Mineral trioxide aggregate.
Explore the source record for details and available documents.
Aluminum Compounds↗
SEARCH · PubMed Health
Results for “Calcium Compounds”
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Comparison of low and high dose of vitamin D treatment in nutritional vitamin D deficiency rickets.
In this study, we compared three different therapy modes (150,000 IU, 300,000 IU, and 600,000 IU vitamin D p.o.) in infants with nutritional vitamin D deficiency rickets (VDR). Our purpose was to determine the most effective dosage of vitamin D with least side effects for treating VDR. The study included 56 patients, 3-36 months of age, with nutritional VDR and 20 age-matched control infants. In all infants, serum calcium, phosphorus, alkaline phosphatase, magnesium, serum 25-hydroxycholecalciferol, plasma intact parathormone levels and urinary Ca/creatine ratio were determined. Of 56 patients, 52 were able to be followed long-term. These patients were reexamined on the 3rd day, 7-10th day, and 25-30th day after treatment. On the 30th day post-treatment, we did not find any difference between the doses in the improvement of rickets. However, hypercalcemia was present in eight infants who had been administered 300,000 IU (two infants) and 600,000 IU (six infants) of vitamin D. In conclusion, our findings showed that 150,000 IU or 300,000 IU of vitamin D was adequate in the treatment of VDR, but 600,000 IU of vitamin D may carry the risk of hypercalcemia.
Administration, Oral↗
Preparation and characterization of anodized titanium surfaces and their effect on osteoblast responses.
In this study, titanium (Ti) surface was modified by anodizing with a mixture of beta-glycerophosphate sodium and calcium (Ca) acetate, and the anodized surfaces were characterized by scanning electron microscopy, X-ray diffraction, and electron probe microanalysis. In vitro osteoblast response to anodized oxide was also evaluated. The anodic oxide produced was observed to have interconnected pores (0.5-2 microm in diameter) and intermediate roughness (0.60-1.00 microm). In addition, anodic oxide was observed to have amorphous and anatase oxide. Calcium and phosphorus ions were deposited on the Ti oxide during anodization. Osteoblast differentiation, as indicated by alkaline phosphatase production, was enhanced on anodized surfaces. It was thus concluded from this study that Ca phosphate can be deposited on Ti surfaces by anodization. It was also concluded that the phenotypic expression of osteoblast was enhanced by the presence of Ca phosphate and higher roughness on anodized Ti surfaces.
Acetates↗
Dentin penetrability evaluation of three different dyes in root-end cavities filled with mineral trioxide aggregate (MTA).
The purpose of this study was to evaluate the penetration of three dyes in MTA root-end fillings. In 30 single-rooted teeth, cavities for retrofilling were prepared with an ultrasound appliance and filled with MTA. The specimens were randomly assigned to three groups (n = 10) and immersed in the following solutions: 2% methylene blue (MET), 50% silver nitrate (NIT) and 0.2% rhodamine B (ROD). Two transversal slices (1 mm) of the retrofilling region were obtained and evaluated using the Image Tool 3.0 software to obtain a quantitative evaluation (in mm2) of the dye penetration around the retrofillings. Data were submitted to statistical analysis using Students t-test. The lowest degree of dye penetration was observed for the NIT group, in both slices (p < 0.05). Dye penetration was significantly larger in the ROD group when compared to the NIT group, in both slices (p < 0.05), and to the MET group, only in slice 1 (p < 0.05). Within the limitations of this study, it was concluded that the choice of dye could influence the penetration evaluation in root-end filling studies, and that the NIT had the lowest penetration capacity in the apical dentine.
Aluminum Compounds↗
Effect of diode laser irradiation on the apical sealing of MTA retrofillings.
