Evaluating the accuracy of 16 intraoral scanners against 3 laboratory scanners and 2 conventional techniques in a partial implant situation: an in vitro study.

OBJECTIVE

The purpose of this in vitro study was to evaluate the trueness and precision of 16 intraoral scanners (IOS) and 3 laboratory desktop scanners compared with conventional implant impression techniques (open-tray and closed-tray) using a partially edentulous four-implant model. The null hypothesis was that no significant differences in accuracy would be detected among the tested impression techniques.

METHODS

A mandibular reference model with four implants placed at predefined positions and angulations was fabricated using additive manufacturing. Digital impressions were obtained using 16 IOS devices, 3 laboratory scanners, and conventional implant impression techniques. All datasets were aligned to a high-resolution industrial reference scan. Linear (dXYZ) and angular (Δangle) deviations were calculated for each implant site. Data were analyzed using a linear mixed-effects model (α = 0.05), and repeated measurements were performed to assess precision.

RESULTS

Significant differences were observed among the tested techniques for both linear and angular deviations (P < .05). Laboratory scanners demonstrated the lowest deviation values. Several IOS devices exhibited significantly lower linear and angular deviations than conventional impression techniques (P < .05). Precision did not differ significantly among techniques (P > .05). Implant angulation did not significantly influence accuracy within the tested configuration.

CONCLUSIONS

Within the limitations of this in vitro study, laboratory desktop scanners demonstrated the highest trueness under controlled conditions. Several intraoral scanners achieved accuracy comparable to or greater than that of conventional implant impression techniques in a partial-arch configuration.

CLINICAL SIGNIFICANCE: Contemporary intraoral scanners may provide a reliable alternative to conventional implant impression techniques in partially edentulous implant situations; however, device-related variability should be considered during scanner selection and digital workflow planning.