Rathee Suprabha, Eswaran B, Eswaran Ma, Prabhu R, Geetha Kr, Krishna Gp
Senior Lecturer, Department of Prosthodontics, Thai Moogambigai Dental College & Hospital , Chennai, India .
Reader, Department of Prosthodontics, Thai Moogambigai Dental College & Hospital , Chennai, India .
J Clin Diagn Res. 2014 Jul;8(7):ZC38-41. doi: 10.7860/JCDR/2014/9139.4585. Epub 2014 Jul 20.
Dimensional accuracy of impression materials is crucial for the production of working casts in Fixed Prosthodontics. The accurate replication of tooth preparations and their arch position requires impression materials that exhibit limited distortion.
This study was conducted to comparatively evaluate the dimensional accuracy of additional silicones by comparing two different techniques and spacer designs, by measuring the linear changes in interpreparation distance. The impressions were made from a stainless steel master die simulating a three unit bridge. A total 80 die stone (type IV, Ultrarock) models were obtained from the impressions made using two different parameters. The two different parameters are Multimix and Monophasic technique and different spacer designs.
The interpreparation distance of the abutments in the casts was measured using a travelling microscope. Each sample was measured thrice and the mean value was calculated. The results obtained were statistically analysed and the values fall within the clinically acceptable range.
The most accurate combination is multimix technique with spacer design which uses less bulk of impression material.
印模材料的尺寸精度对于固定修复术中工作模型的制作至关重要。准确复制牙齿预备体及其牙弓位置需要具有有限变形的印模材料。
本研究旨在通过比较两种不同技术和间隔物设计，测量预备体间距离的线性变化，来比较评估加成型硅橡胶的尺寸精度。印模由模拟三单位桥体的不锈钢主模型制取。使用两种不同参数制取的印模共获得80个石膏（IV型，超硬石膏）模型。这两种不同参数是多重混合和单相技术以及不同的间隔物设计。
使用移动显微镜测量模型中基牙的预备体间距离。每个样本测量三次并计算平均值。对所得结果进行统计学分析，数值落在临床可接受范围内。
最精确的组合是采用间隔物设计的多重混合技术，该技术使用的印模材料体积较小。
