Implant-abutment interface:bacterial leakage and microgap formation in two different type of Implant connections

Aim The aim of this study is to evaluate, both in vitro and in vivo, two different types of implant-abutment connections: screwed connection and cemented connection, analyzing the permeability of the IAI to bacterial colonization and the stability to chewing forces. Materials and Methods In this study were compared two different types of implant-abutment connections: internal hexagon screwed connection (Winsix®, BioSAF IN, Ancona, Italy ) Group 1; and internal hexagon cemented-conical connection (Bone System®, Milano, Italy) Group 2. Group 1 and Group 2 were compared on three levels: impermeability to bacterial penetration an in vitro study, resistance to loading for 5 years a simulated computer model, type of peri-implant bacterial colonization and health of peri-implant soft tissues around the implant for 2 year in an in vivo study. Results The results had showed the lower stability to the screwed implant-abutment connection than the cemented implant-abutment connection both for the permeability to the bacterial colonization than for the stability to the chewing forces. Conclusion Also if the implants long-term failures are consequences of multi-factorial elements the choice of an adequate implant system is fundamental for the long-term success. Also the choice of connection system is very important and would be preferable to choose implants with cemented connection instead of implants with screwed connection