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Response of human dental pulp capped with biodentine and mineral trioxide aggregate.
Nowicka, A, Lipski, M, Parafiniuk, M, Sporniak-Tutak, K, Lichota, D, Kosierkiewicz, A, Kaczmarek, W, Buczkowska-RadliĆska, J
Journal of endodontics. 2013;(6):743-7
Abstract
INTRODUCTION Biodentine is a new bioactive cement that is similar to the widely used mineral trioxide aggregate (MTA). It has dentin-like mechanical properties, which may be considered a suitable material for clinical indications of dentin-pulp complex regeneration such as direct pulp capping. The purpose of the present study was to compare the response of the pulp-dentin complex in human teeth after direct capping with this new tricalcium silicate-based cement with that of MTA. METHODS Pulps in 28 caries-free maxillary and mandibular permanent intact human molars scheduled for extraction for orthodontic reasons were mechanically exposed and assigned to 1 of 2 experimental groups, Biodentine or MTA, and 1 control group. Assay of periapical response and clinical examination were performed. After 6 weeks, the teeth were extracted, stained with hematoxylin-eosin, and categorized by using a histologic scoring system. RESULTS The majority of specimens showed complete dentinal bridge formation and an absence of inflammatory pulp response. Layers of well-arranged odontoblast and odontoblast-like cells were found to form tubular dentin under the osteodentin. Statistical analysis showed no significant differences between the Biodentine and MTA experimental groups during the observation period. CONCLUSIONS Within the limitations of this study, Biodentine had a similar efficacy in the clinical setting and may be considered an interesting alternative to MTA in pulp-capping treatment during vital pulp therapy.
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Personal CO2 scrubbing device for use in a disabled submarine.
Arieli, R, Eynan, M, Arieli, Y, Abramovich, A
Aviation, space, and environmental medicine. 2009;(6):561-4
Abstract
INTRODUCTION In the sunken submarine, a breakdown in the power supply can disrupt the provision of fresh air and the absorption of CO2. A personal device based on a breathing mask and the soda lime canisters used in the submarine is proposed for CO2 absorption. METHODS In an unmanned experiment, a breathing simulator provided a flow of air at 8.7 L x min(-1) and a carbon dioxide output of 20.9 L x h(-1), which passed through either one or two 3.8-kg canisters of soda lime. In the manned experiment, four subjects wore the breathing mask, which was connected to two 3.8-kg canisters of soda lime placed in a bag, and remained for 24 h in a sealed hyperbaric chamber. They inspired the chamber atmosphere and expired via the canisters. RESULTS In the unmanned experiment, the concentration of CO2 when a single canister was used reached 1% after 8 h, 2% after 22 h, and 2.5% after 37 h. With two canisters connected in sequence, the concentration of CO2 reached 1% after 48 h, while the pressure at the entrance to the canisters did not exceed 0.7 cm H2O. In the manned experiment, the CO2 concentration decreased over the first 12 h from its initial value of 1.3%, stabilizing during sleep at 0.75%. DISCUSSION The personal carbon dioxide absorption device lowered the ambient CO2 level over a period of 24 h, and could maintain this level for a further 24 h. Keeping CO2 at a low level has an advantage over the peaks of 3% obtained with absorbent LiOH curtains, where elevated pressure and increased P(CO2) may have an adverse effect on the survivors. Some of the crew can remain active without using the device, while the others do the job of clearing the carbon dioxide for the whole crew.
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Comparison of mineral trioxide aggregate and formocresol as pulp-capping agents in pulpotomized primary teeth.
Agamy, HA, Bakry, NS, Mounir, MM, Avery, DR
Pediatric dentistry. 2004;(4):302-9
Abstract
PURPOSE The aim of this study was to use clinical, radiographic, and histologic examinations to compare the relative success of gray mineral trioxide aggregate (MTA), white MTA, and formocresol as pulp dressings in pulpotomized primary teeth. METHODS Twenty-four children, each with at least 3 primary molars requiring pulpotomy, were selected for this study's clinical and radiographic portion. An additional 15 carious primary teeth planned for serial extraction were selected for this study's histologic portion. All selected teeth were evenly divided into 3 test groups and treated with pulpotomies. Gray MTA was used as the pulp dressing for one third of the teeth, white MTA was the dressing for one third, and the remaining one third were treated with formocresol. The treated teeth selected for the clinical and radiographic evaluations were monitored periodically for 12 months. The treated teeth selected for histologic study were monitored periodically and extracted 6 months postoperatively. RESULTS Four children with 12 pulpotomized teeth failed to return for any follow-up evaluations in the clinical and radiographic study. Of the remaining 60 teeth in 20 patients, 1 tooth (gray MTA) exfoliated normally and 6 teeth (4 white MTA and 2 formocresol) failed due to abscesses. The remaining 53 teeth appeared to be clinically and radiographically successful 12 months postoperatively. Pulp canal obliteration was a radiographic finding in 11 teeth treated with gray MTA and 1 tooth treated with white MTA. In the histologic study, both types of MTA successfully induced thick dentin bridge formation at the amputation sites, while formocresol induced thin, poorly calcified dentin. Teeth treated with gray MTA demonstrated pulp architecture nearest to normal pulp by preserving the odontoblastic layer and delicate fibrocellular matrix, yet few inflammatory cells or isolated calcified bodies were seen. Teeth treated with white MTA showed a denser fibrotic pattern, with more isolated calcifications in the pulp tissue along with secondary dentin formation. CONCLUSIONS Gray MTA appears to be superior to white MTA and formocresol as a pulp dressing for pulpotomized primary teeth.
