What Is Driving the Implant Revolution?

 For laboratory owners, staying abreast of the latest advancements and trends impacting this arena is vital when looking to penetrate new markets for clientele, finding solutions to difficult cases, or even understanding the use of the latest new materials. IDT spoke with seven forward-thinking opinion leaders in the industry to weigh in on three of the hottest topics impacting dentistry's implant market.

There's been much debate about the subject of whether general practitioners (GPs) should place implants or leave them to the surgical specialist and, ultimately, which approach is in the best interest of the patient. Natalie Wong, DDS, FRCD(C)-Cert Prostho, who serves as President of the American Academy of Implant Dentistry and has her own private practice in Toronto, Ontario, Canada, believes it is inevitable that GPs tackle implants as part of their service offerings.

"GPs are, in general, doing more procedures in-house. I am a huge supporter of GPs doing implant dentistry as long as they are well trained," says Wong. "When we have a larger population base of older patients, GPs are seeing more patients with missing dentition. If a GP wants to provide comprehensive therapy, it becomes a necessity for them to offer a solution for their patients' missing teeth. Implant dentistry has been overwhelmingly more predictable in terms of long-term results. We now have an over 95% success rate for implants lasting more than 10 years."

With an estimated 58% of GPs now placing implants, financial considerations are certainly a driver behind this trend. According to Barry Levin, a board-certified periodontist practicing in Jenkintown, PA, the decision to keep procedures in-house is a financial one for many established GPs and especially for younger dentists trying to pay down tremendous dental school debt. Kurtis Helm, CDT, owner of Helm Dental, in Wylie, TX, echoes those sentiments.

"They are trying to set themselves apart from the competition or at least keep up with them. GPs are doing everything in-house, including their own orthodontics, endodontics, and implantology. By keeping it in-house, they are able to keep costs lower and case acceptance higher." Greater case acceptance, specifically for implants, correlates directly to a patient's overall health. Not only is it a conservative treatment modality, whereby the adjacent teeth are not prepared in order to accept a three-unit bridge to replace a single missing tooth, for example, but it also preserves a greater amount of functioning dentition, which allows patients to live a healthier lifestyle with proper nutrition and overall health.

Access to care is yet another driver of GPs placing more implants, says Stephen Campbell, DDS, MSc, Professor of Restorative Dentistry and Director of Implant and Innovation and Digital Excellence at University of Illinois at Chicago College of Dentistry. "America's dirty little secret is the growing and staggering size of the edentulous population we have in this country." According to Campbell, the answer for most of these patients is their general dentist. "There are many more GPs than there are specialists in the US. There are approximately 11,000 surgical specialists and over 120,000 active GPs in practice. As primary care providers, GPs are the ones that see the majority of patients and do the volume of oral care in this country. I see this trend [of GPs placing implants] as a good thing because it means that there are more patients who have greater access to best practices in oral health care." He explains that the staggering number of completely edentulous in the US is estimated at 38 million to 40 million people, which means 12% of all adults in this country have no teeth in one or both arches. The partially edentulous population is estimated to exceed 100 million, with almost half of all adults missing at least one tooth, and the average adult having less than 25 teeth. It gets worse as the population ages. The increased number of GPs being trained to place implants offers patients greater access to care and lies at the heart of the significant rise of implant therapy.

Keeping implant therapy in-house also gives the general practitioner a sense of reclaiming the quality control and direction of an esthetic case's outcome. In the surgical specialist case model, the patient would present at the general practice, the GP would make an assessment then refer the patient to a surgical specialist for implant placement; the patient would return to the practice for the final restoration. Many times, the placement of the implant was not ideal for an optimal restorative outcome since the surgeon's focus is on bone density and osseointegration. According to Nicholas Elian, DDS, CEO of Vistara in Englewood, NJ, this resulted in GPs having a great degree of dissatisfaction when the patient returned to the practice for the restorative phase of treatment. "If things go wrong, it was the restorative dentist's responsibility, not that of the placing specialist," he says. Elian believes a synergetic or what he calls "relationship integration" is the work modality that offers optimal results. "GPs should invoke a business model of relationship integration, where they need to look at the whole situation and all the team players," ways Elian. "They should consult with a surgical specialist who could help them with tissue or complexity beyond the GP's skill set; engage the laboratory for the technology and restorative perspectives; and get input from all involved to provide the patient the best treatment modality. That's when the focus is truly on the patient. I don't see any down side."

