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Medical and Biological Applications of Low Energy Accelerators
Published in Vlado Valković, Low Energy Particle Accelerator-Based Technologies and Their Applications, 2022
Bone is a dynamic structure, constantly remodeling in response to changing mechanical and environmental factors. This is particularly evident in the mineral component encrusting the collagenous framework. The mineral is principally in the form of calcium apatite, but calcium can exchange with strontium, both during the cellular processes of mineralization and resorption and by passive exchange with the deposited crystals. Mineralization is generally characterized by densitometry, but because of the differences in absorption cross-sections of calcium and strontium, it can be misleading in studies of composition. In their work, Bradley et al. (2007) have used X-ray diffraction to identify calcium and strontium apatite and X-ray fluorescence to quantify strontium and calcium distribution. The beam characteristics available from SR, this has enabled us to obtain microscopic resolution on thin sections of bone and cartilage from the equine metacarpophalangeal joint.
Cephalopelvic Disproportion and Contracted Pelvis
Published in Gowri Dorairajan, Management of Normal and High Risk Labour During Childbirth, 2022
Nutritional Disorders: Rickets and osteomalacia are the most typical disorders affecting the mineralisation of the bones. This results in soft bones, which tend to deform easily due to pressures of weight-bearing.
Home Parenteral Nutrition*
Published in Fima Lifshitz, Childhood Nutrition, 2020
Adib A. Moukarzel, Marvin E. Ament
Osteopenia is a characteristic of patients who receive long-term parenteral nutrition. Patients may be osteopenic with a mean loss of 25% of the calcium in their trabecular bone.8 A number of factors have been considered that may contribute to the decreased mineralization. Deficiencies in manganese, fluoride, boron, and silicone have been hypothesized as potential factors. In a recent study,9 we found that serum silicone levels in those receiving HPN were 50% lower than those in non-PN controls. Furthermore, the significant correlation between silicone intake and degree of demineralization suggests an involvement of silicone in the pathogenesis of the bone disease.
Development and biocompatibility of the injectable collagen/nano-hydroxyapatite scaffolds as in situ forming hydrogel for the hard tissue engineering application
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2021
Armin Hassanzadeh, Javad Ashrafihelan, Roya Salehi, Reza Rahbarghazi, Masomeh Firouzamandi, Mahdi Ahmadi, Majid Khaksar, Mahdieh Alipour, Marziyeh Aghazadeh
Overall, the results demonstrated the lack of the adverse reaction in the host animal model, which showed that the PCL-PEG-PCL-Col and PCL-PEG-PCL-Col/nHA hydrogels were biocompatible and biodegradable and their degradation products were not toxic to the kidney and liver of the mouse model. Moreover, the addition of the nano-hydroxyapatite significantly induced the mineralization in vitro. Hence, the composite, biodegradable, and biocompatible PCL-PEG-PCL-Col/nHA could be used as an injectable biomaterial for the regeneration of the hard tissues. However, more in vivo induction of the mineralization in bone, cartilage, and tooth should be established in large animal models for better insights on the application of the injectable PCL-PEG-PCL-Col/nHA in the clinical practice.
An analysis of third molar mineralization in Brazilian patients with cleft lip and palate
Published in Acta Odontologica Scandinavica, 2020
Esther Carneiro Ribeiro, Rosa Helena Wanderley Lacerda, Luciana Gabriella Medeiros da Silva, Bianca Marques Santiago, Camila Helena Machado da Costa, Manuella Santos Carneiro Almeida
The degrees of third molar mineralization were evaluated according to the classification proposed by Demirjian et al. [9] and Nolla [10]. A 2-week interval was considered for calibration purposes. To assess the intra-examiner concordance, the examiners scored 20 randomly selected digital panoramic radiographs (which were not part of the final sample), and after 4 weeks rescored the same 20 exams. Differences in the diagnostic performance of evaluating dental mineralization between the first and second observations of the radiographs were compared by paired t-tests. For comparisons, all the p-values were greater than .05. The inter-examiner concordance was evaluated by the weighted kappa statistic and a satisfactory concordance was obtained (weighted κ value> .87). The three examiners evaluated simultaneously the radiographic images for each method, and the mineralization stages of the third molars were determined by consensus. Thus, all three examiners evaluated the whole sample of radiographic images sequentially in anticlockwise direction from tooth #18 (maxillary right third molar) to tooth #48 (mandibular right third molar).
The role of bioactive glass in the management of chronic osteomyelitis: a systematic review of literature and current evidence
Published in Infectious Diseases, 2020
Yashwant Singh Tanwar, Nando Ferreira
Bioactive glass is one of the unique discoveries during the pursuit for the ideal void filler. It has a unique mechanism of action and early results of its efficacy have been encouraging. Bioactive glass was developed by Professor Larry Hench in 1969 [8]. The most common form of bioactive glass is denoted as S53P4 and used in orthopaedic surgery. It consists of 53% SiO2, 23% Na2O, 20% CaO and 4% P2O5. Bioactive glass undergoes rapid surface and chemical changes as soon as it is implanted in the body. This complex procedure can be simplified into five basic steps which include [9]:Cation exchange: Sodium and calcium ions from the glass diffuse out and are replaced with hydrogen ions.Hydrolysis: Si–O–Si bonds are broken and results in the formation of Si–OH (silanol) at the material surface.Gel formation: Silanol molecules condense and re-polymerize to form a gel like substrate. This gel phase is the most biological active form in vivo.Precipitation of calcium and phosphorus salts on the gel substrate.Mineralization, resulting in formation of hydroxyapatite like substrate.