Accuracy of Complete-arch Digital Implant Impression With Newly Designed Scan Bodies
Conditions: Edentulous Jaw
Sponsor: Sun Yat-sen University

 
 
 
 
 
 
 
Accuracy of complete-arch digital implant impression with newly 
designed scan bodies. 
 
2020/10/10 
 
 
 
 
 
 
 
 
 
 
 

Accuracy of complete-arch digital implant impression with newly 
designed scan bodies. 
 
Objective 
To investigate the accuracy of complete-arch digital implant impression using newly 
designed scan bodies. 
 
Inclusion Criteria: 
At least 18 years old and able to understand an informed consent 
Fully edentulous jaw 
2-6 dental implants have been placed in the edentulous jaw 
The implants have been osseointegrated 
Mouth opening larger than 4.5 cm 
 
Exclusion Criteria: 
Poor oral hygiene 
Presence of peri-implantitis or peri-implant mucositis 
Presence of temporamandibular joint disease 
Unwilling to paticipate in the researchInclusion criteria 
 
Study design 
(1) Test data: for each patient, the follow three impressions are made. 
① Conventional splinted open-tray impression: A preliminary stone cast are 
produced using alginate impression material. Impression copings are 
connected to the implant analogs and splinted with self-cured pattern resin. 
The splinted assemblies are cut and connected to the abutments intraorally, and 
then reconnected. Open-tray impressions are made using siloxane impression 
material. The stone casts are poured with low expansion type IV gypsum. Scan 
bodies without extensional structure are connected to the analogs fixed in the 
stone casts, which are then digitalized with a laboratory scanner. The digital 
models are exported as STL files. 
② Digital impression using scan bodies without extensional structure: scan 
bodies without extensional structure are connected to the abutment intraorally 
and scanned with an intraoral scanner. The digital models are exported as STL 
files. 
③ Digital impression using scan bodies with extensional structure: scan bodies 
with extensional structure are connected to the abutment intraorally and 
scanned with an intraoral scanner. The digital models are exported as STL files. 
(2) Reference data 
The scan bodies with extensional structure are connected with self-cured 
pattern resin intraorally. The splinted scan bodies are scanned with a laboratory 
scanner and exported as STL files. 
(3) Data analysis 
The STL files are imported to an inspection software. Each of the test data is aligned 

with the reference data using “best-fit” algorithm. The deviations between test data 
and reference data are calculated automatically. 
(4) Statistics 
Differences between groups in trueness and precision are evaluated using two-way 
ANOVA, Post-hoc analysis is performed with Bonferroni test. The level of 
significance was set at α = .05.