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Objective: This study evaluated the microshear bond strength of a resin cement to Y-TZP after different methods of TiO 2 nanotubes (nTiO 2 ) incorporation on pre-sintered Y-TZP surfaces., Methods: nTiO 2 were synthesized and incorporated on Y-TZP slices as follows (n = 15): 1) nTiO 2 mixed with isopropyl alcohol/manual application (MAl); 2) nTiO 2 mixed with acetone/manual application (MAc); 3) nTiO 2 mixed with isopropyl alcohol/high-pressure vacuum application (HPVAl); 4) nTiO 2 mixed with acetone/high-pressure vacuum application (HPVAc). As controls, surfaces were sandblasted with Al 2 O 3 (OX) or Rocatec silicatization (ROC). All ceramics were sintered after nTiO 2 incorporation. Surface treatments of OX and ROC were made after sintering. Surfaces were characterized by confocal laser microscopy, scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). Resin composite cylinders (1.40 mm diameter and 1 mm height) were cemented with a resin cement, stored in water at 37 °C for 24 h and thermocycled for 10 000 cycles before microshear bond strength evaluation. Data were analyzed with one-way ANOVA and Games-Howell (α = 0.05), and fracture analysis was performed using a stereomicroscope., Results: EDS confirmed the presence of TiO 2 on treated Y-TZP. The confocal analysis showed higher roughness for HPVAc and OX. There were significant differences between surface treatments (p < 0.001). HPVAl (22.96 ± 10.3), OX (34.16 ± 7.9) and ROC (27.71 ± 9.4) showed higher microshear bond strengths and were statistically similar (p > 0.05). MAC showed intermediary values, and HPVAc and MAl presented decreased bond strength, with a high percentage of premature debonding., Conclusion: High-pressure vacuum application of nTiO 2 mixed with isopropyl alcohol was able to produce bond strength values compared to conventional air abrasion and Rocatec silicatization., Significance: The infiltration of TiO 2 nanostructures on the pre-sintered Y-TZP is an interesting approach that can improve bond strength without the need of sandblasting methods., (Copyright © 2022 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.)

Objective: To evaluate the influence of the addition of functionalized and non-functionalized TiO 2 nanostructures on properties of a resin composite., Methods: TiO 2 nanostructures were synthesized and functionalized, using 3-(aminopropyl)triethoxysilane (APTMS) and 3-(trimethoxysilyl)propyl methacrylate (TSMPM). Characterizations were performed with XRD, EDS, TEM, and TGA. Resin composites containing Bis-GMA/TEGDMA, CQ, DABE, and barium-aluminum silicate glass were produced according to TiO 2 nanostructure (nanotube or nanoparticle), concentration (0.3 or 0.9 wt%), and functionalization (APTMS or TSMPM). The resin composite without nanostructures was used as control. The amount of fillers was kept constant at 78.3 wt% for all materials. The degree of conversion (DC - at 0 h and 24 h), maximum polymerization rate (Rp max ), and Knoop microhardness (KHN before and after ethanol softening) were evaluated. Data were analyzed with two-way ANOVA with repeated measures and Tukey's HSD (α = 0.05)., Results: TGA results demonstrated that functionalizations were effective for both nanostructures. For DC, resin composites, time and interaction effect were significant (p < 0.001). Higher DC was found for 0.3-wt%-functionalized-nanotubes at 24 h. For nanoparticles, only 0.9-wt%-non-functionalized and 0.3-wt%-APTMS-functionalized showed DC similar to the control and all other groups showed higher DC (p < 0.05). Rp max was higher for 0.3-wt%-APTMS-nanotubes, which corresponded to higher DC after 24 h. The lowest Rp max occurred for 0.9-wt%-TSMPM-nanotubes, which showed smaller DC at 0 h. For KHN, resin composites, ethanol softening and interaction effect were significant (p < 0.001). KHN decreased after ethanol softening all groups, except for 0.3-wt%-TSMPM-nanotubes, 0.9-wt%-TSMPM-nanotubes, and 0.3-wt%-non-functionalized-nanoparticles., Conclusion: The resin with 0.3-wt%-TSMPM-nanotubes showed higher DC after 24 h, while being the most stable material after the ethanol softening., Significance: The addition of functionalized TiO 2 nanostructures in resin-based materials may improve the properties of the material., (Copyright © 2020 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.)

Purpose: To evaluate the shear bond strength (SBS) between Y-TZP and a resin luting agent, after 1 of 2 enhancing strategies with TiO 2- -nts was applied, either to the resin luting agent or the Y-TZP mass, in different concentrations., Methods: In the Strategy TiO 2 -nts on ceramic, the resin luting agent Panavia F2.0™ (Kuraray) and an experimental Y-TZP with added concentrations of TiO 2- -nts (0%, 1%, 2%, and 5% vol/vol) and a commercial Y-TZP, comprised 5 different groups (n = 10). In the Strategy TiO 2 -nts on cement, the resin luting agent RelyX U200™ (3 M ESPE) was added with different concentrations of TiO 2- -nts (0%, 0.3%, 0.6%, 0.9% wt/wt) luted to a commercial Y-TZP, comprising 4 different groups (n = 10). The Y-TZP discs were included in acrylic bases, and a cylinder (3 × 3 mm) of the correspondent luting agent for each respective group was applied over them. After 24 h, specimens were subjected to SBS assessments in a universal testing machine. Field emission scanning electron microscopy and energy dispersive X-ray spectroscopy analyses were also performed on Y-TZP surfaces. Data were analyzed via analysis of variance and Tukey tests (α = 0.05)., Results: TiO 2 -nts on ceramic influenced the bond strength significantly, but not linearly; TiO 2 -nts on cement did not influence bond strength when analyzed separately, nor in comparison with the first., Conclusion: Y-TZP enhancements with TiO 2 -nts led to a higher SBS with Panavia F2.0, a 5% TiO 2- -nt concentration presented the highest bond strength. Modified Rely X U200 did not improve SBS., Competing Interests: Declarations of Competing Interest None., (Copyright © 2019. Published by Elsevier Ltd.)

