RESUMEN
Biodegradable fixation devices made of the polymers polylactide, polyglycolide and their copolymers are used routinely during maxillofacial, craniofacial, and orthopedic reconstructive surgical procedures, thanks to their property of biodegradation that avoid the need for implant removal. In particular, they are used in the treatment of craniosynostosis in pediatric patients affected by Pfeiffer syndrome, where the resorption time of 1 year or less does not interfere with the normal growth of the skull. To study the mechanism how polylactide-polyglycolide (PLPG) acid plates can induce osteoblast differentiation and proliferation in normal osteoblasts and in osteoblasts derived from a patient with Pfeiffer syndrome, the expression levels of bone-related genes were analyzed using real-time reverse transcription-polymerase chain reaction. Osteoblasts grown on the PLPG acid plates resulted in significant upregulation of mRNA expression of many genes related to osteodifferentiation during the treatment, indicating that polylactide, polyglycolide biopolymers enhance proliferation, differentiation, and deposition of matrix in osteoblasts. This study also revealed some differences in gene expression between normal osteoblasts and osteoblasts derived from patients with Pfeiffer syndrome, cultivated on PLPG acid plates.
Asunto(s)
Implantes Absorbibles , Acrocefalosindactilia/genética , Acrocefalosindactilia/cirugía , Placas Óseas , Osteoblastos/metabolismo , Fosfatasa Alcalina/genética , Biomarcadores/análisis , Técnicas de Cultivo de Célula , Diferenciación Celular , Proliferación Celular , Colágeno Tipo I/genética , Cadena alfa 1 del Colágeno Tipo I , Colágeno Tipo III/genética , Subunidad alfa 1 del Factor de Unión al Sitio Principal/genética , Regulación hacia Abajo , Expresión Génica , Humanos , Osteocalcina/genética , Poliésteres/metabolismo , Ácido Poliglicólico/metabolismo , Proteínas Proto-Oncogénicas c-fos/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factor de Transcripción Sp7 , Factores de Transcripción/genética , Resultado del Tratamiento , Regulación hacia ArribaRESUMEN
BACKGROUND: The aim of research was to study spiral family implant by finite element analysis (FEA) inserted in different bone qualities connected with abutments of different angulations. METHODS: The biomechanical behaviour of 4.2 × 13 mm dental implants, connecting screw, straight and 15° and 25° angulated abutments subjected to static loads, in contact with high and poor bone qualities was evaluated by FEA. RESULTS: The lowest stress value was found in the system composed by implants and straight abut-ments loaded with a vertical force, while the highest stress value was found in implants with 15° angulated abutment loaded with an angulated force. In addition, we found the lower the bone quality, the higher the distribution of the stress within the bone. CONCLUSION: Spiral family implants can be used successfully in low bone quality but applying a straight force is recommended.