Effects of fluoride in bone repair: an evaluation of RANKL, OPG and TRAP expression

Odontology. 2014 Jan;102(1):22-30. doi: 10.1007/s10266-012-0083-0. Epub 2012 Aug 10.

Abstract

The objective of this study was to evaluate comparatively the effect of fluoride in the expression of the receptor activator of nuclear factor kappa B ligand (RANKL), osteoprotegerin (OPG) and tartrate-resistant acid phosphatase (TRAP) in alveolar bone repair in rats. We used 3 groups of male Wistar rats (n = 5/group), which received drinking water containing different doses of F (NaF): 0, 5 and 50 ppm, for 60 days before the incisors extraction. The upper incisors were extracted and the animals were killed 7, 14, 21 and 30 days after extraction. The hemi-maxillae were collected for microscopic examination (histomorphometric and immunostaining for RANKL, OPG and TRAP). Histomorphometric analysis confirmed an increase in the volume density of neoformed bone between 7 and 30 days for groups control, 5 and 50 ppm of F, with a concomitant decrease in the volume density of connective tissue and blood clot. Higher blood clot for groups 5 and 50 ppm of F at 30 days was observed. The RANKL and OPG expressions were not changed by chronic exposure to fluoride in the drinking water during the studied periods; on the other hand, TRAP expression was changed (at 7 days) by chronic exposure to fluoride (p < 0.05). It was concluded that F in high concentrations can slow the blood clot remission and bone repair, and alter the TRAP expression in the beginning of the bone tissue repair. However, a better understanding about this blood clot remission phenomenon is required.

MeSH terms

  • Acid Phosphatase / metabolism*
  • Animals
  • Bone Regeneration*
  • Fluorides / administration & dosage*
  • Isoenzymes / metabolism*
  • Male
  • Osteoprotegerin / metabolism*
  • RANK Ligand / metabolism*
  • Rats
  • Rats, Wistar
  • Tartrate-Resistant Acid Phosphatase

Substances

  • Isoenzymes
  • Osteoprotegerin
  • RANK Ligand
  • Tnfrsf11b protein, rat
  • Acid Phosphatase
  • Tartrate-Resistant Acid Phosphatase
  • Fluorides