June 2018
Volume 14, Issue 6

Striking A Balance

Optimize your implant treatment strategy for each patient

As more general practitioners add immediate implants to their clinical armamentaria, many may face a fundamental decision about how to deliver this solution. Historically, the two-stage approach to immediate implant restorations, in which the restorative treatment follows a period of unencumbered implant site healing, has been viewed as the standard of care. However, as technology has continued to advance, more practitioners are adopting the immediate extraction/immediate implant/immediate provisionalization model. For our annual implants issue, Inside Dentistry convened a panel of experts to discuss the two modalities and what practitioners should consider in order to provide the most optimal outcome for their implant patients.

The evidence supporting immediate implant placement and provisionalization is no longer anecdotal, even if data cited in the literature regarding the timing of implant placement and restoration can be confusing. Instead, according to numerous experts, the research has been fairly definitive. Among all implant treatment modalities-including immediate, early, and delayed implant placement and restoration-true endpoint outcomes are virtually equal.

If that's the case, then why do debates continue among clinicians who advocate exclusively for a particular implant placement technique and/or implant restoration protocol? After all, if great outcomes can be achieved with both immediate and delayed protocols, it seems unreasonable for clinicians not to always have both at their disposal.

"Oftentimes, when procedural outcomes are equal, operator preference becomes the biggest deciding factor," emphasizes Dean E. Kois, DMD, MSD. "To be clear, clinicians should be utilizing all of the procedures necessary to achieve great outcomes, and great outcomes typically require adjunctive therapies-such as hard- and soft-tissue grafting (regardless of the timing)-as well as favorable patient anatomy."

The reality is that there are many ways to successfully manage implant outcomes in the dental practice. In fact, there are more options available than delayed, two-stage approaches and immediate placement/provisionalization.

"These include two-stage implant placement with submucosal healing, one-stage approaches with transmucosal healing, immediate implant placement into fresh extraction sockets, and the immediate provisionalization of implants placed either into healed ridges or into fresh extraction sockets," notes Lyndon F. Cooper, DDS, PhD, associate dean for research and head of the department of oral biology at the University of Illinois at Chicago College of Dentistry. "Under the proper local conditions, in accordance with the patient's specific physiology, and with regard to the clinician's knowledge and ability, each of these approaches has merit."

In addition, there are many factors that potentially can result in unsuccessful outcomes. "If someone isn't familiar with immediate tooth replacement therapy, I certainly wouldn't recommend undertaking it; I would recommend that he or she learn delayed treatment first," explains Stephen J. Chu, DMD, MSD, CDT, an adjunct clinical professor in the Ashman Department of Periodontology & Implant Dentistry and the Department of Prosthodontics at the New York University College of Dentistry. "But even with delayed therapy, you can still end up with unfavorable results if you don't know what you're doing. Each respective treatment approach requires a certain level of knowledge and competency to perform it at a satisfactory level."

However, if a clinician is equally competent in both delayed and immediate approaches, then immediate therapy is preferred, Chu says. Why? Because the bottom line is about doing no harm to the patient, and this includes minimizing the number of surgical interventions that the patient will endure in order to accomplish the treatment goal as well as avoiding esthetic complications that can result from poor execution.

"The delayed technique requires a minimum of two, if not three, surgical interventions, although the third may only involve exposing the implant(s)," Chu notes.

This may explain why, today, immediate implant placement and provisionalization is the standard of care and the patient-preferred transition from hopeless teeth to implant-supported prosthetic replacement, according to David A. Gelb, DDS. From a patient perspective, this approach provides both resolution of clinical tooth pathology and immediate esthetic replacement in one surgical procedure.

Talking About Tradition

"The main advantage of the traditional model is that you have an osteotomy site that is perfected for the form of the implant, which enables a tight fit when placing the implant in the alveolus," explains Michael Sesemann, DDS. "If the technique involves a full-thickness mucoperiosteal flap that can be sutured closed with primary intention, then there is the added benefit of having the implant closed off from the oral environment."

In addition, if implant placement incorporates a surgical guide that is planned and fabricated from merged cone-beam computed tomography (CBCT) files (ie, DICOM) and digital oral scanning files (ie, STL), then the procedure can be performed through the gingiva and periosteum atop the ridge, Sesemann elaborates. The osteotomy site can be further coordinated and perfected for the implant, and because a supragingival healing cap is employed, in a majority of cases this technique requires no suturing.

And although there isn't a single implant modality that can trump deficient patient anatomy, the consensus among the interviewees who advocate for a two-stage model is that in situations where extensive hard- or soft-tissue ridge augmentation is performed (either during the extraction appointment or a separate appointment) this approach allows the final form after healing to be nicely visualized and planned.

However, one drawback to the two-stage approach is the healing time required after the extraction, and/or grafting, and/or possible socket preservation treatment. These delays could necessitate provisional options, either fixed or removable, which adds to cost of treatment and potentially creates difficulty for the patient if he or she isn't familiar with removable prosthodontics, Sesemann adds.

