几种常用印模材制取固定义齿模型伯三维精度比较

目的：评价硅橡胶类、琼脂类、藻酸盐类（水粉剂与糊剂）等4各临床常用印模材料的取模精度。方法：分别用4种模型材料制取10个同一金属实验模具的石膏模型,用测量显微镜测量金属模型和石膏模型上各标志点的距离,精度为0．001mm,所得数据进行统计分析。结果：藻酸盐糊剂印模材料制取的石膏模型在长径方向上与其他组有显著差异,且超出了临床允许的精度范围;硅橡胶印模材料制取的石膏模型线性变化率最小且比金属模型略大;琼脂印模材料与藻酸盐印模材料（水粉剂）制取的印模在三维尺寸变化率方面无显著差异。结论：藻酸盐糊剂印模材料取模精度差;硅橡胶印模材料的取模精度最高,且可以起到补偿义齿后续操作中的收缩及提供冠桥粘结剂间隙的作用;琼脂印模材料具有印模精度高,操作比较简单,且价格易于接受等优点,值得在临床应用中进一步普及和推广。     

戊二醛消毒液对4种高分子印模尺寸变化的影响

目的:比较Impregum聚醚橡胶印模、Express硅橡胶印模和Silagum硅橡胶印模以及GC EXAFINE硅橡胶印模用20ml/L碱性戊二醛处理不同时间后对模型精度的影响。方法:用这4种印模材料各制取15个同一金属实验模具的石膏模型,每种模型材料分为3组:一组用清水冲洗作对照组,其余2组用20ml/L碱性戊二醛浸泡20、40min后用超硬石膏灌模,静置24h后用测量显微镜测量金属模型和石膏模型上各标志点的距离,精度为0.001mm,所得数据进行统计分析。结果:Express硅橡胶印模材料制取的石膏模型线性变化率在浸泡20min时均为正值且比主模型稍大。4种印模材料印模在浸泡40min后灌注的石膏模型和金属模型相比有显著性差异。结论:在这4种印模材料中,浸泡20min时,Express硅橡胶印模材料的印模精度最高。     

三种模型材料在不同印模材料中尺寸变化的实验研究

目的：本实验旨在观察印模材料对工作模型精度的影响以及模型材料与印模材料间的配伍性。方法将普通石膏、硬石膏、超硬石膏３种模型材料分别灌入金属印模,硅橡胶印模,藻酸盐印模和旨印模中,用激光热膨胀仪（日本产１０００型）测量各组试件的凝固时的尺寸变化,将所得数据换算成尺寸变化率并进行统计分析。结果①普通石 在金属印模中呈现为收缩,而在硅橡胶,藻酸盐及琼脂印模中为高度膨胀,其在各种印模材料中的凝固尺寸变化率有显著性差异。②硬石膏在四种印模材料中的凝固尺寸变化率为均小于０．１５％,尤以在金属及藻酸盐印模中尺寸变化较小,性能较稳定。③超硬膏在金属印模中呈现为膨胀,在硅橡胶及藻酸盐印模中尺寸变化稳定,均不超过０．１０％。而在琼脂中表面为明显的收缩。结论各种模型材料同一种印模中的尺寸变化率不同,同一种模型材料在不同的印模中尺寸变     

口腔印模消毒处理对模型精度的影响

目的:比较藻酸钾印模、琼脂藻酸钾联合印模和Express Putty硅橡胶印模分别用2％戊二醛、1％84消毒液不同方式、不同时间处理后对模型精度的影响。方法:用20mm×20mm×40mm标准试件制取藻酸钾、琼脂和硅橡胶印模。每种材料取45个,分9组,每组5个;一组用清水冲洗作对照组,其余各组分别用2％戊二醛、1％84消毒液喷涂后静止10min或浸泡10min、20min、30min后用超硬石膏灌模,静止2h后用螺旋测位仪测量模型。实验结果用SPSS 11.0统计软件包进行统计分析。结果:清水冲洗立即灌模与喷涂消毒处理相比,无显著性差异(P>0.05,);藻酸钾和琼脂印模材料浸泡前与浸泡后各时段相比,均有显著差异,且随着时间的增加,产生统计学显著意义的尺寸变化(P<0.01):Express Putty硅橡胶印模材料浸泡前与浸泡后各时段无显著性差异(P>0.05);2％戊二醛浸泡消毒对各种印模材料精度的影响与1％84消毒液相比,无显著性差异(P>0.05)。结论:2％戊二醛、1％84消毒液浸泡消毒藻酸钾印模、琼脂藻酸钾联合印模和Express Putty硅橡胶印模,在20min内不影响修复体制作的精度,可试用于临床。     

