Study On The Accuracy Of Implant Placement In Posterior Region Of Maxilla And Mandible Via Digital Implant Template

Objective:To compare the accuracy of implant placement guided by digital implant template with different support forms,the accuracy of implant placement guided by template in different tooth position,accordingly explore the influence of support form and implant positon on the accuracy of implant placement guided by implant template.To compare the accuracy of implant placement guided by digital implant template intraoral and in vitro,to estimate the proportion of errors caused by clinical factors in total errors,to evaluate the influence of clinical factors on the accuracy of implant placement guided by implant template.To observe the adjacent relationship of prefabricated provisional resin crown and evaluate whether the accuracy of implantation assisted by digital implant template meets the requirement to use a prefabricated provisional crown.To provide guidance for clinicians on the practice of dental implantation assisted by digital implant template.Methods:Subjects of the study include patients who underwent implantation guided by a digital implant template in the First Affiliated Hospital of Zhejiang University School of Medicine from May,2018 to September,2018.Basic information,CBCT before and after implantation of the patients were collected.Proximal and distal adjacent relationship of the provisional crown were recorded.Ultra-anhydrite models of the patients were collected,implant sockets were prepared under the guidance of digital implant template,scan bodies were placed in the implant sockets and the location of the implants were calculated.The linear and axial angle deviation between the actual and the ideal implant position were measured and analyzed.The direction of radial angle deviation were described.The linear and axial angle deviation between the planned implant position in Ultra-anhydrite models and the ideal implant position were measured and analyzed.And the direction of radial angle deviation were described.Measurement data was analysed using SPSS 17.0,the differences between two groups were compared with t-test,among multiple groups with one-way ANOVA.The difference was statistically significant with p<0.05.The linear and angular deviations between the actual implant position and the ideal implant position,between the planned implant position in Ultra-anhydrite models and the ideal implant position were analyzed to explore the following points:1)The relationship between support form of digital implant template and accuracy of implant placement;2)The difference of accuracy between implant placed in vivo and implant placed in vitro;3)The relationship between implantation site and accuracy of implant placement;4)The accuracy of the provisional resin crown.Results:There was no significant difference in the linear and axial angle deviation of implant position between the two types of digital implant template(p>0.05).The linear deviation and axial angle deviation of implant position were significantly higher in model mimic situation than in vitro via digital implant template.In addition,the direction of the maximum axial angle deviation of the implant located mainly on the distal lingual quadrant,accounting for 53%of the total,while on the Ultra-anhydrite model it was evenly distributed in four quadrants.There was no significant difference in the linear and axial angle deviation of implant position between implant locations(in the four quadrants A,B,C,D)(p>0.05).Of the prefabricated provisional resin crown,precise adjacent relationship accounts for 39%,general accuracy accounts for 28%,inaccurate adjacent relationship accounts for 33%.Conclusions:In this study,no differences of implant accuracy were found between the types of digital implant template,the location of implantation.Comparison of the accuracy of implant placement in model and in vitro reveals that clinical conditions are important factors leading to imprecise implant placement under the guidance of digital implant template.In addition,the precision of half-guided implant surgery cannot meet the requirements of prefabricated provisional crown.