Компаративна анализа на димензионална стабилност и прецизност на силиконски отпечаточен материјал со користење на различни отпечаточни техники – in vitro студија

Abstract

Introduction: A quality-made dental impression is a prerequisite for successful fixed-prosthodontic fabrication and is directly dependent on the dimensional stability, accuracy and flexibility of the elastomeric impression materials, as well as on the appropriately used impression techniques. Silicone impression materials are most widely used in dentistry for the reproduction of oral cavity structures due to their high accuracy and dimensional stability. Aim: The purpose of this research is to determine the dimensional stability and accuracy of silicone-based impression material by using various impression techniques. Material and method: This research was carried out by using a precise stainless steel master model and 3 individual aluminium trays. The abutments of the master model were compared with the abutments of the stone cast made with: double-phase impression technique in 2 steps, double-phase impression technique in 1 step, double-phase impression technique in 2 steps with spacers of 1mm, 2mm and 3mm, double pouring of the same double-phase impression in 2 steps and a delayed pouring of double-phase impressions in 2 steps, performed over time intervals of 1h, 24h and 72h. The stone casts were scanned using 3D scanner and digitally measured with appropriate software. Then the acquired data were statistically analyzed. Results and discussion: After analyzing of the obtained results, they showed that dimensional stability and accuracy of silicone-based impressions is related to the material and the impression technique used. Also it is dependent of the putty material thickness, the bulk of light silicone and the impression shear stress. Conclusion: This study shows that dimensional stability and accuracy of addition silicone is superior to condensation silicon. The double-phase impression technique in 1 step is a better choice than double-phase impression technique in 2 steps. There is no difference in dimensional stability and accuracy using double pouring or delayed pouring of impressions.