Magnesium oxide (MgO). An inorganic compound that occurs in nature as the mineral periclase. In aqueous media combines quickly with water to form magnesium hydroxide. It is used as an antacid and mild laxative and has many nonmedicinal uses.

Unstable isotopes of strontium that decay or disintegrate spontaneously emitting radiation. Sr 80-83, 85, and 89-95 are radioactive strontium isotopes.

An element of the alkaline earth family of metals. It has the atomic symbol Sr, atomic number 38, and atomic weight 87.62.

The use of a treatment material (tissue conditioner) to re-establish tone and health to irritated oral soft tissue, usually applied to the edentulous alveolar ridge.

Disorder caused by an interruption of the mineralization of organic bone matrix leading to bone softening, bone pain, and weakness. It is the adult form of rickets resulting from disruption of VITAMIN D; PHOSPHORUS; or CALCIUM homeostasis.

Carbonic acid calcium salt (CaCO3). An odorless, tasteless powder or crystal that occurs in nature. It is used therapeutically as a phosphate buffer in hemodialysis patients and as a calcium supplement.

Decalcification of bone or abnormal bone development due to chronic KIDNEY DISEASES, in which 1,25-DIHYDROXYVITAMIN D3 synthesis by the kidneys is impaired, leading to reduced negative feedback on PARATHYROID HORMONE. The resulting SECONDARY HYPERPARATHYROIDISM eventually leads to bone disorders.

The methyl esters of methacrylic acid that polymerize easily and are used as tissue cements, dental materials, and absorbent for biological substances.

Stable strontium atoms that have the same atomic number as the element strontium, but differ in the atomic weight. Sr-84, 86, 87, and 88 are the stable strontium isotopes.

A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.

A specialized CONNECTIVE TISSUE that is the main constituent of the SKELETON. The principle cellular component of bone is comprised of OSTEOBLASTS; OSTEOCYTES; and OSTEOCLASTS, while FIBRILLAR COLLAGENS and hydroxyapatite crystals form the BONE MATRIX.

Plutonium. A naturally radioactive element of the actinide metals series. It has the atomic symbol Pu, atomic number 94, and atomic weight 242. Plutonium is used as a nuclear fuel, to produce radioisotopes for research, in radionuclide batteries for pacemakers, and as the agent of fission in nuclear weapons.

Radioactive substances which act as pollutants. They include chemicals whose radiation is released via radioactive waste, nuclear accidents, fallout from nuclear explosions, and the like.

Americium. A completely man-made radioactive actinide with atomic symbol Am, atomic number 95, and atomic weight 243. Its valence can range from +3 to +6. Because of its nonmagnetic ground state, it is an excellent superconductor. It is also used in bone mineral analysis and as a radiation source for radiotherapy.

Energy released by nuclear fission or nuclear fusion.

'Water Pollution, Radioactive' is the contamination of water bodies with radioactive substances, typically as a result of human activities such as mining, nuclear power generation, or improper waste disposal, which can lead to harmful health effects in humans and aquatic life due to radiation exposure.

Devices containing fissionable material in sufficient quantity and so arranged as to be capable of maintaining a controlled, self-sustaining NUCLEAR FISSION chain reaction. They are also known as atomic piles, atomic reactors, fission reactors, and nuclear piles, although such names are deprecated. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)

A series of radioactive elements from ACTINIUM, atomic number 89, to and including LAWRENCIUM, atomic number 103.

Thorium. A radioactive element of the actinide series of metals. It has an atomic symbol Th, atomic number 90, and atomic weight 232.04. It is used as fuel in nuclear reactors to produce fissionable uranium isotopes. Because of its radioopacity, various thorium compounds are used to facilitate visualization in roentgenography.

Unstable isotopes of lead that decay or disintegrate emitting radiation. Pb atoms with atomic weights 194-203, 205, and 209-214 are radioactive lead isotopes.

Thorium oxide (ThO2). A radiographic contrast agent that was used in the early 1930s through about 1954. High rates of mortality have been linked to its use and it has been shown to cause liver cancer.

Uranium. A radioactive element of the actinide series of metals. It has an atomic symbol U, atomic number 92, and atomic weight 238.03. U-235 is used as the fissionable fuel in nuclear weapons and as fuel in nuclear power reactors.

Actinium. A trivalent radioactive element and the prototypical member of the actinide family. It has the atomic symbol Ac, atomic number 89, and atomic weight 227.0278. Its principal isotope is 227 and decays primarily by beta-emission.

The spontaneous transformation of a nuclide into one or more different nuclides, accompanied by either the emission of particles from the nucleus, nuclear capture or ejection of orbital electrons, or fission. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)

A soft, grayish metal with poisonous salts; atomic number 82, atomic weight 207.19, symbol Pb. (Dorland, 28th)