Er,Cr:YSGG激光照射对窝沟封闭剂粘结性的影响

目的 :探讨Er,Cr:YSGG激光照射作为窝沟封闭前釉质预处理方式的可能性。方法 :以 40颗离体前磨牙做为标本 ,随机分成 4组 ,唇面釉质分别采用下列方式处理 ,A组 :杯状刷处理 酸蚀 ,B组 :钻切割 酸蚀。C组 :Er ,Cr :YSGG激光照射 ,D组 :Er,Cr :YSGG激光照射 酸蚀。测试窝沟封闭剂与釉质面的抗剪强度 ,并用扫描电镜观察 4种方式处理后釉质表面的形态特征。结果 :Er ,Cr :YSGG激光照射与传统杯状刷或钻处理后酸蚀的釉质面抗剪强度相似无显著性差异 (P >0 .0 5 ) ,Er ,Cr:YSGG激光照射后酸蚀也不增大抗剪强度。SEM观察Er ,Cr :YSGG激光照射后的釉质面不规则 ,鱼鳞状 ,无玷污层。结论 :Er ,Cr :YSGG激光照射可代替传统杯状刷或钻处理后酸蚀 ,是一种较好的窝沟封闭前预处理方式     

变形链球菌CH43变链素Ⅰ基因片段的克隆及表达

目的:获得编码变形链球菌CH43变链素Ⅰ前体肽基因片段,并诱导其在不杀伤工程菌的前提下高效表达。方法:用PCR技术从变形链球菌CH43基因库中扩增出编码变链素Ⅰ成熟肽mutA基因片段相应大小的DNA片段,将片段与pMD18 T载体连接后测序。将测序正确的mutA按照BamHⅠ和HindⅢ酶切位点克隆入原核表达载体pProEX,将连接产物转化入E.coliDH5α,挑出阳性克隆,IPTG诱导表达重组的6×His融合蛋白。以IPTG浓度、A600值、诱导时间各梯度优化表达。结果:PCR获得的mutA序列与GenBank报道的一致(为147bp)。优化了诱导条件使重组载体在E.coliDH5α中高效表达,融合蛋白经SDS PAGE,在相对分子质量为5. 7×103处有特异的蛋白条带,在A600为1. 666时,加入IPTG至终浓度为1. 0mmol/L,诱导6h,目的蛋白表达量最高,占菌体总蛋白量的20%左右。结论:成功克隆变形链球菌CH43变链素ⅠmutA基因片段,并在E.coliDH5α中高效表达。     

Can anti‐erosion dentifrices also provide effective plaque control?

To cite this article:
Int J Dent Hygiene 9 , 2011; 223–228
DOI: 10.1111/j.1601‐5037.2010.00480.x
Bellamy PG, Prendergast M, Strand R, Yu Z, Day TN, Barker ML, Mussett AJ. Can anti‐erosion dentifrices also provide effective plaque control? Abstract: Objective: While gingivitis and caries continue to be prevalent issues, there is growing concern about dental erosion induced by dietary acids. An oral hygiene product that protects against all these conditions would be beneficial. This study investigated the potential of two anti‐erosion dentifrices to inhibit plaque. Methods: This was a randomized, three‐period, two‐treatment, double‐blind, crossover study evaluating a stannous chloride/sodium fluoride dentifrice (SnCl₂/NaF, blend‐a‐med^® Pro Expert) and a popular anti‐erosion dentifrice (NaF, Sensodyne^® ProNamel^?). During Period 3, subjects were randomized to repeat one treatment to evaluate any product carryover effects. Each treatment period was 17 days. Test dentifrices were used with a standard manual toothbrush. Digital plaque image analysis (DPIA) was employed at the end of each period to evaluate plaque levels (i) overnight (am prebrush); (ii) post‐brushing with the test product (am post‐brush); and (iii) mid‐afternoon (pm ). Analysis was conducted via an objective computer algorithm, which calculated total area of visible plaque. Results: Twenty‐seven subjects completed the study. At all time points, subjects had statistically significantly (P ≤ 0.0001) lower plaque levels after using the SnCl₂/NaF dentifrice than the NaF dentifrice. The antiplaque benefit for the SnCl₂/NaF dentifrice versus the NaF dentifrice was: am prebrush = 26.0%; am post‐brushing = 27.9%; pm = 25.7%. Conclusions: The SnCl₂/NaF dentifrice provided significantly greater daytime and overnight plaque inhibition than the NaF toothpaste. When recommending dentifrice to patients susceptible to dental erosion, clinicians can consider one that also inhibits plaque.     

应用脱细胞真皮基质修复口腔黏膜缺损22例报道

目的：评价脱细胞异体真皮基质组织补片用于口腔黏膜缺损修复的临床效果。方法：对22例因肿瘤手术、外伤、瘢痕、不良增生物切除术及修复前外科等原因引起的口腔黏膜的缺损,应用脱细胞异体真皮基质口腔组织补片进行修复。缺损部位主要为软硬腭、舌、口底、颊部、牙龈、前庭沟等。使用的口腔组织补片面积为1cm×1cm～4cm×6cm。术后随访1周～6个月。结果：共修复22例口腔黏膜缺损,其中2例患者2周后失访。随访的20例病例中,成活18例,脱落2例。术后补片收缩发生在2～4周。2个月后补片较稳定,未发生进一步挛缩。结论：脱细胞真皮基质作为一种黏膜缺损替代品,应用于口腔内各种原因引起的黏膜缺损修复,效果满意。     

