Effect of disinfection/sterilization treatments on Gluma-mediated dentin shear bond strengths

This in vitro study investigated Gluma-mediated dentin shear bond strengths after treatment by three commonly used disinfection/sterilization methods: 1) proprietary phenolated glutaraldehyde (Sporicidin); 2) 1% NaOCl and; 3) autoclaving. Varying numbers of bonds were too low to be measured, failing prior to, or early in testing. Failed bonds were scored as zero. When all attempted bonds were subjected to ANOVA, there was a significant difference between groups (P less than 0.0001) in bond strengths. These results demonstrate the significant differences were due to statistical management; that is, inclusion of zeros. When only measurable bonds were similarly analyzed, no significant differences in bond strength were found. When the measurable bonds were tested by Fisher's exact test, significant differences were detected among and between the experimental groups. Additionally, the experimental treatments probably altered or removed dentinal protein constituents. A plea is made for clarity and uniformity in statistical management and reporting of bonds which are too low to be measured.