Effect of fluoride ions on apatite crystal formation in rat hard tissues

Aspects Regarding Fluoride Treatment for Reinforcement and Remineralization of Apatite Crystals

“…Exposure to Cd ions also caused crystal defects similar to those resulting from F exposure 1,27) . In particular, Cd exposure is well known as a risk factor for developing itai-itai disease accompanied by osteomalacia and osteoporosis 28) .…”

“…In particular, Cd exposure is well known as a risk factor for developing itai-itai disease accompanied by osteomalacia and osteoporosis 28) . This similarity of crystal structure defects led us to speculate that daily exposure to F ions may be a latent risk factor for bone disease 1) because the mechanism of crystal formation between enamel, dentin and bone is basically the same 29,30) . Despite some studies postulating a relationship between F in drinking water and an increased risk of bone fractures [31][32][33] , many people remain unaware of the bone damage posed by F exposure.…”

“…Recently, we demonstrated that fluoride (F) intake caused crystal structure defects in calcified hard tissues 1) . The World Health Organization, however, still supports F delivery programs such as water fluoridation, salt fluoridation, and milk fluoridation in an effort to protect against dental caries, although these methods have ambiguous beneficial effects 2, 3) .…”

“…Considering this possibility, we also conducted experiments to investigate the harmfulness of F exposure during hard tissue formation compared to that of Cd. To assess the harmfulness of unwanted chemicals on calcified hard tissues, we examined carbonic anhydrase activity in developing rat tooth enamel because this enzyme, not alkaline phosphatase, plays a key role in initiating the nucleation process for central dark line formation 1,[27][28][29][30][34][35][36][37][38] .…”

Fluoride Exposure May Accelerate the Osteoporotic Change in Postmenopausal Women: Animal Model of Fluoride-induced Osteoporosis

“…This occurs because a high content of F ions absolutely inhibits the synthesis or activity of certain enzymes such as enolase and carbonic anhydrase [13,14,[38][39][40][41][42]. This might be fatal to cellular metabolism and eventually lead to pathological calcification, which might be similar to the vascular calcification accompanying cellular degeneration [43]. On the other hand, the increase of osteoid caused by the relatively low dose of F treatment may be interpreted as an increase of amorphous minerals due to the failure of crystal nucleation observed in the present and the previous studies [13,14,43].…”