可卸代型的制作体会

在制作冠和嵌体修复体之前,需要制作可卸式代型,以便利技术室工作,确保制作出的修复体的精确性.本文提出对在制作工作模型时直接加钉技术来制作可卸式代型的一些体会.     

托盘粘结剂对硅橡胶印模材料与托盘材料间粘结强度的影响

目的：研究托盘粘结剂对硅橡胶印模材料与不同托盘材料间粘结强度的影响。方法：分别选用GC和3M二种硅橡胶,托盘材料为不锈钢和自凝塑料,托盘粘结剂为GC和3M公司提供的专用粘结剂,进行交互使用,不涂粘结剂的作为对照组,共12组。各组均为6个样本。印模材料的调和按厂商说明进行,注入专门的测试装置中。等印模材料完全凝固后,把整个装置连接到万能测力仪上进行拉力测试,以5mm／min的速度拉伸直到粘附脱落。所得数据用SAS软件进行统计分析。结果：托盘粘结剂的使用能显著提高硅橡胶印模与托盘的粘结强度（P〈0．01）。在不使用托盘粘结剂时,不同托盘之间的粘接强度差异无统计学意义（P=0．1559）;且不同托盘材料与不同硅橡胶印模材料间无交互影响作用（P=0．8226）。无论使用哪种硅橡胶印模材料或哪种托盘材料,应用GC托盘粘结剂组的粘结强度均高于3M托盘粘结剂组（P〈0．01）。结论：临床取模过程中在托盘表面应用粘接剂能有效的改善硅橡胶印模材料和托盘的粘接强度,从而提高印模的精确性。不同厂家提供的专用粘结剂可交互使用。     

托盘粘接剂对硅橡胶印模材料与不同粗糙度托盘材料间结合强度的影响

目的：研究托盘粘接剂对硅橡胶印模材料与不同粗糙度的托盘材料间结合强度的影响。方法：2种托盘材料：自凝树脂和不锈钢;分3种粗糙度：45目,220目,400目加自然表面分成4大组;每种材料每种粗糙度各分2组,一组涂布粘接剂,另一组不涂布,总计16组,每组6个试件,共96个试件。采用GC公司的加成型硅橡胶印模材料和专用粘接剂。拉力测试,所得数据用SAS软件进行统计分析。结果：在所有托盘材料中,都显示应用粘接剂的那组具有更高的结合强度（P〈0.05）。使用粘接剂前,托盘材料对结合强度的影响具有统计学意义（P〈0.05）。使用粘接剂前后,托盘材料的表面粗糙度对结合强度的影响都具有统计学意义（P〈0.05）。结论：应用托盘粘接剂能改善加成型硅橡胶印模材料和托盘的结合强度。应用粘接剂前,不同托盘材料对结合强度有影响,自凝树脂大于不锈钢材料。在应用粘接剂情况下,结合强度随托盘表面粗糙度的增加而增加。没有应用粘接剂时,则需要把托盘粗糙到一定程度才可以增加结合强度。     

衔铁可卸式磁性附着体的研制及对MRI影响的对比研究

目的：解决磁性附着体应用对MRI的影响。方法：开发衔铁可卸式磁性附着体，比较几种形式衔铁对MRI的影响程度及不同MRI扫描地钛片所造成的伪影大小。结果：（1）几种表式衔铁对MRI的影响由大到小依次为：预成钉帽状衔铁、钴铬合金铸接的衔铁，贵金属合金铸接的衔铁，钛 桩可卸式衔铁，钛桩（拆卸盘状衔铁及中心螺丝后）。（2）可卸式衔铁拆下盘状衔铁及中心螺丝后，钛桩对MRI影像几乎没有影响。（3）标准SE序列拍摄钛片时所造伪影最小。结论：衔铁可卸式磁性附着体解决了MRI的伪影问题。尤其适用于头颅及颜面部肿瘤切除后需要长期追踪观察的患者。     

