April 2014, Volume 10, Issue 4
Published by AEGIS Communications
Guide to Implant Dentistry
Advances in materials and techniques make implants more accessible for general dentists as well as a very desirable option for patients — but are you ready?
If you’re not placing or restoring dental implants, indications are that you soon will. In 2006, the American Academy of Implant Dentistry (AAID) reported that of the dentists placing implants, approximately 56% were general dentists, and the number has continued to grow since then. In fact, a 2013 study in Periodontology 2000 found that an equal number of implants are being placed by periodontists, oral surgeons, and general dentists.
“The majority of implants are still being placed by surgical specialists, but that statistic is slowly changing,” observes Nicholas Caplanis, DMD, MS, president of the AAID. “An increasing number of general dentists and new dentists offering implants in their practices will help drive market growth.”
And that growth is substantial. Last year, an estimated 1,260,000 dental implant procedures were performed in the United States, and that number is expected to double in 7 years to 2,540,000. Simultaneously, the current value of the US dental implant market—estimated at $900 million in 2012—will grow to more than $2 billion in 2021.1
Several factors are influencing this trend. First, dental insurance providers are gradually adding implants to their list of covered services. Secondly, patients have become aware of the benefits of implant-based options (eg, removable partial dentures, fixed 3-unit bridges) versus conventional restorative procedures.
Single-unit implant procedures will remain more popular than multi-unit placements due to declining edentulous rates and improved patient dental education,1 Dr. Caplanis explains. Anterior implant placements will experience faster growth as dentist exposure to these procedures increases; in addition, the increased esthetics and declining cost of dental implant treatments will help boost single-unit placements to nearly 74% of all dental implant procedures in the United States by 2021.
This bodes well for general dentists and their practices. The greater variety of implant and abutment choices, combined with more predictable and less invasive placement procedures, make implant treatments more available, affordable, and attractive to more patients. According to industry sources, Dr. Caplanis notes that general dentists performing both implant placement and final restoration typically charge an estimated 30% less than the combined costs of implant placement by a specialist and restoration by a general dentist.1 An American Dental Association (ADA) survey found an average cost for implant placement to be about $2,000, with the fabrication and placement of the abutment costing an additional $450.2
Despite technological and material advancements that contribute to enhanced implant predictability and success, placing dental implants still requires thorough education, training, and knowledge of what is possible using which materials. To determine whether implant placement and restoration are appropriate additions to your practice, a closer look at major considerations is necessary.
Most people who are missing one or more teeth are candidates for implant treatment. Those with a relatively intact alveolar structure, both hard and soft tissue, are good candidates and more straightforward to treat, explains Louis F. Rose, DDS, MD, clinical professor at the University of Pennsylvania School of Dental Medicine and professor of surgery in the division of dental medicine at Drexel University College of Medicine. Individuals with hard and soft tissue deficiencies are still good candidates, but may need preparatory or simultaneous augmentation procedures for structural or esthetic reasons.
Fortunately, medical contraindications for dental implant treatment are few, Dr. Rose says. Patients must be medically stable for the procedure (ie, someone healthy enough for an extraction is someone healthy enough for an implant). An example of a temporary contraindication is uncontrolled hypertension, which would render patients unsuitable candidates for an extraction or an implant until their blood pressure is controlled. The same is true for patients taking anticoagulants.
“It is essential that the surgeon and physician communicate about the patient’s medical status in order to prevent a medical emergency,” Dr. Rose emphasizes.
Additionally, patients would need to have a relatively normal healing process to allow bone and soft tissue healing to occur. Individuals with connective tissue diseases, on long-term corticosteroid therapy, or poorly controlled diabetes are examples of people who could experience delayed healing that would affect treatment, Dr. Rose adds. Smoking also affects the healing process, and those who smoke should be urged to quit.
“These are not necessarily absolute contraindications, but would require careful work-up to determine someone’s potential as a candidate for implant treatment,” Dr. Rose says. Other health conditions that may disqualify patients for implants include untreated periodontal disease, cancer, immunosuppressive medications, alcoholism, bruxing/grinding habits, and radiation to the jaws.
Implant, Abutment & Treatment Planning Options
In earlier years, most titanium screw implants had a diameter of approximately 4 mm. Today, a variety of implant widths are available, notes Dr. Caplanis, who explains that it is widely believed based on photoelastic and computer-generated model studies that wider diameter implants distribute the force of mastication better than narrower implants.
