ORIGINAL ARTICLE 8 mm 14 mm 16 mm 14 mm 16 mm 14 mm 16 mm 4 20 16 mm 14 mm 14 mm 16 mm 2006;36(4):275-83) 1 11 56 12 onplant 34 12 1314 78 910 15 5 1617
36 4 2006 Table 1 Chemical composition and mechanical properties of Ti-6Al-4V alloy 18 18 1920 ASTM F2146-01 Ti-6Al-4V alloy (Table 1) 23 8 mm (Myungsung Seoul Korea) 14 mm 16 mm 14 mm 16 mm 14 mm 16 mm 4 (Fig 1) 20 21 18 solid rigid (Sawbones Pacific Research Laboratories Vashon WA USA) (Table 2 Fig 2 A) 1/8 (Elcomed SA200C W&H Burmoos Austria) (Fig 2 B) 22
Vol 36 No 4 2006 Korean J Orthod Table 2 Mechanical properties of the solid rigid (sawbones) for insertion of the orthodontic mini-implants Fig 2 Material and equipment for insertion and removal of orthodontic mini-implants A solid rigid (sawbones) with homogeneous density (30 pcf); B surgical engine (Elcomed SA200C) which is able to control the torque and rpm and measure the torque at an interval of 1/8 sec; C insertion of orthodontic mini-implant into the solid rigid with the use of a surgical engine 1 1/2 30 rpm (Fig 1 C) 18 ( 1/8 ) windows release 1201 USA) 0 2 (1 ) 4 (2 ) SPSS 120 for (SPSS Chicago IL (2 ) 8 (4 ) 0 4 4 Kruskall-Wallis Mann-Whitney 1 Bonferroni correction
36 4 2006 Fig 3 Insertion and removal mean torque as a function of the elapsed time for each group A Insertion mean torque; B removal mean torque Fig 4 Mean torque at 8 4 and 0 seconds before the maximum insertion torque and 0 2 and 4 seconds after the maximum removal torque of each group One second corresponds to a half turn of the mini-implant (Table 3) (Fig 3 A) 16 mm 14 mm (Table 3 Fig 3 A) 16 mm 14 mm (Table 3 Fig 3 B) 24 14 mm 16 mm 14 mm 16 mm 15 25 20 ) 4 (2 ) (Table 3 Fig 4) 2 (1 (Fig 3) 1821 14 mm 16 mm
Vol 36 No 4 2006 Korean J Orthod Table 3 Torque (Mean Ncm ± SD) at 8 4 and 0 seconds before the maximum insertion torque and 0 2 and 4 seconds after the maximum removal torque of each group α
36 4 2006 5-6 30 rpm 10-12 10 12 14 10 12-14 26-28 7 18 4 2 4 2 4 5-6 2-3 8 4 8-10 4-5 4-5 (Table 3) 18
Vol 36 No 4 2006 Korean J Orthod 19 20 14 mm 16 mm 18 2 1 7 Ncm 2 (p < 005) 4 2 5 Ncm 3 (p < 005) 4 alloy grade 1 4 Ti alloy Ti-6Al-4V alloy Ti-6Al-4V 15 36% 57% 25 8 mm 14 mm 16 mm 14 mm 1 2 16 mm 14 mm 3 14 mm
36 4 2006 4 16 mm 57% 36% 1 Albrektsson T Direct bone anchorage of dental implants J Prosthet Dent 1983;50:255-61 2 Linkow LI The endosseous blade implant and its use in orthodontics Int J Orthod 1969;7:149-54 3 Block MS Hoffman DR A new device for absolute anchorage for orthodontics Am J Orthod Dentofacial Orthop 1995;107:251-8 4 Wehrbein H Feifel H Diedrich P Palatal implant anchorage reinforcement of posterior teeth: A prospective study Am J Orthod Dentofacial Orthop 1999;116:678-86 5 Kanomi R Mini-implant for orthodontic anchorage J Clin Orthod 1997;31:763-7 6 Umemori M Sugawara J Mitani H Nagasaka H Kawamura H Skeletal anchorage system for open-bite correction Am J Orthod Dentofacial Orthop 1999;115:166-74 7 Park HS A new protocol of the sliding mechanics with Micro-implant Anchorage (MIA) Korean J Orthod 2000;30:677-85 8 Kyung SH Lim JK Park YC The use of miniscrew as an anchorage for the orthodontic tooth movement Korean J Orthod 2001;31:415-24 9 Kim SJ Lee YJ Chung KR An effect of immediate orthodontic force on palatal endosseous appliance (C-Palatal Plate) in beagle dog Korean J Orthod 2003;33:91-102 10 Kim CN Sung JH Kyung HM Three-dimensional finite element analysis of initial tooth displacement according to force application point during maxillary six anterior teeth retraction using skeletal anchorage Korean J Orthod 2003;33:339-50 11 Costa A Raffainl M Melsen B Miniscrews as orthodontic anchorage: a preliminary report Int J Adult Orthodon Orthognath Surg 1998;13: 201-9 12 Herrmann I Lekholm U Holm S Kultje C Evaluation of patient and implant characteristics as potential prognostic factors for oral implant