Impact of design and length on the accuracy of closed tray transfer copings

Abstract

BackgroundThe aim of this study was to evaluate the accuracy of two closed-tray transfer copings for implant impressions (a new design vs. an old design) in two different lengths (short and long).Material and MethodsFour groups of transfer copings (NS - new short, NL - new long, OS - old short and OL - old long) were tested. An epoxy resin model was prepared of missing teeth 1.4, 1.5 and 1.6. Two Alpha-Bio analogues were placed in position of teeth 1.4 and 1.6, at a 10o angulation. Two calibrated operators took 10 closed-tray impressions for each group with polyether in a Rim-Lock impression tray.ResultsAfter measuring and comparing impressions, a significant difference was found between the two new transfer copings and the old short transfer coping.ConclusionsThe new transfer coping design significantly improved impression accuracy. An adequate transfer coping design for the closed-tray impression technique can help to achieve clinically acceptable impressions for two-unit implant supported bridges. Key words:Closed tray, impression coping, transfer coping, implant impression.

In vitro comparison of the accuracy of four intraoral scanners and three conventional impression methods for two neighboring implants

“…Additionally, the type of gypsum might explain the differences between the studies, although some authors consider that the type of gypsum used is not important [36], while other authors claim better accuracy for certain types of gypsum [37]. The morphology and length of the impression copying can also determine differences between different studies [38].…”

“…A possible limitation of this study is the use of a desktop scanner to evaluate conventional models because it is not as accurate as a probe [22]. Nevertheless, we preferred the use of a desktop scanner because it is still highly accurate [38] and, moreover, a desktop scanner is commonly used by lab technicians to capture conventional models to proceed with their prosthodontic designs.…”

Conventional and Digital Impression Techniques in Implant Prosthetics

“…1,45 17 İmplant sistemine bağlı olarak ölçü transfer kopingleri farklı şekillerde, uzunluklarda, genişliklerde, retansiyon sistemlerinde ve derinliklerde olabilir. 47 İmplant üstü ölçülerde direkt teknikte genelde kare ölçü kopingleri kullanılırken indirekt teknikte konik kopingler implant üzerinde kalır ve laboratuvar analoğu ile birleştirilerek çalışma modeli elde etmek amacıyla model dökülür. 48 İmplant seviyesinde protetik tedavi için alınan ölçünün abutment seviyesinde alınan ölçüye göre bazı avantajları vardır.…”