“The choice of diameter is largely influenced by the tooth to be replaced for esthetic reasons,” Dr. Caplanis says. “To make a narrow tooth, narrow implants are typically used. Wider implants are typically used to replace wide teeth such as molars.”
The advent of different implant diameter sizes eliminates the need in some cases for additional grafting and surgical procedures. They have also enabled dentists to provide implant treatments in areas where traditionally sized implants would not fit, explains David Little, DDS, an educator and private practitioner from San Antonio, Texas. These include areas involving limited interradicular bone, teeth with small cervical diameters, or thin alveolar crests.3
Further, although implant length had previously been largely determined by the available bone (ie, the more available bone, the longer the implant typically used), published clinical studies confirmed that longer implants had better survival rates, Dr. Caplanis adds. Today, largely due to improvements in implant surface technology, the advantage of longer implants is in question, and debate continues at many dental implant meetings, he says.
Shorter implant lengths and the ability to angle implants are contributing to enhanced placement, particularly because dentists must avoid anatomic landmarks (eg, mandibular nerve, sinuses), Dr. Little says. However, angled implants necessitate appropriate abutment solutions that can accommodate 15° to 30° angle abutments, he elaborates.
Interestingly, most early implant restorations were attached using screws, Dr. Caplanis says. With efforts to make implant restorations more esthetic, innovations in abutment and restoration design were introduced, such as anatomic, custom, and/or angled abutments supporting cement retention. Use of a custom abutment as opposed to a stock abutment enables clinicians to create the correct emergence profile for the implant, supporting the surrounding tissue and blending with surrounding dentition. Standard abutments do not provide the same leeway, especially when dealing with variable tissue heights, which can affect implant esthetics in the anterior.
Although zirconia—a popular material for dental restorations—shows some promise for implant dentistry, Hans Peter Weber, DMD, professor and chair of the department of prosthodontics and operative dentistry at Tufts University School of Dental Medicine, cautions about the fracture risk observed with zirconia abutments. He advises the discriminate use of zirconia abutments, noting their appropriateness for cases where there is less than 2-mm thickness of peri-implant mucosa or in the esthetic zone.
“With millions of implants currently in function, we are dealing with long-term complications such as gum disease affecting the health of the tissues supporting implants,” Dr. Caplanis observes. “Because trapped cement is a common cause of gum problems around implants, we have come full circle with implant prosthetics and are returning to screw retention, which was initially introduced in the 1970s.”
The evolution of dental implant materials has also included surface treatment developments to enhance healing, the addition of coronal microthreads to implant designs, and platform switching to improve bone maintenance, Dr. Weber adds. Further, CAD/CAM, cone-beam computed tomography (CBCT) scans, digital workflows, and surgical guides are contributing to greater customization and predictability.
Preferred techniques relate to the operator’s skill and experience, observes Stuart J. Froum, DDS, president of the American Academy of Periodontology (AAP) and clinical professor and director of clinical research in the department of periodontics and implant dentistry at New York University Dental Center. Traditionally, implants are placed into sites where teeth have been extracted and allowed to heal, but today, a number of clinicians eliminate that step and place an implant on the same day as the extraction. This may require simultaneous guided bone regeneration. In some cases, particularly those involving the esthetic zone, immediate temporization is also performed.
The most minimally invasive technique for implant placement is a flapless approach, wherein large incisions are not required, but the implant is instead placed transgingivally. This method allows dentists to effectively punch through tissue, ensuring not only an easier procedure but also enabling a shorter healing time for patients. The ability to perform this technique is predicated on sufficient volume and proper gingival tissue in the area (ie, attached keratinized tissue), says Paul Petrungaro, DDS, MS, a private practitioner and speaker/educator.
“With 3D radiography, it is sometimes not necessary for extensive flap reflection to visualize the anatomy,” Dr. Rose elaborates. “The purpose of the flap then changes to protecting or manipulating the soft tissue as opposed to extensive reflection for full visualization of structures.”
Ultimately, treatment planning dictates the type of implants and technique used, such as placing six to eight implants in an edentulous maxillary jaw, or angling distal implants (eg, All-on-4®, Nobel Biocare, www,nobelbiocare.com) to provide a well-functioning solution, says Robert A. Levine, DDS, FCPP, clinical professor in the department of periodontology and oral implantology at Temple University Kornberg School of Dentistry. The techniques really come down to proper treatment planning, which will involve mounted study models, digital intraoral and extraoral photographs of the patient, and CBCTs.
