Photofunctionalised Ti6Al4V implants enhance early phase osseointegration

Abstract

ObjectivesUltraviolet (UV) light-mediated photofunctionalisation is known to improve osseointegration of pure titanium (Ti). However, histological examination of titanium alloy (Ti6Al4V), which is frequently applied in orthopaedic and dental surgery, has not yet been performed. This study examined the osseointegration of photofunctionalised Ti6Al4V implants.MethodsTi and Ti6Al4V implants were treated with UV light, and the chemical composition and contact angle on the surfaces were evaluated to confirm photofunctionalisation. The implants were inserted into femurs in rats, and the rats were killed two or four weeks after the surgery. For histomorphometric analysis, both the bone–implant contact (BIC) ratio and the bone volume (BV) ratio were calculated from histological analysis and microcomputed tomography data.ResultsThe amount of carbon and the contact angle on both implants were significantly reduced after UV irradiation. The BIC ratios for both UV light-treated implants significantly increased at two weeks, but there was no significant difference at four weeks. There was no significant difference in the BV ratios between the UV light-treated and control implants at two or four weeks.ConclusionsThis study suggests that photofunctionalisation of Ti6Al4V implants, similar to that of Ti implants, may promotes osseointegration in early but not in the late phase of osseointegration.Cite this article: R. Yamauchi, T. Itabashi, K. Wada, T. Tanaka, G. Kumagai, Y. Ishibashi. Photofunctionalised Ti6Al4V implants enhance early phase osseointegration. Bone Joint Res 2017;6:331–336. DOI: 10.1302/2046-3758.65.BJR-2016-0221.R1.

An Integrated Overview of Ultraviolet Technology for Reversing Titanium Dental Implant Degradation: Mechanism of Reaction and Effectivity

“…All implants placed in tibias and femurs were unloaded. In detail, most authors reported significantly increased BIC [57,71,[73][74][75][76][77][78][79], push-in values [40,44,[80][81][82][83], bone volume [72,84], or bone mineral [85,86] were noted in all animal models studied for photofunctionalized groups disregarding implant surface modifications/topography. The differences were insignificant for both UV-treated and non-UV-treated reported in four animal studies [87][88][89][90].…”

“…The use of UV light to condition the implant surface has emerged from the knowledge of the photocatalytic degradation properties of TiO 2 based on the photo-induced hydrophilicity and decomposition reaction described above [32]. The effect of photofunctionalization on different surfaces was evaluated by many researchers, and the production of superhydrophilic surfaces with increased and accelerated bone-implant integration was demonstrated in in vitro [21,22,93] and in vivo [58,73,87,96,98] studies.…”

Ultraviolet irradiation improves the hydrophilicity and osteo-conduction of hydroxyapatite

“…Photofunctionalised Ti implants are reported to increase the bone-implant contact ratio 2.5 times after 2 weeks, and 1.9 times after 4 weeks compared to Ti without photofunctionalization. 1 In our previous study, Yamauchi et al reported that UV-treated Ti and Ti6Al4V demonstrated signi cant differences in chemical properties and were more wettable than untreated implants [3]. Furthermore, we showed that antimicrobial activity was induced on Ti and Ti6Al4V for seven days after UV irradiation [8].…”

“…To examine the change in hydrophilicity on the disk surface after UV irradiation, the wettability was evaluated by measuring the contact angle of a water drop [3]. For this test, 10 μL of water was dropped onto the disk surface before UV irradiation, and at 0 minutes, one hour, three hours, six hours, two weeks, and four weeks after UV irradiation.…”

“…Irradiation changes the surface structure of Ti such that radicals are excited and the hydrophilicity is increased. Yamauchi et al reported that the bone-implant contact (BIC) ratio for both Ti and Ti6Al4V UV-treated implants signi cantly increased at 2 weeks [3]. UV irradiation was also found to have an antimicrobial effect in the early stage after implantation [4].…”