Comparison of two systems for rigidly connecting 2.0-mm bone screws to an implantable device: in vitro stability testing.
The stability of a screw-fixed implantable device can be improved by eliminating the freedom of movement between the screws and the device. Two systems have been developed for rigidly connecting 2. 0-mm bone screws to an implantable device, and the aim of this study was to test and compare the stability of the two systems. In system A, a fixing disc locked the screw-head. In system B, the thread of the screw locked directly into the device. The stability of the connection was tested by measuring the resistance against a torque on the screw, against shear loading, against push-out loading, and against dynamic shear loading (70 N) for 5 million cycles. Both systems met the required minimum values for the resistance against a torque, shear loading and push-out loading, and dynamic shear loading did not cause movements between the screw and the device. We conclude that both systems are stable, but prefer system B because it is easier to make and implant than system A.
van Loon
P
P
TMJ Research Group, Department of Oral & Maxillofacial Surgery, University Hospital Groningen, Groningen, The Netherlands.
de Bont
L G
LG
Verkerke
G J
GJ
D001860:Bone Plates; D001863:Bone Screws; D019245:Compressive Strength; D003758:Dental Implantation, Endosseous / Q000295:instrumentation*; D006801:Humans; D007595:Joint Prosthesis; D008422:Materials Testing; D019736:Prostheses and Implants; D011474:Prosthesis Design; D013314:Stress, Mechanical; D013704:Temporomandibular Joint; D013718:Tensile Strength; D019415:Torque