Surface modification of zirconia ceramics through cold plasma treatment and the graft polymerization of biomolecules

Effect of Nd:YAG Laser Surface Pretreatments and Bonding Protocols on Shear Bond Strength of Monolithic Zirconia with Varying Yttria Contents to Composite Resin

This study aimed to evaluate the impact of different surface pretreatments and bonding protocols on the shear bond strength (SBS) of two monolithic zirconia materials to composite resin.A total of 200 zirconia specimens, 3Y-TZP (n = 100) and 5YSZ (n = 100), were allocated into five groups: Control with no treatment, air-particle abrasion (APA), Nd:YAG (neodymium-doped yttrium aluminum garnet) laser treatment (L), a combination of APA and L, and laser treatment followed by cold plasma (CAP). Half of the specimens received a primer application before bonding with resin cement. Surface morphology was assessed using scanning electron microscopy, and SBS testing was conducted with a universal testing machine.The SBS analysis was done using multiway analysis of variance (p ≤ 0.05).Different surface pretreatments and 10-methacryloyloxydecyl dihydrogen phosphate primer application significantly increased SBS values (p ≤ 0.001). APA was associated with the highest SBS values, followed by APA + laser and laser + CAP. However, the combination of APA with L slightly reduce the bond strength. While the application of laser alone possesses the lowest SBS among the surface pretreatment methods, the control group was the worst by far. Different zirconia materials showed no impact on SBS values.APA surface pretreatment might still be the gold standard for zirconia adhesion. Laser surface pretreatment is a viable, less destructive option. Combining APA with laser slightly reduces SBS, while combining two inert surface pretreatment methods, such as laser and CAP, leads to enhancement of SBS compared with laser alone. Zirconia primer is highly recommended for bonding protocol. No special considerations should be taken for different yttria contents, as both materials reported comparable bond strength within the same coupled variables.

Effect of various storage media on the physicochemical properties of plasma-treated dental zirconia

This study investigated the effect of various storage media on the physicochemical properties of plasma-treated 3-mol% yttria-stabilized tetragonal zirconia: air, vacuum, deionized water (DIW), and plasma-activated water (PAW). Each group was divided into five subgroups based on storage periods: immediately after NTP irradiation (T0), and after 1 week (T1), 2 weeks (T2), 3 weeks (T3), and 4 weeks (T4). The control group (C) received no treatment. The storage groups were monitored weekly using various analytical techniques, including contact angle measurements, scanning electron microscopy (SEM), focused ion beam (FIB)-SEM, confocal laser scanning microscopy (CLSM), x-ray photoelectron spectroscopy (XPS), and x-ray diffraction (XRD). Our results demonstrate that plasma-treated zirconia surfaces stored in DIW retained or even increased their hydrophilicity due to the formation of hydrogen bonds and preservation of nitrogen functionalities. In contrast, surfaces stored in air exhibited significant hydrophobic recovery. FIB-SEM analysis showed no adverse internal structural changes regardless of storage medium. The roughness of the zirconia surface slightly increased after plasma treatment and was generally retained across all storage groups for 4 weeks, except for the air storage group. This study concludes that storage in DIW effectively preserves the enhanced surface properties of plasma-activated zirconia for up to 4 weeks.

Impact of ZrO2 Content on the Formation of Sr-Enriched Phosphates in Al2O3/ZrO2 Nanocomposites for Bone Tissue Engineering

This study investigates the profound impact of the ZrO2 inclusion volume on the characteristics of Al2O3/ZrO2 nanocomposites, particularly influencing the formation of calcium phosphates on the surface. This research, aimed at advancing tissue engineering, prepared nanocomposites with 5, 10, and 15 vol% ZrO2, subjecting them to chemical surface treatment for enhanced calcium phosphate deposition sites. Biomimetic coating with Sr-enriched simulated body fluid (SBF) further enhanced the bioactivity of nanocomposites. While the ZrO2 concentration heightened the oxygen availability on nanocomposite surfaces, the quantity of Sr-containing phosphate was comparatively less influenced than the formation of calcium phosphate phases. Notably, the coated nanocomposites exhibited a high cell viability and no toxicity, signifying their potential in bone tissue engineering. Overall, these findings contribute to the development of regenerative biomaterials, holding promise for enhancing bone regeneration therapies.