Abstract
As part of a study of the disinfection of impressions in the dental treatment of elderly patients at home, the present study investigated the effect of long-term storage of alginate impressions in sealed bags on the dimensional accuracy and deformation of stone models in order to evaluate the possibility of storage of impressions following spray with disinfectant solutions.
Eleven brands of alginate impression materials were measured to determine the dimensional changes in 100% relative humidity for 4 hours. Among the brands showing little dimensional change, 3 brands were chosen as test materials to investigate the effect of storage of impressions in sealed bags on the dimensional accuracy and deformation of stone models. The periods for storage of impressions were 2,3, and 4 hours. The stone models obtained from non-stored impressions were also prepared as controls.
The results were summarized as follows:
1. All 11 brands of alginate impression materials showed a tendency to contract in 100% relative humidity over time. However, the amounts of dimensional changes of impressions in 100% relative humidity for 4 hours varied with each brand.
2. When an alginate impression material with a small dimensional change in 100% relative humidity for 4 hours was used for impression taking, the storage of the impression in a sealed bag for 4 hours had little effect on the dimensional accuracy and deformation of stone models.