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Vitamin D, calcium supplementation, and colorectal adenomas: results of a randomized trial.
Grau, MV, Baron, JA, Sandler, RS, Haile, RW, Beach, ML, Church, TR, Heber, D
Journal of the National Cancer Institute. 2003;(23):1765-71
Abstract
BACKGROUND Calcium and vitamin D both appear to have antineoplastic effects in the large bowel. Although these nutrients are inter-related metabolically in bone and in the normal intestine, their potential interactions in large-bowel carcinogenesis are not well understood. METHODS We assessed independent and joint effects of calcium supplementation and vitamin D status on adenoma recurrence in 803 subjects in a multi-center, placebo-controlled randomized clinical trial of calcium supplementation for the prevention of colorectal adenoma recurrence. Serum levels of 25-hydroxy [25-(OH)] vitamin D and 1,25-dihydroxy [1,25-(OH)2] vitamin D levels were determined, and the Taq I and Fok I polymorphisms in the vitamin D receptor (VDR) gene were analyzed by polymerase chain reaction. Risk ratios (RRs) for any adenoma recurrence were computed for calcium supplementation within groups defined by serum vitamin D levels and for serum vitamin D levels within treatment groups. Associations of VDR polymorphisms with recurrence risk were also evaluated. All statistical tests were two-sided. RESULTS Among subjects with baseline 25-(OH) vitamin D levels at or below the median (29.1 ng/mL), calcium supplementation was not associated with adenoma recurrence, whereas among those with levels above the median, calcium supplementation was associated with a reduced risk (RR = 0.71, 95 % confidence interval [CI] = 0.57 to 0.89, P for interaction =.012). Conversely, serum 25-(OH) vitamin D levels were associated with a reduced risk only among subjects receiving calcium supplements (RR per 12 ng/mL increase of vitamin D = 0.88, 95% CI = 0.77 to 0.99, P for interaction =.006). VDR polymorphisms were not related to adenoma recurrence and did not modify the associations with vitamin D or calcium. CONCLUSIONS Calcium supplementation and vitamin D status appear to act largely together, not separately, to reduce the risk of colorectal adenoma recurrence. VDR genotype does not appear to be associated with risk.
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Administration of a supplement containing both calcium and vitamin D is more effective than calcium alone to reduce secondary hyperparathyroidism in postmenopausal women with low 25(OH)vitamin D circulating levels.
Deroisy, R, Collette, J, Albert, A, Jupsin, I, Reginster, JY
Aging clinical and experimental research. 2002;(1):13-7
Abstract
BACKGROUND AND AIMS Supplementation of postmenopausal women with calcium alone or calcium-vitamin D association was suggested to have positive effects on bone turnover and bone density, as well as to lower fracture incidence. The beneficial effect appears to be mediated by a reduction in parathyroid hormone secretion. Our aim was to compare the respective efficacy of calcium and calcium-vitamin D supplements in reducing serum parathyroid hormone levels in postmenopausal women with prevalent low 25(OH)vitamin D levels. METHODS One hundred consecutive ambulatory postmenopausal women with serum 25(OH)vitamin D levels below 18 ng/mL were included in a randomized, prospective, open label study. For a duration of 90 days, the women were randomly assigned to a daily supplementation of either one tablet of calcium gluconolactate and carbonate (500 mg calcium), or one powder-pack of an association of calcium carbonate (500 mg calcium), citric acid (2.175 gr) and cholecalciferol (200 IU). Changes observed during the 90 days of the study in circulating PTH levels were the primary endpoint, while changes in serum 25(OH)D levels were assessed as secondary endpoint. RESULTS A significant difference was observed between the calcium-vitamin D (CaD) and the calcium (Ca) only groups for changes occurring during the 90 days of the study in PTH (-14.5+/-40% and +2.5+/-46%) (p=0.009) and 25(OH)D (+67+/-77% and +18+/-55%) (p<0.001) circulating levels. PTH changes between baseline and day 90 were significant in the CaD group, but not in the Ca group. The odds ratio for a patient in group Ca to experience an absolute (<12 ng/mL) deficiency in circulating 25(OH)vitamin D levels, compared to a group CaD patient was statistically increased (OR: 3.22, 95% CI: 1.33-7.80). CONCLUSIONS Our results support the recommendation of supplementing postmenopausal women with low circulating levels of 25(OH)vitamin D with a combination of calcium and vitamin D, rather than with calcium alone.