KEY POINTS
● Peri-implantitis can be treated, but the treatment outcome is not always successful or predictable.
● The combination of resective and regenerative surgical techniques seemed to have favorable treatment outcomes in the management of peri-implantitis.
● It is best to prevent peri-mucositis, which is the precursor of peri-implantitis. This prevention can be achieved by eliminating bacterial plaque through meticulous oral hygiene practices and professional mechanical debridement. In addition, other contributing factors, such as wrong implant position, poor patient selection, and the presence of residual cement or deep probing depths, should be corrected.
● Peri-implantitis can be treated, but the treatment outcome is not always successful or predictable.
● The combination of resective and regenerative surgical techniques seemed to have favorable treatment outcomes in the management of peri-implantitis.
● It is best to prevent peri-mucositis, which is the precursor of peri-implantitis. This prevention can be achieved by eliminating bacterial plaque through meticulous oral hygiene practices and professional mechanical debridement. In addition, other contributing factors, such as wrong implant position, poor patient selection, and the presence of residual cement or deep probing depths, should be corrected.
INTRODUCTION
Over the past few decades, dental implants have been found to have high predictabil- ity and survival rates because of improvements in knowledge and clinical expertise, together with technological advances in implant designs. They are thus integrated into the clinical management of fully or partially edentulous patients. However, having a high implant survival rate is not equivalent to long-term implant success, which is defined as having a functional and esthetic implant restoration with no pain, mobility, and suppuration and no more than 2 mm of radiographic peri-implant bone loss. Also, despite the high early survival rates, dental implants do have their fair share of long- term esthetic, biological, and mechanical complications. The incidence of esthetic complications might have reduced because of the recent introduction of zirconia, but the incidence of biological and mechanical complications remained high. There- fore, this paper aims to review the current evidence on the management of peri-implant diseases in an attempt to answer the following question: Can peri-implantitis be treated?
Definition
Peri-implant diseases, which are infectious inflammatory diseases of the peri-implant tissues, can be broadly categorized into peri-implant mucositis and periimplantitis. In sites with peri-implant mucositis, the inflammatory lesion is found to be limited to the peri-implant soft tissues with no evidence of progressive peri-implant bone loss beyond the initial physiologic bone remodeling that occurred following implant place- ment (Fig. 1). Sites with periimplantitis, on the other hand, exhibit progressive peri- implant bone loss following the initial physiologic bone remodeling that occurred after implant placement as the inflammatory lesion progresses in both the mucosa and bone (Fig. 2). As the discriminating feature is progressive bone loss beyond physio- logic bone remodeling, it is, thus, important to establish baseline peri-implant bone levels, which is recommended to best occur at the time of prosthesis installation. Changes in bone levels from the time of implant placement to prosthesis installation are considered the result of physiologic bone remodeling or early implant failure. Therefore, it is challenging to determine the baseline peri-implant bone levels for immediately loaded implants, as time is not allowed for physiologic bone remodeling.
Diagnosis
Based on the abovementioned definitions, peri-implant mucositis is diagnosed by the presence of bleeding on probing, which is a key clinical parameter that indicates gingival inflammation. In addition, the presence of suppuration and/or increase in probing pocket depth (eg, ≥4 mm) are also used to detect peri-implant mucositis. Periimplantitis often presents with similar clinical signs as peri-implant mucositis but with progressive bone loss as the main feature that distinguishes periimplantitis from peri-implant mucositis. Baseline and follow-up radiographs are needed to detect changes in peri-implant bone levels over time, however, these are only useful for assessing the interproximal regions. Changes in buccal or lingual bone levels can be determined by probing depths or recession of the peri-implant mucosa resulting in exposure of the implant threads. When the baseline peri-implant bone levels cannot be accurately determined, for example, in immediately loaded implants or when base- line radiographs are not taken, it is recommended to consider 2-mm vertical bone loss from the expected bone level as a threshold for the diagnosis of periimplantitis. In addition, marginal peri-implant bone loss of more than 0.44 mm per year has been suggested to be an indication of progressive bone loss. Clinical detection of mobility of the implant fixture signifies failure of the implant restoration, which is the end point of peri-implant diseases.
