Implant Impression Techniques for the Edentulous Jaw: A Summary of Three Studies

PurposePrecise implant-supported restorations require accurate impressions. Transfer, pick-up, and splinted pick-up are commonly used techniques. Several in vitro studies have compared these impression techniques; however, all studies used mechanical evaluation methods. The purpose of this study was to compare the discrepancies of these impression techniques digitally in vitro and in vivo. Materials and MethodsFour dental implants were inserted in ten polymer mandibular models bilaterally in the regions of the first molars and canines. Three different impressions were made of each model and the models (original and stone casts) were scanned and digitized. Clinically, four implants were inserted in ten edentulous jaws; transfer and splinted pick-up impressions were made. With inspection software, discrepancies between the different impressions were calculated. ResultsThe mean discrepancies in the in vitro study of the original polymer model to stone casts were 124 34 m for the transfer type, 116 +/- 46 m for the pick-up type, and 80 +/- 25 m for the splinted pick-up type, resulting in a mean discrepancy between the transfer and splinted pick-up type of 44 m (124 - 80 m). Clinically, the mean discrepancy between these two impression techniques was 280 m. ConclusionsThe differing results between the transfer and splinted pick-up techniques of in vitro and in vivo data showed the need for clinical data; however, splinted pick-up impressions seemed to produce the most precise results.