IADR Abstract Archives
Mechanical Properties of Adhesives With and Without a Desensitizer
Objectives: Adhesive systems that simplify procedures without increasing post-operative sensitivity are of high interest in dentistry. We compared shear bond strength (SBS) and elastic modulus (EM) of 4 universal adhesives with a self-etch adhesive and a fluoride-releasing, single-component, total-etch adhesive commonly used in practice. We further tested whether results were affected by use of a desensitizer.
Methods: Extracted human molars were embedded in epoxy, ground coronally to expose dentin and finished with 600 grit. Teeth were randomly assigned to one of six products and further to receive gluma or no gluma (n=7 to 8/group) (table 1). Gluma (Kulzer, South Bend IN) and the adhesive were applied and cured according to manufacturer’s instructions. A SBS testing button of IPS Empress Direct composite was applied to the prepared surface and cured. Samples were stored for 1 or 7 days in water at 37° C. SBS was measured using an Ultradent testing jig (Ultradent Products, South Jordan, UT) on an Instron ElectroPuls E-300 with a crosshead speed of 0.5mm/min. Three-way ANOVA with post-hoc comparisons tested whether time (Day 1, Day 7), product, or Gluma use interacted to affect SBS or EM. All statistics were performed in R (version 4.2.1).
Results: Data passed all normality tests, although four extreme outliers were identified and replaced via subgroup means substitution (representing <2% of the sample). SBS results show a significant main effect of product only (p-value<0.0001, F=12.643). Posthocs show ExciTE and iBOND Universal have significantly lower SBS than the other products tested (Fig. 1). Results for EM show a significant, 3-way interaction (p-value=0.015, F=2.934), indicating the effect of Gluma over time differs by product. However, pairwise tests show ExciTE and iBOND often have significantly lower values.
Conclusions: The consistently lower mechanical properties for ExciTE and iBOND may increase risk of premature failure. The effect of Gluma varies by product.
Methods: Extracted human molars were embedded in epoxy, ground coronally to expose dentin and finished with 600 grit. Teeth were randomly assigned to one of six products and further to receive gluma or no gluma (n=7 to 8/group) (table 1). Gluma (Kulzer, South Bend IN) and the adhesive were applied and cured according to manufacturer’s instructions. A SBS testing button of IPS Empress Direct composite was applied to the prepared surface and cured. Samples were stored for 1 or 7 days in water at 37° C. SBS was measured using an Ultradent testing jig (Ultradent Products, South Jordan, UT) on an Instron ElectroPuls E-300 with a crosshead speed of 0.5mm/min. Three-way ANOVA with post-hoc comparisons tested whether time (Day 1, Day 7), product, or Gluma use interacted to affect SBS or EM. All statistics were performed in R (version 4.2.1).
Results: Data passed all normality tests, although four extreme outliers were identified and replaced via subgroup means substitution (representing <2% of the sample). SBS results show a significant main effect of product only (p-value<0.0001, F=12.643). Posthocs show ExciTE and iBOND Universal have significantly lower SBS than the other products tested (Fig. 1). Results for EM show a significant, 3-way interaction (p-value=0.015, F=2.934), indicating the effect of Gluma over time differs by product. However, pairwise tests show ExciTE and iBOND often have significantly lower values.
Conclusions: The consistently lower mechanical properties for ExciTE and iBOND may increase risk of premature failure. The effect of Gluma varies by product.
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