Alendronate may protect against increased periodontitis-related bone loss in estrogen-deficient rats.
BACKGROUND
The aim of this study was to evaluate the impact of alendronate (ALD) and estrogen (EST) therapies and their withdrawal on bone loss in experimental periodontitis in ovariectomized rats.


METHODS
Eighty-seven Wistar rats were divided into six groups: group 1 (N = 15): sham surgery; group 2 (N = 15): ovariectomy (OVX); group 3 (N = 15): OVX plus alendronate administration for 80 days (AT); group 4 (N = 14): OVX plus alendronate administration for 40 days (AW); group 5 (N = 14): OVX plus 17beta estradiol administration for 80 days (ET); and group 6 (N = 14): OVX plus 17beta estradiol administration for 40 days (EW). Twenty-one days after ovariectomy or sham surgery, one mandibular molar was randomly assigned to receive a ligature, while the contralateral tooth was left unligated. Sixty days later, the animals were sacrificed and the specimens processed.


RESULTS
OVX presented a direct impact on alveolar bone, regardless of plaque accumulation and significantly increased bone loss resulting from periodontitis (P < 0.05). The effect of OVX on unligated sites was significantly reduced by AT, AW, and ET (P < 0.05), but not by EW (P > 0.05). In addition, alendronate administration (AT/AW) significantly reduced the impact of OVX on periodontitis-related bone loss (P < 0.05), while estradiol did not (P > 0.05).


CONCLUSIONS
Within the limits of this study, alendronate administration, but not estrogen replacement, may protect against the impact of estrogen deficiency on alveolar bone presenting a significant residual effect after its withdrawal.
Duarte
Poliana Mendes
PM
Department of Prosthodontics and Periodontics, Division of Periodontics, School of Dentistry at Piracicaba, University of Campinas, Piracicaba, São Paulo, Brazil.
de Assis
Daniel Roberto
DR
Casati
Marcio Zaffalon
MZ
Sallum
Antonio Wilson
AW
Sallum
Enilson Antonio
EA
Nociti
Francisco H
FH
D019386:Alendronate / Q000627:therapeutic use*; D000469:Alkaline Phosphatase / Q000097:blood; D016301:Alveolar Bone Loss / Q000517:prevention & control*; D000539:Alveolar Process / Q000187:drug effects; D000818:Animals; D003774:Dental Plaque Index; D004958:Estradiol / Q000627:therapeutic use; D015914:Estrogen Replacement Therapy; D004967:Estrogens / Q000172:deficiency*; D005260:Female; D017823:Furcation Defects / Q000517:prevention & control; D010052:Ovariectomy; D010518:Periodontitis / Q000150:complications; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors
D004967:Estrogens; D004958:Estradiol; D000469:Alkaline Phosphatase; D019386:Alendronate