Evaluation of concordance between CAD/CAM and clinical positions of abutment shoulder against mucosal margin: an observational study

Abstract Background While working on CAD/CAM-customized abutments, the use of standard impression copings with a circular diameter produces inconsistency within the emergence profile. It may begin with a collapse of the supra-implant mucosa during impression taking, then lead to a computer-generated...

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Bibliographic Details
Main Authors: Jan K. Pietruski, Anna Skurska, Anna Bernaczyk, Robert Milewski, Maria Julia Pietruska, Peter Gehrke, Małgorzata D. Pietruska
Format: Article
Language:English
Published: BMC 2018-05-01
Series:BMC Oral Health
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Online Access:http://link.springer.com/article/10.1186/s12903-018-0534-2
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Summary:Abstract Background While working on CAD/CAM-customized abutments, the use of standard impression copings with a circular diameter produces inconsistency within the emergence profile. It may begin with a collapse of the supra-implant mucosa during impression taking, then lead to a computer-generated mismatch of the position and outline of the abutment shoulder, and consequently result in a compromised outcome of anticipated treatment. The aim of the study was to compare the virtual and clinical positions of the abutment shoulder in relation to the mucosal margin after the abutment delivery. Methods Conventional open-tray impression takings followed uncovering surgery. Master casts were scanned with a desktop scanner. Clinical examinations took place after abutment’s insertion and temporization (T1) and prior to cementation of the definitive crown (T2). The distances between the abutment shoulder and marginal soft tissue were measured intraorally in four aspects and juxtaposed with those on the virtual model. Results The study evaluated 257 dental implants and CAD/CAM-customized abutments. As T1 and T2 showed, there was a positive correlation between the virtually designed abutment shoulder position and matching clinical location relative to the mucosal margin. In 42.1% of cases, the distance between the mucosal margin and the abutment shoulder did not change. It increased in 36.3% of cases while a decrease occurred in 21.6% of them. Conclusions Computer-set position of the abutment shoulder in relation to the mucosal margin can be predictably implemented in clinical practice.
ISSN:1472-6831