Too many tooth fillings could lead to mercury poisoning

Getting tooth decay treated may prove to be injurious to health, depending on what materials are used to restore damaged teeth. New research from the University of Georgia has shown that dental surface restorations that are made up of dental amalgam, a mixture of mercury, silver, tin and other metals, contribute significantly to prolonged mercury levels in the body.

The public health research team behind the study analysed data from 15,000 individuals in the United States and found elevated levels of methyl mercury, the most toxic form of mercury, related to dental fillings. Dental amalgam has been used in dentistry for 150 years because it is cheap and affordable. But hald the compound contains mercury, which is known to cause damage to the brain, heart, kidneys, lungs and immune system at high levels.

The researchers say that there is little risk of mercury poisoning if a person has one or two fillings but individuals with more than eight fillings had about 150% more mercury in their blood than those without any fillings. The study published in Ecotoxicology and Environmental Safety also suggested that microorganisms in the human gut may transform different types of mercury, making them more toxic.

New cheap and flexible printed bones

Fractures and bone defects may become easier to fix in the future with the use of 3D printed synthetic bones. Material scientists at Northwestern University in the United States say that they have developed hyper-elastic bones that are flexible, that do not require growth factors to repair damages and that can be quickly deployed in operating rooms.

A study published in the journal Science Translational Medicine described the use of such synthetic bones to repair spinal injuries in rodents and the skull of a monkey. The research team said that human trials could begin within five years.

The synthetic bone made of ceramic and a polymer is highly porous and absorbent, which allows it to integrate seamlessly with surrounding tissue, support blood vessel growth and regenerate real bone. The scientists saw no indications of infections or other side effects.

The researchers said that the hyper-elastic bone could be particularly useful in treating paediatric patients born with orthopedic defects and deformities of the face and jaw bones.

A protein to fight sepsis

A bacteria-killing protein could hold the key to warding of sepsis, a life-threatening condition triggered by infection in which the immune system attacks the body. Researchers at the Indian Institute of Science in Bangalore have demonstrated that bactericidal/permeability increasing protein or BPI protein neutralizes bacterial toxins in the blood that lead to sepsis.

The study published in Nature Scientific Reports describes how BPI is produced in the human body but not in enough quantities to counter sepsis when it occurs. To fight sepsis BPI needs to be produced externally and delivered into the body. The team found that gas nanovesicles produced by Halobacteria can be used to enhance BPI production while being inert enough not to evoke an immune response in humans.

The researchers tested BPI produced Halobacteria into which cloned mouse BPI protein gene had been introduced on 50 mice. Some mice were administered the BPI and then given sepsis causing chemicals. These test animals survived. However, the mice that were given BPI along with or after doses of sepsis-causing agents died, which indicated that BPI proteins should be administered before sepsis sets in so that it is present in the circulatory system to flush out sepsis-causing endotoxins. The researchers now plan to move to trials in larger animals.