Objectives: Recently, we developed a new light-cured glass ionomer cement, Fuji LINING LC Paste Pak(LCPP, GC, paste-paste type). The objective of this study was to evaluate characteristics of LCPP. The important features for glass ionomer lining cement are its bonding characteristics to tooth structure and high physical properties. To compare these characteristics, the shear bond strength and diametral tensile strength ofLCPP, Fuji LINING LC(FLC, GC, powder-liquid type) and Vitrebond(VB, 3M, powder-liquid type) were measured.
Methods: Test method of the shear bond strength was as follows. The bovine teeth were mounted in self-cured acrylic resin and polished with silicon carbide paper(#600) to get the flattened dentin surface. The dentin surface were prescribed at 3mm in diameter with masking tape. Cement was mixed according to the directions for use and applied on the tooth surface. After light cure, the specimens were stored in a chamber(37°C,100%R.H.) for 24 hours. Then, shear bond strengths were measured before and after thermocycling(n=5). Thermocycling condition was between 5 and 55°C with 30 seconds dwell time for 2,000 cycles.
|
Products |
FLC |
VB |
LCPP |
|
Shear bond strength (24h) |
9.3(3.2) |
4.4(1.7) |
7.0(1.5) |
|
Shear bond strength (2,000cycles) |
10.0(3.4) |
2.2(2.4) |
9.3(1.8) |
|
Diametral tensile strength(24h) |
19.3(1.8) |
12.0(1.5) |
25.6(3.0) |
Unit: MPa, ( ): S.D.
Results: Results were analysed with Student t-test. Shear bond strength of LCPP to bovine dentin before and after thermocycling were as high as those of FLC and significantly higher than those of VB(p<0.05). Diametral tensile strength of LCPP was the highest of three materials.
Conclusion: New light-cured glass ionomer cement, LCPP, showed excellent bonding durability and higher diametral tensile strength.