ABSTRACT
This study investigated the effects of disinfecting alginate impressions on the scratch depth of resultant stone models. Eleven brands of alginate impression material and two disinfectants, 1% sodium hypochlorite and 2% glutaraldehyde, were used. Impressions were immersed in disinfectant solutions or stored in sealed bags after spraying with disinfectants, and then poured with a type V dental stone. The scratch depth of the stone model obtained from disinfected impression was measured. The storage of alginate impressions after spraying with disinfectants did not increase the scratch depth of resultant stone models. However, the effect of immersion in disinfectants on scratch depth varied with the brand of the alginate impression material.
Subject(s)
Alginates/chemistry , Dental Impression Materials/chemistry , Disinfectants/adverse effects , Models, Dental , Glucuronic Acid/chemistry , Hardness , Hardness Tests/methods , Hexuronic Acids/chemistryABSTRACT
This study investigated the effect of storage period on dimensional change and deformation of stone models to determine an acceptable period of alginate impression storage in a sealed bag after spraying with disinfectant solution. Two alginate impression products: Aroma Fine DFIII and Alginoplast EM, characterized by greater or smaller contraction in 100% relative humidity, were used. The impressions were sprayed with 1% sodium hypochlorite or 2% glutaraldehyde solution and then stored in sealed bags. The storage periods were 1 hour, 2 hours, 3 hours, and 4 hours. The sectional profiles of the stone models obtained from each impression were measured using a three-dimensional coordinate measuring system. The results indicated that the impression characterized by greater contraction in 100% relative humidity should not be stored for even 1 hour, and that storage for up to 3 hours of the impression characterized by smaller contraction was clinically acceptable.
Subject(s)
Alginates , Dental Disinfectants , Dental Impression Materials , Models, Dental , Alginates/chemistry , Calcium Sulfate , Dental Impression Materials/chemistry , Dental Stress Analysis , Drug Storage , Glutaral , Humidity , Materials Testing , Sodium Hypochlorite , Statistics, NonparametricABSTRACT
In this study, wedge-shaped CP titanium castings and Ti-6Al-7Nb alloy castings were produced by three types of investment. The effects of the castings' thickness on surface reaction layer were investigated by measuring Vickers hardness, observing the microstructure, and analyzing the oxygen concentration. It was found that the thickness of the surface reaction layer was affected by the thickness of the wedge-shaped castings, and that the hardness value near the surface became lower toward the tip of the wedge-shaped CP titanium and Ti-6Al-7Nb alloy castings. The surface reaction layer of the Ti-6Al-7Nb alloy castings was thinner than that of the CP titanium castings.
