scholarly journals Transformation from calcium sulfate to calcium phosphate in biological environment

2021 ◽  
Vol 32 (12) ◽  
Author(s):  
Ying-Cen Chen ◽  
Wei-Hsing Tuan ◽  
Po-Liang Lai
Keyword(s):  
Surface Layer ◽  
Calcium Sulfate ◽  
Comprehensive Evaluation ◽  
Fibrous Tissue ◽  
Inflammatory Cells ◽  
Octacalcium Phosphate ◽  
Phosphate Solution ◽  
Femur Bone ◽  
Biological Environment ◽  
Apatite Surface

AbstractThe formation of a nano-apatite surface layer is frequently considered a measure of bioactivity, especially for non-phosphate bioceramics. In the present study, strontium-doped calcium sulfate, (Ca,Sr)SO4, was used to verify the feasibility of this measure. The (Ca,Sr)SO4 specimen was prepared by mixing 10% SrSO4 by weight with 90% CaSO4·½H2O powder by weight. A solid solution of (Ca,7.6%Sr)SO4 was then produced by heating the powder mixture at 1100 °C for 1 h. The resulting (Ca,Sr)SO4 specimen was readily degradable in phosphate solution. A newly formed surface layer in the form of flakes was formed within one day of specimen immersion in phosphate solution. Structural and microstructure–compositional analyses indicated that the flakes were composed of octacalcium phosphate (OCP) crystals. An amorphous interface containing OCP nanocrystals was found between the newly formed surface layer and the remaining (Ca,Sr)SO4 specimen. The specimen was also implanted into a rat distal femur bone defect. In addition to new bone, fibrous tissue and inflammatory cells were found to interlace the (Ca,Sr)SO4 specimen. The present study indicated that a more comprehensive evaluation is needed to assess the bioactivity of non-phosphate bioceramics.

scholarly journals Comparison of the effect of hemihydrate calcium sulfate granules and Cerabone on dental socket preservation: An animal experiment

2018 ◽  
Vol 12 (4) ◽  
pp. 238-244
Author(s):  
Naser Sargolzaie ◽  
Mehrnaz Rafiee ◽  
Hamideh Salari Sedigh ◽  
Reza Zare Mahmoudabadi ◽  
Hooman Keshavarz
Keyword(s):  
Connective Tissue ◽  
Calcium Sulfate ◽  
Inflammatory Cells ◽  
Histological Evaluation ◽  
Sign Test ◽  
Rank Test ◽  
Fibrous Connective Tissue ◽  
Socket Preservation ◽  
Tissue Proportion

Background. Early bone loss due to tooth extraction can be significantly reduced by socket preservation. The aim of this study was to compare the in vivo effects of hemihydrate calcium sulfate granules (an alloplastic material) and Cerabone (a bovine-derived xenograft) on socket preservation in dogs. Methods. Six male Mongrel dogs were randomly divided into 2 groups (n=3) for sacrificing and histological evaluation 4 and 8 weeks after a surgery. The second and third premolars on both sides of the lower jaw were extracted surgically. The sockets on one side were filled with Cerabone, and with calcium sulfate on the opposite side. In the slides, the ratio of the area of newly formed bone to the area of the entire cavity, and the ratio of the area of fibrous connective tissue to the area of the entire cavity were measured. The presence of inflammation was also examined. Wilcoxon signed-rank test, Sign test and McNemar test were used for statistical analyses (ɑ=0.05). Results. The means of new bone proportion were 11% and 8% for Cerabone and calcium sulfate, respectively (P=0.58). The means of connective tissue proportion were 29% and 33% for Cerabone and calcium sulfate, respectively (P=0.72). No inflammatory cells were observed in the Cerabone group, although 50% of the samples in the calcium sulfate group showed inflammation (P=0.50). Conclusion. The effects of calcium sulfate and Cerabone on socket preservation in dogs on bone formation, fibrous connective tissue and inflammation levels were not significantly different at 4- and 8-week postoperative intervals.

scholarly journals Iatrogenic Inflammatory Fibrosis of Hard Palate in a 13-Year-Old Female Patient

2013 ◽  
Vol 2013 ◽  
pp. 1-3 ◽  
Author(s):  
Shanthan Mettu ◽  
Radhika Muppa ◽  
G. Siva Prasad Reddy ◽  
Srinivas Nallanchakrava ◽  
Sri Veda Gurugubelli
Keyword(s):  
Female Patient ◽  
Hard Palate ◽  
Unusual Case ◽  
Fibrous Tissue ◽  
Surgical Excision ◽  
Inflammatory Cells ◽  
Nerve Tissue ◽  
Rare Occurrence ◽  
Reactive Process ◽  
Tooth Number

