Scan Body Discrepancies in Bone- and Tissue-Level Implants: In Vitro Study

This study assessed horizontal and vertical discrepancies in polyetheretherketone implant scan bodies on bone-level tapered and tissue-level implants at varying torque levels using scanning electron microscopy.

Seventy-eight polyetheretherketone scan bodies were installed in bone-level tapered and tissue-level implants. Subgroups of 13 implants each underwent 5, 10, and 15 Ncm torque, followed by scanning electron microscopy analysis using magnifications of x15 to x250. Bone-level tapered measurements included scan body length and implant-scan body angles on buccal, mesial, distal, and lingual surfaces. Tissue-level measurements included scan body angles, ap lengths, and scan body length.

Within the TL group, vertical discrepancies varied significantly with torque levels. Higher torque resulted in reduced upper and lower scan body lengths. Horizontal deviation showed a significant difference in one angle, with lower values at the lowest torque. In the BLT group, no significant vertical or horizontal differences were found. However, mesial tilting occured at 10 Ncm. Higher torque reduced scan body length up to 314 µm (P < .001) in tissue-level implants and showed horizontal deviation in one angle up to 1.43 ° (P = .012). In bone-level tapered implants, no significant differences were found based on torque, except mesial tilting at 10 Ncm.

Significant deviations in vertical and horizontal measurements were observed in the tissue-level group, with optimal outcomes at ≤ 10 Ncm. Both the tissue-level and bone-level tapered groups showed horizontal shifts and tilting.