义齿软衬材料与念珠菌的粘附

义齿软衬材料常用于全口义齿和游离端可摘局部义齿组织面的衬垫。软衬材料具有弹性和缓冲作用,可以使应力均匀分布,患者戴义齿舒适,并减少慢性疼痛。但目前义齿软衬材料尚不完美,微生物在其表面的粘附是一个较严重的问题,特别是白色念珠菌。本文着重就义齿软衬材料对朱菌会影响的研究进展作一综述。     

义齿软衬材料与念珠菌的粘附

义齿软衬材抖常用于全口义齿和游离端可摘局部义齿组织面的衬垫。软衬材料具有弹性和缓冲作用,可以使应力均匀分布,患者戴父齿舒适.开减少慢性疼痛。但目前义齿软衬材料尚不完美,微生物在其表面的粘附是一个较严重的问题,特别是白色念珠菌,本文着重就义齿软衬材料对念珠菌粘附影响的研究进展作一综述。     

义齿软衬材料表面白色念珠菌粘附的实验研究

义齿软衬材料表面白色念珠菌粘附的实验研究蔡鸿丹赵信义杨聚才王忠义何惠明随着义齿软衬材料在临床的广泛应用，许多学者发现在其表面有霉菌滋生，结果可加速材料老化，甚至导至义齿性口炎的发生。白色念珠菌（Ｃａｎｄｉｄａ，ａｌｂｉｃａｎｓ）是其主要菌株。本研究通...     

义齿软衬材料表面白色念珠菌粘附的研究进展

临床上应用义齿软衬材料的历史已达百年之久,但白色念珠菌易在其表面粘附及繁殖限制了其使用。本文就白色念珠菌在义齿软衬材料表面的粘附及其影响因素,白色念珠菌的检测、预防和治疗作一综述。     

影响白色念珠菌在义齿软衬表面粘附的因素

义齿软衬材料适用于牙槽嵴萎缩的全口义齿修复患者.但在使用过程中,不可避免地会产生真菌在其表面粘附现象.真菌在义齿软衬材料表面大量黏附,一方面可以导致义齿性口炎的发生,另一方面也会加速材料的老化,影响其使用.本文从软衬材料及口腔环境两个方面,就影响白色念珠菌在义齿软衬表面粘附的因素作一综述.     

义齿软衬材料

对全口义齿和局部义齿而言,修复效果取决于其舒适性、美观性和功能,遗憾的是,相当一部分义齿戴用者均患有慢性疼痛,尤其是糖尿病、衰弱性疾病及老年病者.此外,重度磨耗和磨牙症病人也存在类似问题.位于义齿基托与骨之间的软组织在行使功能运动时,支持组织就会受到损伤而导致慢性疼痛、病理性变化以及骨组织的吸收.而义齿软衬材料能均匀地分布功能性和非功能性应力,并且由于其有弹性而具缓冲作用,为患者提供了舒适的感觉;此外,软衬材料也能通过伸入组织倒凹区而改善义齿的固位,取得良好效果,因此软衬材料易被患者接受.     

义齿软衬材料使用性能的影响因素

义齿软衬材料应用于义齿组织面，可改善义齿的固位，提高义齿基托与牙槽嵴的密合性，缓解疼痛。义齿软衬材料临床功能的发挥受其使用性能的影响。本文就近年来国内外有关义齿软衬材料使用性能（包括软衬材料与义齿基托之间结合的牢固性、软衬材料的弹性、尺寸稳定性、色泽稳定性，微生物的黏附等）及影响因素等方面的研究进展进行综述。     

义齿软衬材料的理化性能

义齿软衬材料为一种固化后具有一定弹性的衬垫材料。其具有分散咀嚼力,减轻义齿对支持组织的局部压力,改善义齿固位的功能。义齿软衬临床应用及功能的发挥与其理化性能密切相关。本文就软衬的粘结强度、吸水性和溶解性、粘弹性、润湿性、微生物粘附、抗老化等几方面主要性能及有关影响因素作一综述。     

义齿基托软衬材料的研究进展

义齿基托软衬材料能缓冲压力，增加义齿的固位和稳定。近年来随着材料的改进和临床研究的深入，对其临床应用的意义又有了新的进展。本文从软衬材料的分类、性能、临床意义及适应症和使用注意事项等方面进行综述。     

口腔微生物在义齿材料表面粘附的研究近况

很多口腔疾病的发生都与口腔微生物有关。健康情况下，口腔微生物与宿主口腔保持着相对的平衡状态。当这种平衡遭破坏时即可导致口腔疾患。［１］牙列缺损或缺失后进行义齿修复也可以引起口腔微生态平衡的失调，从而造成龋发率增高、义齿覆盖区粘膜病变——义齿性口炎，也...     

