Bennani Vincent, Aarts John M, Schumayer Daniel
Senior Lecturer, Department of Oral Rehabilitation, Faculty of Dentistry, University of Otago, Dunedin, New Zealand.
Senior Teaching Fellow, Department of Oral Rehabilitation, Faculty of Dentistry, University of Otago, Dunedin, New Zealand.
J Prosthet Dent. 2016 Mar;115(3):296-300. doi: 10.1016/j.prosdent.2015.08.008. Epub 2015 Nov 6.
Although numerous gingival displacement materials are available, information is limited regarding the pressures that can atraumatically produce sufficient gingival displacement for a successful impression.
The purpose of this in vitro study was to measure pressure and the resulting movement of artificial gingiva during simulated gingival displacement.
An idealized tooth model was made from acrylic resin and polyvinyl siloxane to simulate the free gingiva, sulcus, and attachment. The pressure and displacement achieved by 3 materials (Expasyl, Expasyl New, and KnitTrax Cord) were measured. A stereoscopic digital measuring microscope was used to quantify the space generated by the displacement material. A pressure gauge was used to measure the corresponding pressures.
The injection of Expasyl resulted in a displacement distance of 1.31 mm, Expasyl New 1.07 mm, and KnitTrax Cord 0.85 mm, which are within acceptable clinical parameters. The correlation between pressure and gap showed that Expasyl and Expasyl New behaved similarly, while KnitTrax Cord was different. Expasyl, Expasyl New, and KnitTrax Cord all had maximum pressures that would be considered atraumatic to the epithelial attachment.
An increase in pressure resulted in an increase in displacement for the 2 paste materials. However, contrary to expectation, displacement decreased as pressure increased for the cord material.
尽管有多种牙龈退缩材料可供使用，但关于能在不造成创伤的情况下产生足够牙龈退缩以获得成功印模的压力的信息却很有限。
本体外研究的目的是测量模拟牙龈退缩过程中人工牙龈的压力及由此产生的移动。
用丙烯酸树脂和聚乙烯基硅氧烷制作理想化牙齿模型，以模拟游离龈、龈沟和附着情况。测量了三种材料（Expasyl、Expasyl New和KnitTrax Cord）产生的压力和退缩量。使用立体数字测量显微镜对退缩材料产生的间隙进行量化。用压力计测量相应压力。
注射Expasyl产生的退缩距离为1.31毫米，Expasyl New为1.07毫米，KnitTrax Cord为0.85毫米，均在可接受的临床参数范围内。压力与间隙之间的相关性表明，Expasyl和Expasyl New表现相似，而KnitTrax Cord则不同。Expasyl、Expasyl New和KnitTrax Cord的最大压力均被认为对上皮附着无创伤。
对于两种糊剂材料，压力增加导致退缩量增加。然而，与预期相反，对于绳状材料，随着压力增加退缩量减少。