玉洁新消毒液调拌藻酸盐印模材临床效果评价

目的:应用玉洁新消毒液调和藻酸盐印模材料拓取牙颌模型后,评价印模表面细菌含量及模型尺寸精度的变化。方法:取印模前用无菌棉拭子在志愿者前牙舌侧窝采样,而后用玉洁新消毒液漱口,3min后应用玉洁新消毒液调和藻酸盐印模材料取模,于印模所对应的前牙舌侧窝处取样,4h内送检,接种于营养琼脂平皿,37℃培养48h,进行细菌定性分析。再以同一金属模型为母模,应用玉洁新消毒液调和藻酸盐印模材料制取10个印模,以超硬石膏灌模,比较石膏模型与母模之间指标线段长度差异。结果:(1)消毒前有细菌存在,消毒后印模细菌阴性培养率为100%。(2)经测量灌制的石膏模型与母模之间指标线段长度形变率为0.15%-0.18%。结论:结果显示从统计学和临床的观测,应用玉洁新消毒剂自体消毒印模所合成的石膏模型并不引起显著的尺寸改变。     

调合消毒法对藻酸盐印模精度的影响

目的：研究藻酸盐印模材料与消毒液直接调合对印模精度的影响。方法：用0．25％NaClO、0．525％NaClO、0.5％84、1％84消毒液调合藻酸钾印模材作实验样本,以蒸馏水调合相同材料制取印模做对照,分别制取试件印模,用超硬石膏灌模,60min后脱模,石膏模型静置2h后测微显微镜下测量石膏模型,进行统计学分析。结果：实验组模型与对照组模型精度没有显著性变化,4组实验组模型间比较,其精度亦无显著性差异。结论：0．25％NaClO、0．525％NaClO、0．5％84、1％84消毒液调合藻酸盐印模材料消毒,在60min内不影响模型精度,可作为口腔印模的临床消毒方法。     

简易正畸托槽间接粘结技术的临床应用

1材料与方法 1．1制取标准石膏模型 用藻酸盐印模材料取上下颌的准确印模，灌制硬石膏或者超硬石膏，修整石膏模型表面的气泡和悬突。     

自制个别取模器颈缘取模技术精确度的研究

目的：对比个别取模器龈下取模技术与常用藻酸盐及硅橡胶取模方法的颈缘精度的差异。方法：在患口中用3种方法制取印模,灌模后分别在体视显微镜下测量代型标志点到龈沟底的距离。结果：个别取模器法的标志点到龈沟底的距离大于常用藻酸盐法,与硅橡胶法相比,其颊侧点到龈沟底的距离较大,但在近、远中标志点无差异。结论：使用个别取模器的取模效果优于常用藻酸盐方法,与硅橡胶取模技术相类似。     

加聚型硅橡胶一次法、两次法印模三维精度研究

目的评价加聚型硅橡胶一次法、两次法印模的精确性。方法使用轻、重体成分的加聚型硅橡胶采用一次法和两次法分别制取同一实验主模具的人造石模型,用高精度数显游标卡尺测量主模型及人造石模型上各标志点的距离,对测量数据进行统计学分析。结果在横径、纵径上,一次法较二次法更为精确,其中二次法与原始模型数据虽具统计学差异,但变化率微小,两种方法垂直径变化率均较大,但仍在美国齿科协会(ADA)标准允许值内。结论加聚型硅橡胶弹性印模材料使用一次法、二次法印模技术均具理想的印模精度。     

采用体积轮廓扫描仪直接测量口腔印模材料的尺寸变化率

目的:测量4种临床常用EP模材的三维形变率。方法:制作母模及个别托盘,使用2种藻酸盐和2种橡胶EP模材在母模上分别制取EP模材试件(n=3),用三维轮廓测量扫描仪进行扫描及建模,通过计算机测量模型3个轴向上标记线段长度的变化。结果:在印模120 min后,Zhermark藻酸盐在3个轴向上的变化率分别为3.615%、3.037%、2.836%;CAVEX藻酸盐的变化率分别为2.836%、3.358%、4.276%;在印模8 h后,Impregum Penta聚醚橡胶在3个轴向上的变化率分别为0.039%、0.071%、0.057%;Express XT Penta H加成硅橡胶的变化率分别为0.033%、0.088%、0.084%。结论:4种材料线性尺寸变化率均达到ISO1563∶1990标准,藻酸盐类EP模材在3个轴向上的形变率均明显大于橡胶类EP模材。     

不同印模材料对石膏模型表面性能影响的实验研究

目的 观察不同印模材料对石膏模型表面性能的影响以及印模材料与模型材料间理想的配伍关系。方法 用弹性打样膏液I和水粉型印模材料Ⅱ分别采印及灌注普通石膏、人造石和超硬石膏模型，然后拍摄各模型表面状态的照片，并分别测定其表面硬度。结果 不同印模材料采印及灌注的普通石膏模型，人造石和超硬石膏模型，其表面光滑度及硬度均有有差异。用两种印模材料分别采印及灌注的模型，除普通石膏模型外，人造石和超硬石膏模型其表面硬度相比较，差异有显著性（P＜0．05）。结论 不同的印模材料采印及灌注的石膏模型，其表面光滑度及硬度均有不同。提示模型的表面性能同印模材料与石膏的配伍有密切关系。     

The effect of a range of disinfectants on the dimensional accuracy of some impression materials

In this study the dimensional accuracy of two model materials; dental stone and plaster of Paris, reproduced from three commonly used impression materials; alginate, polyether and addition-cured silicone, retained by their adhesives in acrylic resin trays and exposed to four disinfectant solutions was evaluated. Ninety casts were used to investigate the effect of the four disinfectants on the dimensional accuracy of alginate, polyether and addition-cured silicone impression material. For each impression material 30 impressions were taken, half were poured in dental stone and half in plaster of Paris. The disinfectants used were Dimenol, Perform-ID, MD-520, and Haz-tabs. Measurements were carried out using a High Precision Reflex Microscope. For the alginate impressions only those disinfected by 5-minute immersion in Haz-tabs solution and in full-strength MD 520 were not adversely affected by the disinfection treatment. All polyether impressions subjected to immersion disinfection exhibited a clinically acceptable expansion. Disinfected addition-cured silicone impressions produced very accurate stone casts. Those disinfected by spraying with fill-strength Dimenol produced casts that were very similar to those left as controls, but those treated by immersion disinfection exhibited negligible and clinically acceptable expansion. The results of the studied demonstrated that the various disinfection treatments had different effects on the impression materials. It is important that an appropriate disinfectant is used for each type of impression material.     

印模消毒后石膏模型的尺寸变化研究

目的 研究不同方式印模消毒后石膏模型的尺寸变化。 方法 对一标准模型制取藻酸盐印模54个,分别采用冲洗（对照组）、1〖JP20〗∶〖JP〗100含氯消毒液或2%戊二醛消毒液消毒后,用普通石膏、硬石膏和超硬石膏灌模,共灌注模型54个。对石膏模型特定位置的尺寸进行测量,并与标准模型对应尺寸进行比较,数据行双因素方差检验和Tukey HSD分析。 结果 经过消毒处理后,无论使用何种石膏材料灌模,尺寸均较标准模型减小;普通石膏组尺寸大小与标准模型更为接近。同一种消毒处理方式下,戊二醛组中的超硬石膏尺寸（17.80±0.13） mm大于硬石膏（17.79±0.26） mm,对照组及含氯消毒液组尺寸均为普通石膏>硬石膏>超硬石膏。统计分析显示,不同消毒处理方式对模型尺寸的影响不存在显著性差异（P=0.843）,不同石膏材料对模型尺寸的影响存在显著性差异（P=0.001）。此外,石膏模型最大尺寸变化为-0.71 mm。 结论 含氯消毒液和戊二醛消毒液处理印模对石膏模型的尺寸影响不大。     

Fit of implant-supported fixed prostheses fabricated on master casts made from a dental stone and a dental plaster

STATEMENT OF PROBLEM: The impression and cast on which an implant-supported fixed prosthesis is fabricated must accurately reproduce the intraoral relations. PURPOSE: The fit of fixed prostheses fabricated on master casts poured in a conventional die stone and in an ultra-low-expansion plaster was investigated in vitro. MATERIAL AND METHODS: An impression was made of patient replicas with inter-implant abutment distances of 50 and 35 mm. Ten master casts were poured in a conventional die stone (Velmix, Kerr) and 10 in an ultra-low-expansion plaster (Gnathostone, Zeus). A simulated plaster fixed prosthesis was fabricated on each master cast and then returned in a random order to the appropriate patient replica. The fixed prostheses were screwed into place on one abutment with a torque of 10 Ncm. Vertical discrepancies were measured at the other abutment by an operator blinded to the cast on which the fixed prosthesis was fabricated. A 2-way analysis of variance was performed for distance and materials, and significant differences were identified with regression analysis. RESULTS: For the 50-mm inter-abutment distance, die stone master casts produced a mean vertical discrepancy of 80 microm (SD 32.50 microm). Plaster master casts produced a mean vertical discrepancy of 42.8 microm (SD 12.17 microm). The means were significantly different (P=.01). For the 35-mm inter-abutment distance, the mean vertical discrepancy produced from the die stone and plaster master casts was 84.33 microm (SD 49.9 microm) and 0 microm (SD 0), respectively. The means were significantly different (P<.001). A significant difference was found between the mean vertical seating discrepancies of fixed prostheses produced from plaster casts with inter-abutment differences of 50 mm and plaster casts with inter-abutment distances of 35 mm (P=.003). No significant differences were found between mean vertical seating discrepancies for fixed prostheses fabricated on die stone casts. CONCLUSION: In this in vitro study, master casts poured in an ultra-low-expansion plaster limited to a maximum inter-abutment dimension of 35 mm were more accurate than casts with 50-mm inter-abutment spans or those poured in a conventional die stone.     

A clinical evaluation of materials used in registering interjaw relationships

Three recording media used to relate stone casts for 15 dentate patients were compared for accuracy. Interjaw relationships at the maximum intercuspation position and the retruded contact position were recorded using impression plaster, wax, and Duralay acrylic resin. A Lucia programming jig was used in the retruded contact position. The vertical distance and horizontal deviation between the casts were measured from reference points on the casts using each recording material. The average percentage differences between the recording materials were calculated. Hand articulation was the most accurate method of relating the casts at maximum intercuspation. The most accurate recording medium was impression plaster, followed by dental wax and Duralay resin at the maximum intercuspation and retruded contact positions.     

Comparison of impression materials for direct multi-implant impressions

STATEMENT OF PROBLEM: Given that meticulous implant prosthodontic procedures are recommended to obtain the best possible intraoral fit, impression materials that are suitable for use with a direct impression technique warrant further investigation. PURPOSE: This in vitro study compared the amount of torque required to rotate a square impression coping in an impression and evaluated the accuracy of solid implant casts fabricated from different impression materials. MATERIAL AND METHODS: Two direct transfer implant impressions were made using 8 impression materials; the torque required to rotate an impression coping in the impressions was calculated. Ten direct transfer implant impressions were made from the master model and poured in a die stone (Resin Rock) for 3 of the 8 initial impression material groups. Linear distances between steel balls placed on each abutment replica were measured with a traveling microscope to determine distortion in the impression procedure for each group. Data were analyzed (P =.05) with ANOVA and Ryan-Einot-Gabriel-Welsch multiple range test for post hoc. RESULTS: With a 1-way ANOVA, average torque values among the material groups differed significantly (P =.001). Polyether (medium consistency) was found to produce the highest overall torque values, followed by addition silicone (high consistency), and then polysulfide (medium consistency). Statistically significant difference was also found among the 3 material groups' mean absolute cast error using a 1-way ANOVA (P =.0086). Implant casts made from polyether (medium) or addition silicone (high) impressions were significantly more accurate than casts made from polysulfide medium impressions. CONCLUSION: On the basis of the results of this study, the use of either polyether (medium) or addition silicone (high) impression is recommended for direct implant impressions.     

数字化口腔修复（10）--传统印模对游离龈位置影响的三维分析

目的：利用三维模型分析法比较不同印模材料印模对游离龈位置的变化量。方法：随机选取10位健康人的60颗上前牙为实验对象,实验前后分别行口内光学扫描（CEREC?AC Omnicam）,获取光学模型数据。用3种印模材料（藻酸盐、聚醚、加成型硅橡胶）取口内印模,分别灌制超硬石膏模型,并扫描石膏模型获取三维数据。将口内扫描的光学模型数据通过软件（Geomagic Qualify 2013）与石膏模型扫描的光学模型数据进行重叠,比较不同印模材料制取印模后游离龈位置变化量。结果：3种印模材料印模后的游离龈位置变化量的差异有统计学意义（P＜0．05）;藻酸盐印模与聚醚印模的游离龈位置的差异无统计学意义（P＞0．05）;而加成型硅橡胶印模与藻酸盐印模和聚醚印模的游离龈位置之间的差异均有统计学意义（P＜0．05）;加成型硅橡胶印模的游离龈位置的变化量最大（P＜0．05）。结论：印模过程所产生的压力会导致游离龈位置发生不同程度的改变,不同印模材导致游离龈位置的改变不一样;口内光学印模可以精确评价游离龈位置。     

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. .