Open AccessComparative Evaluation of Dimensional Accuracy and Tensile Strength of a Type IV Gypsum Using Microwave and Air Drying Methods
Author(s) -
Anuraag Sharma,
Manoj Shetty,
Chethan Hegde,
Neeta Shetty,
D Krishna Prasad
Publication year - 2012
Publication title -
the journal of indian prosthodontic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.419
H-Index - 20
eISSN - 1998-4057
pISSN - 0972-4052
DOI - 10.1007/s13191-012-0183-0
Subject(s) - microwave oven , open air , ultimate tensile strength , materials science , gypsum , microwave , composite material , compressive strength , architectural engineering , physics , quantum mechanics , engineering
To evaluate dimensional accuracy and tensile strength of a type IV gypsum product, at different time intervals, dried in air or a microwave oven. Eighty specimens prepared from a cylindrical mould were used for measuring tensile strength (group A). Twenty specimens from a master die mould were used for determining dimensional accuracy (group B). In group A, 40 specimens were dried in open air at room temperature (A1). The other 40 were removed after 30 min and air dried for 20 min. These were subjected to microwave oven drying for 5 min (A2). Ten specimens each were tested under diametral compression at each of the following time periods: 1, 2, 4 and 24 h after drying. In group B, ten specimens were dried in open air at room temperature (B1). Ten specimens were removed from the mould after 30 min and air dried for 20 min. These were then dried in a microwave oven for 5 min (B2). The data was statistically analyzed using students unpaired "t" test. At all time intervals, diametral tensile strength (DTS) values for specimens dried in microwave oven were significantly higher than for those dried in open air. There were no significant differences between the dimensional accuracy of the two groups. In this study, microwave oven drying had a positive effect on the DTS of a type IV gypsum and the microwave oven dried specimens were as accurate as the air dried specimens over the same time period.