Objectives: Primary implant stability is related to local bone density. After insertion of an implant, implant stability is subject to changes due to bone remodeling. In patients who have undergone radiotherapy in the head and neck region, implant stability is impaired because irradiation reduces bone vitality. The current study was designed to monitor and test implant stability immediately after implant placement and during osseointegration in irradiated and non-irradiated minipig alveolar bone.
Materials And Methods: All maxillary and mandibular premolars and molars of six adult Göttingen minipigs were extracted. The maxilla and mandible of three minipigs received three irradiation exposures at a total dose of 24 Gy. After irradiation, five initial implant holes were drilled in the residual alveolar ridge of each edentulous site. In order to assess bone vascularity, laser Doppler flowmetry recordings were carried out in the initial holes. A total of 120 implants were placed in the six minipigs. Subsequently, and at 8, 16, and 24 weeks after implant placement, implant stability was recorded by resonance frequency analysis (RFA). RFA values were expressed as an implant stability quotient (ISQ).
Results: ISQ values recorded immediately after implant placement showed no differences between irradiated and non-irradiated minipigs. Repeated measurements at the four recording moments showed a decrease of ISQ values in all minipigs, being more pronounced in irradiated bone, when compared with non-irradiated bone. The results at the third and fourth recording moments showed a stabilization or even a slight increase of ISQ values.
Conclusions: The results document the negative effect of irradiation on bone vascularity and hence on implant stability.
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http://dx.doi.org/10.1111/j.1600-0501.2007.01457.x | DOI Listing |
ACS Nano
January 2025
School of Mechanical and Manufacturing Engineering, University of New South Wales, Sydney, New South Wales 2052, Australia.
Implantable systems with chronic stability, high sensing performance, and extensive spatial-temporal resolution are a growing focus for monitoring and treating several diseases such as epilepsy, Parkinson's disease, chronic pain, and cardiac arrhythmias. These systems demand exceptional bendability, scalable size, durable electrode materials, and well-encapsulated metal interconnects. However, existing chronic implantable bioelectronic systems largely rely on materials prone to corrosion in biofluids, such as silicon nanomembranes or metals.
View Article and Find Full Text PDFJ Mol Cell Biol
January 2025
Key Laboratory of Animal Cellular and Genetics Engineering of Heilongjiang Province, College of Life Science, Northeast Agricultural University, Harbin 150030, China.
The zygotic genome activation (ZGA) is crucial for the development of pre-implantation embryos. Long noncoding RNAs (lncRNAs) play significant roles in many biological processes, but the study on their role in the early embryonic development of pigs is limited. In this study, we identify lncFKBPL as an enhancer-type lncRNA essential for pig embryo development.
View Article and Find Full Text PDFCureus
December 2024
Trauma and Orthopaedics, PSG Institute of Medical Sciences and Research, Coimbatore, IND.
Background Numerous classifications exist for intertrochanteric (IT) fractures, commonly focused on stability. However, the currently utilized Arbeitsgemeinschaft Osteosynthesefragen and Orthopaedic Trauma Association (AO/OTA) classification has limitations in identifying irreducible fractures. This study aims to answer the following questions: does fracture stability imply irreducibility; which fracture fragments complicate reduction; and which reduction techniques should be employed? Materials and methods Eligibility criteria included fractures in adult long bones without pathological fractures being treated by native conservative means.
View Article and Find Full Text PDFTunis Med
December 2024
Department of trauma and orthopedics surgery. Mouwasat Hospital Dammam, 32263 Eastern Province Kingdom of Saudi Arabia.
Unlabelled: Introduction-Aim: Full-polyethylene glenosphere reverse shoulder arthroplasty (FP-RSA) known commonly as inverted-bearing concept utilizes a polyethylene glenosphere and metallic humeral liner. The aim was to assess mid-term outcomes of FP-RSA focusing on the incidence of scapular notching.
Methods: A retrospective analysis of 24 consecutive primary FP-RSA performed between 2017 and 2020 was conducted.
Chronic fracture-related infection is a complex, costly clinical problem with a wide spectrum of clinical presentations. The goals of treatment are infection control with a healed fracture covered by well-vascularized soft tissue and improvement of patient pain and function. Management is both medical, with culture-targeted antimicrobial agents, and surgical, requiring meticulous irrigation and débridement.
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