Study On The Accuracy Of Dental Implant Under Digital Guidance

Study ? Comparative the accuracy of digital dental implantat with the guidance of surgical template: in vivo and in vitro studyAim: To evaluate the accuracy of implant surgery with the computer-aided design and computer-aided manufacture(CAD/CAM)surgical template in vivo and vitro.To analyze the influencing factors which may affect the accuracy.Materials and Methods:(1)In vitro:The 3DP resin partly edentulous mandibular models was scanned by CBCT and extra oral scanner.Then implant surgical template is designed by Guidemia surgical guide design software based on anatomic structure and parameters of the prosthesis and fabricated by a stereolithography technique.With the aid of surgical template,60 implants were inserted into 15 3DP resin mandibular models.The resin mandibular models were then scanned using CBCT again.Three-dimensional information of CT data was matched to virtual implant plan images that contained the planned implant position in Mimics software.After the superposition,the positional discrepancies between the actual implant and the planned implant could be calculated.The actual implants direction of horizontal linear deviation in mesiodistal and buccolingual at hex levels were observed.Linear and angular discrepancies of the dental implant positions were measured in seven parameters(cdh,cda,hdh,hda,vdh,vda,and ad)in 3-matic.(2)In vivo: With the approval of the ethic committee of Stomatology Hospital of Guangzhou Medical University,26 cases are chosen from patients in Stomatology Hospital of Guangzhou Medical University during the period August 2016 and May 2018.The patients were subjected to CBCT scan and impression preparation according to the clinical protocol of the implant surgical template.Then implant surgical template is designed by Guidemia software based on anatomic structure and parameters of the prosthesis and fabricated by a stereolithography technique.With the aid of surgical template,74 implants were inserted.The patients were then scanned by CBCT again.The CBCT data was matched to virtual implant plan images that contained the planned implant position in Mimics software.The actual implants direction of horizontal linear deviation in mesiodistal and buccolingual at hex levels were observed.After the superposition,the positional discrepancies between the actual implant and the planned implant could be calculated.Linear and angular discrepancies of the dental implant positions were measured in seven parameters(cdh,cda,hdh,hda,vdh,vda,and ad)in3-matic software.Statistical analysis was performed on the results of the two groups.A statistical analysis was performed with SPSS 18.0 with 95% confidence interval to investigate the volumetric deviations from comparisons.For analyzing deviations,T-test and chi-square test was done(?=.05).Results:(1)In vitro : the 60 implant mean central deviation at the hex and apex was0.88±0.43 mm and 1.00±0.48 mm respectively.Mean angular deviation was 2.14±1.38°.When evaluating the actual implants direction of horizontal linear deviation in mesiodistal and buccolingual at hex levels,it was observed that at hex levels,the deviations were mostly in the mesial(13%)and buccal(38%)directions.(2)In vivo:the 74 implant mean central deviation at the hex and apex was 1.45±0.81 mm and 1.62±0.90 mm respectively.Mean angular deviation was 3.27±2.47°.When evaluating the actual implants direction of horizontal linear deviation in mesiodistal and buccolingual at hex levels,it was observed that at hex levels,the deviations were mostly in the mesial(55%)and buccal(66%)directions.Conclusions: Digital implant surgical template can increase the accuracy of implant surgery.Compared to the results of in vitro model experiment,the accuracy of implant surgery in clinical experiment is relatively poor.The mobility of the patient,the positioning of template and the mouth's opening degree could influnce the accuracy of dental implant surgery.Study ? Comparative study on accuracy of surgical template and dynamic navigation for dental implantAim: To Comparative study on the accuracy between static surgical template and dynamic navigation in implant placement.Materials and Methods:(1)Surgical template group: The 3DP resin partial edentulous mandibular models with right and left second premolar and first molar missing was scanned by CBCT and extra oral scanner.Then implant surgical template is designed by Guidemia surgical guide design software based on anatomic structure and parameters of the prosthesis and fabricated by a stereolithography technique.With the aid of surgical template,40 implants were inserted into 10 3DP resin mandibular models.The resin mandibular models were then scanned using CBCT again.Three-dimensional information of CT data were matched to virtual implant plan images that contained the planned implant position in Mimics software.After the superposition,the positional discrepancies between the actual implant and the planned implant could be calculated.Linear and angular discrepancies of the dental implant positions were measured in three parameters(gh,ga,ad)in 3-matic software.