Plaque calcium

A few authors have investigated the possible association between calcium and phosphorus levels in plaque and caries, and obtained reasonably consistent findings. Schamschula with various co-workers [80, 81] found the intuitively expected inverse association between plaque calcium and caries experience in two independent studies. In one of the studies they also found a significant inverse association for plaque phosphorus. Similarly, Shaw et al. [77] found significantly more calcium and phosphorus in plaque from caries-free children than in plaque from caries-active children. 

Ashley and Wilson [82] reported inverse relationships between 3-year caries increments and levels of calcium and inorganic phosphorus in the plaque. Of importance, these authors were able to show that the time relationship between caries diagnosis and plaque sampling appeared to be crucial. They had taken both caries and plaque measurements yearly during a 3-year clinical trial. Plaque calcium and phosphorus data correlated significantly with the 1-year DFS increments obtained one year later, but did not correlate with the corresponding 1-year DFS increments obtained one year earlier. 

Whitford GM, Wasdin JL, Schafer TE, Adair SM Plaque fluoride concentrations are dependent on plaque calcium concentrations. Caries Res 2002 36 256-265. 

First, we describe the chemical composition of plaque fluid in relation to caries, then the role of plaque structure. Next, we discuss the influence of F retained in plaque, including site-to-site differences, followed by the effect of treatments that seek to deposit plaque calcium (Ca) and/or inorganic phosphate (Pi). A combination of small sample volumes and low constituent concentrations typically leads to high measurement variability that results, in turn, with authors often having difficulty in discriminating between subject groups. 

The sequestering agent tetrasodium pyrophosphate (TSPP) removes calcium and magnesium from the saliva, so they can t deposit on teeth as insoluble deposits called tartar (calcified plaque). In this respect it acts as a water-softening agent. However, it won t remove tartar that already exists. 

Repeated injury and repair within an atherosclerotic plaque eventually lead to a fibrous cap protecting the underlying core of lipids, collagen, calcium, and inflammatory cells such as T lymphocytes. Maintenance of the fibrous plaque is critical to prevent plaque rupture and subsequent coronary thrombosis. 

Increasing Oxygen. It was once believed that the cause of Alzheimer s dementia was poor oxygen snpply to the brain. This theory suggested that atherosclerosis, hard plaques of fat and calcium, accumulate in blood vessels and block the arteries that snpply the brain, depriving it of oxygen-rich blood. In fact, atherosclerosis does occnr in the carotid arteries that snpply the brain and is the most common cause of stroke and vascnlar dementia. There is no evidence that this mechanism is involved in the pathology of Alzheimer s disease. 

Fig. 8.2 (A) Intravascular ultrasound (IVUS) image of a coronary artery using Revolution 45 MHz IVUS imaging catheter. (B) Plaque composition imaging using volcano VH IVUS system. Green areas represent Fibrous plaque. Yellow is fibro-fatty areas. Red is the necrotic core and white represents areas of dense calcium...

Many types of materials accumulate on teeth. By far the most widespread and important deposit is dental plaque. Plaque consists primarily of microorganisms in an organized matrix of organic and inorganic components. Bacteria account for at least 70% of the mass of plaque. In fact, one cubic millimeter of dental plaque contains more than 100 million bacteria consisting of more than 400 species. The organic matrix of plaque consists of polysaccharide, protein, and Upid components, while the inorganic matrix is composed primarily of calcium and phosphorous ions. 

The present studies on calcium phosphate in bacteria are mostly of dental interest. Through the mineralization of the dental plaque dental calculus forms the soft, adherent and predominant coating which forms on the surface of teeth567. X-ray diffraction studies have shown the dental calculus to be composed of four principal minerals hydroxyapatite, octacalcium phosphate, brushite and whitelockite568. The mechanism by which mineralization of oral calculi is initiated is not fully understood567. Two types of mineralization centres can be distinguished which... 

The HDPE samples were compression-molded plaques (1.25 mm thick) prepared from Dow 04452N HDPE pellets. Styrene was vacuum distilled from calcium hydride, and ethylbenzene and tert-butyl perbenzoate (TBPB) were used as received (Aldrich). 

Atorvastatin calcium possesses an anti-inflammatory property and reduces the accumulation of inflammatory cells in the atherosclerotic plaques. The drug also inhibits the vascular smooth muscle cell proliferation a key event in the atherogenesis. Atorvastatin also inhibits the platelet function, thereby limiting both the atherosclerosis and the superadded thrombosis and also improves the vascular endothelial function, largely through the amplification of nitric oxide (NO) generation [3-5]. 

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