cholecalciferol and Tooth-Resorption

Dentin in permanent teeth rarely undergoes resorption in development, homeostasis, or aging, in contrast to bone that undergoes periodic resorption/remodeling. The authors hypothesized that cells in the mesenchymal compartment of dental pulp attenuate osteoclastogenesis. Mononucleated and adherent cells from donor-matched rat dental pulp (dental pulp cells [DPCs]) and alveolar bone (alveolar bone cells [ABCs]) were isolated and separately cocultured with primary rat splenocytes. Primary splenocytes readily aggregated and formed osteoclast-like cells in chemically defined osteoclastogenesis medium with 20 ng/mL of macrophage colony-stimulating factor (M-CSF) and 50 ng/mL of receptor activator of nuclear factor κB ligand (RANKL). Strikingly, DPCs attenuated osteoclastogenesis when cocultured with primary splenocytes, whereas ABCs slightly but significantly promoted osteoclastogenesis. DPCs yielded ~20-fold lower RANKL expression but >2-fold higher osteoprotegerin (OPG) expression than donor-matched ABCs, yielding a RANKL/OPG ratio of 41:1 (ABCs:DPCs). Vitamin D3 significantly promoted RANKL expression in ABCs and OPG in DPCs. In vivo, rat maxillary incisors were atraumatically extracted (without any tooth fractures), followed by retrograde pulpectomy to remove DPCs and immediate replantation into the extraction sockets to allow repopulation of the surgically treated root canal with periodontal and alveolar bone-derived cells. After 8 wk, multiple dentin/root resorption lacunae were present in root dentin with robust RANKL and OPG expression. There were areas of dentin resoprtion alternating with areas of osteodentin formation in root dentin surface in the observed 8 wk. These findings suggest that DPCs of the mesenchymal compartment have an innate ability to attenuate osteoclastogenesis and that this innate ability may be responsible for the absence of dentin resorption in homeostasis. Mesenchymal attenuation of dentin resorption may have implications in internal resorption in the root canal, pulp/dentin regeneration, and root resorption in orthodontic tooth movement.

Topics: Adult; Alveolar Process; Animals; Bone Density Conservation Agents; Cell Aggregation; Cell Culture Techniques; Cell Differentiation; Cholecalciferol; Coculture Techniques; Dental Pulp; Dental Pulp Cavity; Dentin; Dentin, Secondary; Homeostasis; Humans; Macrophage Colony-Stimulating Factor; Male; Mesenchymal Stem Cells; Osteoclasts; Osteoprotegerin; Pulpectomy; RANK Ligand; Rats; Rats, Inbred F344; Rats, Sprague-Dawley; Rats, Transgenic; Spleen; Tooth Replantation; Tooth Resorption

It has been suggested that tooth resorption (TR) in cats is associated with vitamin D3 status. The purpose of this study was to evaluate any correlation between serum 25-OH-D concentrations and the prevalence of TR. The healthy adult domestic cats (n=64) of this study had been fed similar premium dry-expanded foods throughout their lives. Serum 25-OH-D was measured, and cats received a single, complete periodontal examination, with periodontal probing of each tooth and exploration of the tooth surface using a dental explorer A complete set of 10 dental radiographs was taken for each cat. There were 168 TRs diagnosed in 40 of 64 cats (85 were Type 1 TR and 83 were Type 2). The mean serum 25-OH-D concentration was 187.7 +/- 87.3 nmol/L. The mean serum 25-OH-D in cats with one or more TR was 164.2 +/- 78.8 nmol/L, compared with 226.8 +/- 88.2 nmol/L for those without TR (p = 0.14). The mean serum 25-OH-D in the 13 cats with >5 TR was 131.2 +/- 49.5 nmol/L, which was significantly less than in cats with no TR (p < 0.05). There was no relationship between TR type and serum 25-OH-D. There was no effect of age or sex on serum 25-OH-D. On the contrary, variations in serum 25-OH-D were observed according to the studied breeds. There was no relationship between TR type and serum 25-OH-D. TR prevalence was greater in cats with lower serum 25-OH-D concentrations. In conclusion, the hypothesis that higher serum 25-OH-D concentrations are associated with a higher prevalence of TR is not supported by this study.

Topics: Animal Feed; Animals; Cat Diseases; Cats; Cholecalciferol; Diet; Female; France; Male; Prevalence; Regression Analysis; Tooth Resorption; Vitamin D