Sinus graft or sinus lift by crestal route

There are two sinus graft techniques depending on the volume of bone to be regenerated: sinus graft by crestal route or sinus graft by lateral route.

Why carry out a sinus graft ?


  • After dental extraction is performed, the sinuses tend to enlarge naturally.
  • The bone volume found around the upper molars may not be sufficient for insertion of an implant. 
  • It is therefore essential to move the sinus out of the way.
  • Bone grafting can be carried out before or even at the same time as implant insertion.

Sinus graft by crestal route

  • This surgical procedure is carried out under local anaesthesia.
  • Drilling of the sinus floor is carried out around the crestal area where the implant is to be placed to allow subsequent mounting of an implant.
  • The dentist uses a round, metal instrument (called an osteotome) to raise this floor.
  • A grafting material is inserted in order to push back the sinus. 
  • The implant can be mounted during the same session or four to six months after surgery.


What are the risks of these surgical techniques ?

Perforation of the sinus membrane

  • Perforation of the sinus membrane may occur during surgery.
  • If this is minor, the dental surgeon can repair it. On the other hand, if the perforation is more serious surgery may have to be stopped and the site closed.
  • This is not an absolute failure because the surgical procedure can be repeated three to four months later.


  • Infection may occur in some rare cases (less than 5%). This is why surgery is performed with antibiotic cover.
  • In the case of infection, your dentist may carry out a procedure to clean the surgical site. This may compromise the volume of regenerated bone and require a second graft to be performed.
  • For patients who smoke, the risk of failure and complications is higher (10% risk instead of 5% risk). It is better to stop smoking permanently before starting this kind of treatment or talk about this with your dental surgeon.


When the bone is not thick enough and there is not enough of it, a sinus graft must be performed prior to the implant procedure.

Two techniques are used to increase bone volume: sinus graft by crestal route and sinus graft by lateral route.

Sinus grafts or lifts allow better fixing of the implant to the root.