"A detriment to the two-stage approach, for example, is the need to provide a removable denture to a patient who has just received a full arch of implants that are experiencing lateral forces during chewing," explains Sanda Moldovan, DDS, MS, CNS, a diplomate of the American Academy of Periodontology.

Moreover, if all of the necessary anatomical and tissue structures are present (eg, bone volume, gingival architecture, correct positioning), incorporating a delayed approach poses the risk of losing those beneficial structures, cautions Chu. "The current thinking is that if we need to recreate and reconstruct what's been lost, then a delayed approach is used. But if everything necessary is present, and we're trying to maintain it, then an immediate approach is preferred."

Immediate Gratification

The immediate placement of dental implants following tooth extraction is a predictable and routine procedure for most clinicians in modern dental practices that offer implant treatment. The biggest advantages to immediately placed implants are minimization of the surgical invasiveness and preservation of the soft-tissue profile and architecture, says Michael D. Scherer, DMD, MS, FACP, diplomate of the American Board of Prosthodontics.

"With a flapless approach, the procedure maximizes retention of site dimensions and soft-tissue landmarks essential for the final esthetics of the site," Scherer continues. "The provisional restoration guides the maturation of the soft tissue to optimal contour, ensuring the existence of mature tissue at the time of final impression taking when integration has been confirmed."

Moldovan admits that, in her practice, most of her implants are immediately loaded, with the advantage being preservation of the bone and tissue, especially the soft-tissue architecture surrounding the dental implant. She notes that tissue is better preserved when a restoration is placed on the implant, as opposed to letting it heal or, worse yet, placing a removable restoration that impinges the gingival tissue.

In addition, current implant thread designs can be stabilized in a prosthetically correct position in compromised bone sites to support the planned prosthesis, explains Gelb. Furthermore, implant surfaces are now osteophillic, possessing the ability to accomplish bone regeneration and osseointegration simultaneously.

"Today's implant designs allow us to anchor them with more than 35 cm stability nearly 100% of the time, which permits the placement of immediate restorations," says Moldovan, adding that implant design is significantly important when it comes to determining implant placement and the restorative approach. "This underscores how important it is for clinicians to understand the properties of the implants they are choosing, because that choice influences whether they can perform a two-stage or an immediate approach."

According to Gelb, immediate procedures accelerate the treatment sequence, providing a site that is ready to restore in minimal time. They also provide a more cost-efficient sequence for patients. Analytically speaking, beyond reporting that the provisionalization of immediate implants does not result in less successful outcomes, the literature has also documented some outcomes of immediate implants that were more successful than implants placed in healed sites.

"Immediate implant placement approaches have been surrounded by misconceptions and assumptions that clinicians are shortcutting some of the treatment steps," Chu observes. "That's not the case. You're providing the same treatment and performing the same procedures, but in a more efficient manner and in fewer appointments."

In practice, the first appointment may be longer and more involved. The procedures performed could include tooth extraction, tissue grafting, temporary fabrication, and placement. Subsequently, the treatment becomes more streamlined, actually requiring less chair time, Chu elaborates. It's about gaining efficiency without shortcutting any steps.

However, the advantages of immediately placed implants are not realized without some of the disadvantages associated with the model itself. As Scherer explains, the biggest disadvantage of immediately placed implants is technique sensitivity, because the procedure is more demanding than the delayed process of extracting, grafting, and placing an implant at a later date.

"Due to less contact with the bone, primary stability is often much lower when compared with traditional, delayed implant placement, so additional procedures have to be performed to ensure surgical success," Scherer says. "In addition, extraction sockets may cause implants to drift and lean in directions where the angle of the long-axis of the dental implant is not ideal, creating headaches for the prosthetic phase of treatment."

It's not surprising, then, that the success of the immediate implant procedure with immediate provisionalization is predicated on a thorough knowledge of what occurs during the healing phase, so that the implant's placement accounts for what the surrounding, healed tissues will look like after healing, Sesemann asserts. Anytime a practitioner deviates from the two-stage, traditional model, there is a greater risk of issues arising, and there are more ways to encounter less-than-optimal results.

"A more strenuous pursuit of continuing education is mandatory to undertake the immediate implant procedure with immediate provisionalization so that all of the facets of the more complex treatment can be taken into consideration," Sesemann asserts. "The practitioner needs to be coordinating many different aspects of treatment, including biologic, surgical, and prosthodontic considerations-all while taking care of the patient's psychological needs."

It's a tall order, but the wealth of experience represented in the literature and solid recommendations from experts can help clinicians plan for success and, ultimately, shorten and simplify treatment sequences and/or otherwise enhance the predictability of implant therapies for both the patient and themselves.

Planning for Success

For any given case, selecting from among implant placement and restoration options requires careful consideration of several patient characteristics as well as systemic and site-specific factors (See Table 1 and Table 2). For example, according to Kois, in some cases the nature of the implant site influences his decision more than anything. When considering the timing of implant placement, sequencing adjunctive procedures in a different order could be a key factor.

"Oftentimes, I will perform a hard-tissue procedure and then come back and place an implant in concert with a connective tissue graft," Kois elaborates. "Immediate implant procedures typically combine all of the ingredients in the pot at the same time."