Classification
A newly proposed classification schema for periimplantitis has attempted to catego- rize periimplantitis into early, moderate, and advanced based on the percentage of bone loss, which is differentiated as less than 25%, 25% to 50%, and greater than 50% of the implant length (Fig. 3) and the probing depth of 4 mm or greater, 6 mm or greater, and 8 mm or greater with the presence of bleeding or suppuration on prob- ing, respectively. This classification hopes to provide a standardized method for cli- nicians and researchers to better share information relevant to the management of periimplantitis. Considering different defect configurations, several investigators have endeavored to categorize the pattern of peri-implant bone loss. In a human and dog comparative model, peri-implant bone defects were divided into well- defined intrabony defects (class Ia–e) and horizontal bone loss (class II). Circumferen- tial bone loss with buccal and lingual dehiscences was the most common defect configuration. Another classification system described the radiographic presenta- tion of peri-implant bone loss as 5 main types, namely, saucer-shaped, wedge- shaped, flat, undercut, and slitlike defects. It was found that the saucer-shaped defects were the most common. This finding is important because the defect config- uration may impact the chosen treatment approach.
Epidemiology
Epidemiologic studies on peri-implant diseases often report varying prevalence rates because of the distinct differences in the disease case definitions, sample size, sam- ple population, and follow-up periods. In particular, the different case definitions resulted only in an average agreement (52%) among examiners. Table 1 clearly demonstrates the wide variation in the prevalence of peri-implant mucositis and peri- implantitis from epidemiologic studies published from 2011 to 2015. In attempt to reduce the effects of confounders, the 11th European Workshop on Periodontology recently published a meta-analysis of the current epidemiology of peri-implant dis- eases. An estimated weighted mean prevalence of 43% (range: 19%–65%) for peri-implant mucositis was reported in a European, South American, and North Amer- ican sample population consisting of 4209 implants in 1196 patients. For periimplan- titis, it was 22% (range: 1%–47%) in a similar ethnic sample population of 8893 implants in 2131 patients. These values seemed to concur with those reported by the American Academy of Periodontology.
Goals of Treatment
The progression of peri-implant diseases is assumed to be similar to that of periodontal diseases, whereby healthy peri-implant mucosa under persistent inflammatory challenge can transform into peri-implant mucositis and eventually periimplantitis. Therefore, the primary goal of the management of peri-implant disease is clearly to eradicate the inflammatory lesions so that healthy and stable peri-implant tissues can be achieved in the long-term. The secondary goals are the elimination of poten- tial contributing factors to prevent recurrence of disease and the reestablishment of function and esthetics, so that long-term clinical success can be acheived.
CONTROL OF CONTRIBUTING FACTORS
Several contributing factors that were thought to facilitate the initiation and progres- sion of peri-implant disease have been identified, and they can be broadly categorized into patient- and implant-related factors (Table 2).
Patient-Related Factors
Smoking
Numerous studies have demonstrated that smoking is associated with increased implant failure rates and periimplantitis, with an odds ratio of 3.6 to 4.6. This finding may be attributed to the increased levels of inflammatory cytokines in the peri-implant crevicular fluids in smokers compared with nonsmokers, thus leading to an increased rate of peri-implant bone loss of 0.164 mm per year and compro- mised midfacial and interproximal soft tissue remodeling adversely affecting the long-term functional and esthetic stability of the implant restoration. Some recent studies showed that smoking did not exert a significant effect on the risk of periimplan- titis. A recent patient-based meta-analysis reported that smoking had no signifi- cant effect on the risk of periimplantitis (risk ratio of 1.7). However, an implant-based analysis showed that smoking significantly increased the risk of periimplantitis (risk ra- tio of 2.1). The conflicting results might be caused by heterogeneous case definitions for smoking and periimplantitis, small study sample sizes, and inferior patient compliance to regular periodontal maintenance. Future studies in this area are required.
