Critical appraisal of implant impression accuracies: A systematic review.
BACKGROUND
Different assessment methods have been used to measure the accuracy of implant impression techniques; therefore, the readers should understand the benefits and limitations of each assessment method used.


OBJECTIVE
The purpose of this systematic review was to classify the implant impression studies by the assessment methods and techniques used and to understand the characteristics of each assessment method. The results of published studies were also analyzed to draw meaningful conclusions about the accuracy of the implant impressions.


METHODS
An electronic search of the MEDLINE/PubMed database was performed in February 2013 using specific search terms and predetermined criteria to identify and assess laboratory studies of the accuracy of implant impression techniques. A final list of articles deemed to be of interest was comprehensively reviewed by 2 reviewers to ensure that these were suitable for the purpose of this review. The results of the current review were also compared with results from a previous systematic review.


RESULTS
A total of 56 studies met the inclusion criteria for this review. Thirty-seven studies measured the amount of linear distortion, and 17 studies compared the angular change to assess the accuracy. Most linear or angular distortions were only measured in 2 dimensions, and 3-dimensional analysis was rare. More than 80% of the studies compared nonsplinting versus splinting, direct versus indirect techniques, and different impression materials.


CONCLUSIONS
In recent publications, the direct or splint technique showed more accurate results than the indirect or nonsplinted technique. In contrast to external connection implants, inconsistent results were reported for internal connection implants.
Assistant Professor, Department of Prosthodontics, Yonsei University Dental Hospital, College of Dentistry, Yonsei University, Seoul, Korea.
Jee-Hwan
JH
Kim
Captain, The Armed Forces Medical School; and Former graduate student, College of Dentistry, Yonsei University, Seoul, Korea.
Kyoung Rok
KR
Kim
Professor and Chairman, Department of Prosthodontics, Gangnam Severance Dental Hospital, College of Dentistry, Yonsei University, Seoul, Korea. Electronic address: sunjai@yuhs.ac.
Sunjai
S
Kim
D000044:Dental Abutments; D015921:Dental Implants; D003761:Dental Impression Technique / Q000592:standards* / Q000706:statistics & numerical data; D017267:Dental Prosthesis Design / Q000592:standards / Q000706:statistics & numerical data; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D013499:Surface Properties
D015921:Dental Implants