[Temporary restoration using light-cured resin].
In spite of various problems involved in chemically cured resin (self-curing resin), e.g., irritability, and heat and shrinkage at polymerization, it has traditionally been the material of choice in the production of temporary restorations. However, light-cured resin, which does not have the disadvantages of chemically cured resin, has recently been developed and applied to clinical treatment. The present study was conducted to examine the clinical application of light-cured resin to temporary crowns. Two types of light-cured resin and one type of chemically cured resin were examined for their mechanical properties. The properties involved in handling and setting, and the methods of producing crowns were also studied. The results were as follows: 1) In the tensile strength test, there was no significant difference between the two types of light-cured resin, i.e., Triad and Unifast LC. The tensile strength of Unifast, a chemically cured resin, was slightly greater than the others, the difference being significant. 2) The Vickers hardness test showed no significant differences between the three types of resin. 3) The mechanical properties of Triad were not influenced by differences in the curing unit (the unit for general oral use or exclusive use) used for polymerization. 4) The test of setting properties revealed that Unifast LC needed longer than Unifast from the 2nd through the 4th clinical stage. In particular, Unifast LC required about 2.5 times the duration needed by Unifast at the 2nd stage in the tray method. 5) The heat generation test showed that the exothermic temperature in Unifast was significantly higher than in the two types of light-cured resin. 6) Heat generation associated with light curing was noted during the use of a light-curing unit for oral use.
Chiba
E
E
Tsukamoto
N
N
Sakurai
K
K
Horikawa
S
S
Yoshiura
A
A
Mitsui
Y
Y
Tsurumi
M
M
Shinya
A
A
Yokozuka
S
S
D003794:Dental Restoration, Temporary / Q000379:methods*; D008027:Light; D012117:Resins, Synthetic
D012117:Resins, Synthetic