Periodontal status
Longitudinal studies, systematic reviews, and meta-analyses have stressed that the history of treated periodontitis is a major risk factor in the develop- ment of periimplantitis leading to implant loss. Patients with compromised periodontal status were more susceptible to peri-implant diseases compared with periodontally healthy patients with an odds ratio of 3.1 to 4.7 and a risk ratio of 2.17. A recent systematic review reported that plaque accumulation around the implant restoration initiates the development of peri-implant mucositis, presaging periimplantitis Pa- tients with poor plaque control were associated with an increased risk of periimplan- titis (odds ratio of 14.1). Those with a full-mouth plaque score of less than 25% had only 5% of their implants with periimplantitis compared with 23% in patients with a full-mouth plaque score of 25% or greater. Patients with residual probing depths and noncompliance to a strict periodontal maintenance program are at risk of devel- oping peri-implant diseases, with a lower 10-year implant survival rate of 92.1% and approximately 3-times greater marginal peri-implant bone loss over time. In contrast, patients who adhered to a periodontal maintenance program had a 2.5-times lower risk of periimplantitis. Therefore, the value of good periodontal health before implant placement and after prosthetic installation is paramount to long-term implant success; this can be achieved by stringent periodontal maintenance.
Implant-Related Factors Implant position
In order to achieve a stable functional and esthetic restoration for the long-term, the dental implant has to be placed in a prosthetically driven position. This position will ensure that the restoration has an appropriate emergence profile and occlusal loading so that maintenance of healthy peri-implant tissues is feasible. In addition, implant placement is governed by rules so thatadjacent anatomic tissues are not violated. Mesiodistally, there shouldbe at least 1.5 mm of space between implant and adjacent teeth. This dimension may be increased to 3 mm in the posterior region in order to accommodate the emer- gence profile of the restoration. It is recommended that at least 3 mm of space be kept between 2 implants. These dimensions allow for proper bone remodeling and osseointe- gration with minimal risk of damage to adjacent teeth or implant. Buccolingually, the implant shoulder should be about 1.5 to 2.0 mm palatal to the buccal plate to compensate for buccal bone remodeling and to provide support for the overlying soft tissue. Implants that are buccally placed have a 3-times greater risk of esthetic complications, such as midfacial mucosal recession. In general, the implant platform should be placed 2 mm below the expected cementoenamel junction or the midfacial gingival margin. However, in the esthetic zone, it may be prudent to place the implant shoulder 0.5 to 1.0 mm subcrestal so that a proper emergence profile can be achieved. Recent litera- ture also found that subcrestal placement of the microgap and the presence of a plat- form switch aid in the preservation of the marginal bone level and, therefore, can be a useful feature in the anterior region where the implant can be placed slightly subcrestal. If the implant is placed too shallow, esthetic complications, such as poor contours of the restoration and visible metal margins, may ensue. Also, any physiologic bone and soft tissue remodeling may result in exposure of the implant threads to the oral environment, leading to increased plaque accumulation and subsequent peri-implant bone and soft tis- sue loss. If the implant is placed too deep, the peri-implant sulcular depth will increase, thus favoring the growth of anaerobic microbiota, which will facilitate peri-implant tissue breakdown.
Prosthetic considerations
Although peri-implant tissue response around screw-retained restorations seems to be more favorable compared with that around cement-retained restorations, a recent systematic review and meta-analysis found no difference in peri-implant mar- ginal bone loss around cement- and screw-retained implant restorations. Studies have shown that, in the presence of excess cement at the crown-abutment interface, peri- implant mucosal inflammation or bone loss occurs 80% to 85% of the time. The use of certain cement, for example, methacrylate-based cement, is associated with increased residual cement and consequently a higher prevalence for peri-implant dis- eases because they are less viscous and also more susceptible to bacterial in- vasion. In contrast, zinc oxide eugenol–containing cements are more viscous, thus, easier to remove and can inhibit biofilm growth at the crown-abutment interface. Customized abutments that bring the restorative margins coronally or screw- retained restorations may be considered if the restorative margins are located more subgingivally, as it is technically more challenging to remove excess cement around such restorations.
The ability to clean around the implant restoration plays a role in the development of peri-implant diseases. A poor emergence profile impedes proper plaque control and, thus, expedites the progression of peri-implant diseases. A clinical trial demonstrated a 12-times reduction in prevalence of peri-implants in patients who were able to effectively clean their implant restorations (4%) as compared with those who could not maintain good plaque control (48%).
