Torsion-axial force characteristics of SR-PLLA screws

Evaluation of in vitro resistance of titanium and resorbable (poly-l-dl-lactic acid) fixation systems on the mandibular angle fracture

“…SHETTY et al 19 evaluated the characteristics of the axial torsion force of SR-poly-L-lactic acid screws with a length of 20 and 40 mm. Remarkable deformation was observed and was more pronounced in the longer screws and at higher torques.…”

“…The poly-L-DL-lactic (70:30) acid was probably less stiff and friable than the titanium-based system evaluated in that study. Resorbable polymers adapt by reorganising their polymeric chains when a continuous force is applied 19 . In the present study, the percentages of failure due to fracture and stretching of the plates were remarkably lower (7% and 19%, respectively).…”

Pullout strength of a biodegradable free form osteosynthesis plate

“…They have been used for craniofacial and pediatric fractures (Shetty et al, 1997;Gosain et al, 1998;Yerit et al, 2005a, b), midfacial fractures (Bahr et al, 1999;Bell and Kindsfater, 2006), mandibular fractures (Tormala et al, 1987;Bos et al, 1989;Gerlach, 1993;Tams et al, 1999Tams et al, , 2001Hasirci et al, 2000;Wiltfang et al, 2000;Yerit et al, 2002;Ylikontiola et al, 2003;Bell and Kindsfater, 2006;Rasse et al, 2007) and orthognathic surgery (Suuronen et al, 1992a(Suuronen et al, , b, 1997Maurer et al, 2002). Many patients still undergo the removal of titanium plates because of temperature sensitivity, palpation of the plates or the unacceptability of an incorporated foreign-body.…”

In vitro resistance of titanium and resorbable (poly l-co-dl lactic acid) osteosynthesis in mandibular body fracture

“…Other observations have been made by Shetty et al, 24 who indicated that resorbable screws present a decrease in tensile strength despite the screw thread used in the perforation stage. In order to overcome this problem, the resorbable material used in this research included screws with flat crystals and a thread pitch of 1.2 mm, whereas the metallic system had screws with angled crystals and a thread pitch of 0.6 mm.…”