Objective: The objective of this study was to compare 30 professors in prosthodontics, operative dentistry and biomaterials with regard to mixing impression materials. Variables investigated included the quality, quantity and duration of mixing, amount of wasted material, and preferences of professors.
Method: Evaluation was divided into 3 groups. The first group compared medium-body polyether impression material (Impregum Soft, 3MESPE) mixed by hand and with an electronic mixer (Pentamix3). The second group compared putty-viscosity c-silicone impression material (Speedex, Coltene) mixed by hand and a vinyl poly siloxane impression material (VPS) (Express XT PuttyPenta, 3MESPE) with an electronic mixer (Pentamix3). The third group compared light-body VPS (Express XT, 3MESPE) mixed with the auto-mix system (Garant) and a light-body condensation-silicone material (Speedex, Coltene) mixed by hand. The mixing process for each participant was timed and the amount of wasted material was measured. Participants completed a survey at the conclusion of the mixing exercises regarding preferences. Mean values were compared within participant groups with paired t test (a=.05).
Result: Overall preference for the electronic and auto-mixing techniques was statistically significantly higher when compared with hand-mixing (p=.001). The duration of mixing was statistically significantly lower when electronic mixing was used over hand-mixing (p=.001). There was no statistically significant difference in the amount of material used when comparing the electronic and the hand-mixing technique (p=.001). There was a large variability in wasted material with hand-mixing.
Conclusion: Under the limitations of this study, it was concluded that the electronic and the auto-mix techniques were preferred by most professors. Furthermore, the electronic and auto-mix techniques provided faster mixing with less variation in waste. (This study was supported by 3MESPE, Seefeld, Germany)
Keywords: Dental materials, Impression materials, Mixing techniques and Prosthodontics