The effects of zoledronic acid and dexamethasone on osseointegration of endosseous implants: histological and histomorphometrical evaluation in rats.
BACKGROUND
Bisphosphonates are a widely used class of drugs that prevent bone loss. Several side effects related to bisphosphonate therapy have been reported, including osteonecrosis of the jaws associated with invasive dental procedures and implants placement.


OBJECTIVE
To evaluate the influence of intravenous nitrogen-containing BPs in combination with or without dexamethasone on osseointegration of titanium implants placed in an animal model.


METHODS
Twenty-seven male Wistar rats were divided into three groups: group 1 was treated solely with zoledronic acid, group 2 was treated with zoledronic acid and dexamethasone, and group 3 did only receive saline solution injections. Two endosseous implants were placed in each tibia, and three animals from each group were sacrificed at postoperative times of seven, 14, and 28 days. Non-decalcified sections were observed with light microscopy for histological and histomorphometrical analyses.


RESULTS
Histomorphometrical analysis using the animals and the implants as unit of measurement revealed no statistically significant difference regarding bone-implant contact and bone density among the three groups. Histological observation revealed that zoledronic acid-treated animals in combination with or without dexamethasone showed expressive less bone remodeling activity at 14 and 28 days after implants placement, compared with control specimens.


CONCLUSIONS
The studied bisphosphonate regimens did not interfere with the osseointegration of the implants, cortical, or medular bone deposition, but a possible lack of bone remodeling of the original cortical bone may affect long-term osseointegration.
Department of Stomatology, School of Dentistry, University of Sao Paulo, Sao Paulo, Brazil.
Marcio A
MA
de Oliveira
Department of Stomatology, School of Dentistry, University of Sao Paulo, Sao Paulo, Brazil.
Denise A
DA
Asahi
Department of Rheumatology, School of Medicine, University of Sao Paulo, Sao Paulo, Brazil.
Celey A E
CAE
Silveira
Department of Stomatology, School of Dentistry, University of Sao Paulo, Sao Paulo, Brazil.
Luiz Antonio P A
LAPA
Lima
Department of Oral Medicine, Dental School of University at Buffalo, Buffalo, NY, USA.
Michael
M
Glick
Department of Stomatology, School of Dentistry, University of Sao Paulo, Sao Paulo, Brazil.
Marina
M
Gallottini
D000818:Animals; D015519:Bone Density / Q000187:drug effects; D050071:Bone Density Conservation Agents / Q000494:pharmacology*; D016723:Bone Remodeling / Q000187:drug effects; D003758:Dental Implantation, Endosseous; D015921:Dental Implants; D003907:Dexamethasone / Q000494:pharmacology*; D004164:Diphosphonates / Q000494:pharmacology*; D005938:Glucocorticoids / Q000494:pharmacology*; D007093:Imidazoles / Q000494:pharmacology*; D020007:Implants, Experimental; D008297:Male; D023421:Models, Animal; D016348:Osseointegration / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar; D013977:Tibia / Q000601:surgery; D014025:Titanium; D000077211:Zoledronic Acid
D050071:Bone Density Conservation Agents; D015921:Dental Implants; D004164:Diphosphonates; D005938:Glucocorticoids; D007093:Imidazoles; D000077211:Zoledronic Acid; D003907:Dexamethasone; D014025:Titanium
animal model; bisphosphonates; endosseous implants