The Microbial Neck: A Biological Review of the Various Implant: Abutment Connections
Longevity of an implant-supported prosthesis bases its core principles on the biological stability of the implant itself. A seal maintained against microbial infiltration is supposed to maintain this stability and ensure a relative constancy in the periimplant crestal bone levels. But, in the oral environment this hermetic seal is difficult to achieve given the lack of a pristine niche for these implants. This study reviews the importance of selecting implant systems with connection designs that optimize the seal and ensure better long-term prognosis of the prosthesis, thus placed. For an accurate review, an electronic search of the PubMed database was done using keywords to review studies that compare the crestal bone levels and microleakage around various implant-abutment connection designs. Based on the studies reviewed, the conical connection design proved to be the most biologically stable junctional geometry due to the better microbial seal and the lesser micromovement observed in these types of implants during functional loading. Moreover, this review even emphasizes the need for more longitudinal clinical trials to evaluate the microbial seal of these connection designs within the actual oral environment to evaluate long-term changes in the peri-implant tissues and subsequently, thus even factor the prognosis of the planned prosthetic intervention.