Time Dependant Hydrophilicity of Quick Setting Monophase Impression Materials

Objectives: Hydrophilicity in the unset stage is an important parameter for elastomeric impression materials regarding detail accuracy of final impressions. Monophase impression materials are used as syringable and tray materials simultaneously. Depending on the dentistsx procedure it is possible that the tray material comes into contact with the teeth towards the end of the materialxs working time. Therefore hydrophilicity during the unset stage of a monophase impression material should remain as good as possible until the entire working time. The goal of this study was to compare the time dependant initial hydrophilicity of different monophase impression materials.

Methods: Drop Shape Analysis System DSA10 (Krüss GmbH, Hamburg) was used to determine the hydrophilicity by measuring the initial contact angles (Video analysis calculation, circle fitting method) of two Polyethers [IP (Impregum Soft Quick Step, 3M ESPE,  #343406), EM (Experimental Polyether, 3M ESPE, #B:ELA130509Q/C:MTD120309)] and four silicone based impression materials [AQ (Aquasil Ultra Monophase Fast Set, Dentsply, #070313), GE (Genie Magic Mix Rapid Set, Sultan, #041026133), T1 (Take 1 Advanced Monophase Fast Set, Kerr, #8-1093) and EX (Exa'lence Monophase Fast Set, GC, #0810071)] at room temperature.

Results: Mean values (N=5) of initial contact angles are shown (standard deviations in brackets). They were determined 15sec after beginning of mix (CA1), at the end of working time (CA2) and in the set stage 20min after start of mixing (CA3). Results were analyzed by one-way-ANOVA and Tukey test (p<0.05).

Means with the same letters are not significantly different within the same column.

Conclusion: Polyether impression materials showed significantly lower initial contact angles as silicone based impression materials over the complete time range.