Although dental implantology has come a long way in recent years and the procedure is now known as one of the most widely successful dental procedures that can be done, failure still unfortunately occurs. Implant failure is typically separated into two broad categories: early implant failure and late implant failure. Early implant failure is often caused by issues like a contaminated implant, infection, excessive trauma during the surgical procedure, or lack of primary stability of the implant hardware. Late implant failure is less common, and have fewer causes. Generally, once a patient is out of the woods of early implant failure, the chances of late failure are low. However, traumatic occlusion, occlusal overload, and dental cement that is retained subgingivally. Late implant failure typically occurs within one to three years after the placement of the implant. Bruxism, or nighttime teeth grinding and clenching, is a common cause of late implant failure.
The lateral window technique, or external sinus graft, is the creation of an access point to the maxillary sinus through its lateral wall. The access is used to elevate the Schneiderian membrane for the placement of graft material in the inferior part of the sinus space. The lateral window technique is often used when resorption of alveolar bone leads to severely decreased bone height which impairs the placement of dental implants. An external sinus graft is achieved by placing a bone graft in the new space, or window, that has been created. The bone used in the grafting procedure may be autogenous, come from a human donor, or come from donor bovine bone. Though autogenous bone grafts have been shown to heal faster than grafts from the other two sources, their success rates are similar. If implants are needed, they may be placed during the same procedure or after the graft has healed.