BMC Oral Health (Nov 2024)
Comparative evaluation of desensitizing agents on shear bond strength of zirconia to dentin
Abstract
Abstract Background The purpose of the study is to evaluate the effect of 7 different desensitizing agents on the shear bond strength (SBS) of zirconia restorations to dentin with a self-adhesive resin cement and determine the failure modes. Methods Eighty molars’ occlusal surfaces were ground to expose dentin and were randomly divided into 8 groups (n = 10): 1. Gluma (HEMA/Glutaraldehyde) 2. Bifluoride (Sodium Fluoride/Calcium Fluoride) 3. Admira (Bis-GMA/HEMA) 4. Smart Protect (Glutaraldehyde) 5. Teethmate (Tetracalcium phosphate, Dicalcium phosphate) 6. Clinpro White (Sodium fluoride) 7. BisBlock (Oxalic acid) and 8. Control (No-treatment). After applying the agent, a self-adhesive resin cement (Rely-X U200) was used to lute zirconia discs (4 mm height and 4 mm diameter) to dentin. After stored in distilled water at 37 °C for 24 h, all groups were thermocycled for 2500 cycles between 5 ± 2 °C and 55 ± 2 °C. Specimens were submitted to SBS test with a universal testing machine at a crosshead speed of 0.5 mm/min until failure. SBS values were compared with ANOVA. Post-hoc multiple comparisons were performed with Dunnett T3. The failure modes of specimens were examined with stereomicroscope at a magnification of 20X and the distribution of the failure modes were evaluated with Pearson Chi-Square test. Results Regarding mean SBS values in MPa’s; Admira (10.70 ± 3.99), Smart Protect (9.62 ± 3.93), and Gluma (8.90 ± 3.76) treatments showed higher SBS values compared to control group (p .05). BisBlock (2.33 ± 1.94) and Bifluouride (1.60 ± 1.47) groups showed the lowest SBS values but their difference between control group was not found statistically significant (p > .05). Most specimens showed adhesive failure but no statistically significant difference was found in the distributions of failure modes according to Chi-square test. Conclusion Within the limitation of the study; Admira, Smart Protect, and Gluma increased the SBS of the zirconia restorations to dentin and can be recommended to use on prepared dentin surfaces prior to the cementation.
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