Insertion Force of Tray Impression Materials

Objective: The purpose of this study was to compare the insertion force of an experimental polyether tray material and six commercially available VPS tray materials. All materials were dispensed using the hand-held dispenser made by Mixpac Systems, AG.

Methods: Seven regular set impression materials were investigated: Impregum Soft Tray Material (IP, LOT B304552, C304560), 3M ESPE, Aquasil Ultra Monophase (AqUM, LOT 010815), Aquasil Ultra Heavy (AqUHB, LOT 070822), both Dentsply, Affinis MonoBody (AffM, LOT 0138005), Affinis Heavy Body (AffHB, LOT 0132677), both Coltene, Examix NDS Monophase (ExM, LOT 0708281), Examix NDS Heavy Body (ExHB, LOT 0705111), both GC. The test was performed (in accordance to CED/NOF/IADR 2004 #140) using a universal testing machine (Z010, Zwick). Equal quantities of each material were placed between specially formed stamps which were moved together under a controlled velocity of 500 mm/min until reaching a defined gap of 2 mm. The force during the movement was recorded (n=5). One-way ANOVA and a Tuckey test for pair wise comparisons was used for analysis (p<0.05).

Results:

Impression Material*	Insertion force [N] (SD)
IPa	1104.40 (41.22)
AqUMa	1084.45 (37.01)
AqUHBa	1126.34 (16.97)
AffMb,c	1523.99 (135.09)
AffHBb	1679.19 (149.79)
ExMa,d	1244.64 (43.77)
ExHBc,d	1355.26 (59.72)

* Materials identified with same letters (^a,b,c,d) are not significantly different.

The measured force values were between 1084 N (AqUM) and 1679 N (AffHB).

Conclusions: There are differences in the insertion force among the materials tested. Within the limitations of this study, the new polyether IP demonstrated an insertion force comparable to commercially available VPS tray materials. The data supports the suitability of IP for the monophase and 1-step tray/wash techniques.