Stickiness of different VPS putty Impression Materials

Objectives: Stickiness of VPS impression materials, especially of putties, impacts handling when loading into an impression tray. The aim of this study was to evaluate stickiness of 5 different VPS impression materials with a newly developed testing method. Methods: To evaluate stickiness of the impression materials a water-filled test tube (Schott Duran) mantled with a glove finger (total weight 100 g) was fitted to a universal testing machine (Zwick 1435-MOPS) where it was then placed in contact with the surface of freshly mixed (1 min) impression material. After 15 sec contact time between glove and impression material, the relative stickiness was measured by determination of the tensile force in a pull-off test at a traverse speed of 35 mm/min. Measurements were repeated seven times for each impression material. The following VPS impression materials were compared: Flexitime Easy Putty (F) (Heraeus Kulzer), experimental automix putty (AP) (Heraeus Kulzer), Express 2 Penta Putty (E) (3M ESPE), Affinis Putty Soft (A) (Coltene) and Panasil binetics Putty fast (P) (Kettenbach). Results: The tensile force values determined (in N) were: F 0,52^a, AP 0,56^a, P 0,88^b, A 1,07^c and E 1,59^d. Letters denote statistical difference recorded with ANOVA and Duncan (p= 0,95%). F and AP showed significantly less stickiness than the other impression materials. Conclusions: The new test method presented is a simple, fast and practical approach for assessing the stickiness of impression materials. It may, for example, help to develop less sticky materials to make loading impression trays more convenient for the dentist.