托盘粘接剂对藻酸盐印模材料与三种不同材料托盘间粘接强度的影响

目的研究托盘粘接剂对藻酸盐印模材料与不同材料托盘间粘接强度的影响。方法选择自凝树脂、光固化树脂和不锈钢3种托盘材料,每种材料分2组,一组涂布粘接剂,另一组不涂布粘接剂作为对照,总计6组,每组8个试件。采用藻酸盐通用型粘接剂以及临床常用的藻酸盐印模材料,装置在万能测力仪上进行拉力测试,所得数据用SAS软件进行统计分析。结果研究结果显示所有托盘材料中,应用托盘粘接剂组具有更高的粘接强度（P〈0．01）。不同托盘材料对粘接强度的影响具有统计学意义（P〈0．01）。结论在托盘表面应用粘接剂能改善印模材料和托盘的粘接强度,涂布粘接剂前后不锈钢材料托盘的粘接强度均大于树脂。     

利用弹性基托材料制作可摘式食物防嵌器

水平型食物嵌塞常见于中、老年人。针对此种嵌塞类型,夹板式食物嵌塞阻塞器在防止食物嵌塞的同时能固定松牙,保护裸露牙根,避免牙周炎进一步加重,是可摘式食物嵌塞阻塞器的主要设计形式之一。针对包括前磨牙在内的后牙水平型食物嵌塞患者,本文用新型弹性基托材料试制了可摘夹板     

孔数和孔径对可拆卸式托盘取模模型精度的影响

目的:研究可拆卸式托盘的固位孔孔数及孔径对托盘取模精度的影响,为临床提供取模精度较好的托盘.方法:制作金属模型,用2号成品托盘,孔数44、孔径2.6 mm的可拆卸式托盘,孔数32和29、孔径分别为3.0 mm、3.5 mm及4.0mm的2号可拆卸式托盘各取模并灌制5个石膏模型.用体视显微镜测量模型各标志点的距离,对所得数据进行统计分析.结果:①相同孔数不同孔径的可拆卸式托盘,随着孔径的增大,制取的石膏模型也变大,各线段的长度变化有明显统计学意义(p＜0.01).②相同孔径不同孔数的可拆卸式托盘,孔数多的托盘制取的石膏模型较大,变化有统计学意义(P＜0.05).③可拆卸式托盘中精度较好组的精度优于传统托盘,差异有统计学意义(p＜0.05).结论:按照适宜的孔数和孔径制成的可拆卸式托盘,精度优于其它托盘,可作为临床新型托盘应用.     

可摘式牙周夹板修复治疗牙周炎的临床效果分析

目的：评价可摘式牙周夹板对牙周炎伴牙列缺损患者的修复效果。方法：选取40例,随机分为2组,每组20例。两组患者行牙周基础治疗后,分别采用可摘式牙周夹板修复和可摘局部义齿修复,观察并记录不同时段各相关牙周指数。结果：可摘式牙周夹板组修复后24个月时菌斑指数（ plaque index,PLI）和出血指数（ bleeding in-dex,BI）较修复前增加（P＜0.05）;但修复后12个月和24个月时牙周探诊深度（periodontal probing depth,PD）较修复前下降,差异均有统计学意义（P＜0.05）。可摘局部义齿修复组修复后12个月和24个月时均出现PLI、BI和PD较修复前明显增加（P＜0.05）。结论：可摘式牙周夹板可改善牙周炎伴有牙列缺损患者的牙周状况,其修复疗效优于可摘局部义齿。     

口腔义齿基托软衬材料的研究进展

口腔软衬材料主要用于可摘义齿修复,能均匀分布义齿承载区功能负荷,调节义齿基托下的创伤组织,提高义齿口内外的固位力.然而其疏松多孔的结构易使细菌在表面粘附,导致义齿性口炎、材料老化、耐用性下降.本文就软衬材料的机械性能、粘接性能、抗菌性能、清洁与消毒方面的改进及新型材料的研究进展作一综述.     

