Amalgam (dentistry) can cross the placenta leading to stillbirths and birth defects. A combination of mercury and non-ionizing radiation has been suggested as a factor in the recent increase in reported autism spectrum disorders. It has been reported that there is a positive correlation between the maternal and cord blood mercury levels. Although there is no evidence linking amalgam use and pregnancy damage, it is advisable to delay or avoid dealing with amalgam fillings in pregnant patients. Dentists are urged by some to consider the selection of restorative material more seriously and avoid using amalgam when possible. The dental operating team should
Real element formula_1, Every involution is strongly real. Furthermore, every element that is the product of two involutions is strongly real. Conversely, every strongly real element is the product of two involutions. If and formula_1 is real in formula_2 and formula_30 is odd, then formula_1 is strongly real in formula_2. The extended centralizer of an element formula_1 of a group formula_2 is defined as making the extended centralizer of an element formula_1 equal to the normalizer of the set The extended centralizer of an element of a group formula_2 is always a subgroup of formula_2. For involutions or non-real elements, centralizer and