Evaluation of micro-gap at implant abutment interface using different connection design

The persistent presence of a micro-gap at the implant-abutment interface continues to pose biological and mechanical challenges, yet the influence of different connection designs remains insufficiently understood. Therefore, it is of interest to evaluate 100 implant abutment assemblies external hex, internal hex and internal conical using SEM before and after cyclic loading. External hex connections showed the largest micro-gaps, internal hex showed moderate values and internal conical exhibited the smallest and most stable interface. Statistical analysis confirmed significant differences among the designs, with conical connections demonstrating superior resistance to micro-gap enlargement under functional loading. Thus, we show new comparative evidence showing that internal conical connections provide the most stable interface, thereby advancing knowledge on optimal implant-abutment design for improved clinical outcomes.