Deviations caused by tightening torque on Polyetheretherketone scan body of bone versus tissue level implant
Dr. Ameer Biadsee, Reema Yusef, Prof. Zeev Ormianer
Tel Aviv University
Objectives
This study aimed to evaluate horizontal and vertical discrepancies in PEEK implant scan bodies attached to two implant connection types (bone-level tapered and tissue-level implants) at varying torque levels using scanning electron microscopy (SEM).
Materials and Methods
78 PEEK scan bodies were evenly divided between bone-level tapered implants (BLT) and tissue-level implants (TL). Subgroups of 13 scan bodies underwent torque application at 5, 10, and 15 Ncm, followed by argon gas coating and SEM analysis. BLT measurements included scan body length and implant-scan body angle on four surfaces (Buccal, Mesial, Distal, and Lingual). TL measurements covered PEEK scan body angles, gap lengths on all four surfaces, and scan body length on upper and lower surfaces.
Results
Significant differences in vertical discrepancies were seen in the TL group, decreasing from 5 Ncm to 15 Ncm (p < .001). At 5 Ncm, Angle L was smaller than at higher torques (p = 0.012), and gaps M, L, and D trended as 5 Ncm < 15 Ncm < 10 Ncm (P =.007, .018, .014), respectively. 15 Ncm resulted in upper-side tilting (P=.038), while all torques led to shifting to L (P=.049). In the BLT group, no significant differences were found in discrepancies with varying torque levels, but horizontal shifting to M occurred at 5 Ncm (P=.001) and 10 Ncm (P=.001) , and tilting was noted to D at 5 Ncm (P=.017) and to B at 15 Ncm (P=.016).
Conclusions
This study found significant deviations in vertical and horizontal measurements within the Tissue-level group due to torque application, with optimal outcomes observed at 5 Ncm or less. Both TL and BLT scan body groups exhibited significant horizontal changes and tilting towards specific surfaces, emphasizing the importance of considering torque levels for accurate digital workflows.