failures Int J Oral Maxillofac Implants 2005;20:220-30 13 Himmlova L Dostalova T Kacovsky A Konvickova S Influence of implant length and diameter on stress distribution: a finite element analysis J Prosthet Dent 2004;91:20-5 14 Lim JW Kim WS Kim IK Son CY Byun HI Three dimensional finite element method for stress distribution on the length and diameter of orthodontic miniscrew and cortical bone thickness Korean J Orthod 2003;33:11-20 15 Kim JW Ahn SJ Chang YI Histomorphometric and mechanical analyses of the drill-free screw as orthodontic anchorage Am J Orthod Dentofacial Orthop 2005;128:190-4 16 Martinez H Davarpanah M Missika P Celletti R Lazzara R Optimal implant stabilization in low density bone Clini Oral Implants Res 2001;12:423-32 17 O'Sullivan D Sennerby L Meredith N Influence of implant taper on the primary and secondary stability of osseointegrated titanium implants Clin Oral Implants Res 2004;15:474-80 18 Kim JW Cho IS Lee SJ Kim TW Chang YI Mechanical analysis of the taper shape and length of orthodontic mini-implant for initial stability Korean J Orthod 2006;36:55-62 19 Hansson S Werke M The implant thread as a retention element in cortical bone: the effect of thread size and thread profile: a finite element study J Biomech 2003;36:1247-58 20 Palmer RM Palmer PJ Smith BJ A 5-year prospective study of Astra single tooth implants Clin Oral Implants Res 2000;11: 179-82 21 Ueda M Matsuki M Jacobsson M Tjellstrom A Relationship between insertion torque and removal torque analyzed in fresh temporal bone Int J Oral Maxillofac Implants 1991;6:442-7 22 Sennerby L Dasmah A Larsson B Iverhed M Bone tissue responses to surface-modified zirconia implants: A histomorphometric and removal torque study in the rabbit Clin Implant Dent Relat Res 2005;7(Suppl 1):13S-20S 23 Stephen DC Jeanette ED Biocompatibility and biofunctionality materials: tissue response to implanted materials In: Michael SB John NK Endosseous implants for maxillofacial reconstruction Phladelphia: WB Saunders; 1995 p 71 24 Zdeblick TA Kunz DN Cooke ME McCabe R Pedicle screw pullout strength Correlation with insertional torque Spine 1993;18:1673-6 25 Ozawa T Takahashi K Yamagata M et al Insertional torque of the lumbar pedicle screw during surgery J Orthop Sci 2005;10: 133-6 26 Huiskes R Nunamaker D Local stresses and bone adaption around orthopedic implants Calcif Tissue Int 1984;36 (Suppl 1): 110S-7S
ORIGINAL ARTICLE Effect of dual pitch mini-implant design and diameter of an orthodontic mini-implant on the insertion and removal torque Jong-Wan Kim DDS MSD a Il-Sik Cho DDS b Shin-Jae Lee DDS MSD PhD c Tae-Woo Kim DDS MSD PhD d Young-Il Chang DDS MSD PhD d Objective: Small orthodontic mini-implants are useful as anchorage However they have some weaknesses such as loosening This study was carried out to analyze the mechanical effects of the dual pitch and diameter on the insertion and removal torque of mini-implants Methods: The threads of mini-implants were mono and dual pitch The diameters of mini-implants were 14 mm and 16 mm Four groups were tested (mono 14 mm mono 16 mm dual 14 mm and dual 16 mm) All were inserted and removed on with the torques being measured Results: The maximum torque of the dual pitch groups was higher than the mono pitch groups during removal but lower during insertion The maximum torque of the 16 mm diameter groups was higher than the 14 mm diameter groups during insertion and removal The dual pitch 14 mm group showed the lowest insertion torque but had similar or superior levels of removal torque to that of the mono pitch 16 mm group Conclusions: The dual pitch especially showed a continuous high removal torque after the peak Despite the small diameter the dual pitch might improve the initial mechanical stability (Korean J Orthod 2006;36(4):275-83) Key words: Orthodontic mini-implant Stability Dual pitch Diameter