Therefore, the more compromised the site, the more that successful outcomes with immediate implant surgery become predicated on the clinician's ability to simultaneously manage each step effectively.  Even more specifically, most anterior implants require minimally invasive techniques to manage tooth removal, debridement, guided implant surgery, hard- and soft-tissue procedures, and provisionalization procedures-all of which can be demanding, Kois explains.

Understandably, although the combined immediate tooth extraction, implant placement, and provisionalization approach offers patients and clinicians readily appreciated advantages, they do come with associated risks, cautions Cooper. The caveats to remember include the following:

Actual implant survival may be incrementally lower for this procedure when compared with implants placed in healed ridges.

The healing responses of bone and mucosa can result in less-than-ideal esthetic outcomes.

Related, major deficiencies in healing can result in nearly unresolvable outcomes that challenge subsequent revision and re-treatment.

Fortunately, these cautionary considerations can be translated into thoughtful recommendations for addressing the risk factors and planning for implant treatment success. In fact, to determine if an immediate approach can yield predictable results, Cooper offers the following specific guidelines:

The socket should be without significant dehiscence or fenestration and permit the implant to engage sufficient host bone beyond the socket walls (ie, apically [3 to 4 mm] and laterally).

The implant should be of sufficient length to engage host bone and permit location of the implant abutment interface within 3 to 4 mm of the planned restoration's gingival zenith.

The diameter of the implant should not impinge on the buccal alveolar wall (ie, the implant/abutment interface should be palatally displaced approximately 2 mm from the planned gingival zenith).

"Regarding function, we have consistently recommended that immediate placement and provisionalization be reserved for otherwise intact and stable dentitions with stable posterior tooth support," Cooper advises. "The provisional restoration must be free from occlusal contact in maximum intercuspation or excursions."

It also behooves clinicians to remember that immediate placement and provisionalization after recent orthodontic therapy exposes implants to potentially mobile adjacent teeth and related functional overloading, Cooper says. The provisional restoration should be reduced incisally (or occlusally) and may be placed 0.5 mm labially to avoid excursive contact.

If an immediate approach is deemed appropriate, then success will be predicated on the experienced clinician's ability to atraumatically extract a tooth without compromising or altering the anatomy of the site. According to Scherer, this involves the following:

Fully debriding the site of root remnants and inflammatory granulation tissue down to sound bone. Once fully debrided, the clinician can evaluate for the presence of intact buccal and lingual plate, thin bone walls, fenestration, and/or dehiscence.

Selecting implants with the proper design and thread pitch for stabilization in minimal volume bone, the proper diameter to support the planned prosthesis, and the proper length so that, once apically stabilized, the head of the implant is approximately 3 mm apical to the base of the planned prosthesis and not too deep within the site.

Precisely and delicately developing the provisional restoration with a proper emergence profile to support the tissue.

If the provisional is cement-retained, in order to minimize the introduction of subgingival cement, extrude the cement on an analog of the abutment extraorally prior to seating the restoration.

Maximizing the Advantages of Treatment-Enhancing Technologies

Whether clinicians choose to follow a delayed or immediate approach, all of the digital technologies available today can help them enhance the predictability with which they provide life-changing implant treatments to their patients (See Table 3). According to Moldovan, innovations such as virtual surgery prior to seeing the patient, digital impression scanning, and 3D printing allow dentists to treat their patients better, more effectively, and more precisely.

"Digital technologies have become such wonderful assets to my practice in numerous ways," Kois shares, adding that his team uses "several technologies every day to improve patient outcomes, minimize sequelae, and frankly, make the provision of treatment more fun. The ability to communicate complex treatment needs in 3D using the patient's own anatomy is absolutely invaluable because it creates a better connection to the procedure and its perceived value. It just feels more like precision medicine."

And thanks to these digital dental technologies, in many ways, it really is. CBCT scanning and 3D printed surgical guides can greatly optimize the proper implant position and potentially enhance the primary stability of dental implants, Scherer explains.

"I've routinely used guided surgical techniques, even for simple single tooth cases," Scherer admits. "Using 3D printing technology has greatly enhanced both my dental implant surgical and prosthetic treatments."

Although CBCT enables analysis of an implant site and guided implant placement with prior fabrication of provisional restorations, two downsides are the additional patient exposure to ionizing radiation and the expenses associated with the CBCT imaging and implant placement guide, Scherer notes.

Conclusion

It's important to remember that surgical procedures are best performed with careful attention to the human tissues, advises Scherer. Some clinicians consider immediate implant placement risky and will use a two-stage approach; others consider it highly predictable, he adds.

"I maintain that there is a case-by-case basis for selecting each approach, and both work extremely well. It all depends upon case selection," Scherer reiterates.

That said, Chu offers a pretext to each of these modalities by emphasizing that dentists must be knowledgeable and feel comfortable with whichever approach they undertake. He notes that "doctors are their own ‘gatekeepers,' and they must feel comfortable performing certain procedures. If a procedure puts them outside of their comfort zone, then I would recommend either pursuing advanced training until they feel comfortable, making a proper referral, or not doing it at all."

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