Shelf life of the Gluma bonding system

The objective of this study was to determine by shear bond strength testing the efficacy of Gluma batches produced between 1985 and 1990 and stored at either 23 degrees C or varying temperatures between 19 degrees and 32 degrees C. The average bond strength figures for the thirty variable conditions tested were not significantly different from each other on the 0.05 significance level. Chemical analysis of the individual Gluma Primer batches investigated proved that the concentration of the main active ingredients of the mixture, glutaraldehyde and HEMA, were not or only moderately reduced when compared with the composition determined on the dates of manufacture. It was concluded that this bonding system is stable over a period of 6 years when possible extremes in storage temperature are avoided.