IADR Abstract Archives
Susceptibility of Novel Self-Adhesive Materials to Changes in Dentin Mineralization
Objectives: This study aims to evaluate the effect that artificial hypermineralization and demineralization have on the shear bond strength (SBS) of three novel materials – a self-adhesive resin-based composite (SC), a resin-modified glass ionomer cement (RMGIC) and a high-viscosity glass ionomer cement (HVGIC) – to human dentin.
Methods: A total of 180 human dentin specimens were randomly assigned to 9 groups (n=20). Either healthy, artificially hypermineralized or demineralized dentine was used as bonding substrate for each material. SBS was determined according to ISO 29022 after aging the specimens in distilled water (37°C) for 1 week, followed by fractographic analysis to determine the origin of fracture by light microscopy and analysis of bond morphology by scanning electron microscopy. One- and two-way ANOVA, Tukey’s post hoc test (α = 0.05) and Weibull analysis was used for statistical evaluation.
Results: The univariate analysis confirmed a significant influence (p < 0.0001) of the material (ηp2 = 0.641), the dentin substrate (ηp2 = 0.155) and their combined effect (ηp2 = 0.173) on the SBS. Fractographic analysis revealed that adhesive fracture occurred in 74% (SC), 92% (RMGIC) and 96% (HVGIC) of the specimens. Bond reliability decreased in RMGIC and HVGIC and increased in SC when hypermineralized dentin was used. On demineralized dentin it decreased with SC and persisted with the other materials. Regardless of the dentin substrate, SC exhibited higher SBS values than RMGIC and HVGIC (p < 0.0001). The results are summarized in the table below.
Conclusions: De- and hyper-mineralization appear to have a slightly detrimental effect on HVGIC SBS values. In contrast, SC SBS values appear to be negatively impacted only by artificial demineralization, while RMGIC was more robust to changes in dentine conditions. Changes to the degree of dentin mineralization display a significant effect on the bond reliability of all the studied materials.
Methods: A total of 180 human dentin specimens were randomly assigned to 9 groups (n=20). Either healthy, artificially hypermineralized or demineralized dentine was used as bonding substrate for each material. SBS was determined according to ISO 29022 after aging the specimens in distilled water (37°C) for 1 week, followed by fractographic analysis to determine the origin of fracture by light microscopy and analysis of bond morphology by scanning electron microscopy. One- and two-way ANOVA, Tukey’s post hoc test (α = 0.05) and Weibull analysis was used for statistical evaluation.
Results: The univariate analysis confirmed a significant influence (p < 0.0001) of the material (ηp2 = 0.641), the dentin substrate (ηp2 = 0.155) and their combined effect (ηp2 = 0.173) on the SBS. Fractographic analysis revealed that adhesive fracture occurred in 74% (SC), 92% (RMGIC) and 96% (HVGIC) of the specimens. Bond reliability decreased in RMGIC and HVGIC and increased in SC when hypermineralized dentin was used. On demineralized dentin it decreased with SC and persisted with the other materials. Regardless of the dentin substrate, SC exhibited higher SBS values than RMGIC and HVGIC (p < 0.0001). The results are summarized in the table below.
Conclusions: De- and hyper-mineralization appear to have a slightly detrimental effect on HVGIC SBS values. In contrast, SC SBS values appear to be negatively impacted only by artificial demineralization, while RMGIC was more robust to changes in dentine conditions. Changes to the degree of dentin mineralization display a significant effect on the bond reliability of all the studied materials.
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