口呼吸与鼻呼吸儿童牙弓、基骨形态差异的研究

目的：比较口呼吸与鼻呼吸儿童牙弓、基骨形态的差异，探讨呼吸方式与牙弓、基骨形态的关系。方法：通过口鼻气流同步测定系统的随机检测，选择鼻呼吸比例≤70％(口呼吸组)及≥95％(鼻呼吸组)的11～14岁儿童各34人，测量石膏模型，比较其牙弓、基骨形态的差异。结果：①口呼吸儿童与鼻呼吸儿童相比腭盖较高，上颌基骨较窄，形态相对窄长。②口呼吸儿童比鼻呼吸儿童的上颌中、后段牙弓较长，牙弓形态相对窄长，下颌牙弓后段形态也相对窄长。结论：口呼吸可以引起儿童牙弓、基骨形态的改变。     

Ultrastructural study of adenolymphoma

Ultrastructure of 10 adenolymphomas of parotid gland were studied. The neoplastic epithelium consists of "oncocytes" which are arranged in pseudostratified pattern. Their cytoplasm is almost totally packed with a large numbers of hypertrophic mitochondria showing a variety of peculiar forms. The amount and alteration of the mitochondria gradually increase in the order of pyramidal cell, common columnar cell and degenerated columnar cell. This might be a process of transposition representing degeneration due to metabolic disorder in the tumor. The obvious alterations of mitochondria are found in the cases with not only "hot" nodule but also "cold" nodule shown in the studies of 99mTc scintigraphy. There seems no relationship between "hot" nodule and alteration of mitochondria.     

Oxygen distribution and consumption in rat lower incisor pulp

The aim was to determine the oxygen tension (P(O(2))) and rate of oxygen consumption in the pulp. Twelve rats were anaesthetised and artificially ventilated. Under an operating microscope, a recessed oxygen-sensitive microelectrode was inserted into the pulp through a small saline-covered cavity on the labial surface of the lower incisor. P(O(2)) was measured as a function of the transverse distance from the saline medium through to the middle of the pulp. Oxygen profiles were characterised by a decline of oxygen tension outside the pulp in the saline medium and a steeper gradient across the interface, before a localised oxygen consuming region corresponding to the odontoblasts. A plateau with some localised fluctuations was then followed by an increase in oxygen tension in the middle of the pulp. The average oxygen tension in the plateau region was 23.2 mmHg+/-2.1 mmHg (n=12). A mathematical model was used to extract oxygen consumption data from P(O(2)) profiles recorded from non-perfused pulp (created by reducing systemic blood pressure). The analysis revealed that there was a distinct oxygen consumption zone in the outer pulp, which anatomically corresponded to the odontoblast layer. The average oxygen consumption rate of the odontoblasts was 3.2+/-0.2 ml O(2)/min per 100g pulp tissue. The zone of high oxygen consumption was 68.7 micro m+/-6.9 micro m (n=24) thick. It is concluded that pulpal oxygen distribution is heterogeneous and that the odontoblast could be a major oxygen consumer within the rat incisor pulp.     

人牙周膜细胞体外三维立体培养模型的建立

目的：建立人牙周膜细胞（PDLC）体外三维立体培养模型，初步探讨两种支架材料应用于牙周组织工程的可行性，为进一步研究牙周组织生理病理及牙周组织工程奠定实验基础。方法：组织块法培养人PDLC，传代扩增后，接种于珊瑚和珊瑚转化羟基磷灰石（CHA）两种三维支架上，体外继续培养3d，进行细胞计数和扫描电镜观察。结果：细胞在两种支架材料上均能形成良好贴附并增殖，扫描电镜可见两种支架材料均具有良好的多孔网状结构，细胞在支架材料上生长旺盛，伸展充分。结论：可通过将人PDLC接种到珊瑚或CHA上建立体外三维立体培养模型，珊瑚和CHA均有望成为牙周组织工程的支架材料。     

Effects of erbium,chromium:YSGG laser irradiation on canine mandibular bone

BACKGROUND: Only relatively few reports have described the morphological effects on bone produced by erbium,chromium: yttrium,scandium,gallium,garnet (Er,Cr:YSGG) laser irradiation, and none has investigated the atomic changes or estimated the temperature increases involved. The objectives of this study were to investigate the morphological, atomic, and temperature changes in irradiated areas during and after laser irradiation, and to evaluate the cutting effect on canine mandibular bone in vitro. METHODS: Two canine mandibular bones were cut into 3 to 5 cm pieces and irradiated by an Er,Cr:YSGG laser utilizing a water-air spray at 5 W and 8 Hz for 10 or 30 seconds. During and after laser irradiation, temperature increases in the irradiated areas were measured by thermography. The samples were then observed by stereoscopy and scanning electron microscopy to determine morphological changes and by energy dispersive x-ray spectroscopy to evaluate atomic alterations. RESULTS: Regular holes or grooves having sharp edges and smooth walls were produced, but no melting or carbonization was observed. The maximum temperature increase was an average 12.6 degrees C for 30-second irradiation. The continuous time of a temperature increase of more than 10 degrees C was consistently less than 10 seconds. An atomic analytical examination revealed that the calcium:phosphorus ratio was not significantly changed between the lased and unlased areas (P>0.0 1). CONCLUSION: These results showed that the Er,Cr:YSGG laser cuts canine mandibular bone effectively without burning, melting, or altering the calcium:phosphorus ratio of the irradiated bone.