Objectives: Resin-modified glass ionomer cement (RMGIC) is expected to improve anti-abrasion behavior by resin-based matrix. However, fluoroaluminosilicate-glass used in RMGIC, have been known its erosion in acid condition. The objective of this study was to reveal abrasion durability for RMGIC, by comparison between experimental RMGIC and other cements on their acid eroded surface. Methods: JDC-100 (EXP: Kuraray Medical) as the experimental RMGIC, RelyX Luting Cement (LC: 3M ESPE), Fuji Plus (FP: GC), Ionotite F (IF: Tokuyama Dental) and a resin cement RelyX Unicem (UC: 3M ESPE) were evaluated. Surface of the each cured cements were polished (#1500 Si-C, 1 μ m diamond). Specimens were immersed (37˚C, 7d) in pH 5.6 citric acid buffer. After the immersion, the specimens were examined on toothbrush with toothpaste abrasion test (250g loading, 80000 strokes, 25˚C). All specimens were evaluated by laser roughness gauge and SEM. Results: After acid erosion and abrasion, arithmetic-averaged surface roughness (Ra) and abrasion depth of EXP were the lowest in all cements. Results in μ (Roughness/ Depth): EXP(1.16/15.50); LC(3.12/119.53); FP(4.24/121.82); IF(2.05/41.01); UC(1.30/14.03). SEM images of all cements after the erosion showed rack of glass fillers on their surface. After abrasion, EXP showed filler-racked surface same as before, and did not wear its resin matrix. However, resin-matrix of LC, FP, IF and UC wore markedly after abrasion, and their fillers were cropped out from under their resin-matrix. Conclusion: EXP showed anti-abrasion behavior even in the acid eroded surface. And these results suggested that reinforcement of resin-matrix would play important role for protection against abrasion, in acidic environment.

Back to the Dental Materials: III - Ceramics and Cements Program
Back to the IADR/AADR/CADR 83rd General Session (March 9-12, 2005)

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