治疗6个月后的正面口内照片，分别经口腔医生与非口腔专业的大学生对白垩斑改善程度进行评估。结果与结论：除1例氟漆治疗患者失访外，其余患者均按期完成了复诊。口腔医生和非口腔专业的大学生评分结果显示，两组治疗后白垩斑均显著改善(P<0.05)；且渗透性树脂对于正畸治疗后白垩斑的治疗效果要优于氟漆治疗。可见渗透性树脂治疗具有复诊次数少，治疗效果好等优点，是治疗正畸后白垩斑的较理想方法。     

漂白剂对牙釉质和树脂黏结强度的影响

目的:比较漂白后不同时间黏结操作时,釉质与复合树脂黏结后的剪切强度,评价漂白对黏结的影响。方法:18颗人磨牙切取釉质共36片,按照随机数字表法随机分为4组。1组:漂白2周+即刻黏结;2组:漂白2周+延迟7d黏结;3组:漂白2周+延迟14d黏结;4组:生理盐水2周+即刻黏结。万能材料试验机测量剪切强度。结果:对照组为(24.4±3.7)MPa,漂白后即刻黏结,釉质剪切强度为(14.2±2.5)MPa,与漂白前有明显差异(P=0.000,95%CI7.6344～12.8478)。7d后剪切强度有所恢复,为(19.0±2.0)MPa,但与漂白前仍有差异(P=0.000,95%CI2.8322～8.0456),约14d后,剪切强度可恢复至漂白前水平,为(21.9±2.5)MPa(P=0.056,95%CI-7.0031～5.1434)。结论:漂白后即刻黏结,牙齿与树脂的黏结强度会降低。延迟黏结时间2周,黏结强度可以恢复。