MICROSCOPY RESEARCH AND TECHNIQUE, sa.4, ss.936-946, 2025 (SCI-Expanded, Scopus)
This study evaluated the effects of immediate dentin sealing (IDS) using different universal adhesives on microtensile bond strength (mu TBS) of pretreated monolithic translucent tetragonal polycrystalline zirconia-based CAD/CAM restoration to dentin and microscopic morphological alterations. Mid-coronal dentin were obtained from 32 human molars and randomly allocated into 8 groups according to the presence/absence of IDS, universal adhesives for IDS (Single Bond Universal/SBU, Clearfil Quick Bond/CUQ, Optibond Universal/OBU) and zirconia surface pretreatments (tribochemical silica coating-30 mu m CoJet particles/TSC, sandblasting-50 mu m Al2O3/SB): Group TSC, Group TSC+SBU, Group TSC+CUQ, Group TSC+OBU, Group SB, Group SB+SBU, Group SB+CUQ, Group SB+OBU. CAD/CAM restorations (Lava Plus High Translucency Zirconia Disc) were produced, luted, and subjected to 10.000 thermocycles (5 degrees C-55 degrees C). Zirconia-dentin bars (2 x 2 x 8 mm) were subjected to mu TBS test (n = 16). Surface morphology of zirconia and zirconia-dentin interfaces were analyzed under SEM (n = 1). Two-way ANOVA and Bonferroni tests were used for statistical analyses (p < 0.05). Regarding the presence of IDS, Group TSC + OBU showed statistically higher mu TBS than Group TSC (p < 0.05). Comparing the IDS applied groups, Group TSC+OBU and Group SB+OBU showed statistically higher mu TBS than Group TSC+CUQ and Group SB+CUQ, respectively (p < 0.05). According to the surface pretreatments, no significant differences in mu TBS were found (p > 0.05). A thick, intact hybrid layer with long resin tags were observed for Group TSC+OBU and Group SB+OBU. After tribochemical silica coating or sandblasting pretreatments of monolithic zirconia, IDS procedure with Optibond Universal could affect the bond strength to dentin and morphological appearance, positively.