In vitro evaluation of Candida albicans adherence to soft denture-lining materials.

The adherence of Candida albicans to seven commercial soft denture-lining materials was studied in vitro with BCA protein assay reagent. A good correlation was observed between the amount of protein in yeast cells and the number of yeasts (r = 0.993, p < 0.01), and it was revealed that the adherence of C. albicans to bare surfaces of these soft denture-lining materials correlated well with their relative hydrophobic properties (r = 0.905, p < 0.01); thus there was consistency with the thermodynamic theory. These results combined corroborated the accuracy of this method. To know the effect of pellicle on fungal adherence, the adherence of C. albicans to saliva-coated samples was examined. It was revealed that neither the amount of protein adsorbed by substrates nor the adherence of yeast to saliva-coated substrates correlated with the relative hydrophobic properties of these samples, suggesting that factors other than hydrophobic interaction play an important role in the adherence of C. albicans to pellicle-coated soft liners and tissue conditioners.     

Changes in stress relaxation property and softness of soft denture lining materials after cyclic loading

Objectives

Soft denture lining materials show varied and changeable stress relaxation property and softness under cyclic loading conditions. The purpose of this study was to determine the changes in the stress relaxation property and the softness of commercial soft lining materials after cyclic loading.

Methods

One plasticized acrylic-based material (Coe Soft: COS) and two silicone-based materials (Mucosoft: MUS; Sofreliner S: SFL) were investigated. For each material, 10 cylinder-shaped specimens were subjected to 29 days of cyclic loading, 1800 times per day; other 10 unloaded specimens were used as control groups. Stress relaxation ratio and softness were measured after 1, 4, 8, 15, 22 and 29 days of cyclic loading or storage.

Results

During 29 day period, the stress relaxation ratios of the cyclic loaded and unloaded COS, MUS and SFL specimens were 28.5-31.6% and 30.9-32.6%, 6.4-15.1% and 1.8-15.4%, 14.0-38.2% and 19.8-40.6%, respectively. The softness values of the cyclic loaded and unloaded COS, MUS and SFL specimens were 42.6-60.6% and 56.4-61.8%, 47.6-52.5% and 46.9-51.5%, 56.6-58.4% and 58.0-65.1%, respectively. Based on repeated-measures, 3-way ANOVA, the stress relaxation ratio was influenced by the loaded or stored period and the type of material (p < 0.05), but not by the application of cyclic loading; the softness value was influenced by the loaded or stored period and the application of cyclic loading (p < 0.05), but not by the type of material.

Significance

Soft lining materials showed the loaded or stored period and the material type dependent stress relaxation properties regardless of the application of cyclic loading. Softness value was influenced by the loaded or stored period and the application of cyclic loading.     

自凝水凝胶义齿软衬材料粘结强度实验研究

目的　探讨自凝水凝胶软衬材料与义齿基托之间的粘结强度 ,并评价水份存在对该材料粘结强度的影响。同时将其与硅橡胶和自凝丙烯酸酯类软衬的粘结强度作比较。方法　用牙科型盒通过常规方法制备基托试样 ,使其长为 40mm ,粘结面为 10mm× 10mm。两粘结面之间预留 3mm间隙 (用金属模型 ) ,充填软衬材料 ,使其在室温下固化。用LJ - 5 0 0型拉力试验机测试软衬与基托粘结强度。结果　自凝水凝胶软衬的粘结强度明显优于SDG -A硅橡胶及自凝型丙烯酸酯类软衬 ,高达 5 .433Mpa。当浸入 37℃蒸馏水中 1d、3d ,其值有不同程度下降 ,并于第 3d后趋于稳定。结论　自凝水凝胶软衬材料具有很高的粘结强度 ,但水对其有一定影响。     

