Implant osseointegration in irradiated bone: an experimental study.
OBJECTIVE
The aim of this study was to evaluate the effect of radiotherapy on the osseointegration of dental implants in the tibia and the action of platelet-rich plasma (PRP) as an adjuvant therapy.


METHODS
A total of 18 rabbits received two implants in each tibial epiphysis, totalizing 72 implants. The control group (group I) was composed by six rabbits and did not receive radiotherapy. The test groups (II and III) received a single dose of 1727 cGy. Group II was composed by six irradiated animals and group III by six animals that received irradiation and PRP during implant placement. The implant success rate, the bone-implant contact (BIC), and the bone volume were analyzed.


RESULTS
There was no osseointegration in four of the implants, three in group II and one in group III. Total BIC was significantly higher in group I, when compared to the other groups. There was a significant difference of osteoid BIC only between irradiated animals (group II, 8.5%; group III, 4.7%; p = 0.001). On the other hand, the mineralized BIC was significantly higher in group I. Furthermore, group II had a lower mineralized BIC than group III (p = 0.002). Bone volume was higher in the control group (41.3%), followed by group III (33.4%) and II (25.1%), with differences between groups I and II (p = 0.001) and groups II and III (p = 0.022).


CONCLUSIONS
The present study showed that both the bone volume and BIC were higher in the control group. However, the failure rates of the implants were low in both irradiated groups. The PRP was a positive adjuvant in the osseointegration process.
Department of Stomatology, AC Camargo Cancer Center, São Paulo, Brazil.
R P
RP
Ocaña
Department of Stomatology, AC Camargo Cancer Center, São Paulo, Brazil.
G D
GD
Rabelo
Department of Stomatology, Erasto Gaertner Cancer Hospital, Curitiba, Brazil.
L M
LM
Sassi
Faculty of Dentistry, University of São Paulo, São Paulo, Brazil.
V P
VP
Rodrigues
Department of Stomatology, AC Camargo Cancer Center, São Paulo, Brazil.|Department of Stomatology, Faculty of Dentistry, University of São Paulo, São Paulo, Brazil.
F A
FA
Alves
D000818:Animals; D003758:Dental Implantation, Endosseous / Q000379:methods; D015921:Dental Implants; D019232:Dental Restoration Failure; D008297:Male; D016348:Osseointegration / Q000528:radiation effects*; D011817:Rabbits; D013977:Tibia / Q000528:radiation effects* / Q000601:surgery; D014025:Titanium
D015921:Dental Implants; D014025:Titanium
bone; dental implants; platelet-rich plasma; radiation therapy