Hypertension may affect tooth-supporting alveolar bone quality: a study in rats.
BACKGROUND
This study evaluates the ligature-induced bone loss (BL) and quality of tooth-supporting alveolar bone in spontaneously hypertensive rats (SHRs) by histometric, histochemical, and immunohistochemical analyses and assesses the effects of lercanidipine on these parameters.


METHODS
Wistar rats and SHRs were assigned to one of the following groups: normotensive rats (n = 15), untreated SHRs (n = 15), and treated SHRs (n = 15). The latter group was treated daily with lercanidipine for 45 days. Two weeks after the beginning of drug administration, the first right mandibular molar received a cotton ligature, whereas the contralateral tooth was left unligated. The following parameters were analyzed in the furcation area of decalcified histologic sections: BL, bone density (BD), number of positive cells for tartrate-resistant acid phosphatase (TRAP+), and expression of receptor activator of nuclear factor-kappa B ligand (RANKL) and osteoprotegerin (OPG).


RESULTS
In ligated teeth, no significant differences among groups were found regarding BL, TRAP+ cells, and the ratio of RANKL/OPG+ cells (P >0.05), although the expression of RANKL was decreased in the treated SHR group (P <0.05). Increased BL and decreased BD were observed around unligated teeth of the untreated and treated SHR groups (P <0.05). In the furcation area of the unligated teeth, the untreated SHR group presented a higher number of TRAP+ cells and higher ratio of RANKL/OPG+ cells compared to the other groups.


CONCLUSIONS
SHRs present harmful alterations in the quality of tooth-supporting bone, independently of inflammation. In addition, the administration of lercanidipine for 45 days decreased the expression of bone-resorption markers.
Bastos
Marta Ferreira
MF
Department of Periodontics, Dental Research Division, Guarulhos University, Guarulhos, São Paulo, Brazil. mfbastos@prof.ung.br
Brilhante
Felipe Vilhena
FV
Gonçalves
Tiago Eduardo Dias
TE
Pires
Amanda Gonçalves
AG
Napimoga
Marcelo Henrique
MH
Marques
Marcelo Rocha
MR
Duarte
Poliana Mendes
PM
D000135:Acid Phosphatase / Q000032:analysis; D016301:Alveolar Bone Loss / Q000473:pathology / Q000503:physiopathology; D000539:Alveolar Process / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology*; D000818:Animals; D000959:Antihypertensive Agents / Q000627:therapeutic use; D015415:Biomarkers / Q000032:analysis; D015519:Bone Density / Q000187:drug effects / Q000502:physiology; D004095:Dihydropyridines / Q000627:therapeutic use; D006973:Hypertension / Q000188:drug therapy / Q000503:physiopathology*; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000032:analysis; D008297:Male; D008963:Molar / Q000473:pathology; D053244:Osteoprotegerin / Q000032:analysis; D053245:RANK Ligand / Q000032:analysis; D051381:Rats; D011918:Rats, Inbred SHR; D017208:Rats, Wistar; D000071681:Tartrate-Resistant Acid Phosphatase; D014092:Tooth Root / Q000473:pathology
D000959:Antihypertensive Agents; D015415:Biomarkers; D004095:Dihydropyridines; D007527:Isoenzymes; D053244:Osteoprotegerin; D053245:RANK Ligand; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase; C060343:lercanidipine