Posterior Mandibular Implants
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 best prognosis, implants should be at least 10 mm in length (13 mm is ideal) and wide in diameter.
- Custom abutments should always be used.
Considerations in mandibular posterior teeth
- Bone is usually D1 and D2, but occasionally there may be D3 or D4 bone in molar sites.
- This bone has a high degree of resorption following extraction. Therefore, if an implant is not planned in two to three months after extraction, the site should be grafted.
- Immediate implants are contraindicated in molar sites. They may be done on premolar sites as long as they meet strict guidelines (see section on immediate implants).
- Minimum implant height should be 10 mm.
- Position of the inferior alveolar nerve must be assessed carefully, and the right implant length should be selected to avoid nerve damage.
- The mandibular anatomy is highly variable on the medial aspect with potential major undercuts. Peroration into the medial plate and periosteum is possible and carries risk of injury to the lingual nerve or severe bleeding in the floor of mouth.
- Sites with horizontal bone loss should be grafted to allow placement of ideal sized implants and position. Avoid narrow implants in the molar sites in order to avoid bone.