| Clinical studies of dental implants systems reveal that commercial pure titanium has the advantage of documented long-term clinical success for its excellent biocompatibility and biologic acceptance in bone in recent years.The physico- chemical and biological characteristics of titanium implants play a critical role in determining biocompatibility. Some surface modification technology can change implants surface features at a microscopic level.Therefore,particular attention must be given to the modification of titanium implants surface.Objective: This experiment studied the effect of Ti-ion implantation on the physicochemical and biological properties of titanium implants by "in vivo" and "in vitro" studies on materials. In animal experiment,we studied the effects of Ti-ion implantation on osseointegration by histologic evaluation. In "vitro" study,we studied the effects of Ti-ion implantation on Elastic Modulus and Nano hardness by Nano hardness tester measurements in contact with Ti-ion-implanted and non- implanted titanium samples.Methods: 1.Material treatments:Titanium implants were manufactured into 22.0x8.0mm,1.5x7.0mm smooth titanium cylindrical rod by machining grade 1 and grade 2 cp Ti.Three different groups of samples were prepared with a different surface preparation: Non-Ti-ion-implanted group(TA00), Ti-ion-implanted groups (TA05,TA30) using 45KeV ions energy with the following two different doses:5x10(16),3x10(17) ions per cm2.Mechanic measurements: the Nano hardness and Elastic modulus of both implanted and non-implanted titanium samples were measured using Swiss CSEM Nano Hardness Tester.Indentation simple:max load 2.00mN;loading rate:4.00mN/min; unloading rate:4.00mN/min. 3.Animal experiments:Twenty-seven healthy male New Zealand white rabbits (4-month-old) were randomly classified into three groups,9 rabbits in each group.Three Groups (GroupI:TA00 group and TA30 group; GroupII:( TA00 group and TA05 group); GroupIII:(TA05 group and TA30 group) were implanted bilaterally into the rabbit tibiae respectively.At 4 weeks,8 weeks,10 weeks post-implantation three rabbits of each group were sacrificed respectively and the implanted tibiae were got,the tissue samples were fixed with 10% Foumaldehyde soaked and 8% formic acid was used to dissolve the calcium for 10 days .After rinsed 24 hours with water,the tissue samples were embedded in paraffin and were sectioned with a thickness of 5 um.The sections were stained with HE for histological examination and bone histomorphometric parameters were measured to quantify the change of new bone around titanium implants and to observe the changes of implant-bone interface. Results:1.Nano hardness and Elastic Modulus measure- ment:V hardness (Hv), hardness (H) in TA05 group and TA30 group were significantly increased compared with TA00 group (P<0.05). Hv(Kg/mm2),H(MPa) in TA05 group were no significant difference with TA30 group (P＞0.05).There were no significant difference in Elastic Modulus (E) among the three groups.The result show the surface hardness of titanium implants increased with Ti-ion implantation into titanium implants,but Ti-ion implantation had no effect on the change of Elastic Modulus (E). 2.General observation:After surgery all experimental animal fed well and exhibited a normal pattern of activity.There were no postoperative inflammation.There is no significant difference in brightness of implants surface between preoperation and postoperation.3.The result observed by light microscopy showed as follows:At 4 weeks after implant surgery,in the TA00 group,the combinded bone lamella was thin and was not contact with implants somewhere.The new bone in cortical bone was mainly formed by woven bone.Some Haversian systems and osteocytes were observed.There were some osteoblast in cancellous bone area; Bone information around the implant in the TA30 group and TA05 group was better than that of the TA00 group ,though a thin layer of unmineralized tissue was abserved between bone and implant.The interface Lamella bone were thicken th...
|
PDF Full Text Request