白色念珠菌在义齿软衬材料表面上发育的研究

目的 探讨白色念珠菌在义齿软衬材料上的发育变化。方法 采用日本临床常用的７种软衬材料。通过测定培养基ｐＨ值变化讨论了白色念珠菌的发育情况。结果 虽然有一些材料固有成分对白色念珠菌有一定的抑菌作用,但会随长时间的使用而显著劣化。结论 攻期使用软衬材料必须做正确的义齿菌斑清除。     

两种冠修复贵金属合金与种植钛对龈下优势菌黏附的影响

目的:研究龈下优势菌在2种冠修复材料(金铂合金与金钯合金)与种植钛材料表面的黏附特征。方法:将金铂合金与金钯合金分别粘结在种植纯钛板上,与4种龈下优势菌:牙龈卟啉单胞菌(Pg),伴放线放线杆菌(Aa),中间普氏菌(Pi),具核梭杆菌(Fn)共同厌氧孵育。采用菌落形成单位(CFU)计数法量化测定培养试件表面的细菌黏附量,扫描电镜观察试件表面细菌黏附的情况。结果:Aa在2组试件上的黏附量最多,其次为Fn、Pg,最少的为Pi;龈下优势菌在金铂合金-钛试件表面细菌黏附量明显多于金钯合金-钛试件。结论:①4种龈下优势菌对同一合金试件的附着能力有差异:Aa>Fn>Pg>Pi。②金钯合金对细菌的生长与黏附有抑制作用。     

四种清洁剂对氟硅橡胶义齿软衬材料物理性能的影响

目的观察长效氟硅橡胶义齿软衬材料浸入4种不同类型清洁剂后物理性能的变化情况。方法将热固化氟硅橡胶软衬材料浸泡于实验型清洁剂、托牙洁美片、0.2%洗必泰和0.5%次氯酸钠等4种不同清洁剂中,用蒸馏水作对照。连续观察2个月,检测材料的吸水率、溶解率、邵氏硬度和黏结强度的变化。结果相同浸泡时间内,在不同溶液中,软衬材料的溶解率和邵氏硬度无明显改变;吸水率和黏结强度的变化有显著差异(P<0.05),吸水率变化在0.2%洗必泰中最小,在0.5%次氯酸钠中最大;在实验型清洁剂中材料黏结强度下降最多。在同一溶液中,不同浸泡时间对软衬材料物理性能的影响均有显著性差异(P<0.05),随浸泡时间延长,吸水率和黏结强度减小,溶解率和邵氏硬度增大。在各组清洁剂中,软衬材料的颜色、表面形貌及多孔性均未见明显变化。结论不同清洁剂对软衬材料的一些物理性能有影响。浸泡时间越长,材料物理性能劣化越明显。     

贵金属合金及粗糙度对种植体龈下优势菌黏附性的影响

目的:观察2种合金及其粗糙度对种植体龈下优势菌黏附性的影响.方法:选用2种常用冠修复合金材料:金铂合金和金钯合金.将其制成2种不同粗糙度的试件,粘固于种植纯钛板上,分别与4种龈下优势菌Pg、Aa、Pi及Fn共同厌氧孵育,采用菌落形成单位(CFU)计数法量化测定培养试件表面的细菌黏附量.应用SPSS13.0软件包,对试件表面粗糙度的测量值及试件上黏附的菌落数进行统计学分析,同时在扫描电镜下观察各种菌在试件上的附着情况.结果:同种合金中.粗糙度大的试件4种细菌附着量均大于粗糙度小者(P＜0.01);同种粗糙度的试件,金铂合金与种植体钛上各种细菌黏附量均大于金钯合金与种植钛上的附着量(P＜0.01).结论:金钯合金对细菌黏附的影响比金铂合金大,同种合金粗糙度大者.细菌黏附量多.     

Effect of denture cleansers on chemical and mechanical behavior of selected soft lining materials

Objectives

The aim of this investigation was to determine the effect of storage in disinfectants and artificial saliva on a series of commercial soft lining materials for dentures. Changes in mechanical properties and the nature of chemicals released into these solutions were studied.

