Biomedical Engineering Reference
In-Depth Information
providing local attachment to different parts of the surrounding tissue.
In the ideal implant, the coating compositions must be tailored to provide
local attachment to both the bone and the gum.
The coating was manufactured by dip coating the titanium implants
in a suspension of ethanol and powdered glass (
m). Then the
glass particles were sintered with a focused CO
2
laser beam to a
coating that consists of micro-sized (diameter
<
45
μ
∼
m) glass drops
[14]. The glass composition used, 1-98, is optimised to show a lower
tendency to crystallisation in thermal treatments than 45S5 glass and
S53P4 glass. Moritz and co-workers compared the osteointegration of
the bioactive glass-coated titanium implants with titanium implants in
rabbit femur. After eight weeks, the implants coated with the bioactive
glass were covered with significantly more bone tissue than the totally
titanium implants (Figure 11.6). In the area spread 250
60
μ
mfromthe
perimeter of the implant, significantly more bone was observed in the
implants with the bioactive glass coating than in the two non-glass-
coated implants. In the area spread 1mm from the perimeter of the
implant, no statistically significant difference between the materials was
detected, although slightly more bone had formed around the implants
coated with the bioactive glass. The results all indicate that bioactive
glass coatings on titanium implants enhance the initial osteointegration.
μ
100
90
80
70
60
50
40
30
20
10
0
NaOH 1
NaOH 2
BG 1
BG 2
Ti 1
Ti 2
Implant material
Figure 11.6
Amount of bone tissue in proximity of the implant after eight weeks
in rabbit femur for titanium alloy, NaOH-treated titanium alloy and bioactive glass
coated titanium. 1: 250
μ
m; 2: 1mm. (Drawn from data obtained from Ref. [14].)
