Radiographic assessment of bone density around integrated titanium implants after ovariectomy in rats.
OBJECTIVE
This study evaluated the influence of ovariectomy 8 weeks after implant placement on bone integrated to titanium implants.


METHODS
Thirty-eight female rats were submitted to a titanium implant at the tibiae proximal methaphysis. After a healing period of 8 weeks the animals were randomly divided into three groups: control (CTL-10 animals), sham-operated (SHAM-14 animals) and ovariectomy (OVX-14 animals). The CTL group was then sacrificed in order to confirm integration of the implant. The SHAM group was submitted to fictitious surgery and the OVX group was submitted to bilateral ovariectomy. After 12 weeks post-implant placement, the SHAM and OVX groups were sacrificed. In order to confirm the systemic osteopenia in rats, a dual-energy X-ray absorptiometry (DXA) was performed. For the evaluation of bone density, digital radiographs were taken. The grey level of the bone adjacent to implant was measured using image software and the bone density was calculated at six points on both sides of the implant.


RESULTS
Densitometry measurements of the femur confirmed systemic bone mass loss in the OVX group. Individualized bone analyses of different regions surrounding the implant showed a significantly lower radiographic bone density (P < 0.05) in the cancellous region of the OVX group (77.48 +/- 23.39 grey levels) when compared with the CTL and SHAM groups (91.61 +/- 32.10 and 102.57 +/- 32.50 grey levels, respectively).


CONCLUSIONS
The present study showed a decrease of the radiographic bone density in the cancellous region of bone around titanium implants placed 8 weeks before ovariectomy in rats.
Department of Oral Diagnosis and Surgery, School of Dentistry, State University of São Paulo, UNESP, Araraquara, SP, Brazil.
Celso Eduardo
CE
Sakakura
Gabriela
G
Giro
Daniela
D
Gonçalves
Rosa Maria Rodrigues
RM
Pereira
Silvana Regina Perez
SR
Orrico
Elcio
E
Marcantonio
D015502:Absorptiometry, Photon; D000818:Animals; D015519:Bone Density / Q000502:physiology; D001851:Bone Diseases, Metabolic / Q000000981:diagnostic imaging / Q000503:physiopathology; D015921:Dental Implants; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000503:physiopathology; D007091:Image Processing, Computer-Assisted / Q000379:methods; D016348:Osseointegration / Q000502:physiology; D010052:Ovariectomy; D011856:Radiographic Image Enhancement; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D013977:Tibia / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery; D014025:Titanium; D014945:Wound Healing / Q000502:physiology
D015921:Dental Implants; D014025:Titanium