characterise the glass phase of the polymerisation
process and varied comparatively less with the
depth. While parameter “d” was not dependent
on specimen thickness, parameter “c” showed a
slightly increase, however only at a depth of 6-mm.
The maximal rate of polymerisation, Rate max , was,
70 70
60 60
50 50
40 40
Considering the indicated 95% confidence
interval, no difference was identified for “a” at
100-µm and 2-mm depths, while “a” decreased
subsequently with depth. In contrast, the parameter
“b” decreased with increased specimen thickness
already in thin layers. Parameters “c” and “d”
30
20
0.1 mm
2 mm
4 mm
6 mm
10
0
0
50
100
150
200
250
30
20
0.1 mm
2 mm
4 mm
6 mm
10
0
300
350
0
5
10
Time, s
15
20
25
30
Time, s
Figure 1. Variation in DC in time measured at the bottom of 100-µm, 2-mm, 4-mm and 6-mm increments (mean value of n = 6), left:
300 s recordings; right a close up view of the first 30 s allowing identifying the different start of the C-C double bond conversion as
function of specimen thickness).
0.1 mm
2 mm
2 mm
30 30
25 25
20 20
15 15
1 mm
10
10
5 5
0 0
-5
0
20
40
-5
60
0
4 mm
25
20 20
15 15
25
10
60
10
5 5
0 0
40
DC, %
40
6 mm
30
DC, %
60
6 mm
30
20
40
DC, %
4 mm
0
20
DC, %
DC, %
DC, %
-5
Polymerisation kinetics in a fibre reinforced resin-based composite
60
-5
0
20
DC, %
DC, %
Figure 2. Rate of C-C double bond conversion versus degree of cure (DC) as function of increment thickness.
Stomatology Edu Journal
167