Characterization of bone around titanium implants and bioactive glass particles: an experimental study in rats.
OBJECTIVE
Many situations in clinical practice require metallic implants to be combined with bone grafts and/or bone substitutes such as bioactive glass (BG). Upon implantation, silica-based BG particles are transformed into a shell containing calcium and phosphate that loses its inner silicon-rich core. The release of silicon by BG particles and its incorporation by newly formed bone tissue in the peri-implant area had not been studied to date.


METHODS
Thirty Wistar rats were used throughout. Under anesthesia, a commercially pure titanium (Ti) laminar implant was placed inside the medullary compartment of the tibia (Ti group), while in the contralateral tibia (Ti/BG group) a titanium laminar implant and melt-derived BG 45S5 particles were implanted. The animals were sacrificed 14, 30, and 60 days postimplantation. The tibiae were resected, radiographed, and embedded in methyl methacrylate resin. Sections were stained with toluidine blue and analyzed by light microscopy and energy-dispersive x-ray analysis (EDX). The presence of silicon, calcium, and phosphorus was evaluated in the BG particles and in the peri-implant bone tissue for each of the experimental times.


RESULTS
The histomorphometric study revealed an increase in peri-implant bone thickness in the Ti/BG group as compared to the Ti group. EDX of newly formed bone tissue showed a transient appearance of silicon at 14 and 30 days postimplantation and a rise in the calcium:phosphorus ratio in peri-implant bone tissue in the Ti/BG group.


CONCLUSIONS
The present study shows an increase in reactive medullary bone formation when BG particles are implanted around a Ti implant.


CONCLUSIONS
The results described in the present study reveal that the release of Si by BG particles is an important issue that warrants further study.
Gorustovich
Alejandro
A
Department of Oral Pathology, Faculty of Dentistry, University of Buenos Aires, Argentina. alegorustov@ciudad.com.ar
Rosenbusch
Mariana
M
Guglielmotti
Maria B
MB
D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D001853:Bone Marrow / Q000601:surgery / Q000648:ultrastructure; D018786:Bone Substitutes / Q000737:chemistry*; D001842:Bone and Bones / Q000648:ultrastructure*; D002118:Calcium / Q000737:chemistry; D002516:Ceramics; D004396:Coloring Agents; D015921:Dental Implants; D004577:Electron Probe Microanalysis; D005898:Glass / Q000737:chemistry*; D008297:Male; D008832:Microchemistry; D016348:Osseointegration; D010012:Osteogenesis; D010758:Phosphorus / Q000737:chemistry; D051381:Rats; D017208:Rats, Wistar; D012825:Silicon / Q000737:chemistry; D013499:Surface Properties; D013977:Tibia / Q000601:surgery; D013997:Time Factors; D014025:Titanium / Q000737:chemistry*; D014048:Tolonium Chloride
D001672:Biocompatible Materials; D018786:Bone Substitutes; D004396:Coloring Agents; D015921:Dental Implants; C425330:bioactive glass 45S5; D014048:Tolonium Chloride; D010758:Phosphorus; D014025:Titanium; D002118:Calcium; D012825:Silicon