Faculty of Dentistry, University of British Columbia, Vancouver, British Columbia, Canada
Research Article
Microhardness of Gypsum Submitted to Different Methods of Pouring and Storage
Author(s): Greciana Bruzi*, Larissa Fernanda Pottmaier and Luana Dutra de Carvalho
Statement of Problem: Whether using different methods of pouring and storage will affect to the surface hardness of gypsum Type IV casts.
Aim: To compare the surficial microhardness (Knoop) of gypsum Type IV submitted to different methods of pouring and storage.
Material and Method: Seventy-five specimens were made with gypsum Type IV (Herostone, Coltene) and distributed in 5 groups (n=15). A metal device was fabricated to simulate the tray and standardize the impression procedures. A Polyvinyl Siloxane (PVS. Express XT, 3M ESPE) was manipulated according to the manufacturer's instructions. After the setting time, the impression was removed and cleaned with water, dried, and disinfected with 2% glutaraldehyde. The experimental groups formed were: 1) Control/15–the die was removed from the impression material 15 min after pouring the cast; 2) 4 hour &ndash.. View More»
DOI:
10.35248/dentistry. 3.5.1-2