Education is the key to success when placing implants, as well as knowing when a case needs to be referred out to a specialist. "There is a lot that goes into formal education, like microbiology, physiology, wound healing, grafting, and more," says Levin. "Specialists are the ones who are trained to manage complications. It is critical to make sure GPs are well trained and utilize implants that have a strong track record and robust research and literature behind them. There are more implant companies than ever but very little, if any, literature and research; to me, that's concerning. Everyone needs to be very careful that the success rates don't drop drastically because of inferior technology, materials, or treatments performed. People knowing their limitations is a very important thing." 

In recognition of the increased numbers of GPs placing implants, one educational trend taking shape is specialist groups offering implant placement courses to their referring GPs. "Because specialists know that their GPs will do the simpler implant cases, educating them will not only aid them in doing it properly, but will also help them recognize when a case is beyond their skill set and needs referral to the surgeon specialist who trained them," says Helm. "Specialists are seeing their business grow with this model."

Laboratories also can find a great opportunity to generate greater growth and revenue for their implant business by simply doing what Helm lives by—getting into the guided surgery market. "Help GPs plan these surgeries, show them how to read a CT and how to utilize surgical guides," he says. "We actually have surgical kits from major implant companies that we loan to dentists to teach them how to do guided surgeries. The main thing is being a resource." If Helm's GPs need answers, he wants his laboratory to be where they call first. As a result, Helm says his business has experienced significant growth over the past decade by becoming the ultimate resource for GPs placing implants. "Learn as much as you can; don't be afraid to get educated," he says. "I go and learn where the GPs and specialists learn. Any implant or surgery course, I am there. Just get involved as much as possible to grow, move forward, and be a resource."

New solutions are being brought to market to address the problem of surgical placement that impedes the restorative team from creating a functional and esthetic final restoration. For decades, implants have been placed in areas where there was sufficient healthy bone with the appropriate density and width; however, the placement didn't always align well with the emergence of the clinical crown to make it esthetic. The industry's first attempt to address the issue was to move toward a cement-retained treatment modality using a custom abutment and a conventional crown to hide the implant access hole. However, implant failures caused by improper removal of the cement below the tissue level resulted in perio-implantitis. Today, the industry has shifted much of the implant restorative case work back to a screw-retained solution. Helm says that 80% of the implant cases coming into his laboratory are now screw-retained. Levin believes this trend is a positive shift. "The whole purpose is to get to screw-retained restorations," he says. "We see so many problems due to cement not being cleaned properly below the tissue level. Plus, retrievability for hygiene and repairability is critical, and that is possible with a screw-retained solution." But even with screw-retained implants, the access channel can emerge at an esthetically compromising position like the incisal edge or, even worse, the labial aspect. For these types of placements, the industry solved the issue by offering an angulated screw access channel of up to 30 degrees in circumference, just enough to move the access hole to a less esthetically compromised area.

This innovation dramatically assists in treatment planning when communicating with the dentist placing the implants. "Angled access channels have really opened up the number and variety of cases and patients that we are able to treat," says Wong. "We can now place angled implants and still have a draw for the prosthesis, which is huge. It allows the placement to avoid structures like the nerve or sinuses and to utilize the best available bone. Angulating them allows us to place the implant in the most beneficial place and then angulate the access hole to achieve the best esthetics." From the laboratory perspective, it affords the ability to restore some of the more difficult implant placement cases, where clinicians want retrievability. "It's nice that most of the major implant companies have adopted it," says Helm. "The greatest benefit is the ability to achieve a high level of esthetics. With most implant restorations prescribed now as screw-retained, the angulated screw channel allows us to relocate or angulate the access hole to a less critically esthetic area. The only real difference is the size of the access hole."

Angulated screw channels solve esthetic issues caused by the use of multi-unit abutments, which are needed to correct implant angulations or develop restorative passivity. As Sander Polanco, MDT, Owner of FMR Prosthetic in New York, NY, shares, "These angulated solutions are great for implant positions and prosthetic development issues. Rather than utilizing multi-unit abutments, angulating the screw channel would reduce implant parts or components and therefore costs. Multi-unit abutments have differing tissue heights that could create undesired space under the prosthetic. Using an angulated channel would keep the prosthetic close to the tissue." Prosthetic space may cause either a potential phonetic or esthetic consequence, and some may erroneously try to ridge lap in order to correct and inadvertently create a bigger consequence with hygiene.

Angulating the screw holes requires using the correct driver. Manufacturers have developed a specific driver that engages the screw from an angle. If a clinician attempts to use a regular driver when seating these restorations, oftentimes it will result in stripped screws. Helm has developed a specific protocol for his clients who utilize these type of restorations. "We stock drivers and give them to the dentist doing these type of cases," says Helm. "Quite frankly, we are in a service industry and the more we can service our clients, the better it is for us. So we educate, consult, loan, and do whatever it is to make their work successful. We have a form that we send out with the case that explains what to do with the driver, the torque values, etc. We don't just send them the case blind. That's service." As an added benefit for his customers, Helm engages with the local implant representative on the first case to provide the dentist with greater service and support. "So when we have a new dentist who is using this solution, we call the implant company and tell them ‘Dr. XYZ is inserting the case for the first time. Can you please be there to support them?'"

Mastication forces must also be considered when restoring these angulated implant-supported restorations, which can often be controlled in the laboratory. "Angulated screw channels mean there is a torquing force on the implant and/or restoration and screw," says Wong. "If the occlusal forces are at an angle, this means there are greater shear forces. If the implants are not aligned axially in the same direction as the force, then shear elements are greater, and this could potentially cause screw loosening, abutment loosening, and/or the prosthetic material to fail, even screw breakage." Helm agrees, "If it's a posterior implant restoration, you want to keep your forces centered over the implant," he says. "You also don't want any excursive movement, contact, or forces on the implant restoration. As long as the forces are over the bone, you shouldn't have any issues."

Parafunctional patients are also a concern. "For parafunction cases, extreme caution is required when restoring with an angled-screw-channel implant solution," Levin says. "Most of the time, any forces fall on the screw, and there are tolerances we just don't know yet. I am still cautious recommending this as a solution because there hasn't been a lot of research on it. Recommending occlusal guards for these restorations is critical to ensure there is not more load on these implants than is absolutely necessary." Elian agrees that caution is needed. "At times we create tools that alleviate inadequacies in our skill sets, and I don't have the most confidence in this. The number of patients referred to me with broken screws has increased in recent years." Polanco suggests that perhaps less angulation than allowed by the manufacturers may be one solution. "Although the allowed amount of angulation is up to 30 degrees, as a rule of thumb, I don't push it beyond 20 degrees; that's my comfort zone."

Another trend impacting the implant arena is the introduction of a new and innovative class of polymers, called high-performance polymers. These materials have been recently approved by the FDA for dental use in this country but have been used in Europe for well over a decade. This is a diverse group of polymer materials; each has different attributes and characteristics to provide for greater comfort and functionality for the patient. "They are stronger than other polymers and incredibly resistant to dimensional changes and permanent deformation," says Campbell. "They are incredibly inert, offering medical grade application with no residual monomers. The level of biocompatibility is remarkable, making many of these materials suitable for medical uses in orthopedics, such as bone and joint replacement." Since these materials act much like natural bone, they have become popular for applications in dental procedures. "High-performance polymers are extremely lightweight and hypoallergenic and act as great shock absorbers in the mouth," says John McMillan, owner of Spitfire Dental Ceramics in Ohio, and international lecturer on the subject. "Zirconia is a very strong material but does not absorb any of the energy and impact force caused by masticatory bite forces, occlusion, etc. The shock absorption qualities of polymers protect the bone and implant fixtures, as well as preventing ocular nerve damage on the maxillary that could otherwise be caused by the use of zirconia hybrids." Polanco adds that the polymers' natural bone-like modulus of elasticity and absorption of the masticatory forces also aid integration in immediate-load cases and provide great advantages over rigid structures.

High-performance polymers feature different compositions; therefore, it is important for the user to understand those differences with respect to processing nuances or completing the case. "Depending on the situation, if the case is well planned and we have the proper restorative space, there are many polymers to choose from, like BioHPP (Bredent Group; bredent.com), Pekkton (Cendres+Métaux SA; cmsa.ch), PEEK, fiberglass-reinforced polymers (such as TriLor; Harvest Dental; harvestdental.com), and more," says Polanco. "I use PEEK for secondary structures. Trilor is good for immediate load or reinforcement bars."