金刚砂车针清洗消毒及灭菌方法的研究现状

金刚砂车针因其结构复杂、直接与患者口腔接触及需要重复使用的特点,因此关于该车针的清洗消毒灭菌方法一直受到人们的关注。常用的金刚砂车针清洗、消毒、灭菌的方法主要有人工清洗法、酶清洗法、超声震荡法、化学液浸泡法、干热灭菌法和湿热灭菌法。上述方法均存在优点和不足,本文综述了上述方法的适用范围和优缺点以及最新的研究进展。     

The effect of custom tray material type and fabrication technique on tensile bond strength of impression material adhesive systems

The purpose of this investigation was to evaluate the tensile bond strengths of two impression material systems (polysulphide and polyvinyl siloxane) to two custom tray materials [autopolymerizing and visible light-cured (VLC) acrylic resin]. The effect of polymerizing the tray materials directly against wax spacer and tin foil was evaluated for each material. Polymerizing tray materials against tin foil significantly increased the bond strengths of polysulphide and polyvinyl siloxane impression materials to VLC and autopolymerizing acrylic resin tray materials. Polyvinyl siloxane VLC cured against tin foil combination produced the strongest bond. The VLC resin tray material generated greater bond strength than autopolymerizing acrylic resin when polymerized against tin foil.     

Long-term effects of seven cleaning methods on light transmittance,surface roughness,and flexural modulus of polyurethane retainer material

Objectives: To evaluate the long-term effects of seven different cleaning methods on light transmittance, surface roughness, and flexural modulus of a polyurethane retainer material.Materials and Methods: Polyurethane retainer specimens (Vivera®, Align Technology Inc) (70 specimens, n = 10 per method, 50.8 mm × 12.7 mm × 1.0 mm) were exposed to seven cleaning methods twice a week for 6 months. Before treatment and after 6 months, light transmittance, surface roughness, and flexural modulus of the specimens were quantified. Qualitative assessment of randomly selected specimens from each solution was performed at baseline and after 6 months using a scanning electron microscope. Statistical analyses were performed at the .05 significance level.Results: Of the three test variables, light transmittance through the specimens was the only one that changed significantly from baseline to 6 months for all cleaning solutions, with all of them causing a decrease. However, except for 0.6% sodium hypochlorite showing a change in surface roughness values and 2.5% vinegar and toothbrushing showing an increase in flexural modulus, none of the other four cleaning methods resulted in significant changes in surface roughness or flexural modulus values for the polyurethane specimens between baseline and after 6 months.Conclusions: Of the seven cleaning methods, Invisalign® cleaning crystals, Polident®, and Listerine® showed the least amount of change in light transmittance values for the polyurethane specimens over 6 months, and they had no effect on surface roughness and flexural modulus values.     

Dimensional accuracy of dental casts: Influence of tray material, impression material, and time

PURPOSE: This study evaluated the influence on dimensional accuracy of dental casts made with different types of trays and impression materials and poured at different and multiple times. MATERIALS AND METHODS: Two types of stock trays (plastic stock tray, perforated metal stock tray) and 4 types of custom tray materials (autopolymerizing acrylic resin, thermoplastic resin, and 2 types of light-polymerized acrylic resins) were used with 2 types of impression materials (addition polymerizing silicone and polyether), to make impressions of a metal master model. Each tray and impression material was used to make 5 impressions. Casts were made by multiple pourings at 30 minutes, 6 hours, 24 hours, and 30 days after impression making. Using a measuring microscope, 12 distances were calculated based on measurements of 8 reference points. The absolute value of the difference of each measurement was calculated, as was the corresponding measurement on the master model. A Bayesian model using a simple noninformative prior was used to analyze these data. RESULTS: Statistical differences within 6 microm were found only with thermoplastic resin tray material for addition silicone, and for thermoplastic resin tray material and 1 type of light-polymerized acrylic resin for polyether. Neither stock trays nor custom trays contributed to the differences in accuracy of the casts. All deviations in casts made with silicone impression material were within a clinically acceptable range. For the polyether, distortions occurred that were clinically unacceptable. Impressions made from polyether distorted over time. Silicone impression material has dimensional stability up to 30 days. CONCLUSION: Accurate casts can be made with either stock trays or custom trays. An impression made from polyether should be poured only once and within 24 hours after impression making, because of the distortion of the material over time. Silicone impression material has better dimensional stability than polyether. .     