Bone formation can result from mild occlusal overloading of 1500 to 3000 micro- strain. When the strain in bone exceeds 3000 microstrain, bone resorption occurs. However, most studies have not measured or defined the amount of occlusal overload on implant restorations. It is thought that bacterial plaque is the main causative factor of peri-implant bone loss. However, a recent case report demonstrated that occlusal overloading in the absence of peri-implant mucosal inflammation resulted in bone loss along the implant surface without affecting marginal bone levels. In addition, reos- seointegration occurred after removal of the heavy occlusal forces. Therefore, it might be possible to have peri-implant bone loss along the implant surface and not on the crestal region in the absence of mucosal inflammation. On the other hand, if there is peri-implant mucosal inflammation, marginal bone loss will ensue. More clinical trials are needed to investigate the effect of occlusal overloading on dental im- plants as current systematic reviews showed limited and conflicting results.
THERAPEUTIC OPTIONS AND THEIR CLINICAL OUTCOMES
Similar to the treatment of periodontal diseases, the management of periimplantitis can be categorized into nonsurgical and surgical interventions (Table 3). Frequently, the nonsurgical interventions, also known as antiinfective measures, are also used in combination with surgical interventions to eliminate biofilm on the implant and restore peri-implant tissue health. An ideal treatment outcome will include a shallow probing sulcular depth of less than 5 mm with no bleeding on probing and stable peri-implant bone and soft tissue levels. Alternative treatment outcomes that are re- ported in the literature include implant loss, persistent or recurrent periimplantitis, changes in bleeding on probing, and diminished peri-implant mucosal level and mar- ginal bone level. Various therapeutic options used in the management of peri- implant diseases are discussed next.
Nonsurgical Interventions
Antiinfective measures
Mechanical debridement Bacterial challenge within the peri-implant tissues is the main cause of peri-implant diseases. Therefore, the main aim of mechanical debride- ment is the restitution of peri-implant tissue health with the removal of peri-implant bio- film from the implant and/or abutment surface. This procedure can be achieved by using specific instruments that are softer than titanium to avoid damage to the implant and abutment surfaces, which would otherwise promote bacterial colonization. These instruments can be coated with titanium, carbon fiber, polytetrafluoroethylene, plastic, polyetheretherketone, or silicon. Ultrasonic tips or polishing cups coated with carbon fiber or plastic ultrasonic and/or air abrasive systems that use low abrasive amino acid glycine powder are also useful. In general, instruments that are softer than the implant fixture are recommended for mechanical debridement to minimize damage to the implant surface. However, as these instruments have often been found to be ineffective, the use of stainless steel curettes and an air-powder abrasive system are advocated for the debridement of rough implant surfaces, as any resultant implant surface modification will not increase the susceptibility of the surfaces to bacterial adhesion. The effectiveness of mechanical debridement in recent randomized clin- ical trials is summarized in Table 4.
Chemotherapeutics Chemotherapeutics can be used adjunctively to mechanical debridement. They can be categorized into antiseptics, which are germicides used on skin or living tissues to inhibit or destroy microorganisms, and antibiotics, which can inhibit or kill selective bacteria by affecting their metabolic processes. In both cases, the aim is to eliminate invasive pathogens and prevent recolonization of these pathogens in the peri-implant tissues so that long-term peri-implant health is sus- tained. The main types of antiseptics used are topically applied essential oils, triclosan, and chlorhexidine. Antibiotics can be delivered either locally or systemically. Locally delivered antibiotics are typically minocycline microspheres or doxycycline hyclate gel. Systemic antibiotics are typically from the penicillin, erythromycin, or tetracycline classes. Other agents that have been used in implant surface decontam- ination are saline, citric acid, and hydrogen peroxide. The effectiveness of these agents in recent randomized clinical trials is summarized in Table 5.
