Analysis of seating and fracturing torque of bicortical screws

Experimental in vivo acute and chronic biomechanical and histomorphometrical comparison of self-drilling and self-tapping anterior cervical screws

“….03 ± 8.22%; P \ 0.0005) and chronic (31.94 ± 3.80% vs. 23.25 ± 6.24%; P \ 0.013) phases. The percentage of bone outside the screw thread area was statistically similar between the two screw modalities in both the acute (33.99 ± 11.7% vs. 25.20 ± 8.48%; P = 0.1) and chronic (32.16 ± 5.26 vs. 33.942 ± 13.28; P = 0.71) phases (Figs 6,7,8,9,10)…”

“…The threads are guided along a rotation axis up to the screw head. The higher insertional torque of SDS compared to STS might present a problem in thick cortical bone ([3 mm) [7,12,36], but this is not a problem for their use in cervical fixation considering their insertion into cancellous bone. The SDS design influences screw pullout resistance, and conically shaped screws have shown the best results in cancellous bone [19].…”

“…The rationale for STS and SDS development was to reduce the number of tools and surgical steps without compromising screw pullout strength [12]. The avoidance of bone necrosis secondary to the large amount of heat generated during drilling of cortical bone [7,13,33] is also another advantage of SDS. However, this advantage may not be valid for vertebral screws, considering that their application to cancellous bone does not require powerful drilling that generates heat as is required for cortical bone.…”

Experimental in vivo acute and chronic biomechanical and histomorphometrical comparison of self-drilling and self-tapping anterior cervical screws

“….03 ± 8.22%; P \ 0.0005) and chronic (31.94 ± 3.80% vs. 23.25 ± 6.24%; P \ 0.013) phases. The percentage of bone outside the screw thread area was statistically similar between the two screw modalities in both the acute (33.99 ± 11.7% vs. 25.20 ± 8.48%; P = 0.1) and chronic (32.16 ± 5.26 vs. 33.942 ± 13.28; P = 0.71) phases (Figs 6,7,8,9,10)…”

“…The threads are guided along a rotation axis up to the screw head. The higher insertional torque of SDS compared to STS might present a problem in thick cortical bone ([3 mm) [7,12,36], but this is not a problem for their use in cervical fixation considering their insertion into cancellous bone. The SDS design influences screw pullout resistance, and conically shaped screws have shown the best results in cancellous bone [19].…”

“…The rationale for STS and SDS development was to reduce the number of tools and surgical steps without compromising screw pullout strength [12]. The avoidance of bone necrosis secondary to the large amount of heat generated during drilling of cortical bone [7,13,33] is also another advantage of SDS. However, this advantage may not be valid for vertebral screws, considering that their application to cancellous bone does not require powerful drilling that generates heat as is required for cortical bone.…”

Surface changes of anodic oxidized orthodontic titanium miniscrew

“…Second, because the miniscrews were subjected to tension or torsion over 12 weeks by the NiTi coil spring, surface changes might occur in the miniscrews. 21,22 Third, the deposits around the miniscrews or the materials precipitated on its surface from contact of the miniscrew with biological fluids were likely due to clogs in open pores.…”

Structure and mechanical properties of orthodontic miniscrew implants

“…Early MIs were pretapped and required an initial pilot hole to be drilled through the entire thickness of the cortical layer. 50 In contrast, the peak removal torque appears to be similar for selfdrilling and self-tapping devices. 1,2 Although self-drilling MI placement is far less invasive than placement of selftapping MIs, the pressure exerted on the bone during perforation of the cortical layer and the greater placement torque required for insertion creates more stress on bone and MI, leading to a greater risk of fracture for both.…”

Experimental in vivo acute and chronic biomechanical and histomorphometrical comparison of self-drilling and self-tapping anterior cervical screws

“….03 ± 8.22%; P \ 0.0005) and chronic (31.94 ± 3.80% vs. 23.25 ± 6.24%; P \ 0.013) phases. The percentage of bone outside the screw thread area was statistically similar between the two screw modalities in both the acute (33.99 ± 11.7% vs. 25.20 ± 8.48%; P = 0.1) and chronic (32.16 ± 5.26 vs. 33.942 ± 13.28; P = 0.71) phases (Figs 6,7,8,9,10)…”

