Fluoride and Orthodontic Treatment  A study by Dr. Car­men
Gonzales, et al investigated the effect of systemic fluoride
intake from birth to 12 weeks on orthodontically induced root
resorption and tooth movement in rat mo­lars. Fifty male rats
were randomly di­vided into the following 5 groups: a neg­ative
control group that re­ceived no so­dium fluoride and had no
tooth movement; a positive control group that re­ceived no
sodium fluoride but had tooth movement; and 3 experiment­al
groups that received 45-ppm sodium fluoride from birth to 2, 4,
and 12 weeks, respectively. At week 10, a 50-g nickel-titanium
coil spring was ap­plied to the maxillary left first molar for 2
weeks. At week 12, movement of the maxillary first mo­lars was
measured in relation to the maxillary second molar on digitized
cephalometric radiographs. Mesial and distal roots were examined
by using scanning electron and 3-dimensional laser microscopes.
The study found that fluoride reduced the depth, volume, and
roughness of the resorption