Comparative Analysis Of Digital Implant Impression & Prothodontic Case Report

Part 1 Study on the accuracy of intraoral scanning and 3D printed resin model in implant-supported restoration of dentition defect.Objective: By comparing the accuracy of intraoral scanning combined with3 D printed resin model and plaster model,the clinical application feasibility of digital technology in implant-supported restoration of large scale dentition defect was discussed.1.Invitro studyMethods: Three kinds of maxillary dental resin models with different dentition defects were used as reference models.Reference model 1,2 and 3 were scanned with 3Shape D810 model scanner for 5 times respectively,and 15 Standard Tessellation Language(STL)data were obtained,and the data were used as control group.Intraoral scanning technology,intraoral scanning combined with3 D printing technology and conventional impression technology were used to copy reference model 1,2,3 for 5 times respectively,and the data obtained were used as the experimental group.The above STL data were imported into the reverse engineering software(Geomagic Control 2014),and the virtual three-dimensional coordinate measuring machine(CMM)was used to measure the linear distance between the reference model and the test model.The average linear deviation((?)R)of the implant distance between the test model and the reference model was calculated as a method to assess the accuracy of the model.SPSS 25.0 software was used to analyze the data statistically.Results:1.1 Reference model 1 comparison results:(1)The average linear deviation of digital model(TM1)was-1.089±0.049 mm.(2)The average linear deviation of 3D printed resin model(TM2)was-0.726±0.032 mm.(3)The average linear deviation of plaster model(TM3)was-1.262±0.044 mm.1.2 Reference model 2 comparison results:(1)The average linear deviation of digital model(TM1)was 0.040 ±0.050 mm.(2)The average linear deviation of 3D printed resin model(TM2)was 0.037±0.013 mm.(3)The average linear deviation of plaster model(TM3)was-0.348±0.015 mm.1.3 Reference model 3 comparison results:(1)The average linear deviation of digital model(TM1)was-0.036±0.014 mm.(2)The average linear deviation of 3D printed resin model(TM2)was-0.024±0.009 mm.(3)The average linear deviation of plaster model(TM3)was-0.317±0.028 mm.Conclusion: In the invitro experiment of this study,compared with the conventional technology,the inter-implant linear deviation between the models obtained by digital technology is smaller.Due to the limitations of invitro research conditions,it is impossible to draw a conclusion on whether intraoral scanning combined with 3D printing technology can replace the conventional impression technology in the case of dentition defect with multi-teeth lost.2.Clinical experimentMethods::Intraoral scanning combined with 3D printing technology was applied to 5 cases of maxillary multiple teeth defect with implant-supported restoration,including 1 case supported by 2 implants in 2 units,1 case supported by 2 implants in 3 units,1 case supported by 3 implants in 3 units,1 case supported by 4 implants in 7 units,and 1 case supported by 4 implants in 9 units.Passive placement stress examination was performed by Sheffield test,combined with clinical and X-ray examination to examine the edge closeness between the implant and the superstructure.Results:(1)In 3 cases with teeth defect less than 5 units,good clinical effect was obtained by intraoral scanning combined with 3D printed resin model.The implant superstructure was completely in place,and there was no gap between the crown and the base abutment,the base abutment and the edge of the implant,and the adjacent contact and occlusal relationship were good.The patients were satisfied with the color and shape of the restoration.(2)When the metal bridge was tried on the 3D printed resin model in 2 cases with more than 5 units of teeth defect,the edge gap between the metal bridge and the angled base abutment was visible to be naked eye.Finally the conventional method was used to complete the restorations.Conclusion: Due to the limitation of lack of clinical cases,it is still necessary to conduct follow-up studies on whether intraoral scanning combined with 3D printing technology can replace the traditional impression technology in the application of dentition defects with multiple tooth loss.Part 2 The accuracy of digital impression for edentulous implant-supported restoration: A systematic analysis and evaluation.Objective: Although digital impression technology has been widely used in the field of implant-supported restoration,due to the lack of anatomical marks of the edentulous arch and the wide range of scanning,it has not been determined whether the accuracy of digital implant impression of the edentulous arch is clinically accepted.The purpose of this systematic review is to analysis and evaluate the accuracy of digital impression for edentulous implant-supported restorations.Materials and methods: An electronic search was conducted in the following databases: Pub Med and FMRS,the search strategy included the following word combinations:(fully edentulous OR completely edentulous)AND(digital implant impression OR intra oral scanning)AND(conventional implant impression OR traditional implant impression)AND(accuracy outcome 3D-deviation OR inter-implant linear distances).Electronic search was conducted for articles on in vitro studies and clinical studies published from January 2015 to December 2020.The main purpose of the included study is to evaluate the accuracy of digital impression and conventional impression for edentulous implant-supported restoration.The second is to assess the evaluation method of accuracy,the type of intraoral scanner and the influence of implant angle on the accuracy of digital impression.Results: Among the 280 articles searched,11 studies were included in the study,including 10 invitro studies and 1 clinical study.The 10 invitro studies of edentulous were quantitatively analyzed.These studies show high heterogeneity value.The random effect model is used to estimate the effect.According to the 10 invitro studys,the average accuracy deviation between conventional impressions and digital impression is-6.86μm(95% confidence range [-49.99,36.27]),and the nominal deviation of digital impressions is small(P=0.76).Due to methodological heterogeneity,one clinical study was not included in the quantitative analysis.Conclusion: The results of analysis based on invitro studies show that the accuracy of digital implant impression is higher than that of conventional implant impression.However,this study only makes a quantitative analysis of the invitro studies,and more clinical trials are recommended for the clinical application accuracy of implant-supported restoration with digital impressions.