Retrospective accuracy comparison of marker-based and marker-free registrations using dynamic implant navigation

The choice between marker-based and marker-free registration in dynamic computer-assisted implant surgery (d-CAIS) presents a trade-off between potential accuracy and workflow efficiency. This study sought to directly compare these two methods by assessing their impact on implant placement precision and overall surgical time, to inform clinical decision-making. A retrospective analysis was conducted involving 48 implants placed using d-CAIS, divided into two groups: marker-based and marker-free. Implant placement accuracy was assessed by comparing actual and planned positions using pre- and post-operative cone beam computed tomography scans. Angular and linear deviations at the implant platform and apex were recorded, along with preparation and registration times. The marker-based group exhibited significantly lower linear deviation compared to the marker-free group, particularly at both the platform and apex. However, the two methods showed no significant difference in angular deviation. The marker-free registration method demonstrated a shorter preparation time but a slightly longer registration time, with no significant difference in overall implant positioning accuracy. The marker-free group showed higher linear deviation, particularly in horizontal measurements at the implant platform and apex. This study highlights that marker-based registration offers superior precision, especially in linear deviation, during dynamic computer-assisted implant surgery. In contrast, the marker-free approach provides greater efficiency in preparation time, despite requiring slightly longer registration times. By eliminating the need for additional hardware, the marker-free method presents a viable alternative in specific clinical situations. These findings contribute valuable insights into optimizing surgical workflows and enhancing clinical outcomes in implant dentistry.