According to McMillan, the main characteristic to keep in mind is that Pekkton polymers are not as strong as other fiberglass-reinforced polymers, which are more brittle, but they need to be completely sealed and can't be highly polished or be exposed to the oral environment without a sealant. "One of the best features about these polymers is that they are easily bondable using the proper primers. I've tried all different primers and cements and personally use Linkforce (GC America; gcamerica.com) because it has some flex and is not rigid, which can cause them to fail. Ivoclar Vivadent's hybrid cement (Multilink Hybrid Abutment Cement HO0; ivoclarvivadent.com) also has some flex to it."

Properly engineering these prostheses can dictate the success of the case. Although polymers are great shock absorbers and have flexibility, those same benefits can compromise the case if it is not designed well. "We need to make sure design parameters are adhered to, because these are not like their extremely stiff metal predecessors," says Campbell. "The longer the distance between each implant site, the greater the structure's flexibility and the more easily it fractures. As the length increases, flexibility increases exponentially by a power of three. So, doubling the length results in approximately eight times more flexure," says Campbell. "You can offset that by changing the height and width. The height is the more important one, because it also has an exponential relationship. If you can increase the height and width, that would offset the distance or flexibility of the framework/bar and improve the resistance to fracture."

McMillan and Polanco have a strict set of parameters they adhere to when fabricating thimble substructures with individual restorations bonded over the bar. "There must be no less than four implants with no more than 10 mm between them, a 4-mm by 4-mm connector, and absolutely no cantilevers," says McMillan. "You can't have a long-span area in a high-force-distribution region because it can create issues. It's all about the engineering when constructing these type of cases." As further guidance, Polanco advises that if there is not enough restorative space, then he chooses a titanium structure rather than polymer. The minimum restorative space, he says, should be 15 mm to 17 mm.

Among the greatest benefits of these materials is the ease of clinical repair. According to McMillan, Pekkton cases are clinically repairable, unlike zirconia. If individually cemented crowns should chip or crack, they can be easily removed. The dentist can cut off the crown using customary procedures and the cement actually disengages with the heat of the bur. Since the laboratory already has the digital STL file for the crown, it can be milled and delivered before the patient presents at the practice for treatment. If the tissue should recede slightly, the dentist can add composite intraorally or remove the restoration, add composite, and seal to correct the recession—all without having to remove the prosthetic or requiring the patient to come back for another appointment. "This way, the patient is never without the prosthesis. The convenience of not needing to send the case back to the laboratory for repairs is immense," says McMillan.

Polanco says that if the case is appropriate, using polymers offers far greater patient benefits. The material is very light—30% of what zirconia would weigh. The noise during masticatory contact is completely eliminated. And the material truly mimics what the patient has lost in their natural dentition. In addition, the light framework behaves much like bone, and the individually seated crowns look and feel much like natural teeth. "Patients truly feel like their natural teeth were restored; the restoration doesn't feel foreign in their mouths."

The indications and uses for these new high-performance polymer materials will continue to evolve. Polanco currently uses it in pressed BioHPP form, which offers a higher concentration of ceramic filler. This makes it a stronger alternative for custom abutments over a temporary titanium cylinder when doing implant combination cases, where there is adjacent natural dentition. The bone color of the material allows for esthetic shade matching with natural preparation shades. McMillan similarly uses it for Maryland bridges because of its exceptional bonding characteristic and strength. He believes this will be the comeback of Maryland bridges for more conservative restorations or long-term implant provisionals.

As patients' access to care increases, implant therapy treatment options will undoubtedly continue to evolve and expand, as will material and techniques, leading to an enhanced level of dental therapy for patients. For laboratory owners and managers, staying on top of these advancements is crucial to maintaining credibility and relevancy in order to become the go-to resource for existing and prospective clientele. Education and knowledge are at the foundation of these trends. Becoming truly invested and engaged at the forefront of education can help ensure business sustainability and provide the laboratory with a great level of success.

1. "Dental Implants and Prosthetics Market by Type (Dental Implants, Bridge, Crown, Abutment, Dentures, Veneers, Inlay & Onlays), Material (Titanium, Zirconium, Metal, Ceramic, Porcelain Fused to Metal), Type of Facility, and Region - Global Forecast to 2023." Markets and Markets Web site. https://www.marketsandmarkets.com/Market-Reports/dental-implants-prosthetics-market-695.html. Published March 2018. Accessed January 30, 2019.