Is grafting needed for immediate implants and sinus lifting?
The introduction of graftless solutions for implant therapy has called into question the need for grafting in certain implant cases. Immediate implant placement at the time of tooth extraction often will require grafting to support gum tissues in the anterior area or, to build up lost bone in the single rooted tooth extraction socket. Clinical experience confirms that grafting during the replacement of single rooted teeth is necessary when there is lack of adequate hard tissue (bone) to support the implant, as well as the overlying gum tissue.
Improvements in the macrogeometry of dental implants allowing greater stability is now making it possible to place immediate implants in molar extraction sites. If the apex of the dental implant can be stabilized in 3 to 5mm of bone in or below the socket, immediate placement is possible. This still is an indication for simultaneous hard tissue grafting in most instances, and often the implant cannot be provisionalized or must be submerged. Recent studies have documented the success rate of immediate molar implant placement.1
Another indication for molar implant placement and simultaneous grafting has historically been in the posterior maxilla. Often the maxillary sinus is expanded and sinus lift bone grafting was thought to be necessary to regenerate bone in the sinus for added implant support. A recent animal study shows that placing a hard tissue graft is not necessary and may in fact inhibit the regeneration of bone in the maxillary sinus. Bilateral sinus lift procedures were performed in rabbits with placement of Bio-Oss grafting material on one side and no graft on the other. The nongrafted side was treated with placement of a minisrew to support the sinus membrane in the elevated position. Immunochemical assay showed that faster and greater new bone formation was observed in sites that received no grafting material.2
A 5 year follow up study of 80 patients shows the clinical application of this concept. In this study, patients had open sinus lift procedures with simultaneous implant placement. The membrane was elevated and supported only by the implants that were placed in bone ranging from 3.5-6.5mm in height. No grafting of the sinus was performed. Conebeam radiographic study showed a 5.4-9mm gain in bone height and 100% success at 5 years.3
The use of tilted posterior implants, as in the All-on-4 technique, avoids the need to perform sinus grafting and is necessary if immediate loading is planned. For single teeth or short-span implant bridges that will undergo late loading, sinus lifting is indicated, but now it appears that the expense and infection risk associated with placing grafting material can be avoided.
We are always looking for ways to simplify implant treatment and improve predictability while at the same time reducing dental implant costs for our patients. Immediate molar implants can save patients 3-4 months of time by allowing implant placement and extraction socket healing to occur simultaneously. Graftless sinus lift implant placement avoids the use of expensive grafting materials and the infection risks associated with allograft placement. Obviously, treatment options must be tailored for individual patients and not all patients may be candidates for these simpified procedures. For more information, contact us to discuss patient referral or to schedule an appointment.
1 Immediate,Early and Late Implant Placement in 1st Molar Sites, Annibali et al, Int J Oral Maxillofac Implants 2011:1108-1122
2 Comparison of New Bone Formation in the Maxillary sinus with and Without Bone Grafts: Immunochemical Rabbit Study, Dong-Seok-Sohn et al, Int J Oral Maxillofac Implants 2011:1033-1042
3 A 5 Year Follow-up of 80 Implants in 44 Patients Placed immediately After the Lateral Trap-door Window Procedure to A complish Maxillary Sinus Elevation Without Bone Grafting, I-Ching Lin et al. Int J Oral Maxillofac Implants 2011;26:1079-1086