Comparison of osteoblast spreading on microstructured dental implant surfaces and cell behaviour in an explant model of osseointegration. A scanning electron microscopic study.
OBJECTIVE
To compare interactions between rat calvarial osteoblasts and titanium dental implants with different microstructured surfaces.


METHODS
Seven commercially available implants were used. Surfaces included plasma-sprayed, grit-blasted and/or acid-etched, smooth-machined and anodised titanium. Two methods were used to compare cell behaviour: (1) A cell-spreading assay in which percentages of cells at four different stages of attachment were identified by scanning electron microscopy and quantified within a 30 min attachment period. (2) Implants were placed in 'pocket culture' within nylon mesh sacs in contact with explanted calvarial bone fragments for 2 and 4 weeks.


RESULTS
Surfaces combining grit blasting and acid etching, of microporous topography, showed significantly enhanced rates of cell spreading in comparison with the others. Differential cell morphology was observed in both suspension assays and pocket cultures. In the latter, cells migrated onto all surfaces. Multicellular layers with extracellular matrix (ECM) were present between the layers and on the material surfaces after 2 weeks. After 4 weeks, cell layers were more consolidated, and microstructures were obscured by layers of cells and ECM. Mineralised tissue was seen in association with ECM on grit-blasted surfaces of rough and smooth microtopography.


CONCLUSIONS
The two methods provided complementary information: a rough surface of porous microstructure may enhance the rate of cell spreading. Differentiation and calcification occurred on surfaces of both rough and smooth microstructure.
Sammons
Rachel L
RL
University of Birmingham School of Dentistry, Birmingham, UK. r.l.sammons@bham.ac.uk
Lumbikanonda
Narong
N
Gross
Michael
M
Cantzler
Philip
P
D000818:Animals; D002448:Cell Adhesion; D018929:Cell Culture Techniques; D002465:Cell Movement / Q000502:physiology*; D048430:Cell Shape; D002478:Cells, Cultured; D045662:Dental Etching; D015921:Dental Implants; D020007:Implants, Experimental; D008855:Microscopy, Electron, Scanning; D008954:Models, Biological; D016348:Osseointegration / Q000502:physiology*; D010006:Osteoblasts / Q000502:physiology*; D010294:Parietal Bone / Q000166:cytology; D051381:Rats; D017208:Rats, Wistar; D013499:Surface Properties; D014025:Titanium
D015921:Dental Implants; D014025:Titanium