Analysis of sealing vs tensile bond strength of eight adhesive restorative material systems

Using a simulated perfusion system, the intent was to determine: 1) the sealing ability of eight restorative materials (five composite resins and three compomers) used together with their corresponding dentin bonding systems, 2) their tensile bond strength, and 3) the correlation (if any) between both parameters.

Permeability in crown segments from sound human third molars (n = 140) subjected to simulated perfusion (32 cm of distilled water) was measured before and after restoring with each material, and the percentage of decrease in permeability (PPD) was recorded. Specimens were later subjected to tensile tests to determine the tensile bond strength (TBS) of the interface. Finally, parameters were analyzed for correlation.

For the eight adhesive systems, the percentage of reduction in permeability was relatively high [mean in %, (SD)]: F2000 93.6 (5.7), SB1 88.6 (11.3), SSC 86.0 (5.7), PB20 81.1 (15.9), COM 77.5 (10.8), OPTS 75.3 (20.6), DYR 73.7 (12.7), SSPR 65.5 (19.8). TBS values were relatively low [mean (SD)], in MPa: F2000 1.8 (0.7), SB1 4.9 (1.4), SSC 2.6 (1.4), PB20 4.3 (1.2), COM 2.4 (1.1), OPTS 4.5 (1.7), DYR 1.6 (0.6), SSPR 4.2 (1.5). We could not demonstrate any statistically significant correlation between both parameters for these results (maximum significance [F2000]: r = 0.39, p = 0.206).

No material completely ceased to filtrate through the interface. The low TBS values were probably due to the large size of adhesive areas. No significant correlation was found between PPD and TBS for the materials tested. There was a statistically significant relationship (r2 = 0.063, p = 0.018) between TBS and TBA (total bonded area), described by the equation TBS = 5.9 - 0.03.TBA.