Objectives: The aim of this study was to determine the physico-mechanical properties of a high viscosity glass ionomer cement (GIC) reinforced with TiO 2 nanotubes (TiO 2 -nt)., Methods: TiO 2 -nt was incorporated into the GIC powder components (Ketac Molar EasyMix™) in concentrations of 0% (control group), 3%, 5%, 7% by weight. Compressive strength (n = 10/group), three point bending for flexural strength (n = 18/group), microshear bond strength to dentin and failure mode (n = 20/group), and surface roughness and weight loss before and after brushing simulation (30,000 cycles) (n = 8/group) were evaluated. Data were submitted to Shapiro-Wilk, ANOVA, Tukey and Chi-square tests (α ≤ 0.05)., Results: Addition of 5% of TiO 2 -nt into GIC presented the highest values for compressive strength and differed from the control, 3% and 7% groups (p = 0.023). There were no significant differences in flexural strength (p = 0.107) and surface roughness before and after the dental brushing (p = 0.287) among the groups. GIC added with 5% TiO 2 -nt showed the lowest weight loss values (p = 0.01), whereas the control, 3% or 5% TiO 2 -nt groups presented similar microshear bond strength values (p ≥ 0.05). The 5% TiO 2 -nt group featured higher microshear bond strength than the 7% TiO 2 -nt group (p = 0.034). Cohesive in material was the most representative failure mode for all groups., Significance: The incorporation of TiO 2 -nt did not affect GIC's adhesiveness to dentin, but improved its compressive strength at 5%. Furthermore, TiO 2 -nt decreased the percentage of weight loss after GIC's surface wear., (Copyright © 2020 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.)

Objectives: A bovine dense hydroxyapatite ceramic (HA) was produced as new biomaterial, however, the production of a material with consistently high flexural strength remains challenging. The objective of this study was to evaluate the effects of ZnO nanoparticles, TiO 2 nanoparticles, and TiO 2 nanotubes (1%, 2%, and 5% by weight) on the microstructure and flexural strength of a bovine dense hydroxyapatite ceramic (HA)., Methods: Discs (Ø=12.5mm; thickness=1.3mm) were prepared and subjected to X-ray diffraction (XRD), and observation with a field emission scanning electron microscope (FE-SEM), biaxial flexural strength (BFS) testing, and Vickers hardness (VH) testing. The BFS and VH data were subjected to ANOVA and Tukey post-hoc tests (α=0.05) and Weibull analysis., Results: The XRD showed that the addition of nanomaterials caused the formation of a secondary phase when 5% of the ZnO nanoparticles was used, or when all percentages of the TiO 2 nanoparticles/nanotubes were used, and the HA crystallographic planes were maintained. Differences were not observed between the higher BFS values obtained with pure HA and those obtained with the 5% addition of TiO 2 nanoparticles. However, the results were different compared with the other groups (α=0.05). The results obtained by Weibull analysis revealed that the 1%, 2%, and 5% addition of TiO 2 nanotubes, and the 1% and 2% addition of TiO 2 nanoparticles decreased the HA characteristic strength (σ 0 ), while the Weibull modulus (m) increased when 5% of TiO 2 nanoparticles, 1% and 2% of ZnO nanoparticles, and 2% of TiO 2 nanoparticles were added, but with no statistical difference from the pure HA. The 5% addition of ZnO 2 nanoparticles decreased the σ 0 without changing m. Moreover, the 5% addition of TiO 2 nanoparticles resulted in an m closest to that of pure HA. Regarding the VH results, the blend of HA with 1% and 2% addition of TiO 2 nanoparticles exhibited the higher values, which were similar between the different addition ratios (p=0.102). Moreover, the addition of 5% TiO 2 nanoparticles resulted in higher value compared with pure HA., Significance: This study demonstrated that the HA blend with 5% of TiO 2 nanoparticles has the greatest potential as a bovine HA dense bioceramic reinforcement., (Copyright © 2019 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.)

Objectives: This study has investigated the influence of Titanium dioxide nanotubes (TiO 2 -nt) addition to self-adhesive resin cement on the degree of conversion, water sorption, and water solubility, mechanical and biological properties., Methods: A commercially available auto-adhesive resin cement (RelyX U200™, 3M ESPE) was reinforced with varying amounts of nanotubes (0.3, 0.6, 0.9wt%) and evaluated at different curing modes (self- and dual cure). The DC in different times (3, 6, 9, 12 and 15min), water sorption (Ws) and solubility (Sl), 3-point flexural strength (σf), elastic modulus (E), Knoop microhardness (H) and viability of NIH/3T3 fibroblasts were performed to characterize the resin cement., Results: Reinforced self-adhesive resin cement, regardless of concentration, increased the DC for the self- and dual-curing modes at all times studied. The concentration of the TiO 2 -nt and the curing mode did not influence the Ws and Sl. Regarding σf, concentrations of both 0.3 and 0.9wt% for self-curing mode resulted in data similar to that of dual-curing unreinforced cement. The E increased with the addition of 0.9wt% for self-cure mode and H increased with 0.6 and 0.9wt% for both curing modes. Cytotoxicity assays revealed that reinforced cements were biocompatible., Significance: TiO 2 -nt reinforced self-adhesive resin cement are promising materials for use in indirect dental restorations. Taken together, self-adhesive resin cement reinforced with TiO 2 -nt exhibited physicochemical and mechanical properties superior to those of unreinforced cements, without compromising their cellular viability., (Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.)