Evaluation of the Impression Accuracy of Tokuyama AP System

Objectives: To evaluate the impression accuracy of the newly developed auto-mixed alginate impression system, "Tokuyama AP system".

Methods: An experimental paste type alginate impression material (Tokuyama AP-1 and AP-mixer III/Tokuyama Dental Corp.) and commercial powder type alginate impression material (A-1a/Tokuyama Dental Corp. ALFLEX/NISSIN Corp. AROMA FINE PLUS/GC Corp. ALGIASE Z/DENTSPLY SANKIN Corp.) were used for this study. The impression accuracy was tested by using model A and model B which can be piled up precisely (Fig.1).

Fig.1 The model for evaluation of impression accuracy

First, the impression of model B is taken and gypsum model is produced. Then, model A and gypsum model is piled up, and a crevice of point A to point F are measured by micro scope. The average of crevices was calculated as the impression accuracy.

Results: The means with standard deviations are listed below. The impression accuracy of AP system is higher than any other powder type impression material. Then, AP system has low standard deviations. On the other hand, powder type has high standard deviations, because it is susceptible to technique error by mixing.

(n=10)

Conclusions: Tokuyama AP system has high ability in impression accuracy and has low technique sensitivity by mixing.