Methods

Four soft lining materials were studied (Vertex Soft^® and Villacryl Soft^®, both of which are plasticized acrylics; Molloplast B^® and Mollosil^®, both of which are silicone elastomers). All were cured according to manufacturers’ instructions, and then cylindrical specimens (6 mm height × 10 mm diameter) prepared. These were stored under various conditions then loaded in uniaxial compression and the stress measured at a strain corresponding to a 10% deformation to determine Young's modulus. Storage involved exposure either to the following disinfectants: 2% aqueous chlorhexidine gluconate, 2% aqueous sodium hypochlorite, Corega Tabs^® cleansing tablets or 3% aqueous hydrogen peroxide; or to artificial saliva. For the latter, storage involved either immersion in artificial saliva at 37 °C for the whole study, or immersion for 16 h a day and dry at room temperature for the next 8 h each day. GC/MS was used to determine species leached into these solutions.

Results

The acrylic materials Villacryl Soft and Vertex Soft became less elastic on storage for up to 28 days whereas the silicone materials Molloplast B and Mollosil, showed no change in elastic properties. Various compounds were found to be released from these materials, including EGDMA, methyl methacrylate and dibutyl phthalate. Generally, the silicones were more stable than acrylics, releasing smaller amounts of the various eluants. In all cases, amounts eluted were well below permitted exposure limits.

Significance

Practical denture cleansing agents affect the properties of soft lining materials, reducing their elastomeric character, acrylics being more adversely affected than the silicones. These changes are associated with the loss of various chemicals, including plasticizers and monomers, from the soft lining materials.     

Evaluation of facial soft tissue parameters for Palestinians using Holdaway analysis

Objective

The aims of this study were to evaluate soft-tissue measurements for a Palestinian sample population with normal occlusion by Holdaway’s analysis, and to check the applicability of Holdaway values to the Palestinian population. Normal Holdaway values for Palestinians will be established if their parameters do not match those of Holdaway.

Material and methods

Cephalometric radiographs of 93 Palestinian university students with normal occlusion (63 women, mean age: 20.1 ± 2.1 years; 30 men, mean age: 20.2 ± 2.4 years) were traced and evaluated. Cephalometric landmarks were located according to Holdaway analysis. Ten linear and two angular measurements were produced on each radiograph.

Results

The soft-tissue measurements for the Palestinians were similar to the Holdaway norms, except for the soft-tissue convexity angle and soft-tissue chin thickness, which were larger than the Holdaway averages. The Palestinian sample had a narrower range for normal nose prominence, as well as thicker lips, deeper superior and inferior sulci, and thicker soft-tissue chins than the Holdaway values.

Conclusions

We determined normal values for the Holdaway soft-tissue analysis for Palestinians, which are appropriate for use in orthodontic practices in these territories.     

髁突囊内骨折软组织损伤分类及预后评价

目的: 分析髁突囊内骨折软组织损伤的类型和自然愈合情况。方法: 回顾2010—2013年收治的髁突囊内骨折（intracapsular condylar fracutre, ICF）自然愈合的患者,要求有受伤1周内及3个月以上冠状CT、MRI随访资料,利用MRI对软组织损伤进行分类和随访,包括关节盘的移位情况、下颌支残端有无关节盘覆盖、盘后区撕裂和改建情况、关节囊外侧损伤、关节腔积液等,分析软组织损伤对ICF愈合的影响。结果: 12例患者的17侧髁突纳入研究。软组织损伤类型中,关节盘随髁突骨折块前移位17侧,占100%;下颌支残端有关节盘覆盖10侧,占58.8%,下颌支残端无关节盘覆盖7侧,占41.2%;盘后区撕裂11侧,占64.7%;关节囊破裂7侧,占41.2%;关节腔积液17侧,占100%。随访MRI显示,17侧关节盘位置与受伤时比较无改变;髁突表面均有新骨形成17侧,占100%;关节盘后区以增厚改建为主15侧,占88.2%;2例出现盘后区类骨样变伴撕裂,占11.8%;7侧关节囊损伤均修复;关节腔积液6侧完全吸收（35.3%）。结论: ICF软组织损伤类型有关节盘随髁突骨折块移位,盘后区撕裂,关节囊破裂和关节腔积液等。愈合方式以盘后区增厚改建、髁突表面新骨形成为主。