Apical sealing is essential for the success of paraendodontic surgery, so any procedure that may favor an adequate sealing of the apical remainder should be performed. The purpose of this study was to evaluate the influence of diode laser irradiation on the apical sealing of root-end cavities with MTA retrofillings. Root canals in twenty extracted human teeth were shaped with K-files and filled with gutta-percha. The apexes were cut off and root-end preparations were performed. The roots were divided randomly in 2 groups. Group 1 (ten specimens) was retrofilled with MTA. Group 2 was irradiated with diode laser, with 1 W for 20 seconds, on the apical surface and root end cavity before retrofilling with MTA. The specimens had their external surfaces impermeabilized with cyanoacrylate, except for the apical surface, and were then immersed in 1% rhodamine B dye for 72 h and placed in plaster stone. After that, the specimens were submitted to longitudinal abrasion until half of the root remained. The linear dye leakage was observed in these mid-roots between the root canal wall and retrofilling. The linear dye leakage was measured with Image Lab software, and the results were statistically analyzed with Student's t test. There were no statistically significant differences between the two groups (p > 0.05). The diode laser irradiation did not improve the apical sealing of MTA retrofillings under the conditions of this in vitro study.
Aluminum Compounds↗
The large intestine compensates for insufficient calcium absorption in the small intestine in rats.
We previously demonstrated that the large intestine compensated for decreased calcium (Ca) absorption caused by renal failure in rats fed a highly fermentable dietary fiber. In this study, we examined whether the large intestine compensated for insufficient Ca absorption in the rat small intestine without ingestion of a fermentable dietary fiber. Rats were fed one of four test diets containing either insoluble (carbonate) or soluble (gluconate, lactate, or citrate) Ca sources. The dietary Ca level was 2.0 g/kg, which is lower than the minimum requirement for rats (3.0 g/kg), to conduct the present study under a condition in which rats can maximally absorb Ca. To prevent Ca absorption in the small intestine, we replaced a primary phosphate (KH2PO4) with secondary phosphates (K2HPO4 and Na2HPO4) in diets. The apparent Ca absorption in the small intestine was estimated by adding chromic oxide (Cr2O3) as an insoluble and an unabsorbed marker to test diets and by measuring the ratio of Ca:Cr in the cecal content. The apparent Ca absorption in the whole intestine was estimated by the intake and fecal excretion of Ca. The apparent Ca absorption in the small intestine was significantly lower from the Ca carbonate diet than from the Ca gluconate, lactate, or citrate diets. The apparent Ca absorption in the whole intestine was not significantly different among the four groups, and the values were similar to the absorption rates in the small intestines of rats fed diets containing soluble Ca sources. These results show the following: (a) In rats fed 0.2% Ca diets containing soluble Ca salts, Ca is mostly absorbed in the small intestine, even in secondary phosphate intakes; (b) In contrast, in rats fed a 0.2% Ca diet containing an insoluble Ca salt (carbonate), Ca is not sufficiently absorbed in the small intestine. However, the large intestine compensates for the small intestinal Ca absorption decreased by dietary secondary phosphates.
Animals↗
Absorbability of calcium from a new calcium supplement prepared from bovine marrow-free bone in rats.
Powdered bovine marrow-free bone was completely solubilized with lactic and citric acids under reduced pressure. The resulting solution was lyophilized to obtain a stable powder form (total bone extract, TBE), and the calcium (Ca) absorbability of TBE from intestine was investigated in normal rats. Each animal perorally received 10 mg of Ca in 1 mL of distilled water as extrinsic 45Ca-labeled TBE, intrinsic 45Ca-labeled Ca lactate, or intrinsic 45Ca-labeled Ca carbonate. The amount of radioactivity in plasma was measured periodically up to 34 h after dosing, and pharmacokinetic parameters were calculated from the radioactivity in plasma. The time taken to reach the maximal 45Ca level (Tmax) did not differ among the three groups. The area under the plasma 45Ca level/time curve (AUC infinity) and the radioactivity at Tmax (Cmax) values for the TBE group were significantly higher than those of the Ca carbonate group. Similar results were observed between the Ca lactate and the Ca carbonate groups. No significant difference was observed in the AUC infinity and the Cmax values between the TBE and the Ca lactate groups. Radioactivity in a femur 34 h after dosing was highest in the Ca lactate group and lowest in the Ca carbonate group among the three groups. Both the TBE and the Ca lactate groups showed significant higher whole-body 45Ca retention than the Ca carbonate group did, although no significant difference was found between the TBE and the Ca lactate groups. These findings indicate that the Ca absorbability of TBE is almost comparable with that of Ca lactate and higher than that of Ca carbonate. Therefore TBE would be useful as a Ca supplement with relatively high absorbability from intestine.
