Calcium Sulphate (calcium + sulphate)

Distribution by Scientific Domains
Medical Sciences80%
Earth and Environmental Science20%

Selected Abstracts

INJECTABLE FORM OF CALCIUM SULPHATE AS TREATMENT OF ANEURYSMAL BONE CYSTS

ANZ JOURNAL OF SURGERY, Issue 5 2008
Mark Clayer
Background: Aneurysmal bone cysts (ABC) are a rare condition in adolescents and teenagers but may result in pain, fracture and growth abnormalities. The gold standard of open curettage carries the risk of surgical complications and still a local recurrence rate of 20,30%. Percutaneous treatment of ABC have rarely been reported and a poor response the usual outcome. This study investigated a new technique of percutaneous aspiration and injection of ABC using an aqueous solution of calcium sulphate. Methods: A radiological diagnosis of a bone cyst was made in 15 consecutive patients and pathologically confirmed as ABC. Most had already sustained a fracture and/or had been previously unsuccessfully treated by minimally invasive techniques including embolization or methylprednisolone injection. The procedure of aspiration and injection with calcium sulphate was undertaken, and the patients were reviewed regularly both clinically and radiologically for a minimum of 2 years. Results: The calcium sulphate cement was reabsorbed completely within 8 weeks. The first osseous response was periosteal new bone formation circumferentially followed by gradual opacification of the cystic cavity. All except one patient that described pain before the procedure reported complete relief of symptoms by 4 weeks. Two patients developed a local recurrence of the cyst, and one subsequently developed a pathological fracture. Two patients sustained pathological fractures through healed cysts, 12 and 22 months after the procedure, respectively. Conclusions: This new technique has shown good early clinical and radiological responses and a low complication rate in a consecutive group of patients with ABC. [source]

Effect of placement of calcium sulphate when used for the repair of furcation perforations on the seal produced by a resin-based material

INTERNATIONAL ENDODONTIC JOURNAL, Issue 2 2007
L. Zou
Abstract Aim, To evaluate the sealing ability of calcium sulphate when used under composite resin for the repair of furcation perforations having different diameters. Methodology, Perforations of different diameter were created in the floors of pulp chambers in 60 extracted human molar teeth with either a number 3 (1 mm diameter) or 5 (1.5 mm diameter) round bur. The specimens of each group were divided into four sub-groups which were repaired with composite resin either alone or in combination with calcium sulphate that created an artificial floor (15 teeth group -1). Eight teeth without furcation perforations served as negative controls. In the leakage detection device, 1 mol L,1 glucose solution was forced under a pressure of 1.5 KPa from the crown towards the pulp chamber floor. The concentration of leaked glucose was measured at 1, 2, 4, 7, 10, 15 and 20 days using a glucose oxidase method and the data evaluated using the rank sum test. Results, The specimens with larger perforations repaired with composite resin alone had significantly more leakage (P < 0.05). Using calcium sulphate as an artificial floor significantly decreased leakage of smaller perforations (P < 0.05). In groups repaired with calcium sulphate under composite resin, leakage in smaller perforations was markedly lower than that in larger ones (P < 0.05). No significant difference was found between the specimens with 1 or 1.5 mm perforations repaired with resin alone (P > 0.05). Conclusions, Calcium sulphate significantly improved the sealing ability of 1 mm perforations repaired with composite resin but not for 1.5 mm perforations. [source]

The use of calcium sulphate (plaster of Paris) in a two step surgery for the treatment of a facial fracture in a foal

EQUINE VETERINARY EDUCATION, Issue 7 2007
J. A. Muñoz Morán
First page of article [source]

Calcite and gypsum solubility products in water-saturated salt-affected soil samples at 25°C and at least up to 14 dS m,1

