INTRAOSSEOUS TRANSCUTANEOUS AMPUTATION PROSTHESES VERSUS DENTAL IMPLANTS: A COMPARISON BETWEEN KERATINOCYTE AND GINGIVAL EPITHELIAL CELL ADHESION IN VITRO
Authors
C.J. Pendegrass, H.T. Lancashire, C. Fontaine, G. Chan, P. Hosseini and G.W. Blunn
Institution
University College London
Country
United Kingdom
Year
2015
Journal
European Cells and Materials
Abstract
Infection is the primary failure modality for transcutaneous
implants because the skin breach provides a route for
pathogens to enter the body. Intraosseous transcutaneous
amputation prostheses (ITAP) are being developed to
overcome this problem by creating a seal at the skinimplant
interface. Oral gingival epithelial cell attachment
creates an infection-free seal around dental implants.
However, this has yet to be achieved consistently
outside of the oral environment. Epithelial cells attach
to metal substrates by means of hemidesmosomes
and focal adhesions. Their density per unit cell is an
indicator of attachment strength. We postulate that
gingival epithelial cells express more hemidesmosomes
and focal adhesions at earlier time points, compared
with epidermal keratinocytes, and this increased speed
and strength of attachment may be the reason why
an infection-free seal is often achieved around dental
implants but less frequently around ITAP. The aim of
this study was to compare epidermal keratinocyte with
oral gingival cell attachment on titanium alloy in vitro,
to determine whether these two cell types differ in their
speed and strength of attachment. We aimed to test the
hypothesis that gingival cells up-regulate focal adhesion
and hemidesmosome formation at earlier time points
compared with extra-oral keratinocytes. To test this
hypothesis we cultured epidermal keratinocytes and oral
gingival cells on titanium alloy substrates and assessed
cell attachment by focal adhesions and hemidesmosome
expression at 4, 24, 48 and 72 hours. Formation and
expression of hemidesmosomes temporally lagged behind
that of focal adhesions in both cell types. Gingival derived
cells up-regulated focal adhesion and hemidesmosome
expression at earlier time points compared with
epidermal keratinocytes. Hemidesmosome expression
in oral gingival cells was 3 times greater compared with
epidermal keratinocytes at 4 hours. Our findings indicate
that earlier attachment may be key to the success of the
dental implant transcutaneous interface.