Palatal swellings are rare in children and the incidence differs from that of the adult counterparts. When the palatal swellings do arise in children, they usually are palatal abscess from periapical region, and few cases like pleomorphic adenoma in young adults have also been reported. But inflammatory fibrosis of palate in children is a rare occurrence. Inflammatory fibrosis is formation of excess fibrous connective tissue in an organ or tissue, as a reparative or reactive process. This report describes an unusual case of iatrogenic inflammatory fibrosis on the palate due to extraction of tooth number 22 in a 13-year-old female patient. The patient presented with a single large well-circumscribed oval palatal swelling that was soft, fluctuant, not fixed, and nontender. Surgical excision of the lesion was done and it was sent for histopathological assessment. The biopsy showed fibrous tissue with collagen fibers, spindle shaped fibroblasts, neovascularization, RBCs, chronic inflammatory cells, and traces of salivary gland and nerve tissue.

scholarly journals Radiologic and Pathological Investigation of Pseudarthrosis in Ankylosing Spondylitis: Distinguishing Between Inflammatory and Traumatic Etiology

2018 ◽  
Vol 46 (3) ◽  
pp. 259-265 ◽  
Author(s):  
Mu Qiao ◽  
Bang-ping Qian ◽  
Yong Qiu ◽  
Sai-Hu Mao ◽  
Yi-hua Wang
Keyword(s):  
Ankylosing Spondylitis ◽  
Insufficiency Fracture ◽  
Fibrous Tissue ◽  
Inflammatory Cells ◽  
Mechanical Trauma ◽  
Apical Region ◽  
Pathological Analysis ◽  
Bone Fragments ◽  
Hemosiderin Deposits ◽  
Excessive Stress

Objective.To investigate the pathogenesis of pseudarthrosis in ankylosing spondylitis (AS) based on the pathological analysis of specimens harvested during surgery.Methods.Radiographic and clinical data for 17 consecutive AS patients with pseudarthrosis were retrospectively analyzed. Meanwhile, the pathological analysis of specimens obtained during surgery was also performed.Results.In total, 18 extensive Andersson lesions were included. Pseudarthrosis located at the apical region were noted in 12 patients. Complete ossified anterior longitudinal ligaments above or below pseudarthrosis and fracture through posterior elements or facet joints were observed in 7 and 6 lesions, respectively. The most definitive pathological characteristic in all cases was proliferating hypovascular edematous fibrous tissue involving disc, bone-disc border, and vertebral body. Fibrinoid necrosis, necrotic bone fragments, hemosiderin deposits, and active subchondral osteogenesis were found, indicating trauma process. Mild perivascular collections of inflammatory cells were detected in only 2 cases.Conclusion.AS-related pseudarthrosis is more likely to originate from mechanical trauma than inflammation. The above-mentioned radiological and histological findings showed that multiple mechanisms lead to the formation of pseudarthrosis. These mechanisms include excessive stress, insufficiency fracture, and an acute fracture involving a 3-column structure.

Osseoinduction Evaluation of Hydroxyapatite and Zinc Containing Hydroxyapatite Granules in Rabbits

2011 ◽  
Vol 493-494 ◽  
pp. 252-257 ◽  
Author(s):  
L. Nascimento ◽  
M. Medeiros ◽  
J. Calasans-Maia ◽  
A. Alves ◽  
Antonella M. Rossi ◽  
...  
Keyword(s):  
Histological Analysis ◽  
Bone Matrix ◽  
Fibrous Tissue ◽  
Particle Diameter ◽  
Inflammatory Cells ◽  
Giant Cells ◽  
Multinucleated Giant Cells ◽  
Ethics Commission

This study investigated the osteoinductive potential of granules of stoichiometric hydroxyapatite (HA) and 0.5% zinc containing hydroxyapatite (ZnHA) in intramuscular (IM) site of rabbit’s abdomen. The biomaterials were both used in granular form, with 75% porosity and particle diameter between 450 and 500μm, sintered at 1100°C. Both materials performed adequately on a multiparametric in vitro cytocompatibility assay, indicating their suitability for in vivo testing. After approval by the Ethics Commission on Teaching and Research in Animals, fifteen rabbits were submitted to general anesthesia, incision and tissue dilatation, and a small site was created for HA (right incision) and ZnHA (left incision) intramuscular implantation. The animals were killed after 2, 4 and 12 weeks for biomaterials and surrounding tissues removal. Histological analysis after 2 weeks revealed the presence of granulation tissue surrounding biomaterials with multinucleated giant cells and no newly formed bone for both materials. After 4 weeks there was fibrous tissue involving the material and few inflammatory cells. Following 12 weeks it was observed the presence of connective tissue surrounding the biomaterial, cellularized enough for the two experimental groups, but it was not observed the presence of bone matrix associated with the biomaterials. We conclude that both biomaterials are cytocompatible and did not present the property of osseoinduction after 12 weeks of implantation.

