An in vitro investigation concerning the bacterial leakage at implants with internal hexagon and Morse taper implant-abutment connections

Abstract

Purpose: To evaluate, in vitro, the leakage observed in internal hexagon and Morse taper implant-abutment connections.

Materials: Ten specimens with internal hexagon and 10 with Cone Morse connection were used. The inner parts of 5 implants, per group, were inoculated with Pseudomonas aeruginosa (PS) suspension and 5 implants, per group, with Aggregatibacter actinomycetemcomitans (AA). The penetration of bacterial suspension into the surrounding solution was determined by observation of turbidity of the broth.

Results: In the internal hexagon implants, bacterial contamination was found in 2 of 5 implant-abutment assemblies seeded with the PS, and in the assemblies seeded with AA, the contamination was found in 3 samples, with a total of leaked assemblies in this group in 5 of 10. In the Cone Morse implants, bacterial contamination was found in 2 of 5 implant-abutment assemblies seeded with the PS, whereas in the assemblies seeded with AA, no contamination was found, with a total of leaked assemblies in 2 of 10.

Conclusion: The data support a not significantly higher permeability to bacterial leakage and a lower infiltration rate of screw-retained abutment connections when compared to Cone Morse taper internal connections.