title: Mechanical strength and stiffness of the biodegradable SonicWeld Rx osteofixation system.
abstract: OBJECTIVE
  To determine the mechanical strength and stiffness of the new 2.1 mm biodegradable ultrasound-activated SonicWeld Rx (Gebrüder Martin GmbH & Co, Tuttlingen, Germany) osteofixation system in comparison with the conventional 2.1 mm biodegradable Resorb X (Gebrüder Martin GmbH & Co) osteofixation system.
  
  
  METHODS
  Plates and screws were fixed to 2 polymethylmethacrylate blocks to simulate bone segments and were subjected to tensile, side bending, and torsion tests. During testing, force and displacement were recorded and graphically presented in force-displacement diagrams. For the tensile tests, the strength of the osteofixation system was measured. The stiffness was calculated for the tensile, side bending, and torsion tests.
  
  
  RESULTS
  The tensile strength and stiffness as well as the side bending stiffness of the SonicWeld Rx system presented up to 11.5 times higher mean values than the conventional Resorb X system. The torsion stiffness of both systems presents similar mean values and standard deviations.
  
  
  CONCLUSIONS
  The SonicWeld Rx system is an improvement in the search for a mechanically strong and stiff as well as a biodegradable osteofixation system. Future research should be done to find out whether the promising in vitro results can be transferred to the in situ clinical situation.
authors.affiliation: Department of Oral and Maxillofacial Surgery, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands. g.j.buijs@kchir.umcg.nl
authors.forename: Gerrit J
authors.initials: GJ
authors.lastname: Buijs
authors.forename: Eduard B
authors.initials: EB
authors.lastname: van der Houwen
authors.forename: Boudewijn
authors.initials: B
authors.lastname: Stegenga
authors.forename: Gijbertus J
authors.initials: GJ
authors.lastname: Verkerke
authors.forename: Rudolf R M
authors.initials: RR
authors.lastname: Bos
mesh_terms: D020341:Absorbable Implants; D001672:Biocompatible Materials / Q000737:chemistry*; D001858:Bone Nails; D001860:Bone Plates; D001863:Bone Screws; D004548:Elasticity; D004868:Equipment Failure; D006801:Humans; D008422:Materials Testing; D009984:Orthopedic Fixation Devices; D018583:Pliability; D011091:Polyesters / Q000737:chemistry*; D019904:Polymethyl Methacrylate / Q000737:chemistry; D013314:Stress, Mechanical; D013696:Temperature; D013718:Tensile Strength; D013997:Time Factors; D054159:Torsion, Mechanical; D014465:Ultrasonics; D014732:Vibration; D014867:Water / Q000737:chemistry
chemical_list: D001672:Biocompatible Materials; D011091:Polyesters; D014867:Water; C033616:poly(lactide); D019904:Polymethyl Methacrylate