The effect of ultraviolet photofunctionalization of titanium instrumentation in lumbar fusion: a non-randomized controlled trial

Evaluation of UV photofunctionalization effect on ultrastructural properties of SLA titanium disks: An in vitro study

Background

The success rate of dental implants diminishes over time; the lack of osseointegration and infection are the major causes of most implant failures. One of the effective methods to improve the surface properties is to irradiate ultraviolet (UV) light. This study investigated the effect of UV photofunctionalization on the ultrasuperficial properties of sandblasted, large-grit, acid-etched (SLA) titanium discs.

Methods

In this in vitro study, 24 sandblasted and acid-etched titanium discs, with a lifespan of more than four weeks, were categorized into three groups (n=8): control, ultraviolet C (UVC), and ultraviolet B (UVB). Then, they were exposed to a UV light source for 48 hours at a 1-cm distance. In addition to measuring the contact angle between the liquid and the disc surface in each of the three groups, the atomic concentrations of carbon, oxygen, and nitrogen atoms were measured at three different sites on each disc. One-way ANOVA and post hoc Tukey tests were used to analyze data.

Results

The mean concentration of carbon atoms significantly differed in the control, UVC, and UVB groups (P<0.001). The mean concentrations of nitrogen atoms differed significantly between the three groups (P<0.001). However, the mean concentrations of oxygen atoms were not significantly different between the three groups. In examining the contact angle, wettability was higher in the UVC group than in the UVB group and higher in the UBV group than in the control group.

Conclusion

Photofunctionalization with UV light significantly decreased carbon and nitrogen concentrations on the surface of titanium implants, indicating that the implant's superficial hydrocarbons were eliminated. It was observed that UVC photofunctionalization was more effective than UVB photofunctionalization in reducing superficial contamination and improving wettability.

Contour Analysis of Three-Dimensional Peri-Implant Mucosal Model as an Endpoint Analysis of Photofunctionalization Effects on Implant Abutment Materials

INTRODUCTION

The objective of this study was to examine the effect of photofunctionalization on the soft-tissue contour formed at the interface of various abutment materials using end-point analyses obtained from the three-dimensional oral mucosal model (3D-OMMs).

METHODS

Commercially pure titanium (CPTi), alumina-toughened zirconia (ATZ), and yttria-stabilized zirconia (YSZ) made into discs shapes were classified into two groups: UV-treated (PTx) and non-treated (NTx). The materials in PTx groups were exposed to UV light for 12 min. Human gingival fibroblasts and TR146 epithelial cell lines co-cultured on the acellular dermal membrane were used to construct the 3D-OMM. After 4 days of culture, the discs were inserted into the holes prepared within the membrane of 3D-OMMs. The contour formed by the tissue was evaluated after 14 days of culture.

RESULTS

The UV treatment of abutment materials resulted in the formation of more non-pocket-tissue types among the PTx group (p = 0.002). Of all materials tested, soft tissue contour around YSZ showed higher scores for the non-pocket type in both non- and UV-treated groups.

CONCLUSIONS

The non-pocket type of tissue attachment was frequently found in all surfaces modified by photofunctionalization, particularly zirconia. The 3D-OMM can be used to evaluate the biological endpoints of implant surface modifications.

Clinical Applications of Photofunctionalization on Dental Implant Surfaces: A Narrative Review

Dental implant therapy is a common clinical procedure for the restoration of missing teeth. Many methods have been used to promote osseointegration for successful implant therapy, including photofunctionalization (PhF), which is defined as the modification of titanium surfaces after ultraviolet treatment. It includes the alteration of the physicochemical properties and the enhancement of biological capabilities, which can alter the surface wettability and eliminate hydrocarbons from the implant surface by a biological aging process. PhF can also enhance cellular migration, attachment, and proliferation, thereby promoting osseointegration and coronal soft tissue seal. However, PhF did not overcome the dental implant challenge of oral cancer cases. It is necessary to have more clinical trials focused on complex implant cases and non-dental fields in the future.

Surface treatment of 3D printed porous Ti6Al4V implants by ultraviolet photofunctionalization for improved osseointegration

Three-dimensional (3D)-printed porous Ti6Al4V implants play an important role in the reconstruction of bone defects. However, its osseointegration capacity needs to be further improved, and related methods are inadequate, especially lacking customized surface treatment technology. Consequently, we aimed to design an omnidirectional radiator based on ultraviolet (UV) photofunctionalization for the surface treatment of 3D-printed porous Ti6Al4V implants, and studied its osseointegration promotion effects in vitro and in vivo, while elucidating related mechanisms. Following UV treatment, the porous Ti6Al4V scaffolds exhibited significantly improved hydrophilicity, cytocompatibility, and alkaline phosphatase activity, while preserving their original mechanical properties. The increased osteointegration strength was further proven using a rabbit condyle defect model in vivo, in which UV treatment exhibited a high efficiency in the osteointegration enhancement of porous Ti6Al4V scaffolds by increasing bone ingrowth (BI), the bone-implant contact ratio (BICR), and the mineralized/osteoid bone ratio. The advantages of UV treatment for 3D-printed porous Ti6Al4V implants using the omnidirectional radiator in the study were as follows: 1) it can significantly improve the osseointegration capacity of porous titanium implants despite the blocking out of UV rays by the porous structure; 2) it can evenly treat the surface of porous implants while preserving their original topography or other morphological features; and 3) it is an easy-to-operate low-cost process, making it worthy of wide clinical application.

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An omnidirectional radiator based on ultraviolet photofunctionalization was invented..

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The omnidirectional radiator can evenly treat the surface of the porous implants..

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The present method can enhance osteoinetegration of porous Ti6Al4V implants in a convenient way with a low cost.