几种消毒剂对藻酸盐印模材料的消毒效果

作者为了选择对藻酸盐印模材料有效的消毒剂和消毒方法，采用２％碱性戊二醛，１％过氧乙酸，２％甲醛为３０名受试者的藻酸印模进行消毒，并在消毒前后进行细菌培养及鉴定，结果发现：消毒前的印模有９种细菌被检出，污染率高达９６％，消毒后的印模细菌检出率为零，作者认为，本研究所有消毒剂，消毒方法效果良好，值得沿用。     

几种消毒剂对藻酸盐印模材料的消毒效果

作者为了选择对藻酸盐印模材料有效的消毒剂和消毒方法，采用２％碱性戊二醛、１％过氧乙酸、２％甲醛对３０名受试者的藻酸盐印模进行消毒，并在消毒前后进行细菌培养及鉴定。结果发现：消毒前的印模有９种细菌被检出，污染率高达９６％；消毒后的印模细菌检出率为零。作者认为，本研究所用消毒剂、消毒方法效果良好，值得沿用。     

藻酸盐印模材料流动性能的比较研究

目的 研究藻酸盐印模材料流动性能随时间变化的特点.方法 利用直径20 mm、高20 mm的圆柱形模具,将藻酸盐印模材料调拌放入其中,在不同时间施加0.7 kg的负荷,测量其直径表示其流动性大小.结果 两种藻酸盐印模材料均在30 s时流动性最好,其后流动性逐渐下降,但红叶藻酸盐印模材料在150 s后流动停止,贺利氏藻酸盐印模材料则在180 s后无流动性;两种藻酸盐印模材料的流动性差别有显著性统计学意义(P＜0.01);同一种印模材料在各时间段的流动性差别有显著性统计学意义(P＜0.01).结论 藻酸盐印模材料的流动性随着时间的延长而逐渐减弱,30 s时为取模的最佳时间.     

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。     

藻酸盐印模材取模的三维精度变化

通过对石膏模型的定量测量评价六种牌号藻酸盐印模材的取模精度,实验金属模型模仿三单位固定义齿,在显微镜放大25倍下,对金属模型翻制的石膏模型上观测线交叉点的间距进行测量,测距包括:颊舌向(BL)、近远中向(MD)、(牙合)龈向(OG)和基牙间距离(IP).结果表明所有牌号的印模材制取的印模均无统计学上显著的三维尺寸变化,石膏模型精度临床可接受.但只有AP组印模材制取的石膏模型可补偿后续制做中的收缩.     

三种形状藻酸盐印模尺寸精确性分析

目的:本实验旨在比较使用藻酸盐印模材料制取不同形状物体阴模过程中的尺寸精确性.方法:分别使用藻酸盐印模材料制取正方体,圆柱体、三角体阴模,并用电子数显卡尺测量灌注的普通石膏、硬石膏、超硬石膏模型试件的尺寸,并与实物尺寸进行比较分析.数据进行ANOVA(α=0.05).结果:圆柱体印模尺寸变化较大,正方体印模尺寸变化较小,而三角体印模尺寸变化居中(P＜0.05).正方体的普通石膏灌注阴模组,硬石膏灌注阴模组和超硬石膏灌注阴模组的尺寸变化百分率分别是0.044%,0.128%,0.370%.圆柱体的普通石膏灌注阴模组,硬石膏灌注阴模组和超硬石膏灌注阴模组的尺寸变化百分率分别是0.745%,0.665%,0.369%.三角体的普通石膏灌注阴模组,硬石膏灌注阴模组和超硬石膏灌注阴模组的尺寸变化百分率分别是0.557%,0.595%,0.561%.结论:三种形状中正方体对藻酸盐印模制取的尺寸变化影响较小,三角形次之,圆柱体变化较大.     

温度老化对藻酸盐印模材料抗压强度的影响

本研究采用温度老化方法观察了藻酸盐的粘度与温度的相关性,同时用老化后的藻酸盐配制成牙科印模材料进一步观察其抗压强度的变化规律。结果表明:高温可以破坏藻酸盐的结构,使它的粘度下降,从而影响了牙科印模材料的抗压强度。低温对藻酸盐粘度和印模材料的抗压强度基本无影响。     

3种调拌方法对藻酸盐印模材料气泡及凝固状态的影响

目的: 比较全自动印模调拌机、顺时针手动和联合八字手动3种调拌方法对藻酸盐印模材料气泡含量、流动性等物理性能的影响。方法: 分别采用3种不同调拌方法调制藻酸盐印模材料,比较印模的气泡数量、总面积和流动性,调拌前、后温度变化以及工作时间和凝固时间差异。采用SPSS 24.0软件包对数据进行统计学分析。结果: 全自动调拌组气泡数量为（2.30±2.50）个,总面积为（0.17±0.18） mm²,小于顺时针手动调拌组数量[（59.60±14.19）个]和总面积[（7.41±2.24） mm²],差异有统计学意义（P<0.01）;顺时针手动调拌组流动性（39.52±0.85） mm,小于全自动调拌组[（50.78±0.90） mm]和联合八字手动调拌组[（50.36±1.75） mm],差异有统计学意义（P<0.01）;3种方法调印模的工作时间和凝固时间均符合临床要求。结论: 全自动调拌法印模在气泡含量、流动性等方面较佳。手动调拌中,联合八字调拌法有助于减少印模气泡与形变量,提高流动性。     

温度对藻酸盐印模材料和聚醚印模材料流动性的影响

在23℃和32℃下,对藻酸盐印模材料和聚醚印模材料调和完成后的流动性进行连续的无间断测定。23℃下,藻酸盐印模材料在调和开始190 s后固化完成,聚醚印模材料在调和后310 s固化完成。32℃下,藻酸盐印模材料在调和开始130 s后固化完成,聚醚印模材料在调和后180 s后固化完成。温度对2种印模材料调和后的操作时间和硬化时间均有影响,对聚醚印模材料的影响更大,临床应用要注意温度的变化。     

Retention of alginate impression material using a polyester fiber-mat textile

To ensure accuracy, alginate, impression materials must be firmly retained in the impression tray. This short report compares the effectiveness of perforated trays with a newly developed self-adhesive polyester fibre mat material which can be used to line the inner surface of stock and custom made impression trays. In all cases, the fibre mat was much more effective as a retention medium when compared with perforations. Also, small perforations proved more effective than larger ones for alginate retention.     

