Week 14 Notes - Fluoride.pdf

Has the highest electronegativity and the second highest electron affinity, making it highly reactive with metals and H; The most favorable metal reactions with fluoride are aluminum, calcium, and magnesium, the most stable compounds are aluminum, iron, and beryllium;...

Has the highest electronegativity and the second highest electron affinity, making it highly reactive with metals and H; The most favorable metal reactions with fluoride are aluminum, calcium, and magnesium, the most stable compounds are aluminum, iron, and beryllium; biological significant CaF2 and MgF2 are highly insoluble and precipitate  Johnston NR, Strobe SA, Principles of fluoride toxicity and the cellular response: a review Arch Toxicol. 2020 April ; 94(4): 1051–1069.  Wei et all. Effect of Fluoride on Cytotoxicity Involved in Mitochondrial Dysfunction: A Review of Mechanism. Front Vet Sci. 2022 Apr 19;9:850771  Kubota et all. Fluoride induces endoplasmic reticulum stress in ameloblasts responsible for dental enamel formation. J Biol Chem. 2005 Jun 17;280(24):23194-202  Found in 296 different species of minerals Free fluoride is present in the ocean at 1.2–1.4 ppm (mg/L) groundwater, particularly in volcanic or mountainous areas, can contain as much as 50 mg/L makes up about 1.5–3% of the final phosphate fertilizers emitted as fumes upon coal combustion fluoride-accumulating plants: tomato, spinach, tea, grapes, and elderberry.  Replaces Ca in bone and teeth making them harder but more rigid, brittle, and porous Cavity prevention: o Strengthen enamel AFTER its formation; acts from outside of the tooth: i.e. saliva or mouth content (gels, toothpaste, mouthwash). o Mild toxic for mouth bacteria o Fluorosilicic acid (H2SiF6) is the most commonly used additive for water fluoridation in the United States as is an inexpensive by- product of phosphate fertilizer manufacture o ameloblasts: growth-inhibition at low concentration →ER stress and caspase-mediated DNA fragmentation; altered email production at higher concentration → dental fluorosis! o children exposed during enamel production (birth to 8-12 yoa) → dental fluorosis!!! o Inhibits metal-enzymes (e.g. known since 1889 about lipase ) 30%–50% of proteins require metal cofactors), organelle disruption, altered pH, and electrolyte imbalance o cell proliferation may be stimulated at higher concentrations o triggers oxidative stress, cell cycle arrest, and apoptosis. o Increases generation of superoxide anions; o Induces mitochondrial toxicity: ❖ decreased activity of mitochondrial enzymes, ❖ decreased mitochondrial protein expression, ❖ damage of respiratory chain, ❖ ER disorder of calcium regulation, ❖ → ↓ATP, accumulation of ROS, opening of the transition pore &release of cytochrome c from mitochondria → apoptosis; o Inhibit cell migration, e.g. of embryonic neurons and sperm; o increases expression of inflammatory factors, e.g. IL-8 and NF-kappaB  Dental plaque is the cause of cavities microbial imbalance, sucrose (sugar), acid pH, long term adherence to the teeth  Kashbour et all. Pit and fissure sealants versus fluoride varnishes for preventing dental decay in the permanent teeth of children and adolescents. Cochrane Database Syst Rev. 2020 Nov 4;11 F not better (or worse) than modern crack sealants