Lasers The use of lasers in dentistry has gained popularity in recent years. The commonly used lasers for the decontamination of the implant surface are Nd:YAG (2940 nm), erbium:yttrium-aluminium-garnet (Er:YAG) (2940 nm), diode (660 nm), and carbon dioxide (10600 nm) lasers. Both the Nd:YAG and Er:YAG lasers have high bactericidal potential on implant surfaces at low-energy density, but there may be some titanium surface alterations if the power settings for the Er:YAG laser are greater than 300 mJ/10 Hz. Thus, it is recommended to use 100 mJ/10 Hz for not more than 2 minutes to decontaminate the implant surface safely. It was reported that ablation of the titanium surface occurs easily regardless of the power settings for the Nd:YAG laser. In addition, the Nd:YAG, diode, and carbon dioxide lasers are less effective in removing calculus compared with the Er:YAG laser. A recent case report demonstrated that the Er:YAG laser could remove the bacterial-contaminated titanium oxide layer, thus promoting reosseointegration and healthy soft tissue adaptation around a failing implant. Consequently, the Er:YAG laser seems to be the laser of choice in the management of peri-implant disease.
The laser-assisted periimplantitis protocol is a variation of the laser-assisted new attachment protocol. In this technique, the Nd:YAG laser is used to remove inflamed peri-implant tissues and decontaminate the implant surface during mechanical debridement. However, this application is still in its infancy as no clinical trial has been reported.
Photodynamic therapy involves the use of a specific wavelength of light (630– 700 nm) to activate photosensitive dyes that are placed at the site of interest, for example, periodontal pockets. The activation of these dyes, such as toluidine blue O, causes the release of oxygen radicals that will decimate periodontal pathogens. The effectiveness of lasers and photodynamic therapy in recent randomized clinical trials is summarized in Table 6.
Summary Nonsurgical interventions, such as mechanical debridement with good oral hygiene practices, are effective in reducing bleeding on probing and mucosal inflam- mation in peri-implant mucositis. The use of a powered toothbrush and adjunctive use of chemotherapeutics or lasers required further validation. Also, as there is no one superior reagent or methodology, additional well-designed randomized clinical trials are needed to validate the effectiveness of various methodologies used in the surface decontamination of dental implants.
Surgical Interventions
Nonsurgical treatment of periimplantitis shows limited improvement in clinical param- eters with no particular treatment having superior performance than mechanical debridement alone. It is, thus, ineffective in arresting disease progression, achieving disease resolution, and preventing disease recurrence. Therefore, similar to the treatment of chronic periodontitis, surgical interventions are needed to gain access to the peri-implant defect in an attempt to debride the implant surface and promote reosseointegration or soft tissue reattachment.
Access flap
The objective of the access flap is to gain contact to the supracrestal but submucosal implant surface for debridement and decontamination (Fig. 4). Debridement can be achieved with the use of curettes, ultrasonic tips, and air abrasive systems. A recent multicentered clinical trial evaluated the effectiveness of an antiinfective protocol in the management of periimplantitis defects. The protocol involved elevation of full- thickness mucoperiosteal flaps at the implants with periimplantitis, debridement of the implant surface with titanium coated or carbon fiber curettes, and decontamina- tion using copious sterile saline irrigation and rubbing the implant surface with saline-soaked sterile gauze before replacing and suturing the flap. Patients were also given postoperative antimicrobial and antiseptic mouth rinses. The results of this trial demonstrated reduction in probing depths, bleeding on probing, and suppu- ration on probing from baseline to 1 year after surgery. Bone levels were stable, but there was significant facial mucosal recession of 1 mm. Therefore, the investigators concluded that periimplantitis could be successfully managed with this specific anti- infective protocol. The advantage of this protocol is that it is straightforward, safe, and economical and yet delivered sustainable clinical outcomes.
Resective and regenerative
Treatment of teeth with horizontal bone loss and deep probing depths involves an access flap or apically positioned flap with osseous bone recontouring to achieve a biologically compatible and maintainable periodontal architecture. Likewise for the management of periimplantitis defects with horizontal bone loss and deep probing depths, which are categorized as class II defects,11 an apically positioned flap with osseous recontouring is a treatment option. However, in order to facilitate optimal pla- que control around the exposed roughened implant surface, implantoplasty is recom- mended. Implantoplasty is a resective procedure that involves the smoothening of the roughened implant surface or threads with a high-speed diamond or tungsten carbide bur to create a polished implant surface that is not plaque retentive (Fig. 5). A 3-year clinical trial reported that implants treated with implantoplasty had a higher implant survival rate compared with those that were treated with an apically positioned flap only.
