Lead in human teeth

Lead (Pb) is a heavy metal distributed in the environment linked to a number of adverse biological effects. The teeth of all humans contain certain amounts of lead. Teeth with elevated levels of lead are usually affected by dental caries and periodontal problems. The highest amount of this metal is located on the tooth surfaces and decreases rapidly with the increase in depth. The highest Pb levels are observed on the palatal surface next to the gums. The lowest values are established on the vestibular side near the cutting edge of the tooth. The concentration of Pb is higher in the tips of the unerupted roots of the deciduous teeth. During the physiological process of resorption of the roots of deciduous teeth, the periapical area may be saturated with this heavy metal. Lead in saliva leads to an imbalance in the oral microbial colonisation. Higher numbers of Salivalis lactobacilli and Mutans streptococci colonies in saliva correspond to elevated levels of Pb in teeth. As age increases, so does the amount of the metal in the teeth, especially over the age of 51. The amount of Pb in the dentin can help determine the age in forensic medicine. There is a clear increase in Pb concentrations in the presence of amalgam obturations and in smokers. Hard dental tissues are valuable for the study of environmental Pb contamination. Isotopic data of Pb in the dentin provide useful information to identify native or foreign status and assess the geographic place of origin of unidentified human remains.