Estrogen and alendronate therapies may prevent the influence of estrogen deficiency on the tooth-supporting alveolar bone: a histometric study in rats.
OBJECTIVE
The aim of this study was to evaluate histometrically the influence of estrogen deficiency, and its therapies, on the quality of the tooth-supporting alveolar bone.


METHODS
Seventy-three female rats were randomly assigned to one of the following groups: group 1 (n = 15), sham surgery; group 2 (n = 15), bilateral ovariectomy (OVX); group 3 (n = 14), OVX plus calcitonin (16 IU/kg); group 4 (n = 14), OVX plus estrogen (20 microg/kg); and group 5 (n = 15), OVX plus alendronate (5 mg/kg). Eighty days after surgery, the animals were killed and their mandibles were removed and processed for histology. Bone density (BD) in the furcation area of the first mandibular molar (i.e. the percentage of demineralized bone tissue in a 1,000 microm zone under the furcation) was histometrically obtained.


RESULTS
Data analysis demonstrated that estrogen deficiency negatively affected the tooth-supporting bone density (79.45% +/- 4.22 and 55.23% +/- 6.45, for groups 1 and 2, respectively), and that estradiol and alendronate therapies prevented this effect (61.67% +/- 6.87, 78.09% +/- 3.12 and 81.47% +/- 4.58, for groups 3, 4 and 5, respectively).


CONCLUSIONS
Within the limits of this study, it can be concluded that the density of tooth-supporting bone is affected by estrogen deficiency, and that estradiol and alendronate therapies, but not calcitonin, provide protection against this effect.
Duarte
P M
PM
Department of Periodontics, Dental Research Division, Guarulhos University, Guarulhos, São Paulo, Brazil. pduarte@ung.br
Gonçalves
P
P
Casati
M Z
MZ
de Toledo
S
S
Sallum
E A
EA
Nociti
F H
FH
D019386:Alendronate / Q000627:therapeutic use*; D000469:Alkaline Phosphatase / Q000097:blood; D000539:Alveolar Process / Q000187:drug effects* / Q000502:physiology; D000818:Animals; D015519:Bone Density / Q000187:drug effects*; D050071:Bone Density Conservation Agents / Q000627:therapeutic use*; D004967:Estrogens / Q000172:deficiency / Q000627:therapeutic use*; D005260:Female; D010024:Osteoporosis / Q000188:drug therapy / Q000517:prevention & control; D051381:Rats; D017208:Rats, Wistar
D050071:Bone Density Conservation Agents; D004967:Estrogens; D000469:Alkaline Phosphatase; D019386:Alendronate