Determination of an optimal magnification for examining voids in elastomeric impressions

Specimens of one polyether impression material and the resulting stone casts were examined at magnifications from 1X to 10X to determine the optimal magnification for identifying defects. Results showed that the number of defects on impressions and stone dies detected by two operators increased with each corresponding increase in magnification up to magnifications of 9X and 8X, respectively. The magnifications that revealed significantly less defects than the highest mean count were 6X for impression voids and 5X for stone die defects. A magnification of 9X optimized reliability by maximizing void detection while minimizing operator variability.