Human tooth decays more rapidly and is subject to severe cavities if not properly treated, but dentin still acts as a protective layer and supports the crown of the tooth. Dentin is a mineralized connective tissue with an organic matrix of collagenous proteins. Dentin has microscopic channels, called dentinal tubules, which radiate outward through the dentin from the pulp cavity to the exterior cementum or enamel border. The diameter of these tubules range from 2.5 μm near the pulp, to 1.2 μm in the midportion, and 900 nm near the dentino-enamel junction. Although they may have tiny side-branches, the tubules do not
Baby Tooth Survey Baby Tooth Survey The Baby Tooth Survey was initiated by the Greater St. Louis Citizens' Committee for Nuclear Information in conjunction with Saint Louis University and the Washington University School of Dental Medicine as a means of determining the effects of nuclear fallout in the human anatomy by examining the levels of radioactive material absorbed into the deciduous teeth of children. Founded by the husband and wife team of physicians Eric and Louise Reiss, along with other scientists such as Barry Commoner and Ursula Franklin, the research focused on detecting the presence of strontium-90, a cancer-causing radioactive isotope created by