Introduction: In recent years, different implant-abutment connections have been developed to achieve greater longevity, improving mechanical and biological failures in implant treatments. Objective: To analyze the types of connections that are external, internal and Morse cone, and evaluate their biomechanics, the impact they have on the alveolar bone and microbial contamination. Methodology: PubMed, SCOPUS and Google Scholar databases were reviwed to find recent articles published on implant-abutment connections with the following keywords