| Objective:To investigate and compare the fracture strength of CAD/CAM custom zirconia all-ceramic restoration abutment and CAD/CAM custom titanium base zirconia restoration abutment and the clinical application effect of the two kinds of restoration combined with all-ceramic crown in maxillary anterior teeth.The purpose of this study is to provide a reference for the selection of the most suitable abutment for maxillary anterior implant restoration to obtain the best aesthetic restoration effect and periodontal health.Methods:The flexural strength of CAD/CAM custom zirconia all-ceramic restoration abutment was compared with that of CAD/CAM custom titanium zirconia all-ceramic restoration abutment:group A:10 CAD/CAM personalized zirconia all-ceramic restoration abutments,group B:10 CAD/CAM custom titanium base zirconia restoration abutments;20 Dentium SuperLine system substitutes are prepared,the repair abutment and the substitute are assembled and fixed with a central screw,and the two groups of repair abutment specimens are fixed in turn in a self-made stainless steel fixture and placed on an electronic universal testing machine with a torque force of 25N cm,.The upper pressure head of the electronic universal testing machine is at an angle of 90° with the long axis of the repair abutment-substitute specimen complex,and the shear pressure head is placed at the 1mm above the abutment specimen.It is 3mm away from the connection between the substitute and the repair abutment,3mm from the stainless steel clamp,and perpendicular to the abutment specimen assembly(90°).Under the control of the computer,the pressure is applied to the repair abutment at the speed of 0.5mm/min until the repair abutment is damaged.The pressure shown on the pressure curve during the breakage of the abutment is recorded as the maximum flexural strength of the specimen.Observation of clinical restoration effect:64 patients with 64 implants were selected from June 2017 to June 2018 in the affiliated Hospital of Qingdao University,including 30 males and 34 females with an average age of 34.67±8.01 years.The patients were randomly divided into two groups:all-ceramic abutment group(n=32)and titanium base abutment group(n=32).32 implants in all-ceramic abutment group were restored with CAD/CAM custom zirconia all-ceramic abutment and all-ceramic crown.32 implants in titanium base abutment group were repaired with CAD/CAM custom titanium base zirconia abutment and all-ceramic crown.One year after the completion of implant restoration in both groups,clinical and imaging examinations were performed,and the success rate of implantation was counted.The clinical restoration effect was evaluated by mechanical complications,pink and white esthetic scores(PES/WES),and peri-implant soft tissue parameters(modified plaque index(mPLI),modified bleeding index(mSBI),probe depth(PD))and patient satisfaction).Results:Without crown restoration,the flexural strength of CAD/CAM custom zirconia all-ceramic restoration abutment with hexagonal+Morse taper connection in group A(488.74±15.46N)was lower than that of CAD/CAM custom titanium base zirconia restoration abutment with hexagonal+Morse taper connection(876.75±5.56N).There was significant difference between the two groups(P<0.05).The patients were followed up for 1 year after crown restoration,and no missing patients were found.The one-year cumulative success rate of 64 implants in the two groups was 100%.There was no phenomenon of crown loss,porcelain collapse,broken abutment and screw loosening,and the difference was not statistically significant(P>0.05).The pink esthetic scores(PES)of all-ceramic abutment group and titanium base abutment group were 9.47±0.84,9.25±1.02 respectively,while esthetic scores(WES)of white aesthetics were 9.50±0.76,9.34±1.04,respectively.There was no significant difference in modified plaque finger(mPLI),modified bleeding index(mSBI)and probing depth(PD)between all-ceramic abutment group and titanium base abutment group.Both groups had higher satisfaction,the average VAS of all-ceramic abutment group and titanium base abutment group was 9.06±0.76 and 8.75±0.88 respectively,and there was no significant difference between the two groups(P>0.05).Conclusion:The fracture strength of CAD/CAM custom zirconia all-ceramic abutment and titanium base zirconia abutment can be used normally for anterior implant restoration.The all-ceramic crowns supported by two kinds of zirconia abutments have achieved excellent results and high patient satisfaction in the implant restoration of anterior teeth in the aesthetic area,which meets the needs of clinical aesthetic restoration and has a good prospect of clinical application. |
