| Research Abstract |
For the purpose of establishment of the manual of the disinfection method for impressions without deterioration of accuracy in dental treatment of elderly patients at home, this study effect of immersion disinfection of alginate impressions on the dimensional accuracy and deformation of edentulous working casts in relation to the W/P ratio of alginate impression materials and the type of tray for alginate impressions.
Two types of alginate impression material : Aroma Fine DFIII (AFIII) and Jeltrate Plus (JLP), characterized by smaller or greater dimensional changes in water, were used. Impressions were immersed in 1% sodium hypochlorite solution for 10 min (1SH), 2% glutaraldehyde solution for 30 min (2GA), or they were not immersed in any disinfectant solutions as a control.
1. Effect of W/P ratio of alginate impression materials :
Impression materials were mixed at the following W/P ratio : manufacturers' instructions (std), std-0.2, and std+0.4. The W/P ratio had no effect on the dimensional accuracy and deformation of resultant edentulous working casts when AFIII impression was disinfected by 1SH processing.
2. Effect of type of tray for alginate impressions :
Four types of experimental metal trays (perforated trays opened or closed mesio-distally, unperforated trays opened or closed mesio-distally) were prepared as impression trays. Whichever tray to use for AFIII impression, the effect on the dimensional accuracy and deformation of edentulous working casts was little in disinfection by 1SH processing.
In summary, in case of immersion disinfection of alginate impression, the choice of the impression material characterized smaller dimensional change in water and treating impression with immersion in 1% sodium hypochlorite solution for 10 minutes proved to be able to reduce the deterioration of reproducibility of stone models.
|
