Magister Scientiae Dentium - MSc(Dent) / Background: The two-stage implant system has proven to be a successful technique in replacing missing teeth (Nascimento et al., 2008). Nevertheless, the presence of micro-gaps that could entrap microbes at the implant-abutment interface (IAI) is unavoidable. This microbial leakage has been considered as one of the causes of peri-implant infection and bone loss (Scarano et al., 2005). Several companies have attempted to manufacture an implant with a connection design that provides hermetic sealing against bacterial leakage. Studies indicated that implants with internal connection, in particular the conical (Morse taper) design, have better sealing capacity in the implant abutment interface than the external design (Koutouzis et al., 2011, Jaworski et al., 2012). An internal conical implant system with a novel connection design, known as the Grand Morse (GM) connection, is reported to offer secure connection against micro-leakage (Neodent® Implant Systems Inc., 2018). Aims: The aim of this study was to test the sealing ability against bacterial leakage in the implant-abutment interface provided by an implant with a novel deep internal conical (GM) connection design.