Imaging for detection of vascular disease in chronic kidney disease patients

2015 ◽  
Author(s):  
Paolo Raggi ◽  
Luis D’Marco
Keyword(s):  
Chronic Kidney Disease ◽  
Kidney Disease ◽  
Vascular Disease ◽  
Mineral Metabolism ◽  
Fibrous Tissue ◽  
Inflammatory Cells ◽  
Arterial System ◽  
Arterial Circulation ◽  
Atherosclerosis Risk Factors ◽  
Calcium Crystals

The well-known severity of cardiovascular disease in patients suffering from chronic kidney disease (CKD) requires an accurate risk stratification of these patients in several clinical situations. Imaging has been used successfully for such purpose in the general population and it has demonstrated excellent potential among CKD patients as well. Two main forms of arterial pathology develop in patients with CKD: atherosclerosis, with accumulation of inflammatory cells, lipids, fibrous tissue and calcium in the subintimal space, and arteriosclerosis. The latter is characterized by accumulation of deposits of hydroxyapatite and amorphous calcium crystals in the muscular media of the vessel wall, and is believed to be more closely associated with alterations of mineral metabolism than with traditional atherosclerosis risk factors. The result is the development of what appears to be premature arterial ageing, with loss of elastic properties, increased stiffness, and increased overall fragility of the arterial system. Despite intensifying research and increasing awareness of these issues, the underlying pathophysiology of the aggressive vasculopathy of CKD remains largely unknown. As a consequence, there are currently very limited pathways to prevent progression of vascular damage in CKD. The indications, strengths and weaknesses of several imaging modalities employed to evaluate vascular disease in CKD are described, focusing on coronary arterial circulation and the peripheral arteries, with the exclusion of the intracranial arteries.

Spontaneous hyperplastic and metaplastic duct epithelium in the sublingual salivary glands of Wistar rats

1986 ◽  
Vol 20 (2) ◽  
pp. 127-131 ◽  
Author(s):  
E. van Esch ◽  
H. C. Dreef-van der Meulen ◽  
V. J. Feron
Keyword(s):  
Salivary Glands ◽  
Small Groups ◽  
Wistar Rats ◽  
Squamous Epithelium ◽  
Fibrous Tissue ◽  
Inflammatory Cells ◽  
Epithelial Hyperplasia ◽  
Duct Epithelium ◽  
Stratified Squamous Epithelium ◽  
Focal Epithelial Hyperplasia

Focal epithelial hyperplasia and metaplasia were observed in the intralobular ducts of the sublingual salivary glands of 302 out of 1142 Wistar rats. These rats (aged 16-145 weeks) served as controls in toxicological experiments. The ductal changes varied from small groups of irregular cylindrical cells with basophilic cytoplasm and vesicular nuclei, with often prominent nucleoli, to large areas of non-keratinized stratified squamous epithelium with marked mitotic activity and necrotic superficial cells being released in the lumen. Mononuclear inflammatory cells were often present in fibrous tissue surrounding altered ducts. Within certain limits the degree and incidence of the changes increased with increasing age; their aetiology is unknown.

Plastic Deformation and Surface Recrystallization of Cu-4 Mass%Zn Alloy under Instantaneous Extrusion and High Speed Friction

2011 ◽  
Vol 467-469 ◽  
pp. 1280-1284
Author(s):  
Jun Hui Yin ◽  
Jian Zheng ◽  
Chang Zhi Jia ◽  
Ming Hui Ye
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Plastic Deformation ◽  
Surface Layer ◽  
High Speed ◽  
Fibrous Tissue ◽  
Equiaxed Grains ◽  
Rotating Band ◽  
Zn Alloy ◽  
Scanning Electron

As a special hot-work progress, artillery shooting test was put in practice, and rotating band specimen of Cu-4 Mass%Zn alloy was prepared. The mesostructure and microstructure evolution of the alloy under instantaneous extrusion and high speed friction were observed by optical microscopy (OM) and scanning electron microscopy (SEM). Severe plastic deformation (SPD) and dynamic recrystallization phenomena were researched. The analysis results are as follows. At the beginning of SPD, under the instantaneous compression, the surface layer of alloy became fibrous tissue with the phenomena of work-hardening. With the plastic deformation continue, temperature of alloy arising rapidly under the high speed friction. Recrystallization occurs within the outermost part of fibrous tissue due to heating, so subgrains gradually become homogeneous equiaxed grains. In addition, SPD has little effect on the inner tissue, which is full of equiaxed grains still. Between equiaxed grains and fibrous tissue, there are many oblique strip grains which formed by radial extrusion stress , tangential slip stress and axial sliding stress .

Fabrication of Porous Titania and Porous Calcium Phosphate Coatings on Titanium Surface

2007 ◽  
Vol 330-332 ◽  
pp. 529-532 ◽  
Author(s):  
Bo Feng ◽  
Jie Weng ◽  
Yu Liang ◽  
Shu Xin Qu ◽  
Jin Wang ◽  
...  
Keyword(s):  
Calcium Phosphate ◽  
Porous Layer ◽  
Titanium Surface ◽  
Octacalcium Phosphate ◽  
Acid Etching ◽  
Phosphate Coatings ◽  
Porous Titania ◽  
Biological Environment ◽  
Calcium Phosphate Coatings

A network-like porous layer on titanium was prepared by acid-etching with a mixture of CaCl2 and HCl. The pores ranged from 1 to 10!m. The small pores distributed in big pores. In the simulated biological environment, porous octacalcium phosphate (OCP) coatings spontaneously formed on the porous- surfaced titanium. Pre-calcification after acid-etching accelerated OCP precipitation. The OCP coatings had big pores of about 25!m and small pores of 1~3!m, the latter distributed in the former at different depth.

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