Accuracy of implant impression techniques with a scannable healing abutment

Abstract

Statement of problem Scannable healing abutments are a convenient option to facilitate impression making for implant-supported restorations. However, studies evaluating the accuracy of the impression technique with scannable healing abutments are lacking.

Purpose The purpose of this in vitro study was to evaluate the accuracy of implant impression techniques with scannable healing abutments.

Materials and methods A partially edentulous mandibular dentiform model was fabricated with an epoxy resin, and implants were placed in the mandibular right second premolar and first molar areas. A maxillary dentiform model was then fabricated, and both models were mounted on an articulator. Scan data were obtained from the mounted models and set as the reference scans. The experimental models were divided into 4 groups (n=10). The conventional pick-up impression technique and definitive casts were used in group CI. The scan data from the definitive casts were obtained with a 3D model scanner. An intraoral scanner with a digital body scan was used in group DS. Group MS yielded definitive casts with dual-arch impressions with scannable healing abutments. The fabricated definitive casts were mounted and scanned with a 3D cast scanner. Intraoral scanning with scannable healing abutments was used in group IS. In all 4 groups, the interarch relationship in the maximum intercuspal position was obtained by scanning the facial aspect. The center of the implant head was set as a measurement point for linear intra-arch deviations and implant angle deviations. The mesiopalatal cusp tip of the maxillary right first molar was used to calibrate the linear interarch deviations. The data obtained from each group were compared with the data from the reference scan. As the data were not normally distributed, the Kruskal-Wallis test and Bonferroni correction were used for the analysis (α=.05).

Results Group MS exhibited significantly higher deviations in linear intra-arch and implant angles compared with the other groups (P<.05). No significant difference was found between the groups in linear interarch deviations (P>.05).

Conclusions The accuracy of intraoral scanning with scannable healing abutments was comparable with that of conventional pick-up impression techniques and digital scans with scan bodies. However, model scanning with scannable healing abutments may not be clinically acceptable for implant impressions.