The Effect Of UV-photocatalysis Titanium Implant On Integration With Bone In2Type Diabetic Rats

Dental implants might be ideal technique for repairing missing teeth, the theory ofOsseointegration has been mature and is necessary for implants to be successful. However,there is some risks in patients with general system disease, especially to diabetes. The lowrate of Osseointegration and postpone the appearance of Osseointegration might lead thefailure of implants. The morbidity of diabetes grows continuously and the patients agebecome younger. In China, the morbidity of diabetes has been reached9.7%and90percent of Type2Diabetes.Periodontitis is one of the diabetic complications, which caneasily cause missing teeth. More and more diabetes have their missing teeth restored byimplants. How to satisfy this and improve the rate of Osseointegration and success is animportant and difficult issue in research. According to the recent research, the bioactivityof implant can decrease with time, but the ultraviolet（UV） treatment can restored thesurface bioactivity, enhance osteoblast proliferation, differention, protein adsorption andcell adhesion and improve the implant Osseointegration. This research firstly used ultraviolet to treat implants and placed these implants inrats animal model with Type2Diabetes, evaluate the Osseointegration of implants withphotocatalysis, supply theory basis for implants clinically application.The main methods and results:1. Ultraviolet irradiation after MAO treat titanium and surface characterizationMethods:64titanium implants and32titanium disks is coarsened by Microarc Oxidationtreatment, the surface morphology was observed SEM. All of the implants and disks werestored under dark conditions for4weeks, then Randomly selected32titanium implantsand16disks were treated by UV treatment48hours and the rest of32titanium implantsand16disks without UV treatment. UV treatment was performed using a15Wbactericidal lamp （Hangyun, Beijing）; intensity; ca.0.05mW/cm²ï¼ˆÎ»=360±20nm） and2mW/cm²(λ=250±20nm.16titanium disks after UV treatment were randomly dividedinto two groups,8in each group, then those disks were compared with untreated controlfor hydrophilic status and the chemical composition. Hydrophilic status of the titaniumsurfaces was examined by the contact angle of8mμ H₂O droplet measured by a contactangle meter. The chemical composition on titanium surfaces were evaluated by electronspectroscopy for chemical analysis （ESCA）. ESCA was performed using an X-rayphotoelectron spectroscopy （XPS）.Results: The surface of implants and titanium disks after MAO treatment becomes rough,form a continuous sample microporous structure similar to the crater of the volcano. AfterUV treatment of titanium disks for48h the contact angle of a H₂O droplet, which was82±3for the MAO surface, plummeted to0. XPS Spectra revealed that the C1s peakdecreased with an increase of UV treatment time, whereas Ti2p and O1s peaks increased.2. The effect of ultraviolet-photofunctionalized titanium implant on integration withbone in2type diabetic ratsMethods: In our experiment we chose369-week-old male SD rats, feed them with thehigh fat-sugar diet for4weeks, then gave low doses of STZ injection retroperitoneal.Eventually we obtained32diabetic rats with blood glucose levels of≥16.7mmol/L wereconsidered diabetic.32type2diabetic rats randomly divided into experimental group （UV-treated implant group16） and the control group （untreated implant group16）.32implants with UV treatment and32without UV treatment were respectively implanted inthe experimental group and control group rats with bilateral tibial epiphyseal near end.After4and8weeks, we sacrificed the animals and harvested the tibias containingimplants, sample were scanned by local Micro-CT, then analyze the parameters of bone.8sample is used to histological examination. Using a high-speed precision microtome, all ofsections were ground and polished to a thickness of40μm. and stained with PonceauTri-Chrome, BIC were analyzed. SEM and EDS test were used to observe bone-implantinterface contact conditions of two groups.Results:1、36SD rats,4rats were weed out whose blood glucose levels is not up to standard,eventually we obtained32diabetic rats with blood glucose levels of≥16.7mmol/L. Theweight of these diabetics rats were increased significantly. meanwhile blood glucose levelskeep in a stable state without death.32type2diabetic rats randomly divided intoexperimental group （ultraviolet treatment implant group16） and the control group （uvuntreated implants group16）.2、The result of Micro-CT: Scanning reconstruction according to the results, after4,8weeks, the surrounding bone deposition of implant for UV-treated implants wasconsistently greater than for control implants, and bone trabecular alignment is moreregular and continuous. From trabecular bone parameters statistical analysis: comparedwith the control group, Tb.Th、BS/BV of the UV-treated group were higher and the Tb.Spwere significantly lower than those of the un-treated group （P<0.05）. After8weeks ofhealing, Tb.N、BS/BV、BV/TV of the UV-treated group were higher and the Tb.Sp weresignificantly lower than those of the un-treated group （P<0.05）.3、From histologic images, in the un-treated group, BIC and bone density around theimplant was lower than the UV-treated after4weeks and8weeks, meanwhile trabecularbone around the implants was loosely organized than the UV-treated. From the histologicthe data analysis: at4weeks, the BIC （%） was41.7±2.4in the un-treated group,61.1±2.5in the UV-treat group（P<0.05）. at8weeks, the BIC （%） was48.8±2.5in the un-treated group,71.7±4.2in the UV-treat group（P<0.05）.4.、From the SEM images and EDS date analysis: UV-enhanced titanium enabled thehigher level of establishment in direct bone–titanium contact with nearly no interpositionby soft tissue, however, in the un-treated group, the lower level of establishment in directbone–titanium contact with interposition by soft tissue.Conclusions:1、In the surface of MAO, superhydrophilic titanium surface obtained after UV treatmentfor48h. Changes in hydrophilicity evaluated by contact angle of H2O after UV treatment.UV treatment can convert the titanium surface from hydrophobic to superhydrophilic,2、 UV-photofunctionalized titanium implant can promote the integration with bone in2type diabetic rats and increase the percentage of bone-implant contact. This study providesan experimental basis and a new way for the clinical problem how to improve the successrate of type2diabetes mellitus.