Flow Properties of Light Bodied Impression Materials During Working Time

Objective: The purpose of this study was to use the Shark-Fin test as a method for accurate measurement of the flow properties of light bodied impression materials under low pressure during the working time given by the manufacturer. Method: Seven light bodied precision impression materials, Impregum Soft Quick Step Light Body (3M ESPE, new fast setting materials, ImSQ), Impregum Garant Soft Light Body (3M ESPE, ImS), Aquasil Ultra LV Fast Set (Dentsply, AqULV), Aquasil Ultra XLV Fast Set (Dentsply, AqUXLV), Take 1 Fast Set Wash (Kerr, Tak1F), Honigum Automix Light Fast (DMG, HoAF), Exafast NDS Injection (GC, ExNDS), Affinis light body fast (Coltène, Aflf) were tested at room temperature. The materials were automatically mixed using the hand dispenser and directly placed in the receptacle. 25 seconds after start of mix (Test 1) and at the end of the working time given by the manufacturer (Test 2) respectively the entire housing including the Shark-Fin mold (weight: 147 g, gap lenght: 1,6 mm) was released and allowed to sink slowly into the paste. Ten minutes after start of mix the mold was separated and the height of the Shark-Fin was measured. Results: The average heights (n = 5) of the Shark-Fins were compared. Test 1/Test 2 (units in mm, SD in brackets): ImSQ: 23,8/18,5 (0,9/1,5), ImS: 22,1/20,0 (0,6/0,9), AqULV: 6,1/2,4 (0,4/0,4), AqUXLV: 16,5/7,6 (0,4/0,6), Tak1F: 13,0/0,7 (0,4/0,3), HoAF: 12,5/3,5 (0,5/1,2), ExNDS: 14,5/9,7 (0,5/1,2), Aflf: 12,3/3,4 (0,8/0,9). Results were analyzed by ONE-WAY ANOVA and Tukey Test (p<0,01). Materials ImSQ, ImS have significantly better flow properties after 25 seconds and at the end of the working time than materials AqULV, AqUXLV, Tak1F, HoAF, ExNDS, Aflf. Conclusion: The materials ImSQ, ImS showed superior flow properties supporting a high clinical reliability during the whole working time.