Age-Related and Surgically Induced Estrogen Deficiencies May Differently Affect Bone Around Titanium Implants in Rats
- Autores: Poliana Mendes Duarte, Patrícia Furtado Gonçalves, Marcio Zaffalon Casati, Enilson Antonio Sallum, Dr. Francisco Humberto Nociti
- Localización: Journal of periodontology, ISSN 0022-3492, Vol. 76, Nº. 9, 2005, págs. 1496-1501
- Idioma: inglés
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Resumen
Background: Valuable information has been obtained using the ovariectomy model; however, clinical studies have indicated that such a model may not be appropriate to parallel with the postmenopausal condition and titanium implants. Thus, this study aimed to comparatively evaluate, by histometric analysis, the influence of age-related (ARED) and surgically induced (OVX) estrogen deficiencies on bone around titanium implants inserted in rats.
Methods: Single screw-shaped titanium implants were placed in rat tibiae and animals were then assigned to one of the following groups: SHAM (N = 15): bilateral sham ovariectomies in 90-day-old rats, 21 days before implant placement; OVX (N = 15): bilateral ovariectomies in 90-day-old rats, 21 days before implant placement; and ARED (N = 15): implant placement in reproductive aged rats (22 months old). After 60 days, the animals were sacrificed and undecalcified sections obtained. Boneto- implant contact (BIC) and bone area (BA) within the limits of implant threads and bone density (BD) in a 500 µm-wide zone lateral to the implant were obtained and arranged for cortical (zone A) and cancellous (zone B) bone regions.
Results: For zone A, intergroup analysis showed no signifi- cant differences regarding BIC and BA (P >0.05). In contrast, ARED negatively influenced BD around the implants (P <0.05). In zone B, OVX negatively affected BIC and BA (P <0.05), and both ARED and OVX groups demonstrated lower BD than the SHAM group (P <0.05).
Conclusion: Within the limits of this study, it can be concluded that ARED mainly affects preexisting bone while OVX more significantly affects both newly formed and preexisting bone. J Periodontol 2005;76:1496-1501.
