Assessing Tray Filling with Various Mixing Techniques and Impression Materials

Objectives: Preferences of twenty dentists', assistants', and 1st year dental students' between electronic and hand mixing for different impression materials were compared. Methods: The mixing and tray filling of Imprint™ 3 Penta™ Heavy Body (IHB) and Impregum™ Penta™ Soft (IPS) were compared using two electronic mixing machines: Pentamix™ 3 (3M ESPE) and Mixstar™-eMotion (Zenith/DMG). Imprint™ 3 Penta™ Putty (IPP) was mixed with Pentamix™ 3 and compared to hand mixed putty Express™ (PP). IPS was mixed with Pentamix™ 3 and compared to hand mixed Impregum™ F (IF). Participants rated their level of satisfaction for control of loading, ease of mixing, quality of mixing, level of cleanliness, duration of tray filling and overall rating. Paired t test, one-way ANOVA test, Tukey's method, and Holm's method were used for statistical analysis. Results: One-way ANOVA showed no significant difference between group comparisons regarding the preference of different electronic mixing machines for their overall ratings (P=1.0) mixing IHB and IPS. However, mixing HB and IPS with Pentamix™ 3 was significantly faster in the dentist and dental assistant groups (P<0.001) compared to Mixstar™-eMotion. Post-hoc pairwise comparison showed that dentists and assistants both had significantly shorter (P<0.001) mixing duration than students for IHB mixing with both electronic mixing machines. Although, the quality of mixing with Pentamix™ 3 was rated significantly higher (P<0.004) than that of Mixstar™-eMotion in the dental assistants group, it was not significantly different for both dentists and dental students. Assistants preferred electronic mixing of IPP with Pentamix™ 3 over the hand mixed PP significantly (P<0.001). Electronic mixing of IPS with Pentamix™ 3 was preferred over the hand mixed IF in all groups (P<0.001). Conclusions: Electronic mixing offers better ease of mixing, control of loading, quality of mixing, and level of cleanliness. Overall, dentists, dental assistants, and dental students preferred electronic mixing over hand mixing.