| Objective: Development of oral implant repair technology for half a century,pure titanium implants have a good biocompatibility of titanium and human biocompatibility,corrosion resistance and oral mechanics,and are widely used in oral clinical implantation.However,with the clinical observation found that the titanium base in the weak area of gingival tissue or gingival parts will appear in varying degrees of titanium color,is due to metal ions gradually precipitated around the surrounding tissue staining and thus affect the aesthetic repair effect.On the basis of this,the biocompatibility and mechanical properties of zirconia ceramics were found to be significantly higher than that of other all-ceramic materials.Compared with all-ceramic crowns,zirconium-based abutment improve the aesthetic level,but in view of the zirconia ceramic has a high brittleness,there is crack,broken phenomenon.In order to make the aesthetic and functional better compatible,the experimental design for the zirconia abutment pure titanium implant and pure titanium abutment titanium implant.In order to promote the quality and speed of bone bonding,the method of blistering and roughening treatment on the surface of the implant was used in clinical practice.Therefore,two groups of implants were blended with two-stage thread cylindrical implant.The fatigue load of zirconia abutment combined with pure titanium implants was investigated by comparing the fatigue limit of the two groups by using the CARE measurement and control electronic dynamic test equipment,so as to be widely used in clinical practice in future.The experimental data and reference are provided in the direction of aesthetic repair of zirconia abutment.Methods: 1 Specimen design and production1.1 Specimen design: Specimen for the combination of pure zirconium titanium implant and titanium titanium pure titanium implant,from 24 pieces surface roughing of pure titanium implants and the corresponding supporting base,the central screw,stainless steel cap Composition,abutment and implant within the hexagonal form of connection,the central screw tightening fixed,stainless steel cap bonded to the base part.1.2 Specimen production: Pure titanium implants 24 pieces: two-stage thread columnar,diameter 4mm,thread length 10 mm,wearing gingival area 2.5mm.Zirconia abutment 12 pieces: the upper diameter of 3.5mm,the bottom of the maximum diameter of 4.5mm,the total length of 7mm,the central screw into the hole diameter 2.1mm,hexagon diameter 1.5mm,outside the hexagonal connector length 1.6mm.Titanium abutment 12 pieces: the upper diameter of 3.5mm,the bottom of the maximum diameter of 4.5mm,the total length of 7mm,the central screw into the hole diameter of 2.1mm,hexagonal diameter of 1.5mm,hexagonal body length of 1.6mm.Pure titanium central screw 24 pieces: diameter 1.4mm,length 9.5 mm,thread length 5.5 mm 24 pieces stainless steel caps: outer diameter 6.5mm,inner diameter 4.6mm,total height of 9.75 mm 1.3 Manufacturer: Zirconia abutment,stainless steel caps made by the Shandong Xinhua Medical Devices Co.,Ltd.completed;pure titanium implants,titanium abutment,the central screw by the Hebei Province Xinhua the production of oral technology Co.,Ltd.completed.2 Experimental grouping Selected 24 pieces implants,the experiment is divided into A,B two groups,each group of 12 pure titanium implants and the corresponding supporting abutment,the central screw,stainless steel cap.Two groups ofimplants with acetone,75% ethanol ultrasonic cleaning 20 min after drying at room temperature.Each group is divided into four groups according to the test standard,divided into four groups,namely A1,A2,A3,A4;B1,B2,B3,B4.Group A(experimental groups): zirconia abutment + pure titanium implant + stainless steel cap(12 sets)Group A1: Apply 300 N dynamic initial load(3 sets)Group A2: Apply 275 N dynamic load(3 sets)Group A3: Apply 250 N dynamic load(3 sets)Group A4: Apply 225 N dynamic load(3 sets)Group B(control groups): titanium abutment + pure titanium implant + stainless steel cap(12 sets)Group B1: Apply 450 N dynamic initial load(3 sets)Group B2: Apply 425 N dynamic load(3 sets)Group B3: Apply 400 N dynamic load(3 sets)Group B4: Apply 375 N dynamic load(3 sets)3 Implant surface treatment The blasting machine nozzle and the implant thread area were 45o angle,0.2Mpa pressure,the diameter of 80 mesh Ti O2(titanium oxide)sprayed on the implant thread area for 7 seconds.With the preparation of 49% sulfuric acid / 18% hydrochloric acid mixture in the 60o constant temperature water bath pickling 40 min.Dry at room temperature.4 Analysis of the appearance of the implant after treatment The morphology of the surface of pure titanium implants was observed by scanning electron microscopy.5 Specimen assembly The abutment and the implant within the hexagonal way to retain the connection,smooth in place,abutment and pure titanium implant connection is good,with pure titanium central screw will implant fixed firmly together,the central screw tightening,Pre-torsion 30 N,the final stainless steel cap stick to the base,the adhesive for the 3M speed spirits.6 Fatigue strength test(ISO14801: 2007),which specifies the fatigue test method for prefabricated repair components of mucosal,single pellets,intraosseous dental implants and implants,with reference to the criteria for dental fatigue testing of dental implants(ISO 14801: 2007).The functional load of the bone implants and their pre-prosthetic components under "worst case" conditions.The lateral shear force of 30o is applied to the long axis of the implant base by applying the electronic dynamic test system of the CARE Measurement and Control.The static load is applied according to the test standard,and then the static load is applied according to the test specimen.80% of the dynamic load to determine the initial value of this study is to combine the relevant literature,the clinical situation to determine the dynamic initial load and then dynamic load test,the frequency of 10 Hz,followed by reducing the load value,record the four peak load of experimental data,until one the three specimens of the group did not undergo any damage at the time of 5×106cycles at the fatigue limit of the implant.7 Comparison and analysis of experimental results Comparing the fatigue limit of the zirconia abutment unit and the pure titanium abutment unit,the bending moment M at the maximum withstand load,drawing the load cycle diagram and recording the damage mode of each component.Results: 1 After the surface treatment of titanium implant scanning electron microscope low magnification(× 30)can be seen under the surface is rough,with lots of tiny dots depression,high magnification(× 2000,× 5000,× 8000)can not see the size of a nest hole,a nest cave also found that many irregular secondary cavity.2 Group A(experimental group): A1 group of dynamic initial load of 300 N,followed by the A2,A3 group of specimens loaded 275 N,250N load,the specimen is destroyed,the destruction of the base station and the implant interface,the central screw break;A4 The final test maximum withstand load is 225N;bending moment M = 1237.5KN.Group B(control group): B1 group set the dynamic initial load 450 N,followed by B2,B3 load 425 N,400N load,the specimen is destroyed,the destruction of the location of the third screw area is the top of the implant;B4 final measured the largest Withstand load of 375N;bending moment M = 2026.5KN.Conclusions: 1 The maximum fatigue resistance of pure titanium implants and titanium pure titanium implants is consistent with the requirement of oral bite force,which is required for oral chewing function.2 Zirconia abutments of titanium implants maximum tolerated load(225N)is less than pure titanium abutment titanium implants maximum tolerated load(375N).3 The fatigue properties of pure titanium implants of zirconia abutment are less than that of pure titanium abutment,but the maximum tolerable load has exceeded the maximum bite force of the anterior teeth,and also belongs to the range of normal occlusal force of the posterior teeth.Suitable for clinical repair applications,taking into account the zirconia abutment in the aesthetic repair effect is good,zirconia base-pure titanium implants in the field of cultivation and repair is a broad prospect. |
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