For example, Dr. Froum notes that in the posterior maxilla, it may be necessary to perform a sinus augmentation with grafting to build up bone under the sinus approximately 6 months prior to implant placement. In some cases, this procedure can be performed in conjunction with implant placement.
Dr. Rose adds that when soft maxillary bone is encountered, osteotomes can be used to expand and condense the bone rather than drill it away. Although the patient’s bone density may not be changeable, how the surgeon works with it can affect the outcome.
Dentists placing implants are increasingly using surgical templates for every case. However, a CT scan showing there is sufficient bone is only partial information, Dr. Rose explains. Having techniques and computer software that allow the surgeons, restorative dentists, and dental technicians to transfer the ideal tooth replacement forms to the CT scan provides even more effective planning information.
For an implant to be considered successful, proper hygiene and care must be maintained, both on the part of the patient and the dental team. Overall, implant patients should be treated just like any other hygiene patient who’s undergone any type of restorative dentistry, says Dr. Little. He emphasizes the importance of getting implant patients on a good maintenance schedule, educating them about proper maintenance and compliance, and instructing the hygienist regarding proper techniques and instruments for maintaining and cleaning implant restorations (eg, proper flossing, rubber tips, plaque-removing brushes and irrigators).
“If we have a screw-retained prosthesis with titanium showing, that’s an area where we need to know to use either titanium or plastic instruments to avoid scratching any of the titanium and preventing plaque accumulation,” Dr. Little explains.
But Dr. Rose notes that although the connection may be not be immediately apparent, ease of implant maintenance begins with careful treatment planning. Preoperative assessment of soft tissue thickness, ideal depth of implant placement for the proposed restoration, emergence profile of abutments, location of cement margins, and pontic design all contribute to an ideally cleanable restoration.
“Implant prosthetic care, with proper planning and execution, should require no more maintenance than healthy teeth,” Dr. Rose says. “Compromised implant positions and ensuing prosthetic and framework designs can complicate the patient’s ability to keep the tissues healthy. Another important aspect of implant restorative maintenance is vigilantly monitoring occlusion.”
Routine maintenance should be scheduled every few months, not only for mechanical debridement of plaque and calculus above and below the gum line, but also to review patient health history, monitor occlusion, and enforce home care, Dr. Rose advises.
According to Dr. Weber, the major reasons for implant treatment complications are lack of careful treatment planning and poor placement/positioning. Restorations should first be designed digitally or in wax so that a proper implant, abutment, and restoration complex can be determined; CBCT radiographs should be taken to ensure adequate bone, as well as facilitate creation of an implant surgical guide; and implant surgery should be planned for proper implant position and angulation.
“One study found that complications occurred within the first 5 years in 38.7% of the implant placements studied, while another study reported 50% of implant treatments evaluated developed complications within the first 10 years,” Dr. Froum says, adding that dental implant treatments do have a very high survival rate of between 90% and 95%. “Complications arise first due to improper planning, so the best way to prevent them is planning the case correctly. This requires collaborative communication and planning between the clinician who is placing the implants and the one restoring them.”
Among the complications that could arise is peri-implantitis.4,5 Use of stock abutments in combination with restorations cemented down to the implant shoulder contributes clearly to the occurrence of peri-implantitis when excess cement is not properly removed. Although stock abutments enable an easier approach for implant restoration, Dr. Weber cautions that residual cement or cement pushed into the tissue will result in damage that will reveal itself 2 to 3 years after treatment, if not sooner.
“If cementation is chosen, dentists must assure that the shoulder to which the crown is cemented is in a reachable area for easy and thorough removal of excess,” Dr. Weber emphasizes. “If the implant is very deep, a custom abutment with the crown shoulder relatively superficial below tissue level is ideal.”
Other complications, Dr. Froum says, include poor initial stability due to poor quality bone, which can be identified when using CBCT scans for planning and prevented, in part, by undersizing the osteotomy so the implant can engage the bone a little tighter. Overheating very dense bone is another complication, which can be prevented by copious irrigation (eg, refrigerated saline), he adds.
Among the reputable programs for implant education and training are the AAID “MaxiCourses,” which are intensive lecture and laboratory training sessions that provide more than 300 hours of continuing education and are designed to educate practitioners on implant dentistry. The AAP also offers programs that are multidisciplinary, provide opportunities for lectures and hands-on practice, and span a broad range of relevant topics. The International Team for Implantology, based in Switzerland, conducts programs on simple and advanced implant treatment. Additionally, there are a number of university-based programs that span months or take anywhere from 1 to 3 years to complete.