Animals↗
CYST FORMATION IN THE PARATHYROIDS AND MUSCULAR DYSTROPHY INDUCED BY DIHYDROTACHYSTEROL AND CALCIUM ACETATE.
Explore the source record for details and available documents.
Acetates↗
In vivo limestone solubilization in commercial Leghorns: role of dietary calcium level, limestone particle size, in vitro limestone solubility rate, and the calcium status of the hen.
Three experiments were conducted to determine the possible interaction of particle size, in vitro limestone solubility rate, and the Ca status of the hen, respectively, with dietary Ca level and in vivo Ca solubilization in laying hens. The in vivo Ca solubilization in hens was determined by subtracting Ca recovered as limestone in the excreta (by repeated washing) from Ca fed as limestone. Limestones of two different particle sizes [.5 to .8 mm (small) versus 2 to 5 mm (large)] with the same in vitro solubility rates were used in Experiment 1. Limestones of two different in vitro solubility rates (4 versus 10%/15 min in .079 N HCl) with the same particle size in Experiment 2 were assessed for in vivo Ca solubilization. In both experiments, laying hens were fed diets containing graded levels of Ca: 1.5, 3.0, 4.5, and 6.0%. In Experiment 3, hens fed a Ca-deficient (1%) diet for 1 wk were compared with hens fed a diet containing 3.75% Ca to assess in vivo Ca solubilization as influenced by graded dietary Ca levels: 1.5, 3.0, and 4.5% Ca. In vivo Ca solubilization in hens was influenced (P less than .05) by dietary Ca level (inverse relationship), limestone particle size (large particle greater than small particle), and Ca status of hens (Ca-deficient hens greater than normal hens). In vivo Ca solubilization in laying hens, for the particle size tested, was not influenced by in vitro limestone solubility rate.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
Effect of calcium source, particle size, limestone solubility in vitro, and calcium intake level on layer bone status and performance.
Experiments were conducted to examine the effect on layer performance of dietary calcium source, particle size (average United States Screen Numbers 6, 8, 12, 18, 35, and 100) and calcium intake level (2.0, 2.5, 3.0, 3.5, 4.0, and 4.5 g/day). Egg production and egg weight were not affected by any of the treatments. Size and calcium intake level significantly affected shell weight, shell weight per unit surface area, specific gravity, and shell thickness. Bone ash expressed as a percentage of fat-free dry weight was not affected by calcium intake level, but bone ash concentration (bone ash per unit volume) and bone-breaking strength were linearly related to calcium intake level. Regressed shell quality traits and various bone parameters related to solubility instead of particle size produced a better fitted line.
Animals↗
Effect of leucite crystals on the strength of glassy porcelain.
Porcelains with leucite crystals dispersed into various glass matrices were prepared for investigating the effects of the leucite crystals on the mechanical strength of glassy porcelain. The strength of glassy porcelains containing leucite crystals was affected by the differences of thermal expansion coefficients, compositions and deformation temperatures of the glass matrices. In the case of a large mismatch of thermal expansion between the leucite crystals and boro-silicate glass, the strength decreased with increasing amount of leucite. In leucite porcelains using a feldspar glass matrix, there was little or no effect of leucite on the strength. However, the strength of porcelains consisting of leucite crystals and a soda-lime glass matrix was enhanced with increasing leucite content, compared with that of the glassy matrix alone. Such an increase in strength is considered to be because the interface between the glassy matrix and leucite particles occurred in continuous phases, with an effect due to fusion occurring during the transition from leucite particles to the glass phase.
Aluminum Silicates↗
Study of resin-bonded calcia investment: Part 1. Setting time and compressive strength.
