CAMLOG and Science

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