Regenerative surgical techniques have been proposed for the management of the intrabony component of peri-implant defects (Fig. 6). Its aim is to regenerate lost peri-implant bone and increase the chance of reosseointegration. Diverse antiinfective methods have been proposed, but no one superior method has been described. Likewise, different grafting materials and barrier membranes have been used. A recent clinical trial found that the additional use of a barrier membrane did not improve the clinical outcomes as both groups demonstrated similar bone fill and reductions in probing depth and bleeding on probing. This finding concurred with the reported re- sults from a review on surgical therapy for the management of periimplantitis. Also, the defect configuration may influence the regenerative potential of the site. Defects that were noncontained, such as class Ib, Ie, and II, tend to have lesser probing depth reduction and clinical attachment gain.
Recently, a combination treatment approach comprising implantoplasty (resective) and guided bone regeneration (regenerative) demonstrated favorable clinical out- comes in terms of probing depth reduction, resolution of inflammation, and defect fill. Therefore, this approach was suggested in the management of periimplan- titis defects with suprabony and intrabony components. Unfortunately there is paucity of current literature comparing the effectiveness of various surgical techniques and grafting materials to treat periimplantitis. In addition, a recent systematic review found that there was only partial bone regeneration in most studies; thus, it is uncertain if guided bone regeneration is superior to other nonsurgical or surgical methods for treating periimplantitis.
Summary Surgical interventions are more effective in the management of periimplan- titis compared with nonsurgical interventions. Periimplantitis defects can be managed conservatively with an access flap and an antiinfective protocol. Alter- natively, regenerative procedures are recommended for periimplantitis defects that have an intrabony component. Through a network meta-analysis, it was found that guided bone regeneration with nonresorbable membranes or resorbable membranes had 3.52 mm and 2.40 mm greater probing depth reduction compared with nonsur- gical therapy, respectively. Recent systematic reviews and meta-analyses showed a weighted mean probing depth reduction of 2.97 mm (2.04 mm [33.4%] for surgical resection and 3.16 mm [48.2%] for guided bone regeneration), clinical attachment level gain of 1.65 mm, bleeding on probing reduction of 45.8%, and a weighted mean radiographic bone fill of 2.1 to 2.17 mm for guided bone regeneration. It is important to realize that there are several limitations associated with the analyses, such as inclusion of case series and cohort studies, a limited number of high-quality studies available, and vast heterogeneity in the study designs and treatment modal- ities. Therefore, further validation of the various surgical techniques is necessary.
PROPOSED WORKFLOW
Based on the available evidence and consensus statement, the authors proposed the following workflow for the management of peri-implant diseases (Fig. 7) as a guide to clinicians. Similar to conventional periodontal therapy, the management of peri- implant diseases should start with the initial therapy, which involves the identification of disease and elimination or reduction of etiologic and contributing factors. This step is crucial in achieving predictable and stable long-term clinical outcomes. Therefore, in the management of peri-implant diseases, the first step is to determine the nature of the disease and identify, remove, or correct the causative and contributing factors, such as bacterial plaque, smoking, and undesirable prosthetic designs. Subsequently, patients should go through mechanical debridement with or without the adjunctive use of chemotherapeutics or lasers. Evaluation of disease resolution, that is, elimination or reduction in mucosal inflammation, probing depths, suppuration on probing and bleeding on probing, presence of clinical attachment gain, and/or mucosal recession and no bone loss, should be performed 2 to 4 weeks after therapy. At sites with periimplantitis, mechanical debridement alone is generally unable to eradicate the disease progression; further surgical interventions are commonly necessary. Clinicians can decide on the surgical intervention based on the degree of peri-implant bone loss. In advanced cases, whereby there is greater than 50% bone loss or if the implant is mobile, explantation and implant site development with guided bone regeneration for future implant placement is recommended. The rationale is to remove the existing inflammation early and prevent further bone loss, especially in the vertical dimension, so that future prosthetic rehabilitation is possible. At sites with early (<25% bone loss) or moderate (25%–50% bone loss), the defect configuration will aid in the selection of the surgical intervention. When there is horizontal peri-implant bone loss, an access flap or implantoplasty with an apically positioned flap can be performed to debride the exposed implant surfaces and promote soft tissue readhesion. Sites with an intrabony defect can be managed with guided bone regeneration to promote reosseointegration and soft tissue read- hesion. Combination defects that have both suprabony and intrabony components can be treated with implantoplasty on the supracrestal exposed implant surface and guided bone regeneration in the intrabony component. This combined approach will facilitate good plaque control and reosseointegration. Surgical interventions are accompanied by postoperative antiinfective approaches that may include antibiotics and/or antimicrobial mouth rinses. Patients are subsequently reviewed for disease resolution, which, in cases of periimplantitis, includes radiographic examination to ensure that there is no further peri-implant bone loss. Consequently, patients who have regained healthy peri-implant tissues will, thus, be enrolled into a strict peri- odontal maintenance program.
