The Comparison And Research Of Early Osteointegration Induced By Two Surface Modification Of Dental Implant

Objective:This research aimed to discuss the difference of early osseointegration induced by different surface modification of dental implant. Micro-arc oxidation(MAO)surface modification of dental implant was selected for experiment,its surface has a TiO2 coating with micro/nano dual structure. The control group were titanium implants with SLA surface treatment and without surface treatment. Providing biological evaluation for the new TiO2 coating.Methods: Six 12-16 months old healthy dogs were recruited in this study., Theirs mandibular second(P2) third(P3) and fourth(P4) premolars were extracted under anesthesia. Implant surgery was performed three months later using BLB system. Based on the surface treatment of implant, the dogs are divided into Group A(no surface treatment implants), group B(SLA surface treatment) and group C(MAO surface treatment). For each dog, two implants were embeded on each edentulous. The 24 implants are numbered randomly. The samples were harvested one month later. Calcein blue and alizarin red were injected 14 d and 4d before getting the samples. Radiologic observation, laser confocal microscope and optical microscopy were operated according to the manufacturer’s suggestion. In addition, Micro-CT reconstruction was introduced to analyze bone volume fraction of trabecularin(BVF), the number of trabecular bone(Tb.N),trabecular separation(Tb.Sp), trabecular thickness(Tb.Th) and other morphological parameters of trabecular bone in these three groups. The slide of grinding bone with the implant twas prepared. Bone mineral apposition was measured through two-color fluorescence labeling method.BA and BIC were analyzed aftercalcein blue staining.Results:1.General observationAll animals survived during the whole process. All implants healed well except one implant in Group A dropped.. The surrounding mucosa had no inflammatory reactions.One implant in group B and group C seperately loosed through the tissue examination.These two implants were excluded from the trial. The crisp tapping sound by metal instruments suggested that the osseointegrations of implant werein good condition.2.Image observation(1)X-ray: There was no transmission area on the surface of implant- bone combination of these three groups. Although the trabecular structure still existed, new bones were evident. Osteoporosis was not detected around the implant. these was no difference of the bone density among these three implants.(2)Bone gray value: The results of IPP6.0 software analysis indicated there was no statistical difference among these 3 groups in bone density.(3)Micro-CT analysis: The 2 mm alveolar bone which located the same place of different samples was used to introduced the CTAN reconstruction image softaware.Firstly, choosing a sense of regional interest(ROI):1.5mm as length of the outer edge of the implant to the near and far each extension,.The rectangular area of implant buccolingual outermost edge which contains trabecular structure was the length of width. The analysis of the trabecular separation and trabecular thickness of the bone with CTAN software showed no significant difference among the three groups.While for the quantity of trabecular bone, the MAO surfacegroup was significantly higher than that of the SLA surfacegroup. Meanwhile SLA titanium surface treatment group is also higher than that of control group with no statistical significance. MAO and SLA titanium surface group had significantly higher trabecular bone volume fraction than the non-treated group. But there was no statistically significant difference between the two treatments of MAO and SLA.3.Bone mineral deposition rateThere were two colorful, blue and red, fluorescence bands of three implants groups after Illuminated by certain wavelengths of the spectrum stimulating fluorescence. By measuring the distance between the fluorescent bands,we described the deposition of new bone mineralization amount and then calculated the mineral apposition rate(MAR).The results showed that both surface treated groups had higher MAR than that of non-treated group. But there is no statistically significant difference among the three groups.4.Toluidine blue staining analysisThe new bone was dark blue, while the original mature bone tissue stained lightly with toluidine blue staining. There were clear boundaries to tell the differences. The osteoid was light blue or bright blue while osteoblast was dark blue. The implant-osseointegration rate(BIC) and peri-implant bone area(BA) were measured by IPP6.0software. It showed that the bone binding capacity of MAO and SLA surface treatment groups was significantly higher than that without surface treated titanium group with statistical differences. But there was no statistically significant difference between the two surface-treated groups.Conclusions:1.The implant with a TiO2 coating with micro/nano dual structure prepared directly by MAO, has good biological activity2. The evaluation of the trabecular bone number of peri-implant bone four weeks after operation,surface the TiO2 coating with micro/nano dual structure provides a potential candidate for clinical application in the future,It has a stronger anti-fatigue load capacity in the early osseointegration.