Background:
The multitude of prosthetic solutions related both to the geometry of the connection of implant connector, as well as the implant itself and its platform, dictates the necessity to perform tests on the fit in the implant connector system to facilitate the right procedural choice.

Aim of the study:
To compare the degree of fit of anti-rotation elements in the hybrid and allceramic abutment system.

Material and methods:
In order to assess the degree of matching of anti-rotation elements, ten individual metal-ceramic connectors and the same number of all-ceramic connectors were prepared.The abutments were placed in Replace Select Taperd Rp 4.3 implants (Nobel Biocare Sweden). Both hybrid and the ceramic abutments were tested in a scanning microscope (SEM). The following were analysed: the dimensions of the implant socket as well as the stabilizing element of the abutment on the basis of the measurements of the inner diameter of the implant socket (tube), the outer diameter of the stabilizing element (tube) and the linear dimensions of the antirotation elements: width (D) and height (H).

Results:
Some differences in the diameters of the stabilizing element between the abutments and the implant groove were found. The obtained results indicate a slightly better fit of the ceramic connector but these differences were not statistically significant.

Conclusions:
The assessment of the degree of fit of anti-rotational elements in the implanthybrid abutment and implant-ceramic abutment, indicates the equal suitability of the proposed solutions in clinical conditions.