THE INFLUENCE OF WATTAGE AND CURING TIME OF MICROWAVE ENERGY ON PHYSICAL PROPERTIES OF THE DENTURE BASE RESIN.
- Author:
Dae Sung JEONG
;
Jang Seop LIM
;
Chang Mo JEONG
;
Young Chan JEON
- Publication Type:Original Article
- MeSH:
Denture Bases*;
Dentures*;
Hardness;
Hardness Tests;
Microwaves*;
Polymethyl Methacrylate;
Porosity;
Water
- From:The Journal of Korean Academy of Prosthodontics
1999;37(6):767-775
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
The purpose of this study was to evaluate the effect of wattage and curing time on surface hardness, three-point bending strength and internal porosity of microwave curing denture base resin. Two sizes of resin spicimens were made of Acron MC ; 3.5x10x60mm for surface hardness and three-point bending strength measurement and 5x12x60mm for internal porosity measurement. They were cured by microwave energy at varing wattages(500W, 700W) and curing times(2min., 3min., 4min.) to determine if a certain wattage/curing time combination would improve physical properties. Surface hardness was measured with Vikers hardness tester, three-point bend-ing strength with universal testing machine and internal porosity was calculated by measuring the weight in air and in water. The results obtained were as follows : 1. There was no significant difference in percent porosity among experimental groups(p>0.05). 2. 500W/3min, group showed the higher surface hardness than 700W/2, 3, 4min. groups(p<0.05), and 700W/4 min. group showed the lower surface hardness than 500W/2, 3, 4min. groups(p<0.05), but there was no significant difference among others(p>0.05). 3. 500W/3min. group yielded the higher value of bending strength than 500W/2min., 700W/3, 4min. groups(p<0.05), but there was no significant difference among others(p>0.05).