“Private implant education (eg, The Implant Learning Center) that offers opportunities for live surgical courses and mentorship can also provide general dentists with hands-on education and training,” says Dr. Petrungaro. “Doctors can bring their patients and have an experienced practitioner/educator perform the surgery with them, hand-in-hand, so they learn basic surgical procedures on their own patients. That provides a tremendous learning experience.”
Dr. Petrungaro adds that there are many institutes that offer anything from a weekend course on basic surgery up to a 9-month or more continuum of education that builds upon the surgery, prosthetics, and grafting at various levels. However, the fact that there is no “fast-track” to implant education and skills development cannot be overstated.
“As an educator, I’m very concerned about weekend-only courses,” cautions Dr. Levine. “Some dentists come away thinking that based on attending a weekend course, they can provide implant surgical services. This can be very dangerous to patients.”
Dr. Little suggests attendance and participation in programs that break down the many aspects of providing dental implant treatments, such as multidisciplinary planning with the end in mind, surgery, and restoration (eg, Misch Institute, Pikos Institute, McGarry Implant Institute, and others). He then advocates mentorship from a seasoned dentist willing to assist through the education and hands-on skills development process.
“When you take a hands-on course, you’re not going to learn everything you need to know. You’re going to learn enough to get started and take baby steps,” Dr. Little elaborates. “You’re going to have to take several courses, complete some cases, then go to the next level of education and continue that path, and I think that’s the key.”
Also important is developing a team approach that involves the surgeons, laboratories, and implant companies that general dentists are working with. This helps to ensure they’ll have “go-to” people to assist in their education, training, and treatment planning.
Participating in study clubs can be instrumental in this endeavor. Dr. Levine, who has been conducting study clubs for 30 years in advanced dentistry and implant therapy, believes study clubs enable dentists to raise the bar for themselves, as well as help others. His study club emphasizes a “team approach” in which the periodontist/surgeon is key, along with the restorative dentist, laboratory, hygienist, and patient, who are all working in harmony for a seamless experience for the patient.
“Study clubs provide a very healthy, supportive environment where dentists gather to share their knowledge with others, and where everybody feels comfortable doing so,” Dr. Levine observes.
Yet, just as dentists are advised to participate in the most comprehensive education programs possible, selecting the right study club is equally important. Dr. Petrungaro notes that some study clubs are straightforward, with eight or 10 meetings per year that feature a lecturer. Although valuable, such a format can be limiting; one that is more interactive and encourages participants to bring in and share their cases are most beneficial, since they foster an open discussion about how to manage different cases.
As a greater number of general dentists begin offering implant treatments, understanding the trends and changes in appropriate materials and techniques for given indications will be significant to success. However, Dr. Petrungaro emphasizes that implant dentistry is not something of which general dentists should be afraid.
“Basic implant surgical placement, restoration in single tooth replacement, and smaller bridge or immediate denture stabilization are very safe, simple procedures to perform following some basic guidelines,” encourages Dr. Petrungaro. “As dental implant treatment becomes more and more popular as a tooth replacement option, this service is something that should be integrated into most general practices on a routine basis, and in many cases it’s simpler than a complex root canal.”
1. US Markets for Dental Implants 2013. Millennium Research Group website. http://mrg.net/Products-and-Services/Syndicated-Report.aspx?r=RPUS22DE13. Accessed February 20, 2014.
2. American Dental Association, Survey Center, 2011 Survey of Dental Fees. http://catalog.ada.org/login/login.aspx?URL=/members/sections/professionalResources/11_sdf.pdf [membership required]. Accessed February 20, 2014.
3. Degidi M, Piattelli A, Carinci F. Clinical outcome of narrow diameter implants: a retrospective study of 510 implants. J Periodontol. 2008;79(1):49-54. doi: 10.1902/jop.2008.070248.
4. Sailer I, Mühlemann S, Zwahlen M, et al. Cemented and crew-retained implant reconstructions: a systematic review of the survival and complication rates. Clin Oral Implants Res. 2012;23(suppl 6):163-201. doi: 10.1111/j.1600-0501.2012.02538.x.
5. Overview of dental implants. International Congress of Oral Implantologists website. https://dentalimplants.com/index.php. Accessed February 20, 2014.