Where is dentistry today regarding treatment of peri-implant diseases?
Donald S. Clem, III, DDS; Hom-Lay Wang, DDS, MSD, PhD; and Stuart J. Froum, DDS
Many consider dental implants to be one of the most significant developments in dentistry. Introduced in the United States in the early 1980s, these revolutionary devices have changed the quality of life for thousands of patients. Since about the middle of that decade, however, recognition of the “ailing, failing” implant began to emerge in both the European and US literature. Numerous implant companies have since come on the scene marketing an almost endless variety of shapes (macrostructures) and surfaces (microstructures). Concurrently, more dentists are delving into implant surgery with minimal training. Patients are aging with more chronic disease and taking more medications than ever before in history. We are now in the era of peri-implant diseases as these medical devices are proving to not be impervious to a multitude of these and other risk factors that make them susceptible to progressive, inflammatory conditions.
With almost three million implants placed per year in this country, the prevalence of peri-implant diseases (ie, peri-mucositis and peri-implantitis) ranges from 10% to more than 40% depending on which source you reference. How are we as practitioners to manage these conditions from both a diagnostic and therapeutic perspective? As periodontists complete their specialty training, they are often called upon to treat patients with these conditions. I (Dr. Clem) sat down with fellow periodontists Drs. Froum and Wang to discuss the current status and future considerations for the treatment of peri-implantitis.
The Less the Better?
Clem: In 2013 the three of us participated in a group developing a white paper on peri-implant diseases for the American Academy of Periodontology (AAP).1 In that manuscript the definition of peri-mucositis was described as inflammation confined to the soft-tissue component surrounding dental implants. What about treatment?
Wang: These inflammatory conditions, if confined to the soft tissues with no progressive bone loss, can usually be treated with nonsurgical approaches. These treatments can include mechanical debridement, local delivery antimicrobials, and even lasers.
Froum: One of the more promising treatments for peri-mucositis is the development of glycine air power abrasion.
Clem: It seems we are in agreement as to a minimally invasive approach. Diagnostically, probing implants on a regular basis and monitoring bleeding on probing, along with radiographic assessments, is essential, isn't it?
Froum: You must remember, however, that probing around an implant is not like probing around a tooth. Light probing, less than 25 N/Cm, is what we try to accomplish, and sometimes the complexity of the prosthesis impedes our ability to gain access. If I see an increased probing depth or a probing depth greater than 4 mm with bleeding on probing and/or suppuration I take an x-ray and compare it to previous films.
Clem: Of course, one of the issues we often contend with is the presence of facial defects. I think because implants are generally placed more palatal than teeth, and significant facial augmentations are frequently performed, we tend to see more facial defect formation around implants, which makes standard periapical radiographs ineffective.
Wang: I also feel that an implant maintenance program, similar to periodontal maintenance, should be tailored to each case. This is essential in preventing and managing the early signs of peri-mucositis. Factors such as past history of periodontal disease, peri-implant health, and systemic health all play a role in determining the maintenance interval.
Clem: Absolutely. As with other health conditions, risk assessment for older adults is a dynamic process that continues to change over time. There is no guarantee of 20- or 30-year success because by then the clinician is dealing with a totally different patient. I tell patients that they are likely not the same patient today as they will be 20, 15, or 10 years from now. While we have been able to achieve very good success, we must always remember we are dealing with medical devices that are not bulletproof. Certainly orthopedics has learned this lesson, as some of its literature reports hip revisions at an incidence rate ranging from 30% to 50% after 10 years.
Froum: Clearly, progressive bone loss around implants caused by peri-implantitis is the greatest risk for implant loss. Unfortunately, I see an increasing number of patients referred to my office for treatment of these conditions. Because of the factors cited earlier—a plethora of implant companies, more dentists attempting to place implants, along with an aging population—I think we as periodontists will see more patients with implants affected by peri-implantitis.
Clem: Because of our training I believe dentists will rely on periodontists to be the “go-to” clinicians to treat or at least mitigate these problems. This is particularly challenging because to date we have no standard protocol for the surgical management of peri-implantitis.
Wang: The problem we face is that there is great variability of treatment outcomes, which can be attributed to patient factors, defect morphology, and the regenerative materials and approaches used. I find that for buccally placed implants, for example, guided bone regeneration does not work and we may be better off using implantoplasty (smoothing off the macro- and microstructure of the exposed implant) with apically positioned flaps.
Clem: This may be an option in the posterior segments but the esthetic zone will be greatly compromised.
Froum: Despite the conflicting literature, our practice has incorporated a regenerative approach because, short of ostectomy, the only way to achieve significant probing depth reduction for a chance at long-term maintenance is by decreasing the osseous defect with bone fill.
Clem: I absolutely agree. The bottom line is that in any peri-implant bone defect there are three contributing components: a contaminated surface, inflamed granulation tissue, and an osseous defect. While we have many approaches to decontaminate the implant surface and remove granulation tissue from within the defect, I believe the key is to achieve defect bone fill, which translates to pocket depth reduction. Sometimes, however, a combination of osseous reduction and regenerative therapy will be required.
Wang: There is one other critical component—an adequate zone of thickened, keratinized tissue, which I feel must be addressed in any treatment of bone defects around implants.
Froum: Yes, our group has published our protocol for regenerative treatment around implants in a consecutive series of 100 patients with a 2- to 10-year follow-up,2 and we augment soft tissue as part of our regenerative therapy in many of those cases.
What About Monotherapy?
