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。     

不同排龈取模方式对固定修复临床效果研究

目的：比较不同排龈取模技术对固定修复模型质量效果的影响。方法：在对门诊金属烤瓷全冠修复患者107例144颗牙中，随机分为3组，分刖采用不同排龈取模技术，制取印模，完成修复体。对排龈止血效果、牙预备体肩台、模型清晰程度进行评价。结果：备牙前排龈组与备牙后排龈组的牙体预备有显著性差异，备牙前排龈组印模质量明显高于备牙后排龈组。结论：正确应用排龈技术可减少牙体预备对牙龈组织的损伤及出血，能帮助取得清晰的印模。     

老年人烤瓷冠修复三种肩台设计的牙龈指数评价

目的：对比3种不同龈缘肩台设计的烤瓷熔附金属全冠对老年患者基牙牙龈指数的影响.方法：收集115例（156颗牙）牙体缺损的老年患者,随机分为3组,分别采用龈上肩台、龈边缘肩台、龈下肩台行烤瓷冠修复.测定修复前及修复后1年基牙牙龈指数变化.结果：3组基牙牙龈指数均有明显上升,与修复前相比差异有显著性.3组基牙牙龈指数上升程度相互之间无明显差异.结论：3种类型肩台烤瓷冠修复,对老年人基牙牙龈健康均有不良影响,其程度与设计类型无明显相关性.     

老年人后牙烤瓷修复高位肩台应用体会

目的：探讨老年人后牙烤瓷修复高位肩台应用的适应症及临床疗效。方法：选择50例60-65岁老年后牙缺失患者,设计高位龈上肩台,复查半年至3年并长期随访,在牙周情况方面与传统齐龈和龈下肩台设计进行比较。结果：1例患者基牙松动拔除,3例冠松动重新粘固,其它患者均对修复体表示满意;除基牙松动拔除患者,其他患者烤瓷冠边缘密合度好,无菌斑牙石附着,牙周探诊基牙无新的附着丧失;X线片显示基牙牙槽嵴顶高度无改变。结论：老年患者进行后牙失牙固定修复设计中应当考虑到患者远期牙周健康,设计高位龈上肩台。     

排龈术的研究进展

固定义齿修复中良好的排龈不仅能够获得基牙颈部龈下肩台清晰准确的印模，而且能够保护龈沟底上皮附着，在一定程度上确保牙周的生物学宽度不受侵犯。本文就国内外排龈术的研究进展作一综述。     

口腔修复学：冠桥

沟槽式精密附着体在倾斜基牙固定修复中的应用;套筒冠义齿修复重度牙周病患者牙列缺损的临床研究;IPS Empress 2全瓷冠前牙美容修复的临床应用;20060721前牙根管闭锁残冠的修复;自制个别取模器颈缘取模技术精确度的研究     

双线排龈技术在固定修复中的应用

目的：通过双线排龈获取精细印模，减轻牙龈损伤，保护牙周组织健康，提高固定修复体的质量。方法：62例冠桥修复病例168个牙随机分成两组，31例按常规单线排龈，另31例牙体预备时，取模前使用双线压排龈法排龈。结果：97．7％双线排龈的印模非常清晰，边缘线均匀连续，模型肩台与游离龈之间出现肉眼可见间隙。修复体戴入后边缘适合性及美观效果均较单线组好。观察6—10个月后软组织健康状况良好。结论：应用双线排龈法，可取得清晰的印模，减少牙龈出血，可提高修复体质量。     

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目的    探讨烤瓷全冠邻面肩台位置设计对基牙邻面继发龋患发生率的影响。方法    对2005年1月至2008年12月在贵港市妇幼保健院口腔科完成烤瓷全冠修复后3年的219例患者临床资料进行整理分析,根据肩台位置分为龈上肩台组、平齐龈缘组、龈下肩台组,每组73例。通过X线对3组患者进行检查,观察修复体邻面单面患龋（只有近中或远中1面继发龋患）例数、双面患龋（近远中面均继发龋患）例数。结果    龈下肩台组、龈上肩台组、平齐龈缘组继发龋患发生率分别为24.66%（18／73）、6.85%（5／73）、5.48%（4／73）,龈下肩台组继发龋患发生率与龈上肩台组、平齐龈缘组比较,差异具有统计学意义（P < 0.05）。结论    平齐龈缘肩台设计能最大程度地减轻基牙继发龋患发生。     

不同取模法和基托材料对牙槽嵴低平无牙颌义齿修复的影响

目的 观察不同取模法和基托材料对牙槽嵴低平无牙颌患者修复效果的影响。方法 选择全口牙列缺失、牙槽嵴高度不足5mm患者48例，用二次取模法，塑胶基托和铸造不锈钢基托修复，半年后观察修复效果。结果 上下颌塑胶基托修复21例，满意16例，满意率76．2％；上颌塑胶基托，下颌铸造基托修复16例，满意10例，满意率62．5％；上下颌铸造基托修复11例，满意3例，满意率27．3％。结论 牙槽嵴低平的无牙颌患者采用塑料基托较铸造基托固位效果好，咀嚼效率高；用自凝塑胶制作个别托盘比修改初印模制作的个别托盘取模修复效果好。     

排龈膏在老年人口腔固定修复中的应用

目的：评价糊剂型排龈材料在老年人固定修复中的临床使用效果。方法：在对60例门诊患者140颗牙进行固定修复时，采用Expasyl排龈膏于取模过程压排牙龈。对排龈止血效果、印模清晰程度、修复体就位后与牙体的适合性进行评价。结果：采用排龈糊剂压排牙龈的患牙，在排龈止血效果、印模清晰程度及修复体与牙体的吻合程度方面，取得良好效果。结论：应用糊剂型排龈材料进行老年人固定修复临床排龈操作，高效省时、减少椅旁操作时间、提高修复体质量，是一种较好的方法。     

Copper-band gingival retraction to produce void-free crown and bridge impressions

A technique for retracting the gingiva by using Thiokol rubber-base or silicone impression material in copper bands has been described. The advantages of the technique include the following: (1) The gingival tissue retraction is maximal and superior to indirect retraction methods; (2) the margins may be established at the maximum subgingival depth; (3) the band impression made under pressure will have no air bubbles or voids; (4) the wax-lined tray has close border adaptation and ensures a bubble- and void-free impression of the adjacent oral structures; (5) the technique can be used for either sectional or complete-arch impression, inlays, three-quarter crowns, or full-coverage crowns; (6) only the tray type of impression material is required; and (7) it is not necessary to pour the cast as soon as the impression is made.     

Direct pressure provisionalization technique: a new open-tray technique for complete-arch rehabilitations.

An innovative direct technique that improves the accuracy of provisional acrylic resin restorations is introduced. A custom impression tray is modified to facilitate complete occlusal closure. This open tray is used to make an accurate overimpression prior to beginning tooth preparation procedures. Following tooth preparation, the acrylic resin-filled overimpression is returned to its intraoral position, and the patient occludes into the previously indexed impression material. The pressure overimpression technique is offered as an expedient technique for improving the accuracy of provisional restorations.     

Accuracy of casts generated from dual-arch impressions

STATEMENT OF PROBLEM: Dual-arch trays are often used to make simultaneous impressions of a prepared tooth and the opposing teeth. Many dentists are concerned with the accuracy of the casts generated from this type of impression. PURPOSE: The purpose of this investigation was to compare the accuracy of stone casts of a prepared tooth generated using 2 types of dual-arch impression tray/impression material combinations. MATERIAL AND METHODS: The maxillary left first molar on a dentoform mounted on an articulator was prepared for a full-coverage gold crown. Ten impressions were made with either a plastic (P) or metal (M) tray and a polyether (PE) or vinyl polysiloxane (VPS) impression material. Each impression was cast in improved dental stone, and the buccolingual dimension of the die was measured at the midpoint of the buccal and lingual gingival margins. The prepared tooth (T) served as the control. The data were analyzed using a 2-factor analysis of variance (ANOVA) alpha=.05. RESULTS: The P/VPS combination (10.673 mm) produced the largest die, followed by P/PE (10.602), T (10.508), M/PE (10.484), and M/VPS (10.472). The 2-factor ANOVA showed a significant difference between the tray types but not between the impression materials. CONCLUSION: The metal trays produced dies smaller than the tooth, and the plastic trays produced dies that were larger.     

2种托盘制取松动基牙模型的精度比较

目的：评价成品托盘和个别托盘使用海藻酸盐印模材料对松动牙取模时模型的精度的影响。方法：用成品托盘和个别托盘对同一松动牙模型取模,各制得20个超硬人造石模型。使用电子游标卡尺测量取得的人造石模型上标各记点间距离,测量精度为0.001mm,将测得数据进行统计分析。结果：采用2种托盘对松动牙取模精度无显著性差异,2种托盘对于松动牙取模精度均已超出临床所允许范围。结论：当使用海藻酸盐作为印模材料时,成品托盘和按照常规方法制作的个别托盘不适于松动牙的取模,及对于松动牙,应尽可能避免使用海藻酸盐印模材料。     

排龈技术在固定修复中的联合应用

目的：研究固定修复中龈下牙体预备时，如何保护龈沟底上皮附着，采集准确印模，确保牙周的生物学宽度不受侵犯。方法：对86例患者242颗牙行冠桥修复时，干备牙术中排龈线排龈及龈挡保护周围组织，术后排龈膏排龈。结果：排龈及止血效果良好，肩台与龈沟处印模清晰程度均取得良好的结果。结论：排龈技术的合理应用，避免了牙体预备时对牙龈组织的损伤及出血，能迅速打开龈沟，并且牙龈收缩是完全可逆的过程。     

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.     

The laminar impression technique

The laminar impression technique is a precise, rapid, and predictable alternative to traditional methods of impression-making in fixed prosthodontics. A preliminary impression is made using plastic "triple-arch" type trays and high-stiffness vinyl polysiloxane jaw relation registration material. After tooth preparation, tissue management, and retraction this registration can be used for provisional fabrication. Two holes are then drilled through the facial wall of the tray into the region of the preparation. The tray is replaced in the mouth and light-bodied vinyl polysiloxane impression material is injected into the holes by using an "automixing" gun system.     

A three-die cast technique for duplicating free gingival form in zirconia crowns: two case reports

This report describes a duplication technique of free gingival form from a provisional restoration to a zirconia crown. Three die casts were manufactured from a silicone impression with an acrylic resin ring tray. The first die cast was for the zirconia framework, the second for the provisionalized transfer coping, and the third for relining the provisional restoration. A free gingival impression was taken using a provisionalized transfer coping, and a soft gingival cast was manufactured. The depth of free gingival transparency was measured using a zirconia shade plate. Then, the zirconia framework was customized to allow for subgingival porcelain space. This technique seems to contribute to the clinical-laboratory interface in computer-aided design/computer-assisted manufacture restorations.     

Impression pressures against teeth in a partially edentulous model with a mobile tooth: influence of impression tray design

The purpose of the present study was to examine the effect of custom tray designs on local pressures against teeth during the impression procedure. In a previous study, a partially edentulous simulation model with a mobile tooth was used, and the effect of custom tray designs on the displacement of the mobile tooth was examined during the impression procedure. Based on that study's results, we have assumed that the differences in impression pressures between the labial and the lingual sides of a mobile tooth could either cause or affect displacement. The present study was undertaken to determine the local impression pressures against each side of three anterior teeth, including one mobile tooth, using the same simulation model and the same custom trays as in the previous study. It was found that the local pressures exerted against teeth during the impression procedure were affected by the custom tray designs and varied according to the coronal shape, axis inclination and location of the teeth.