表面处理对托盘材料与加聚型硅橡胶结合强度的影响

目的研究喷砂及涂布粘结剂对不同托盘材料与硅橡胶结合强度的影响。方法制作不锈钢、自凝树脂、光固化树脂标准试件各40个,随机分组,每组同材质试件各10个,空白组:对试件不做处理;喷砂组:对试件进行喷砂处理;粘结剂组:对试件涂布托盘粘结剂;喷砂+粘结剂组:对试件喷砂后涂布粘结剂处理,与硅橡胶材料在测试装置中接触结合,行拉伸实验,记录结果,计算结合强度。结果 3种托盘材料均在喷砂加粘结剂处理时表现出最佳的结合强度;单独使用喷砂时,树脂材质托盘结合强度与空白组相比明显提高,而不锈钢托盘结合强度却下降明显;单独使用粘结剂时,与空白组相比,3种材质托盘结合强度均有显著提高。结论联合使用喷砂和粘结剂可显著提高托盘与硅橡胶结合强度,对树脂材料托盘单独使用粘结剂或喷砂有一定增加托盘结合强度的作用,金属托盘使用粘结剂亦可增加托盘结合强度。     

口腔诊疗器械清洗质量检查记录表的设计及应用

目的探讨质量检查表的设计应用方法,以提高临床科室椅旁预清洁依从性和口腔诊疗器械的清洗质量。 方法根据中山大学附属口腔医院口腔诊疗器械污染物情况,自行设计专用于口腔器械的清洗质量检查记录表,并应用于器械回收分类及器械包装检查工作中,根据收集的数据,进行科学分析,采取针对性的措施控制影响因素,选取2012年11月与2013年11月改进前后数据进行比较,采用SPSS 13.0软件进行统计分析。 结果改进前后器械清洗不合格率明显降低,调拌刀分别为7.22%和2.30%（χ²= 237.50,P<0.001）,银汞充填器分别为8.29%和3.09%（χ²= 151.01,P<0.001）;改进前后椅旁预清洁不合格率明显降低,水门汀充填器分别为10.80%和3.19%（χ²= 247.70,P<0.001）,近远中雕刻刀分别为8.06%和2.89%（χ²= 212.31,P<0.001）。 结论口腔诊疗器械清洗质量检查记录表结合专科特色,可操作性强,为细化工作流程、修订质量标准以及人员培训提供依据,提高了椅旁预清洁依从性,提高口腔诊疗器械清洗的合格率,促进清洗质量的持续改进。     

Effect of different labio-lingual spaces in tray designs on the displacement of and pressure against a mobile tooth

Summary  The present study aimed to examine the effect of custom tray designs on the displacement of mobile tooth and local impression pressures during the impression procedure, using partially edentulous simulation models with six anterior teeth containing a mobile tooth prepared in previous studies. The custom trays were designed by altering the thickness of the respective spaces on the labial and lingual sides of the remaining tooth arch. In previous studies, the mobile tooth was displaced in the labial direction and local impression pressures of the mobile tooth were greater against the lingual side than the labial side for all custom tray designs. Furthermore, the custom trays perforated with holes on the lingual side were effective to reduce mobile tooth displacement, labial and lingual impression pressures against the mobile tooth, and the differences between them. Therefore, the present study was performed focusing on the labial and lingual thickness of spaces in custom tray designs. It was found that mobile tooth displacement, labial and lingual impression pressures against the mobile teeth and their differences were less in trays with spaces >3·0 mm thick on both the labial and lingual sides, but markedly greater in trays with a 1·5 mm-thick space on the labial side. These results indicate that the thickness of spaces on the labial side in the tray should not be reduced to prevent mobile tooth displacement.     

