Comparison of insertion torque regarding changes in shape, diameter, and length of orthodontic miniscrews.
- Author:
Seon A LIM
1
;
Jung Yul CHA
;
Chung Ju HWANG
Author Information
1. Department of Orthodontics, School of Dentistry, Yonsei university, Korea.
- Publication Type:Original Article
- Keywords:
Miniscrew;
Insertion torque;
Diameter;
Length
- MeSH:
Head;
Korea;
Molar;
Polyurethanes;
Seoul;
Torque*
- From:Korean Journal of Orthodontics
2007;37(2):87-97
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
OBJECTIVE: The purpose of this study was to measure the insertion torque of orthodontic miniscrews regarding changes in their shape, diameter, and length. METHODS: Torque values were measured during continuous insertion of the miniscrews into solid rigid polyurethane foam, using a torque tester of driving motor type with a regular speed of 3 rpm. Orthodontic miniscrews (Biomaterials Korea, Seoul, Korea) of cylindrical type and taper type were used. RESULTS: Increasing the length and diameter of the miniscrews increased the maximum insertion torque value in both cylindrical and taper type screws. Insertion torque was increased at the incomplete head of the cylindrical type screw, and at the tapered part of the taper type screw. The insertion torque value of miniscrews was influenced most by diameter, then shape and length. As a result, it was shown that the diameter of the screw had the most influence on insertion torque, and the taper type screw had a higher torque value than the cylindrical type screw. CONCLUSION: Therefore, a large diameter or taper type screw are adequate for areas of thin cortical bone with a large interdental space, and a small diameter or cylindrical type screw are adequate in the mandibular molar area or the midpalatal area having thick cortical bone.
