In vivo monitoring of the bone healing process around different titanium alloy implant surfaces placed into fresh extraction sockets.
OBJECTIVE
Increasing surface roughness and coating with tricalcium phosphate of titanium and titanium alloy implants has been proposed to provide better rates of osseointegration. However, how these changes in surface topography and chemistry influence the osseointegration process of immediate implants placed in fresh extraction sockets is unclear. This study investigated the influence of three clinically employed implant surfaces on the early bone healing events in vivo.


METHODS
Machined smooth implants were milled from grade 5 Ti6Al4V titanium. Surfaces were moderately roughened by grit blasting, which were then coated with tricalcium phosphate. Implants were placed into freshly extracted incisor sockets of mandibles of normal Wistar rats and left for 1, 3 and 9 weeks. Healing bone tissue around the implants was examined by histochemistry and immunocytochemistry to localise PCNA proliferative cells, and osteoblast differentiation markers osteopontin and osteocalcin. Positive synthesising cells were counted using image analysis.


RESULTS
Histology indicated no differences in the amount or pattern of bone formation within the healing tissue surrounding the different implant surfaces. Bone healing occurred predominantly on exposed bone surfaces (distance osteogenesis) and not on the implant surface (contact osteogenesis). No differences were observed in the number or timing of PCNA, osteopontin and osteocalcin positive cells within the bone healing tissue around each of the implant analysed.


CONCLUSIONS
For immediately placed implants, the surface modifications investigated appeared to have little influence on the activity of bone forming cells surrounding the implant, probably due to the high level of distance osteogenesis seen within this scenario.


CONCLUSIONS
For immediate placement of implants into fresh extraction sockets, titanium implants with roughened surfaces and coating with tricalcium phosphate have negligible influence in accelerating the early bone healing events of osseointegration.
Mineralised Tissue Group, Tissue Engineering and Reparative Dentistry, School of Dentistry, Cardiff University, Heath Park, Cardiff, CF14 4XY, UK.
John S
JS
Colombo
Sanda
S
Satoshi
Joji
J
Okazaki
St John
SJ
Crean
Alastair J
AJ
Sloan
Rachel J
RJ
Waddington
D000497:Alloys; D000818:Animals; D002130:Calcium Phosphates / Q000737:chemistry; D002452:Cell Count; D002454:Cell Differentiation / Q000502:physiology; D049109:Cell Proliferation; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D003722:Dental Alloys / Q000737:chemistry*; D045662:Dental Etching / Q000379:methods; D003758:Dental Implantation, Endosseous / Q000379:methods; D015921:Dental Implants; D017267:Dental Prosthesis Design; D007091:Image Processing, Computer-Assisted; D008297:Male; D008334:Mandible / Q000601:surgery; D008855:Microscopy, Electron, Scanning; D016348:Osseointegration / Q000502:physiology*; D010006:Osteoblasts / Q000502:physiology; D015675:Osteocalcin / Q000032:analysis; D010012:Osteogenesis / Q000502:physiology; D053495:Osteopontin / Q000032:analysis; D018809:Proliferating Cell Nuclear Antigen / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D013499:Surface Properties; D013997:Time Factors; D014025:Titanium / Q000737:chemistry*; D014081:Tooth Extraction; D020390:Tooth Socket / Q000601:surgery*; D014945:Wound Healing / Q000502:physiology
D000497:Alloys; D002130:Calcium Phosphates; D020099:Coated Materials, Biocompatible; D003722:Dental Alloys; D015921:Dental Implants; D018809:Proliferating Cell Nuclear Antigen; C506897:Spp1 protein, rat; D015675:Osteocalcin; D053495:Osteopontin; C031462:titanium alloy (TiAl6V4); D014025:Titanium; C018392:tricalcium phosphate