Parathyroid hormone intermittent administration promotes delay on rat incisor eruption.
OBJECTIVE
This study evaluated the influence of parathyroid hormone (PTH) (1-34) intermittent administration on rat eruption rates of lower incisors under normo, hyper and hypofunctional conditions, Sharpey fibers insertion, and alveolar bone formation.


METHODS
Wistar male rats received PTH (1-34) three times a week during the entire experimental period, 31days. Control animals received the same concentration of the vehicle solution during the same period. Three injections of alizarin were also performed. The experiment evaluated the eruptive rate, the alveolar bone formation and also the morphology, and the area density of Sharpey fibers. After the sacrifice, the mandibles were dissected and samples were prepared for fluorescence and scanning electron microscopy observations.


RESULTS
PTH-treated animals showed significantly reduced eruption rates in all different functional conditions. Analysis evidenced that PTH-treated rats present an increase in bone formation and area density of the Sharpey fibers.


CONCLUSIONS
We concluded that the PTH (1-34) intermittent administration reduced the eruptive process rates, through bone formation enhancement and increase in the area density of Sharpey fibers.
Division of Histology and Embryology, Federal University of Campina Grande, Patos, PB, Brazil. Electronic address: silvamad@cstr.ufcg.edu.br.
M A D
MA
Silva
Division of Histology and Embryology, School of Biomedicine, Federal University of Piaui, Parnaiba, PI, Brazil. Electronic address: vasconcelos@ufpi.edu.br.
D F P
DF
Vasconcelos
Department of Morphology, Division of Histology, School of Dentistry at Piracicaba, University of Campinas, Piracicaba, SP, Brazil.
M R
MR
Marques
Center for Oral and Systemic Diseases, Department of Periodontology, UNC School of Dentistry, University of North Carolina at Chapel Hill, USA.
S P
SP
Barros
D019342:Acetic Acid; D000539:Alveolar Process / Q000187:drug effects; D000818:Animals; D000880:Anthraquinones / Q000494:pharmacology; D007180:Incisor / Q000187:drug effects* / Q000254:growth & development / Q000648:ultrastructure; D008297:Male; D008334:Mandible / Q000473:pathology; D008855:Microscopy, Electron, Scanning; D008856:Microscopy, Fluorescence; D023421:Models, Animal; D009805:Odontogenesis / Q000187:drug effects; D010012:Osteogenesis / Q000187:drug effects / Q000502:physiology; D010281:Parathyroid Hormone / Q000008:administration & dosage* / Q000494:pharmacology*; D010513:Periodontal Ligament / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D014078:Tooth Eruption / Q000187:drug effects* / Q000502:physiology
D000880:Anthraquinones; D010281:Parathyroid Hormone; C010078:alizarin; D019342:Acetic Acid
Bone biology; Microscopy; Mineralized tissue; Odontogenesis; Periodontal ligament; Tooth development