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CAMLOG&Science – Chapter 2
With the help of a three-dimensional computer simulation, the same group
evaluated clinical relevance of the rotational freedom of angulated abut-
ments on the marginal fit of the prosthetic superstructures (Semper et al.,
2010a). The horizontal displacement of virtually constructed idealized
abutments with different angulations (range from 0 to 20°) was simulated
with various degrees of rotational freedom (range from 0.7 to 1.85°) previ-
ously described (Semper et al., 2009b). After quantification of the resulting
displacement, a subsequent simulation was performed where the super-
structure with different defined internal gaps (5 μm, 60 μm and 100 μm)
was positioned pressure-less on the displaced abutments. Finally, the resul-
ting marginal gap between the abutment and the superstructure was mea-
sured with the software (Tab. 3).
Tab. 3:
The size of the marginal fit gap of the superstructures depends on the degree of abutment
angulation and rotational freedom ranging from 17 μm to 2.33 mm maximum when the internal
precision of the superstructure was 5 μm. A range from 18 μm to 802 μm was observed with an
internal precision of 60 μm, and from 19 μm to 162 μm with 100 μm. Based on this investigation
the authors concluded that the rotation of the abutment is of clinical relevance because of its im-
pact on the marginal fit of the prosthetic superstructure. (Adapted from Semper et al. (2010a)).
MARGINAL FIT OF THE SUPERSTRUCTURE AT DIFFERENT ASSUMED INTERNAL PRECISIONS SIMULATED WITH DIFFERENT DEGREES OF
ROTATIONAL FREEDOM AND ABUTMENT ANGULATIONS
Internal gap /
Rotational freedom (
_
/2)
abutment angulation
angulation
0.7 deg
0.95 deg
1.5 deg
1.65 deg
1.85 deg
5 μm assumed internal precision
0 deg
17 μm
40 μm
183 μm
203 μm
266 μm
5 deg
187 μm
316 μm
578 μm
633 μm
782 μm
10 deg
401 μm
597 μm
1.03 mm
1.17 mm
1.31 mm
15 deg
597 μm
868 μm
1.47 mm
1.66 mm
1.87 mm
20 deg
796 μm
1.11 mm
1.82 mm
2.05 mm
2.33 mm
60 μm assumed internal precision
0 deg
18 μm
23 μm
33 μm
43 μm
45 μm
5 deg
18 μm
23 μm
33 μm
43 μm
45 μm
10 deg
18 μm
23 μm
33 μm
43 μm
45 μm
15 deg
18 μm
23 μm
33 μm
89 μm
316 μm
20 deg
18 μm
23 μm
33 μm
576 μm
802 μm
100 μm assumed internal precision
0 deg
19 μm
25 μm
37 μm
44 μm
50 μm
5 deg
19 μm
25 μm
37 μm
44 μm
50 μm
10 deg
19 μm
25 μm
37 μm
44 μm
50 μm
15 deg
19 μm
25 μm
37 μm
44 μm
50 μm
20 deg
19 μm
25 μm
37 μm
44 μm
162 μm