The aim of this case report is to present a clinical example of successful osseointegration of an implant placed immediately following extraction of a mandibular left first molar (tooth No. 19) with a horizontal gap of more than 2 mm and implant threads exposed within the socket, with healing by secondary intention without flap closure, bone grafting, or barrier membrane placement. The healing was photographed every day for the first week to provide photodocumentation of early healing and then was subsequently photographed weekly for the first month and monthly for the first 6 months. The outcome showed that osseointegration of an implant placed immediately in a posterior extraction site is possible without having to graft the gap around the implant.