The Effect of UV Treatment on the Osteoconductive Capacity of Zirconia-Based Materials

Abstract

Objective: Improvements in the bioactivity of zirconia implants for accelerated healing and reduced morbidity have been of continuing interest in the fields of dentistry and orthopedic surgery. The aim of the present study was to examine whether UV treatment increases the osteoconductivity of zirconia-based materials. Materials and Methods: Smooth and rough zirconia-based disks and cylindrical implants were treated with UV light for 15 min and subsequently placed in rat femurs. Surface characterization was performed using scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and contact angle measurements. Results: In vivo histomorphometry revealed that the percentage of bone-implant contact and the amount of bone volume, formed around UV-treated implants, increased by 3–7-fold for smooth surfaces and by 1.4–1.7-fold for rough surfaces compared to non-treated specimens at Weeks 2 and 4 of healing, respectively. A biomechanical test showed that UV treatment accelerated the establishment of bone-zirconia integration and enhanced the strength of the bone-implant interface by two-fold. Additionally, surface characterization of the zirconia disks revealed that UV treatment decreased the amount of surface carbon and converted the hydrophilic status from hydrophobic to superhydrophilic. Conclusions: This study indicates that UV light pretreatment enhances the osteoconductive capacity of zirconia-based materials.

Biological and osseointegration capabilities of hierarchically (meso-/micro-/nano-scale) roughened zirconia

“…75,80,86,93,94 Hydrophilic zirconia created by UV treatment attracted more osteoblasts, facilitated their spread and proliferation, and promoted bone-implant integration. 81,90,91,95 Hierarchical rough zirconia tested in the present study was more hydrophobic than machined zirconia, but it promoted cellular spread and showed a higher bone-implant integration than machined zirconia that was less hydrophobic. The effect of surface chemistry and physicochemistry, including the effect of surface carbon and other elements, hydrophilicity/hydrophobicity, and crystalline property, as well as the interaction between surface morphology and chemistry, will require further studies.…”

Novel Osteogenic Behaviors around Hydrophilic and Radical-Free 4-META/MMA-TBB: Implications of an Osseointegrating Bone Cement

“…UV light-induced hydrophilic titanium promotes the recruitment, attachment, and spread of osteoblasts [26,29,30]. Similarly, hydrophilic zirconia and Co-Cr alloy enhances the initial behavior and response of osteoblasts compared to hydrophobic zirconia and Co-Cr alloy, respectively [41,[43][44][45][46]. Hydrophilic titanium also effectively attracts and retains proteins and other cell types such as endothelial cells [47,48].…”

Surface characteristics and bioactivity of zirconia (Y-TZP) with different surface treatments

“…Recently, researchers have turned their focus on the development of UVP for surface modification of zirconia as it is a simple and inexpensive surface treatment modality to enhance the osseointegration potential of zirconia without compromising its structural changes. [ 4 12 , 13 15 , 50 ] It not only imparts changes in the surface roughness and topography, but also makes the zirconia surface “superhydrophilic” by reducing the hydrocarbon contamination of surfaces to very low levels, which are prime factors for bioactivity and enhanced osseointegration. [ 4 12 , 13 15 , 50 ] UVP can be accomplished by ultraviolet A (UVA) and ultraviolet C (UVC) types of irradiation.…”

“…[ 6 11 , 14 ] Methods such as X-ray diffraction (XRD), atomic force microscopy (AFM), contact angle goniometry, scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX) are used by researchers to assess crystal phase, roughness, wettability, topography, and elemental composition, respectively. [ 4 6 , 9 15 , 16 ]…”