Extra Fluoride Causes Tooth Enamel Defects
The Facilities for Illness Management and Prevention (CDC) named water fluoridation one among 10 nice public well being achievements of the twentieth century for its function in decreasing tooth decay.
Whereas low ranges of fluoride assist strengthen and defend tooth enamel, an excessive amount of fluoride may cause dental fluorosis–a discoloration of enamel, often with opaque white marks, traces, or mottled enamel and poor mineralization.
“The advantages of fluoride for oral well being significantly outweigh the dangers. However given how frequent dental fluorosis is and the way poorly understood the mobile mechanisms liable for this illness are, it is very important examine this drawback,” stated Rodrigo Lacruz, PhD, affiliate professor of fundamental science and craniofacial biology at NYU School of Dentistry and the examine’s senior writer.
To research the molecular bases of dental fluorosis, the researchers analyzed the consequences of exposing tooth enamel cells to fluoride–levels on the upper finish of what you’d discover in ingesting water and per what’s present in areas the place individuals generally have fluorosis. They then assessed fluoride’s affect on calcium signaling inside the cells, given calcium’s function in mineralizing tooth enamel.
The researchers discovered that exposing enamel cells from rodents to fluoride resulted in calcium dysregulation, with decreases in calcium getting into and saved within the endoplasmic reticulum, a compartment inside cells with many capabilities, together with storing calcium. As well as, fluoride disrupted the perform of mitochondria (the cells’ energy turbines), and subsequently power manufacturing was altered.
Lastly, RNA sequencing–which queries the genomes of cells–revealed that, in enamel cells uncovered to fluoride, there was an elevated expression of genes encoding endoplasmic reticulum stress response proteins and people encoding mitochondrial proteins, that are concerned in producing the cell’s power.
“This offers us a really promising mechanistic view of how fluorosis arises,” Lacruz stated. “In case your cells should make enamel, which is closely calcified, and on account of publicity to an excessive amount of fluoride the cells endure continued stress of their capability to deal with calcium, that might be mirrored within the enamel crystals as they’re shaped and can affect mineralization.”
The researchers then repeated the experiment utilizing early-stage kidney cells from people, however they didn’t observe the identical results when the kidney cells had been uncovered to fluoride–suggesting that enamel cells are completely different from cells forming tissue in different elements of the physique.
“You’ll assume that in the event you expose the enamel cells and kidney cells to the identical stressor–treating them with the identical quantity of fluoride for a similar interval of time–that you’d have roughly comparable responses. However that was not the case,” stated Lacruz.
“Beneath the identical circumstances, enamel cells react to dealing with stress in vastly alternative ways than kidney cells. We’re unraveling a mechanism that highlights the distinctiveness of enamel cells and explains why fluorosis is extra of an issue within the enamel than anyplace else within the physique.”