![]() The medical community has been striving continuously to improve available instrumentation to yield better, safer, and stronger implants. Of these two considerations, surgical variables can be controlled and thus are modifiable. These goals are affected by factors including patient characteristics (e.g., curve pattern and flexibility) and surgical variables such as the type of device used (hooks or pedicle screws), rod type, and technique used to achieve curve correction (translation, rod-derotation, or direct vertebral rotation) 2, 3, 4, 5, 6. The goals of surgery for adolescent idiopathic scoliosis (AIS) are to correct the deformity and achieve sagittal and coronal balance with fusion of the least number of vertebral segments 1. Biomechanical studies of Ti and CCM rods in vitro is different in biological condition. In conclusion, Ti and CCM rods showed similar correction rates in the sagittal and coronal planes for the surgical correction of AIS with double major curves. There were no significant differences between the two groups in coronal or sagittal factors ( P > 0.05) except for greater postoperative lumbar lordosis in the CCM group ( P < 0.001). In Group A, thoracic and lumbar curvature correction rates were 71.2% and 66.8% respectively, and in Group B they were 71.2% and 73.3%, respectively ( P = 0.664 and 0.09). ![]() In our study, there were no significant differences between the two groups with respect to demographics or curve characteristics ( P > 0.05). We measured pre- and postoperative indices of coronal alignment (Cobb’s angle, coronal balance, T1-tilt, clavicle angle) and sagittal alignment (sagittal vertical axis, thoracic kyphosis, lumbar lordosis). The rod-derotation maneuver was used for correction. We divided patients into two groups, Group A (n = 29) treated with six-millimeter Ti rods and Group B (n = 16) treated with six-millimeter CCM rods. We enrolled 45 patients with AIS who underwent surgery between 20. Therefore, the purpose of this study is to compare the correction rates of Ti and CCM rods in the treatment of AIS with double major curves. However, there is a dearth of literature comparing the two rod materials in adolescent idiopathic scoliosis (AIS). In all cases, the amounts of metal ions found in the extracts were well within requirements of the international standards that apply when approving these alloys for clinical use.Numerous biomechanical studies comparing titanium (Ti) and cobalt-chrome-alloy (CCM) rods are described in the literature. – Exposure of extracts made of the alloys to two cell lines did not show any sign of toxicity, Morisbak stated. This was especially evident for titanium alloy and cast cobalt-chromium alloy. The surface roughness was influenced by the manufacturing techniques and the type of alloy used, Morisbak says.Īn additional observation was that surface roughness changed during the heat treatment. Some alloys showed a slight decrease in total ion release when CpTi grade 4 was present, Morisbak says. ![]() The total ion release decreased over time for all specimens, and the highest ion release was observed from the cast and milled Co-Cr alloy under acidic conditions. ![]() Specimens were produced using different fabrication techniques, and we also wanted to see if the presence of titanium would affect the ion release, Morisbak says.įive cobalt-chromium alloys (Wirobond 280, Remanium® star, Remanium®star MDII, Remanium®star CL, Zirkonzahn®and Sintermetall), commercially pure titanium (CpTi grade 4) and a titanium alloy (Ti6Al4V), were investigated. – We wanted to investigate whether the metal ion release, surface roughness and toxicity for cobalt-chromium alloys, were different before and after a heat treatment that corresponded to porcelain firing. NIOM senior engineer Else Morisbak participated in the joint study, which was headed by Maria Kassapidou, from The Sahlgrenska Academy, University of Gothenburg. The alloy specimens were fabricated by both traditional casting, by milling and by laser melting and sintering. Cobalt-chromium has become the alloy of choice for the framework of porcelain-fixed-to-metal (PFM) prosthetics also in combination with titanium implants. A recent study tested the behaviour of cobalt-chromium alloys under corrosive conditions mimicking the acidity observed in oral biofilm. ![]()
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