An in vitro investigation of peak insertion torque values of six commercially available mini-implants

作者：Whang C Z Y; Bister D^*; Sherriff M

来源：The European Journal of Orthodontics, 2011, 33(6): 660-666.

DOI：10.1093/ejo/cjq129

This study compared peak insertion torque values of six commercially available self-drilling mini-implants [Mini Spider (R) screw (1.5 x 8 mm), Infinitas (R) (1.5 x 9 mm), Vector TAS (R) (1.4 x 8 mm), Dual Top (R) (1.6 x 8 mm), Tomas Pin (R) (1.6 x 8 mm), and Ortho-Easy (R) (1.7 x 6, 8, and 10 mm)]. Twenty implants each were drilled into acrylic rods at a speed of 8 rpm using a motorized torque measurement stand, and the values were recorded in Newton centimetres (Ncm). A further 20 Ortho-Easy (R) implants with a length of 6 and 10 mm were tested at 8 rpm; 20 implants of 6 mm length were also tested at 4 rpm. Kaplan-Meier estimates of the peak torque values were compared using the log-rank test with multiple comparisons evaluated by Sidak's test.
There were significant differences in the maximum torque values for different mini-implants with the same length. The Mini Spider (R) screw and Infinitas (R) showed the lowest average torque values (6.5 and 12.4 Ncm) compared with Vector TAS (R), Dual ToP (R), Tomas Pin (R), and Ortho-Easy (R) (30.9, 29.4, 25.4, and 24.8 Ncm, respectively). There was no correlation between the diameter of the implants and torque values. The Tomas Pin (R) showed the largest standard deviation (7.7 Ncm) and the Dual Top (R) implant the smallest (0.6 Ncm). Different insertion speeds did not result in significant differences in peak torque values but the 6 mm mini-implants showed significantly higher torque values than the 8 and 10 mm implants. Using a 'torque limiting' screwdriver or pre-drilling cortical bone to reduce insertion, torque appears justified for some of the tested implants.

• 出版日期2011-12