Pathologies of the implant cavity wall currently cannot be diagnosed by direct observation because of the rapid pollution of the optical systems used. A technique to examine prepared implant sites intraoperatively to diagnose possible risk factors for the osseointegration process is presented. Examination of implant cavities is performed with support immersion endoscopy (SIE). Using a specially designed support and irrigation sheath (SIS), a 1.9-mm endoscope can be placed at a certain distance to the underlying bone surface. When immersed in a bleeding implant site, the endoscope window is cleaned by continuous laminar irrigation flow to allow observation of the cavity walls under variable magnification. Cortical and cancellous bone structures can be differentiated in situ and pathologies detected during capillary bleeding. Two case reports citing practical applications are reported. By means of SIE, possible risk factors during and after implant cavity preparation can be detected.