| Objective:This study compared the clinical application effect of prefabricate abutment and CAD/CAM custom abutment,At the same time,uniaxial anti-dislocation tension tests were performed on two abutment crown complexes after abutment and crown bonding.By comparing the adhesive retention force between the two abutment and the prosthesis and comparing the clinical application effect of the two abutment,this paper provides a reference for the selection of clinical abutment of implant supported denture.Method:This study includes two parts: clinical application effect comparison of two kinds of abutment and experimental study of adhesion retention force between abutment and prosthesis.Experiment 1:156 patients were selected from the department of oral and maxillofacial surgery of Qingdao university hospital from October 2016 to October 2017,among whom 82 were males and 74 were females,aged 23-60 years old,with an average age of 42.3±3.5 years.Patients were divided into experimental group A(custom abutment)and control group B(prefabricate abutment)according to their wishes.In group A,79 patients and 135 implants were included with custom abutment to complete the upper restoration of implant supported denture,while in group B,77 patients and 129 implants were included with prefabricate abutment to complete the upper restoration of implant supported denture.The functional and aesthetic effects of implant supported denture and patient satisfaction of the two groups of patients were evaluated by two doctors without knowing the type of abutment one year after the completion of restoratiom..Experiment2:Individual abutment specimens and prefabricate abutment specimens were designed and made by selecting the cases of mandibular first molar missing and second molar without forward tilting displacement(the gap between missing teeth is the gap between normal crowns).custom abutment specimen is according to the requirement of the restoration of normal production like tooth preparation grind to four axis plane and a plane,has made the same personalized base stations(height is 4 mm,degree of polymerization is 3 °)specimen 10;At the same time,select the diameter of the original factory production the biggest(6.5 mm),the height is 4 mm,degree of polymerization is 3 ° and axial plane grinding mill(because of small size can't change)instead of original product base stations10,making the same specimen 10.The surface area of the two kind of abutment was calculated using Magics 19.01 professional STL file processing software.Cobalt-chromium alloy inner crowns corresponding to two kind of the abutment were made by 3D printe.The outer surface of the inner crown is provided with a metal circle on each side of the two opposite axial planes for tensile test.The inner crown is tightly bonded to the abutment with DMG double curing composite resin,and with a clearance of about 15 m.Then,the abutment-crown complex was mounted on the Implant replacement and fixed with a central retainer screw with a torque of 35 N·cm.The specimen was fixed on the self-made jig,and then the jig with the specimen was fixed on the universal testing machine for tensile test,and the maximum loading force when the abutment was separated from the crown was recorded.SPSS23.0 statistical software package was used for statistical processing.Results: During the one-year follow-up,2 patients in the experimental group were lost to follow-up,and 1 patient in the control group was lost to follow-up.A total of 77 patients in the experimental group were followed up with 133 implants,and 76 patients in the control group with 127 implants.After 1 year of clinical observation,the two groups of patients showed good osseointegration,no implant loss,and the implant survival rate was100%.Compared with PIS of patients in the two groups,patients in both groups had no PIS4 level,and the rate of PIS2 level and PIS3 level in the custom abutment group was significantly higher than that in the prefabricate abutment group,and the rate of grade 0and 1 level was significantly lower than that in prefabricate abutment group.The difference was statistically significant.Both the red esthetics score(PES)and the white esthetics score(WES)of the custom abutment group were significantly higher than those of the prefabricate abutment group(P < 0.05),and the difference was statistically significant.In the customm abutment group,133 crowns were not found to fall off or collapse porcelain,while in the stand abutment group,127 crowns were broken porcelain in 2 cases(P > 0.05),and the difference was not statistically significant.In the stand abutment group,there were 6 cases of crown loss(the rate of crown loss was 4.7%),P <0.05,while the difference was statistically significant.In the uniaxial tensile test of the abutment,the retention force of the custom abutment group was higher than that of the prefabricate abutment group(P < 0.05),and the difference was statistically significant.In the correlation analysis,it is found that the retainer force of the abutment is strongly correlated with the surface area.Conclusion: the custom abutment has advantages over the prefabricate abutment in terms of soft tissue morphology,function and retention force.The clinical application prospect is broad. |
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