A comparison of impression techniques for the CeraOne abutment

This study measured the accuracy of two impression techniques recommended by Noblepharma to be used with their CeraOne single tooth implant restoration. The first technique was to lute the impression transfer coping to the impression tray with autopolymerizing acrylic resin. The second was to leave the transfer coping free-standing in the impression material.

Thirty-five samples were made of a polyvinyl impression of the CeraOne transfer coping free-standing in the set impression material. Thirty-five samples were made of a polyvinyl impression of the CeraOne transfer coping luted to the impression tray with autopolymerizing acrylic resin. A jig was fabricated and used to record the spatial relations of the impressions and the transfer copings in reference to the jig. A light microscope was used to measure the distance between fixed markings on pressure sensitive paper, representing impression variations.

The mean discrepancy in the horizontal plane for nonluted impressions was 0.094 mm, and for luted impressions, it was 0.275 mm. The mean discrepancy in the vertical plane for nonluted impressions was 0.154 mm, and for luted impressions, it was 0.192 mm. The differences found between the group with the luted impression tray and the group with the nonluted impression tray were found to be statistically significant.

The more accurate of the two techniques is to transfer the impression coping without luting it to the impression tray.