IADR Abstract Archives
Effects of disinfection and storage methods on shear bond strength
Objectives: Test the effects of storage methods on extracted teeth used for shear bond strength (SBS) tests of bonded composite to dentin and enamel.
Methods: Extracted human teeth were used for enamel and dentin samples which were divided into ten groups (n=8 per group). Groups were stored according to the Centers for Disease Control and Prevention (CDC) sterilization and storage methods as well as an additional control group (see Table 1). Length of storage time was determined based on previous literature and educational standards. Enamel specimens (groups 1,2,3,4,5) were etched for 30 seconds, dentin specimens (groups 6,7,8,9,10) for 15 seconds (Ultra-Etch®, Ultradent), and then rinsed. Adhesive (ExciTE® Total-Etch Adhesive, Ivoclar Vivadent) was placed according to manufacturer’s instructions. Composite (Filtek™ Supreme Ultra Universal Restorative, 3M ESPE) was added and light-cured for 30 seconds (DEMI™, Kerr). Samples were stored in deionized water for 24 hours. SBS was tested using a universal testing machine (Instron® 5566A, Norwood, MA); crosshead speed moved at 5mm/min until failure. One-way ANOVA and Tukey’s HSD were used for analysis.
Results: Means and SDs for compressive stress at maximum compressive load were calculated (Table 1). The enamel group difference was not statistically significant (p-value=0.668). The dentin group difference was statistically significant (p-value=0.003), with differences between groups 2 and 10 (p-value=0.002) and between groups 4 and 10 (p-value=.040)(Table 1).
Conclusions: Storage method did not impact the SBS results for enamel. For dentin the mean of group 10 (deionized water) was significantly less than groups 6 and 8 (bleach for 1 week and formalin). This may have an impact on future studies, as storage methods did not appear to negatively affect the SBS results on enamel, however, there was a difference in SBS results for the dentin samples.
Methods: Extracted human teeth were used for enamel and dentin samples which were divided into ten groups (n=8 per group). Groups were stored according to the Centers for Disease Control and Prevention (CDC) sterilization and storage methods as well as an additional control group (see Table 1). Length of storage time was determined based on previous literature and educational standards. Enamel specimens (groups 1,2,3,4,5) were etched for 30 seconds, dentin specimens (groups 6,7,8,9,10) for 15 seconds (Ultra-Etch®, Ultradent), and then rinsed. Adhesive (ExciTE® Total-Etch Adhesive, Ivoclar Vivadent) was placed according to manufacturer’s instructions. Composite (Filtek™ Supreme Ultra Universal Restorative, 3M ESPE) was added and light-cured for 30 seconds (DEMI™, Kerr). Samples were stored in deionized water for 24 hours. SBS was tested using a universal testing machine (Instron® 5566A, Norwood, MA); crosshead speed moved at 5mm/min until failure. One-way ANOVA and Tukey’s HSD were used for analysis.
Results: Means and SDs for compressive stress at maximum compressive load were calculated (Table 1). The enamel group difference was not statistically significant (p-value=0.668). The dentin group difference was statistically significant (p-value=0.003), with differences between groups 2 and 10 (p-value=0.002) and between groups 4 and 10 (p-value=.040)(Table 1).
Conclusions: Storage method did not impact the SBS results for enamel. For dentin the mean of group 10 (deionized water) was significantly less than groups 6 and 8 (bleach for 1 week and formalin). This may have an impact on future studies, as storage methods did not appear to negatively affect the SBS results on enamel, however, there was a difference in SBS results for the dentin samples.
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