釉质-树脂-金属粘结系统粘结强度对比研究

目的　比较粘结剂的粘结强度以指导临床粘结桥修复治疗。方法　用三种粘结剂将 48颗离体牙与镍 -铬合金粘结 ,生理盐水中储存 72小时后测量抗拉及抗剪切粘结强度。结果　All-Bond 2的抗拉强度明显高于SuperbondC&B ,剪切向强度无明显差别。DM正畸釉质粘结剂的抗剪切强度最高 ,抗拉强度明显高于SuperbondC&B ,与All-Bond 2无明显差别。 结论　All-Bond 2的综合粘结效果好于SuperbondC&B ;DM釉质粘结剂粘结效果较好 ,建议临床使用     

调拌方法对藻酸盐印模材料操作时间固化时间的影响

藻酸盐普通型印模材料用手工、调拌器和搅拌机(8 s)调和的操作时间分别为71、66、53 s;快凝型印模材料用手工、调拌器调和的操作时间分别为56 s和51s.普通型印模材料用手工、调拌器和搅拌机(8 s)调和的固化时间分别为163、160和124 s;快凝型印模材料用手工、调拌器调和的固化时间分别为131 s和121 s.普通型印模材料较适用于手工30 s、调拌器20s和搅拌机8 s调拌;快凝型印模材料较适用于手工30 s和调拌器20 s调拌.     

藻酸盐印模的不同保存状态对尺寸稳定性的影响

目的探讨藻酸盐印模在非密封或密封状态下放置不同时间对尺寸稳定性的影响。方法实验分为藻酸盐印模非密封10min组4、0min组和80min组,藻酸盐印模密封10min组、40min组和80min组,另设1组空白对照。分别用普通石膏、硬石膏和超硬石膏制取模型,电子数显卡尺测量标准实物及石膏模型尺寸,进行ANOVA比较(α=0.05)。结果在藻酸盐印模非密封10min、40min和80min三组中,普通石膏、硬石膏和超硬石膏所灌注的模型尺寸表现为逐渐增加的趋势;在藻酸盐印模密封10min4、0min和80min三组中,三种石膏模型尺寸变化表现为先减小后增大的趋势。各组间存在显著性差异(P<0.05)。结论随放置时间的延长,藻酸盐印模在非密封和密封不同状态下,可发生不同的印模尺寸变化。     

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.     

水温变化对藻酸盐印模材料精度及凝固时间的影响

目的 探究水温变化对藻酸盐印模材料流动性、工作时间、凝固时间和形变量的影响。方法分别将液剂控制在4种不同水温（8℃、14℃、23℃和32℃）下用全自动印模调拌机调拌藻酸盐粉体,通过比较4组藻酸盐印模材料在玻璃板上的流动性,观测测量工作时间、凝固时间;利用模具套件制取印模,再观察印模形变量。采用SPSS 24.0软件包对数据进行统计学分析,比较各组之间的差异。结果 4种不同温度液剂调制的藻酸盐印模材料的流动性从大到小依次为8℃组>14℃组>23℃组>32℃组,且不同组别间差异具有统计学意义（P<0.05）。工作时间及凝固时间从短到长依次为32℃组<23℃组<14℃组<8℃组,各组间差异具有统计学意义（P<0.05）,32℃组的工作时间（29.3±1.0）s和凝固时间（41.0±1.4）s以及8℃组的凝固时间（133.2±3.8）s均不符合临床使用要求。各组形变量之间存在差异,但不具有统计学意义（P>0.05）。结论在一定范围内,水温变化和藻酸盐印模材料的流动性、工作时间及凝固时间呈负相关,临床使用时以14℃～25℃的水温较合适。     

Accuracy and dimensional stability of extended-pour and conventional alginate impression materials

BackgroundThe authors conducted a study to determine if two irreversible hydrocolloid impression materials (Cavex ColorChange, Cavex Holland BV, Haarlem, Netherlands; Jeltrate Plus Antimicrobial Dustless Alginate Impression Material, Dentsply Caulk, Milford, Del.) stored for five days were dimensionally accurate.MethodsThe authors modified Ivorine teeth (Columbia Dentoform, Long Island City, N.Y.) on a Dentoform model (1560 series model, Columbia Dentoform) to allow measurements of tooth and arch width. They made impressions and generated casts immediately and at five additional times. They recorded tooth and arch widths on the casts and compared the measurements with those for the standard model.ResultsCompared with measurements for the model, the greatest measured difference in casts was 0.003 inches for Cavex ColorChange (extended-pour alginate) and 0.005 inches for Jeltrate Plus Antimicrobial Dustless Alginate Impression Material (conventional alginate). The percentage of dimensional change ranged from ?0.496 to 0.161 percent for the extended-pour alginate and from ?0.174 to 0.912 percent for the conventional alginate.ConclusionsResults of analysis of variance and paired t tests indicated that when generated immediately and at day 5, casts produced from both impression materials were not statistically different from the standard model (P < .05).Clinical ImplicationsWhen stored properly, both alginate materials can produce accurate impressions at day 5 for diagnostic casts and for fabrication of acrylic appliances.