Clem: Your protocol is quite intricate, Dr. Froum, with a multistep approach. One of the ideas that has recently emerged is the suggestion that using various laser technology as a monotherapy is all you need in treating peri-implantitis. How do you both consider the evidence for this approach?
Wang: So far, there is no evidence supporting use of laser as a monotherapy for treating peri-implantitis. However, short-term data suggest that laser may be a good adjunctive tool in detoxifying the contaminated implant surface,3 which may pave the way for implant bony defect repair or even regeneration.
Froum: If we look at a recent systematic review of human studies on lasers for peri-implantitis by Natto and colleagues (with Dr. Wang)4 we see that while some lasers, such as carbon dioxide (CO2), diode, and Er:YAG, show capability for surface decontamination, there is a risk of implant surface damage, which may interfere with the goal of reosseointegration or repair around an implant surface with bone loss caused by peri-implantitis. Moreover, as that review pointed out, as did a review by Geisinger et al5 (and a yet unpublished article by the AAP), there is a paucity of human studies on the use of lasers in the treatment of peri-implantitis. Certainly, the potential for surface decontamination has been demonstrated with CO2, Er:YAG, and soft-light lasers, but most studies have been in vitro. I believe more human controlled studies are needed before we consider replacing any current effective methods of surface decontamination or other aspects of peri-implantitis treatment with lasers. Conflicting data shown in a review5 reported that these lasers can damage implant surfaces and in some cases result in further bone loss. The reviews I've cited stress that insufficient evidence is available and there are no long-term outcome studies following laser therapy for peri-implantitis. I myself have used three different lasers in treatment of peri-implantitis with mixed results.
I feel that the laser, if used properly with developed “standardized ideal laser decontamination protocols that fully characterize the wavelength, time, power, and presence of cooling,”5 may be an excellent adjunct in the decontamination of peri-implantitis–affected implants. This, however, as we discussed, is just one part of treatment. I believe the rebuilding of bone and soft tissue must include grafting and use of membrane barriers along with soft-tissue grafts in certain cases of peri-implantitis. In addition, I agree with Dr. Wang that there is no evidence for using a laser as a monotherapy in treating peri-implantitis.
Clem: When you look at the evidence for the different conditions associated with peri-implantitis, such as retained intra-defect cement, the intricacies of the microstructure harboring a pathogenic microbiome, and the tortuous osseous defects associated with implant bone loss, it is inconceivable to me that one universally applied monotherapy can be effective in managing large numbers of patients. Isolated case reports are no substitute for long-term follow-up data, and when it comes to lasers of any type used as a monotherapy, either nonsurgically or surgically, the evidence is just not there.
I believe at this juncture in treatment development of peri-implantitis a multistep surgical approach is required that employs surface decontamination, granulation tissue removal, and regeneration, with probing depth reduction being the goal. Depending on the defect this may mean performing ostectomy. If a laser is used it should be only part of the therapy for a very specific purpose, such as surface decontamination for example, and not the sole therapy.
Removing an Ailing Implant?
Clem: inally, when should you consider removing an implant affected by peri-implantitis?
Wang: As I wrote in my decision tree,6 I recommend removal of the implant when there is more than 50% bone loss with signs of inflammation, such as bleeding on probing, suppuration, and deep probing pocket depth of at least 8 mm. Removal is also recommended for buccally placed dehiscence implants or implants that create an esthetic challenge that cannot be easily corrected.
Froum: I would consider removal of an implant affected by peri-implantitis for several reasons: (1) if the implant is mobile; (2) if I don't have access to fully decontaminate the implant surfaces; or (3) if surface decontamination would risk damage to a vital structure (ie, inferior alveolar nerve or sinus membrane). Decision trees have been presented6-8 that suggest removing an implant when it has bone loss of at least 50% or that is at least two-thirds the length of the implant. In our study of the treatment of 170 consecutive implants, 47 of the 48 implants that fell into this category were successfully treated and retained.2 So, I feel the three criteria I listed are better indicators for treatment than bone loss per se. I also agree that the treatment for a malposed implant with peri-implantitis is implant removal.
Clem: It is clear that dental implants require long-term maintenance with management of multiple risk factors as patients age. Clinicians who practice implant dentistry should not think of it as a “technique” but rather as a “reconstructive treatment” that requires careful considerations of the risk factors discussed here. In addition, as patients age, their susceptibility to inflammatory changes may also contribute to an increased risk for these conditions. As restorative dentists encounter more patients with different types of implants coming into their offices, it is important to establish accurate clinical and radiographic baselines once the final restoration is placed. If these baselines change, differentiation of peri-mucositis versus peri-implantitis is critical in terms of treatment and prognosis. If an implant develops peri-mucositis that cannot be resolved or if signs of developing peri-implantitis become evident, advanced treatment options need to be instituted on a timely basis. Periodontists are becoming increasingly involved in managing these conditions and partnering with restorative colleagues because, ultimately, a regenerative approach focusing on both hard and soft tissues may be the best opportunity to reduce inflammation and probing depth and return the patient to a maintainable condition.
About the Panel:
Donald S. Clem, III, DDS
Adjunct Professor, University of Texas Health Science Center, San Antonio, Texas; Private Practice, Fullerton, California
Hom-Lay Wang, DDS, MSD, PhD
Professor and Director of Graduate Periodontics, Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, Michigan
Stuart J. Froum, DDS
Adjunct Clinical Professor and Director of Clinical Research, Ashman Department of Periodontology and Implant Dentistry, New York University College of Dentistry, New York, New York; Private Practice,
New York, New York