(2)Dynamic navigation group:U-tubes were mounted on the missing teeth area of the3 DP resin mandibular models for CBCT scans.The surgery design was performed in the Yi Zhimei oral implant navigation software to simulate implant placement.With the aid of dynamic navigation,40 implants were inserted into 10 3DP resin mandibular models.The resin mandibular models were then scanned by CBCT again.The CBCT data were matched to virtual implant plan images that contained the planned implant position in Yi Zhimei implant navigation verification software.Linear and angular discrepancies of the dental implant positions were obtained in three parameters(ghd,gad,ad).A statistical analysis was performed with SPSS 18.0 with 95% confidence interval to investigate the volumetric deviations from comparisons.Results: In surgical template group,the mean global deviation at the hex and apex position of 40 placed implants was 1.15±0.34 mm and 1.37±0.38 mm respectively.Mean angular deviation was 2.6 ± 1.11°.In dynamic navigation group,the mean deviation at the hex and apex of 40 placed implants was 0.40±0.41 mm and 0.34±0.33 mm respectively.Mean angular deviation was 0.97 ± 1.21°.The deviation of dynamic navigation group gradually decreased with the increase of training times and decreased significantly after 19 times and stabilized.The correlation between deviation of static surgical template group and the training time have no significant difference.It tends to fluctuate around certain deviation values.Conclusions: For implant placement in models,both dynamic navigation and surgical template have better accuracy.The accuracy of dynamic navigation was higher than surgical template.The linear deviation at apex level is larger than that at hex level in surgical template surgery.Study ? Feasibility of determining dental implant location via digital scanner:an in vitro studyAim: To exploring the feasibility of determining implant position by digital scanning via evaluating the accuracy differences of implant locations between digital scans and CBCT scans.Materials and Methods: Fourty implants were inserted into 10 3DP resin mandibular models.The resin mandibular models were then scanned using CBCT to obtain the implant actual position.Scan bodies were placed onto the implants in the mandibular model.Then using an intraoral scanner and an extra oral scanner scan the mandibular model respectively.The standard tessellation language(STL)files of the digital models obtained from the intraoral scanner(IS group)and the extra oral scanner(ES group)were then superposed with positioning component and three-dimensional information of CT data to obtain the implant simulative position.Every group performed 3 times.After superposition,the positional discrepancies between the actual implant and the simulative implant could be calculated.Linear and angular discrepancies of the dental implant positions were measured in seven parameters(cdh,cda,hdh,hda,vdh,vda,and ad).A statistical analysis was performed with SPSS 18.0with 95% confidence interval to investigate the volumetric deviations from comparisons.For analyzing deviations,paired-samples t-test was done(?=.05).Results: In intraoral scanner group,the mean central deviation between actual implant and test implant at the hex and apex was 0.23±0.13 mm and 0.27±0.14 mm respectively.Mean angular deviation was 0.72±0.52°.In the extra oral scanner group,the mean central deviation between actual implant and test implant at the hex and apex was 0.25±0.12 mm and 0.28±0.14 mm respectively.Mean angular deviation was 0.68±0.54°.There were no significant differences in all seven parameters(cdh,cda,hdh,hda,vdh,vda,and ad)between both groups(p > 0.05).Conclusions: Digital intraoral scanning has been proven to be a valid method to valuate the precision of dental implant surgery and determine the 3D location of dental implants,this method can replace the traditional CBCT scan.