Guidelines for replacement of posterior teeth:
- Consider site grafting at the time of extraction whenever appropriate.
- Plan for one implant per missing tooth. Implant supported bridges are not routinely recommended.
- For the best prognosis, implants should be at least 10 mm in length (13 mm is ideal) and of wide diameter.
- Custom abutments should always be used.
Considerations in maxillary posterior teeth:
- Implants should be a minimum of 10 mm in length.
- Short implants have high failure rates and should be avoided in this area.
- Sinus level can limit the height of available bone. If there is at least 10 mm of bone height from the floor of the sinus, the implant may be placed without grafting.
- If there is 5-9 mm of available bone height, then a single stage implant and sinus lift bone graft will be necessary.
- If there is less than 5 mm of existing bone, then a two-stage surgery should be done. First, augment the vertical height of bone via a sinus lift procedure. Allow six months of healing, and follow it with placement of an implant.
- If bone grafting is necessary, but not accepted by the patient, use of implants with shorter lengths may be considered.
- Maxillary posterior bone (especially in area of first and second molars) is often D3 or D4 bone, and therefore may require a lengthier integration, submergence to avoid any kind of load during healing, and the use of immediate restorations with great caution. The bone in the premolar region is more typically D2 or D3 bone and may be more compliant with single stage surgery.
- Immediate or early restorations should be done with great caution providing there is great stability and high torque during placement.
- The healing time for implants may range from three to six months as determined by individual factors.
- Immediate implants may only be considered in premolar sites providing they meet strict guidelines (see section on immediate implants).
- Immediate implants in molar sites are contraindicated, except in very unique circumstances. It is best to perform a two stage procedure.
Video: sinus lift bone grafting for implants:
Case: single stage sinus lift & implant:
Case: two-stage sinus lift & implant: