Use of alendronate in peri-implant defect regeneration.
BACKGROUND
Previous studies have demonstrated an increase in bone mass and density with use of systemic alendronate sodium. This agent acts as an inhibitor of osteoclast activity, and is thought to result in more net osteoblastic activity. The objective of this study was to determine the effects of locally applied alendronate sodium on guided bone regeneration around dental implants.


METHODS
Six adult mongrel dogs were divided into 2 groups: one group received alendronate-coated dental implants, and the other group served as control. Two types of dental implants were used in each dog: hydroxyapatite (HA)-coated and titanium machine-polished (TMP), for a total of 4 groups. Dental implants were placed immediately after extraction of the right and left second, third, and fourth mandibular premolars; a resorbable collagen membrane was secured over the implants and defects; and the flaps were closed primarily. Fluorescent labels were administered intravenously on days 0, 6, 12, and 22 to measure bone formation rate. Dogs were sacrificed on day 28. The specimens were sectioned and mounted, and bone formation rate was recorded with a computerized microscopic digitizer. Specimens were stained with Stevenel's blue and van Gieson's picric fuchsin. Bone-to-implant contact was recorded with a computerized microscopic digitizer.


RESULTS
The results indicated a significant effect of locally applied alendronate (P < 0.0001) with both types of implants (HA and TMP), as well as the HA coating (P< 0.02) on increased bone formation rate. Additionally, alendronate had a significant effect on bone-to-implant contact, with an increase in the TMP model (P < 0.0001) and a decrease in the HA model (P < 0.0001 ). HA coating also had a significant effect on increasing bone-to-implant contact (P < 0.04).


CONCLUSIONS
The results indicate that alendronate increases early bone formation rate around dental implants. Additionally, the local application as described resulted in greater bone-to-implant contact with TMP implants.
Meraw
S J
SJ
Department of Dental Specialties, Mayo Clinic and Mayo Foundation, Rochester, MN 55905, USA.
Reeve
C M
CM
Wollan
P C
PC
D019386:Alendronate / Q000627:therapeutic use*; D000818:Animals; D001861:Bone Regeneration / Q000187:drug effects*; D020099:Coated Materials, Biocompatible; D003094:Collagen; D003758:Dental Implantation, Endosseous; D015921:Dental Implants; D017267:Dental Prosthesis Design; D004285:Dogs; D017886:Durapatite; D005456:Fluorescent Dyes; D016557:Guided Tissue Regeneration, Periodontal; D007091:Image Processing, Computer-Assisted; D008334:Mandible / Q000187:drug effects* / Q000473:pathology / Q000601:surgery; D008567:Membranes, Artificial; D016348:Osseointegration; D010012:Osteogenesis / Q000187:drug effects; D013499:Surface Properties; D014025:Titanium
D020099:Coated Materials, Biocompatible; D015921:Dental Implants; D005456:Fluorescent Dyes; D008567:Membranes, Artificial; D003094:Collagen; D017886:Durapatite; D014025:Titanium; D019386:Alendronate