“…The threads are guided along a rotation axis up to the screw head. The higher insertional torque of SDS compared to STS might present a problem in thick cortical bone ([3 mm) [7,12,36], but this is not a problem for their use in cervical fixation considering their insertion into cancellous bone. The SDS design influences screw pullout resistance, and conically shaped screws have shown the best results in cancellous bone [19].…”

“…The rationale for STS and SDS development was to reduce the number of tools and surgical steps without compromising screw pullout strength [12]. The avoidance of bone necrosis secondary to the large amount of heat generated during drilling of cortical bone [7,13,33] is also another advantage of SDS. However, this advantage may not be valid for vertebral screws, considering that their application to cancellous bone does not require powerful drilling that generates heat as is required for cortical bone.…”

Surface changes of anodic oxidized orthodontic titanium miniscrew

“…Second, because the miniscrews were subjected to tension or torsion over 12 weeks by the NiTi coil spring, surface changes might occur in the miniscrews. 21,22 Third, the deposits around the miniscrews or the materials precipitated on its surface from contact of the miniscrew with biological fluids were likely due to clogs in open pores.…”

Structure and mechanical properties of orthodontic miniscrew implants

“…Early MIs were pretapped and required an initial pilot hole to be drilled through the entire thickness of the cortical layer. 50 In contrast, the peak removal torque appears to be similar for selfdrilling and self-tapping devices. 1,2 Although self-drilling MI placement is far less invasive than placement of selftapping MIs, the pressure exerted on the bone during perforation of the cortical layer and the greater placement torque required for insertion creates more stress on bone and MI, leading to a greater risk of fracture for both.…”

Experimental in vivo acute and chronic biomechanical and histomorphometrical comparison of self-drilling and self-tapping anterior cervical screws

“….03 ± 8.22%; P \ 0.0005) and chronic (31.94 ± 3.80% vs. 23.25 ± 6.24%; P \ 0.013) phases. The percentage of bone outside the screw thread area was statistically similar between the two screw modalities in both the acute (33.99 ± 11.7% vs. 25.20 ± 8.48%; P = 0.1) and chronic (32.16 ± 5.26 vs. 33.942 ± 13.28; P = 0.71) phases (Figs 6,7,8,9,10)…”

“…The threads are guided along a rotation axis up to the screw head. The higher insertional torque of SDS compared to STS might present a problem in thick cortical bone ([3 mm) [7,12,36], but this is not a problem for their use in cervical fixation considering their insertion into cancellous bone. The SDS design influences screw pullout resistance, and conically shaped screws have shown the best results in cancellous bone [19].…”

“…The rationale for STS and SDS development was to reduce the number of tools and surgical steps without compromising screw pullout strength [12]. The avoidance of bone necrosis secondary to the large amount of heat generated during drilling of cortical bone [7,13,33] is also another advantage of SDS. However, this advantage may not be valid for vertebral screws, considering that their application to cancellous bone does not require powerful drilling that generates heat as is required for cortical bone.…”

Surface changes of anodic oxidized orthodontic titanium miniscrew

“…Second, because the miniscrews were subjected to tension or torsion over 12 weeks by the NiTi coil spring, surface changes might occur in the miniscrews. 21,22 Third, the deposits around the miniscrews or the materials precipitated on its surface from contact of the miniscrew with biological fluids were likely due to clogs in open pores.…”

Structure and mechanical properties of orthodontic miniscrew implants

“…Early MIs were pretapped and required an initial pilot hole to be drilled through the entire thickness of the cortical layer. 50 In contrast, the peak removal torque appears to be similar for selfdrilling and self-tapping devices. 1,2 Although self-drilling MI placement is far less invasive than placement of selftapping MIs, the pressure exerted on the bone during perforation of the cortical layer and the greater placement torque required for insertion creates more stress on bone and MI, leading to a greater risk of fracture for both.…”