In fact, there is air leakage after trephine bur. When the bone block is pushed upward with an osteotome, the mesial sinus floor is approximately 1 mm thick, whereas distal ~ 4 mm (Fig.4 (measured in a preop PA)). The sinus membrane is torn apparently non-reparable with collagen dressing (Impladent) packing. The trephine bur is off the target. It would be safer if the trephine bur were used for 1 mm and X-ray were taken.
Internal Sinus Lift Perforation
Xin Wei, DDS, PhD, MS 1st edition 05/20/2015, last revision 05/21/2015