What Determines Immediate vs Delayed Implant Placement?
Francis G. Serio, DMD, MS, MBA | Eric Rindler, DDS, MBA | Sonia Leziy, DDS, Dipl Perio, FCDS(BC), FRCD(C)
Francis G. Serio, DMD, MS, MBA: Many studies have shown that the survival of immediate implants is similar to those placed in a healed site. While the statistics may be similar, there are several treatment planning and execution factors that must be recognized.
First among these factors are the patient’s wishes. Immediate implant placement with a non–load-bearing provisional restoration shortens total treatment time by several months. Many patients find this advantageous when dealing with an esthetic impairment. Timing of implant placement may be altered despite the patient’s wishes. Caveats to consider, especially in the esthetic zone, include the presence of infected bone; thin soft- and hard-tissue biotype where interdental bone and subsequent papillae support may be lost despite scrupulous attention to surgical details; sufficient bone height; loss of facial bone; and the ability to place the osteotomy to ensure initial stability and correct emergence of the implant to accept the subsequent restoration. A graft of the implant–bone gap may also be necessary.
Due to potential loss of soft tissue and bone, it is generally accepted that adjacent teeth should not be simultaneously extracted and two implants placed immediately. Extractions should be staged with one tooth removed and implant placed. Once healing has occurred, the adjacent tooth can then be removed.
While some highly skilled clinicians advocate for the immediate placement of implants in molar areas, this placement is more complex than for a single-rooted tooth and is usually not indicated.
Eric Rindler, DDS, MBA: That is a big topic for a quick discussion. In my opinion, these are two very distinct questions: 1) immediate implant placement following extraction; and 2) immediate provisional restoration at time of implant placement. For the purpose of this roundtable I am not discussing full-arch fixed cases.
Regarding the time to place the implant, I consider there to be three options: immediately, 8 weeks or longer if no bone grafting, or 4 months or longer for ridge preservation (ridge augmentation is 6 to 9 months in my practice).
It is my goal to minimize the chance of complications; therefore, does delaying eight weeks significantly increase the chance of long-term success? Are we achieving a better outcome by placing the implant immediately? Some points to consider when answering these questions include medical history, bone quality, and cost implications. Some common variables to avoid include smoking, diabetes, and tight occlusion. I look for no lost interproximal or palatal/lingual bone. In addition, I am comfortable with implant placement with a fenestration, as long as it is graftable.
My bias is generally not toward immediate implants; however, when it is appropriate I do not hesitate to move forward with an immediate placement. I usually limit this to anterior teeth in which primary stability is at 35 Ncm with bone 360 degrees around implant, however it does not necessarily need to be in intimate contact. I prefer a screw-retained provisional restoration. Finally, the occlusion is the most important part: When I make the provisional I prefer to leave it visibly out of occlusion, even if it compromises the esthetics.
Sonia Leziy, DDS, Dipl Perio, FCDS(BC), FRCD(C): The replacement of teeth with dental implants may involve any of four treatment approaches. All of these protocols have a place in practice today.
• Late (> 6 months post-extraction);
• Delayed (12 to16 weeks post-extraction);
• Early (4 to 8 weeks post-extraction);
• Immediate placement.
Along with the timing of implant placement, clinicians must also decide on a restoration strategy: after integration; or coupled with implant placement.
Other than in situations in which patients present with missing teeth, a delayed protocol is generally considered in cases with significant infection, where ridge augmentation is required for restoratively driven placement, and where anatomy precludes immediate implant placement. However, delayed implant placement increases treatment time, along with esthetic and functional inconveniences. Aside from the time- and cost-savings of accelerated treatment, clinical advantages include the potential of enhanced control over bone and soft tissue healing.
An accelerated protocol may be considered when:
1. A CBCT confirms adequate bone both beyond the root apex, palatally, as well as sufficient proximal bone to avoid encroachment on adjacent roots.
2. Adequate primary implant stability can be achieved (≥20 Ncm, ideally 35 Ncm or higher). This is influenced by implant design/size selected, and bone density- based drilling and osseodensification protocols.
3. Unique to immediate implant placement is the goal of generating 4 mm buccal bone. If less than this, delayed placement is preferred.
4. Literature indicates greater esthetic risk in thin, highly scalloped tissues. Our observations are that bone volume impacts tissue stability more so than gingival quality.
Immediate provisionalization and avoidance of removable prostheses offers esthetic, function, and comfort advantages. Transmucosal tissue anatomy defined by the extracted tooth and preserved with the provisional provides the technician with a subgingival contour template. Immediate restoration with a full contour provisional can be considered when the primary implant stability is adequate, occlusal forces minimized, and parafunction controllable. If implant stability is not ideal, customized healing abutments can also support marginal tissues as defined by the emergence profile of the tooth to be removed.
Provisional design criteria and considerations:
1. Supportive but not overly compressive transmucosal design.
2. Screw retained to avoid negatives associated with cementation.
3. Minimize mechanical stresses: restoration insertion torque > 20 Ncm and up to the maximum allowable abutment screw torque; no occlusal forces on single implant restorations. Distribute light occlusal forces on multiple implants and minimize cantilevers.
4. Control healing phase insults: Maintain a hermetic microgap and limit the microbial challenge; avoid prosthetic dis/reconnection; and monitor occlusal stresses.
Francis G. Serio, DMD, MS, MBA is a Diplomate of the American Board of Periodontology and has a private practice in Bayboro, North Carolina.
Eric Rindler, DDS, MBA has a private practice limited to periodontics and dental implants in San Antonio, Texas. He lectures on multiple topics in periodontics and the business of dentistry.
Sonia Leziy, DDS, Dipl Perio, FCDS(BC), FRCD(C) has a private practice in North Vancouver, British Columbia, Canada.