This study was carried out to develop a new titanium casting investment consisting of calcia as the refractory material and a cold-curing resin system as the binder. The setting time of the investment was investigated under different N,N-dimethyl-p-toluidine (DMPT) contents in methyl methacrylate monomer (MMA) and benzoyl peroxide (BPO) contents in calcia without any sintering agent. The effects of the sintering agents, which were calcium fluoride (CaF2) and calcium chloride (CaCl2), on the compressive strength of the investments were investigated at room temperature before and after heating to two different temperatures. The shortest setting time (68 minutes) of the investment was obtained at 0.37 DMPT/BPO (1.5 vol% /1.0 mass%) ratio by mass. The highest strength (16.5 MPa) was obtained from the investment which contained 2 mass% CaF2 and was heated to 1,100 degrees C. It was found that the developed calcia investment containing 2 mass% CaF2 has a possibility for use in titanium castings.
Alloys↗
Relaxation modulus of denture base resin reinforced with woven glass fibers.
This study examined the reinforcing effect of woven glass fibers on the relaxation modulus by three-point loading of denture base resin. Three sandwich-type flexure test specimens polymerized by heating were used, all 3 mm thick: glass fibers in compression (U type); glass fibers in the center (C type); and glass fibers in tension (L type). Unreinforced specimens (ACR) were produced as a control. The relaxation modulus after 8 sec from the start of stress (Er(8)) was calculated from stress relaxation curves. In the glassy state, the Er(8)s of the U and L types were greater than those of the ACR and C types. In the rubbery state (plateau region), the Er(8)s of the U and L types were greater than those of the ACR and C types. The woven glass fibers added to the U and L type specimens increased the relaxation modulus of PMMA near the oral temperature; moreover, they inhibited stress relaxation when the temperature increased.
Algorithms↗
Study of resin-bonded calcia investment: part 2. Effect of titanium content on the dimensional change of the investment.
In the present study, titanium powder was chosen as an expanding agent of an experimentally prepared resin-bonded calcia investment. The effect of Ti content on the dimensional change was investigated. In addition, the effects of the heating rate and heating temperature on the dimensional change of the investment were investigated during setting and after heating. The expansion increased with Ti content and the highest expansion (1.57%+/-0.58) was obtained at 10 mass% Ti. The highest expansion was obtained at 900 degrees C for 30 min heating and was independent of the heating rate. These findings mean that the titanium powder in the calcia investment oxidized sufficiently at that heating condition. It was found that the developed resin-bonded calcia investment was able to compensate for casting shrinkage of pure titanium by adding some Ti powder to the investment.
Algorithms↗
Mineral trioxide aggregate as a pulpotomy agent in primary molars: an in vivo study.
The retention of pulpally involved deciduous tooth in a healthy state until the time of normal exfoliation remains to be one of the challenges for Pedodontists. A scientific noise has been generated about several materials some of which have been popular pulpotomy medicaments. Concerns have been raised about the toxicity and potential carcinogenicity of these materials, and alternatives have been proposed to maintain the partial pulp vitality, however to date no material has been accepted as an ideal pulpotomy agent. Mineral trioxide aggregate (MTA) is a biocompatible material which provides a biological seal. MTA has been proposed as a potential medicament for various pulpal procedures like pulp capping with reversible pulpitis, apexification, repair of root perforations, etc. Hence the present study was done to evaluate the efficacy of MTA as a pulpotomy medicament. A clinical and radiographic evaluation was done on children where MTA was used as pulpotomy medicament in primary molars for a period of 6 months and it was found to be a successful material.
Aluminum Compounds↗
Perforation repairs.
Management of instrument perforations in the periodontal ligament space during endodontic or restorative procedures is an ongoing problem in dentistry. The introduction of microscopes, new instruments and materials has resulted in more controllable and predictable surgical and nonsurgical outcomes. This paper discusses some of the newer techniques and materials used to manage perforations effectively.
Aluminum Compounds↗
Mineral trioxide aggregate: a new material for the new millennium.
A midroot strip perforation can be a difficult problem to treat. Surgical treatment is arduous and has a poor prognosis. Variable success has been seen with the classic repair materials for nonsurgical treatment. Mineral trioxide aggregate seems to have incredible promise for sealing these defects with a good long-term prognosis.
Aluminum Compounds↗