口腔科常用医疗器械清洗消毒效果的评价

目的评价口腔科医疗器械常规清洗消毒的效果。方法选择2013年7月～12月口腔科使用过的非一次性医疗器械（拔牙钳、车针）共36669件,消毒供应室清洗消毒处理前后,对物体表面口腔常见的变形链球菌、白色念珠菌、金黄色葡萄球菌以及乙肝病毒进行检测,并用目测法分析清洗的质量,测评临床的满意度。结果（1）器械清洗消毒质量的合格数为35395件,合格率达到96．52％;（2）细菌和病毒检测结果显示,除了工作室桌子有10次细菌不达标以外,其余均未检出细菌和病毒;（3）紫外照射与高压的消毒效果差距较大,未高压的灭菌消毒效果低于高压的灭菌消毒效果;（4）临床使用满意度达到95．83％。结论经规范化清洗消毒与管理,基本能确保口腔器械的卫生安全,所采用的清洗消毒措施,在一定程度上能有效控制医院感染的发生。     

Drying time of tray adhesive for adequate tensile bond strength between polyvinylsiloxane impression and tray resin material

STATEMENT OF PROBLEM

Use of custom tray and tray adhesive is clinically recommended for elastomeric impression material. However there is not clear mention of drying time of tray adhesive in achieving appropriate bonding strength of tray material and impression material.

PURPOSE

This study is to investigate an appropriate drying time of tray adhesives by evaluating tensile bonding strength between two types of polyvinylsiloxane impression materials and resin tray, according to various drying time intervals of tray adhesives, and with different manufacturing company combination of impression material and tray adhesive.

MATERIAL AND METHODS

Adhesives used in this study were Silfix (Dentsply Caulk, Milford, Del, USA) and VPS Tray Adhesive (3M ESPE, Seefeld, Germany) and impression materials were Aquasil Ultra (monophase regular set, Dentsply Caulk, Milford, Del, USA) and Imprint II Garant (regular body, 3M ESPE, Seefeld, Germany). They were used combinations from the same manufacture and exchanged combinations of the two. The drying time was designed to air dry, 5 minutes, 10 minutes, 15 minutes, 20 minutes, and 25 minutes. Total 240 of test specimens were prepared by auto-polymerizing tray material (Instant Tray Mix, Lang, Wheeling, Il, USA) with 10 specimens in each group. The specimens were placed in the Universal Testing machine (Instron, model 3366, Instron Corp, University avenue, Nowood, MA, USA) to perform the tensile test (cross head speed 5 mm/min). The statistically efficient drying time was evaluated through ANOVA and Scheffe test. All the tests were performed at 95% confidence level.

RESULTS

The results revealed that at least 10 minutes is needed for Silfix-Aquasil, and 15 minutes for VPS Tray Adhesive-Imprint II, to attain an appropriate tensile bonding strength. VPS Tray Adhesive-Imprint II had a superior tensile bonding strength when compared to Silfix-Aquasil over 15 minutes. Silfix-Aquasil had a superior bonding strength to VPS Tray Adhesive-Aquasil, and VPS Tray Adhesive-Imprint II had a superior tensile bonding strength to Silfix-Imprint II at all drying periods.

CONCLUSION

Significant increase in tensile bonding strength with Silfix-Aquasil and VPS Tray adhesive-Imprint II combination until 10 and 15 minutes respectively. Tray adhesive-impression material combination from the same company presented higher tensile bonding strength at all drying time intervals than when using tray adhesive-impression material of different manufactures.