EUROPEAN JOURNAL OF SOIL SCIENCE, Issue 2 2010
F. Visconti
Calcite and gypsum are salts of major ions characterized by poor solubility compared with other salts that may precipitate in soils. Knowledge of calcite and gypsum solubility products in water-saturated soil samples substantially contributes to a better assessment of processes involved in soil salinity. The new SALSOLCHEMIS code for chemical equilibrium assessment was parameterized with published analytical data for aqueous synthetic calcite and gypsum-saturated solutions. Once parameterized, SALSOLCHEMIS was applied to calculations of the ionic activity products of calcium carbonate and calcium sulphate in 133 water-saturated soil samples from an irrigated salt-affected agricultural area in a semi-arid Mediterranean climate. During parameterization, sufficiently constant values for the ionic activity products of calcium carbonate and calcium sulphate were obtained only when the following were used in SALSOLCHEMIS: (i) the equations of Sposito & Traina for the free ion activity coefficient calculation, (ii) the assumption of the non-existence of the Ca (HCO 3)+ and CaCO3o ion pairs and (iii) a paradigm of total ion activity coefficients. The value of 4.62 can be assumed to be a reliable gypsum solubility product (pKs) in simple aqueous and soil solutions, while a value of 8.43 can only be assumed as a reliable calcite solubility product (pKs) in simple aqueous solutions. The saturated pastes and saturation extracts were found to be calcite over-saturated, with the former significantly being less so (p IAP = 8.29) than the latter (p IAP = 8.22). The calcite over-saturation of saturated pastes increased with the soil organic matter content. Nevertheless, the inhibition of calcite precipitation is caused by the soluble organic matter from a dissolved organic carbon threshold value that lies between 7 and 12 mm. The hypothesis of thermodynamic equilibrium is more adequate for the saturated pastes than for the saturation extracts. [source]

Effect of placement of calcium sulphate when used for the repair of furcation perforations on the seal produced by a resin-based material

INTERNATIONAL ENDODONTIC JOURNAL, Issue 2 2007
L. Zou
Abstract Aim, To evaluate the sealing ability of calcium sulphate when used under composite resin for the repair of furcation perforations having different diameters. Methodology, Perforations of different diameter were created in the floors of pulp chambers in 60 extracted human molar teeth with either a number 3 (1 mm diameter) or 5 (1.5 mm diameter) round bur. The specimens of each group were divided into four sub-groups which were repaired with composite resin either alone or in combination with calcium sulphate that created an artificial floor (15 teeth group -1). Eight teeth without furcation perforations served as negative controls. In the leakage detection device, 1 mol L,1 glucose solution was forced under a pressure of 1.5 KPa from the crown towards the pulp chamber floor. The concentration of leaked glucose was measured at 1, 2, 4, 7, 10, 15 and 20 days using a glucose oxidase method and the data evaluated using the rank sum test. Results, The specimens with larger perforations repaired with composite resin alone had significantly more leakage (P < 0.05). Using calcium sulphate as an artificial floor significantly decreased leakage of smaller perforations (P < 0.05). In groups repaired with calcium sulphate under composite resin, leakage in smaller perforations was markedly lower than that in larger ones (P < 0.05). No significant difference was found between the specimens with 1 or 1.5 mm perforations repaired with resin alone (P > 0.05). Conclusions, Calcium sulphate significantly improved the sealing ability of 1 mm perforations repaired with composite resin but not for 1.5 mm perforations. [source]

Exceptionally preserved tadpoles from the Miocene of Libros, Spain: ecomorphological reconstruction and the impact of ontogeny upon taphonomy

LETHAIA, Issue 3 2010
MARIA E. MCNAMARA
McNamara, M.E., Orr, P.J., Kearns, S.L., Alcalá, L., Anadón, P. & Peñalver-Mollá, E. 2010: Exceptionally preserved tadpoles from the Miocene of Libros, Spain: ecomorphological reconstruction and the impact of ontogeny upon taphonomy. Lethaia, Vol. 43, pp. 290,306. The Libros exceptional biota from the Upper Miocene of NE Spain includes abundant frog tadpoles (Rana pueyoi) preserved in finely laminated lacustrine mudstones. The tadpoles exhibit a depressed body, short tail, low tail fins, dorso-laterally directed eyes and jaw sheaths; these features identify the Libros tadpoles as members of the benthic lentic ecomorphological guild. This, the first ecomorphological reconstruction of a fossil tadpole, supports phylogenetic evidence that this ecology is a conserved ranid feature. The soft-tissue features of the Libros tadpoles are characterized by several modes of preservation. The space occupied previously by the brain is defined by calcium carbonate, the nerve cord is defined by calcium phosphate, and jaw sheaths and bone marrow are preserved as organic remains. Gut contents (and coprolites adjacent to specimens) comprise ingested fine-grained sedimentary detritus and epiphyton. The body outline and the eyespots, nares, abdominal cavity, notochord, caudal myotomes and fins are defined by a carbonaceous bacterial biofilm. A similar biofilm in adult specimens of R. pueyoi from Libros defines only the body outline, not any internal anatomical features. In the adult frogs, but not in the tadpoles, calcium phosphate and calcium sulphate precipitated in association with integumentary tissues. These differences in the mode of preservation between the adult frogs and tadpoles reflect ontogenetic factors. ,Anuran, ecology, soft-tissue, tadpoles, taphonomy. [source]

INJECTABLE FORM OF CALCIUM SULPHATE AS TREATMENT OF ANEURYSMAL BONE CYSTS

ANZ JOURNAL OF SURGERY, Issue 5 2008
Mark Clayer
Background: Aneurysmal bone cysts (ABC) are a rare condition in adolescents and teenagers but may result in pain, fracture and growth abnormalities. The gold standard of open curettage carries the risk of surgical complications and still a local recurrence rate of 20,30%. Percutaneous treatment of ABC have rarely been reported and a poor response the usual outcome. This study investigated a new technique of percutaneous aspiration and injection of ABC using an aqueous solution of calcium sulphate. Methods: A radiological diagnosis of a bone cyst was made in 15 consecutive patients and pathologically confirmed as ABC. Most had already sustained a fracture and/or had been previously unsuccessfully treated by minimally invasive techniques including embolization or methylprednisolone injection. The procedure of aspiration and injection with calcium sulphate was undertaken, and the patients were reviewed regularly both clinically and radiologically for a minimum of 2 years. Results: The calcium sulphate cement was reabsorbed completely within 8 weeks. The first osseous response was periosteal new bone formation circumferentially followed by gradual opacification of the cystic cavity. All except one patient that described pain before the procedure reported complete relief of symptoms by 4 weeks. Two patients developed a local recurrence of the cyst, and one subsequently developed a pathological fracture. Two patients sustained pathological fractures through healed cysts, 12 and 22 months after the procedure, respectively. Conclusions: This new technique has shown good early clinical and radiological responses and a low complication rate in a consecutive group of patients with ABC. [source]

Back-scattered electron imaging and elemental microanalysis of retrieved bone tissue following maxillary sinus floor augmentation with calcium sulphate

CLINICAL ORAL IMPLANTS RESEARCH, Issue 8 2008
Nicola Slater
Abstract Objectives: To investigate the presence and composition of residual bone graft substitute material in bone biopsies from the maxillary sinus of human subjects, following augmentation with calcium sulphate (CaS). Material and methods: Bone cores were harvested from the maxillary sinus of patients who had undergone a sinus lift procedure using CaS G170 granules 4 months after the initial surgery. Samples from seven patients, which contained residual biomaterial particles, were examined by field emission scanning electron microscopy and energy dispersive X-ray spectroscopy was used to determine the composition of the remaining bone graft substitute material. Results: Residual graft material occurred in isolated areas surrounded by bone and consisted of individual particles up to 1 mm in length and smaller spherical granules. On the basis of 187 separate point analyses, the residual material was divided into three categories (A, B and C) consisting of: A, mainly CaS (S/P atomic% ratio ,2.41); B, a heterogeneous mixture of CaS and calcium phosphate (S/P=0.11,2.4) and C, mainly calcium phosphate (S/P,0.11; C), which had a mean Ca : P ratio of 1.63±0.2, consistent with Ca-deficient hydroxyapatite. Linescans and elemental maps showed that type C material was present in areas which appeared dense and surrounded, or were adjacent to, more granular CaS-containing material, and also occurred as spherical particles. The latter could be disintegrating calcium phosphate in the final stages of the resorption process. Conclusions: CaS resorption in the human maxillary sinus is accompanied by CaP precipitation which may contribute to its biocompatibility and rapid replacement by bone. [source]