SUMMARY
Systematic reviews and meta-analyses concluded that
● Mechanical plaque control, either professionally or home care, should be the goal in the management of peri-implant mucositis and the prevention of the development of periimplantitis. Therefore, strict adherence to periodontal main- tenance is of paramount importance.
● The evidence to support the use of systemic or locally delivered antibiotics in the management of peri-implant diseases is inconclusive.
● The use of locally delivered antibiotics (minocycline or doxycycline hyclate), Er:YAG laser treatment, or submucosal air polishing with glycine powder together with mechanical debridement using curettes show greater reductions in probing depth and bleeding on probing compared with adjunctive submucosal chlorhexidine irrigation.
● The use of lasers for nonsurgical debridement in the management of periimplan- titis offered no additional benefits over conventional mechanical debridement with curettes.
● There is no single superior antiinfective method available.
● Surgical interventions achieved greater probing depth reduction and clinical attachment gain compared with nonsurgical interventions.
● Access flap surgery shows resolution in only 58% of the lesions.
● The combination of resective and regenerative surgical techniques seemed to have favorable treatment outcomes in the management of periimplantitis.
● Reosseointegration of a previously contaminated implant surface is possible but highly variable and unpredictable.
The question posed for the paper was as follows: Can periimplantitis be treated? Based on the available evidence, the authors have found that periimplantitis could be treated to a certain extent; but the treatment outcome is not always successful or predictable, as indicated by favorable short-term treatment outcomes and further progression or recurrence of the disease. A mean patient-based success rate of 69% was reported, with periodontal access flap surgery being the most frequently performed procedure (47%) compared with regenerative therapy (20%). Also, the success rate was significantly reduced in patients with severe peri- odontitis, severe marginal bone loss, poor oral hygiene, and low compliance. Therefore, it is best to prevent peri-mucositis, which is the precursor of periimplan- titis. This prevention can be achieved by eliminating bacterial plaque through metic- ulous oral hygiene practices and professional mechanical debridement. In addition, other contributing factors, such as unfavorable implant position, poor pa- tient selection, and presence of residual cement or probing depths, should be erad- icated. Patients who maintained excellent oral hygiene standards and are enrolled in a strict periodontal maintenance program exhibited stable peri-implant tissues over time.
Over the past few decades, dental implants have been found to have high predictabil- ity and survival rates because of improvements in knowledge and clinical expertise, together with technological advances in implant designs. They are thus integrated into the clinical management of fully or partially edentulous patients. However, having a high implant survival rate is not equivalent to long-term implant success, which is defined as having a functional and esthetic implant restoration with no pain, mobility, and suppuration and no more than 2 mm of radiographic peri-implant bone loss. Also, despite the high early survival rates, dental implants do have their fair share of long- term esthetic, biological, and mechanical complications. The incidence of esthetic complications might have reduced because of the recent introduction of zirconia, but the incidence of biological and mechanical complications remained high. There- fore, this paper aims to review the current evidence on the management of peri-implant diseases in an attempt to answer the following question: Can peri-implantitis be treated?
Definition
Peri-implant diseases, which are infectious inflammatory diseases of the peri-implant tissues, can be broadly categorized into peri-implant mucositis and periimplantitis. In sites with peri-implant mucositis, the inflammatory lesion is found to be limited to the peri-implant soft tissues with no evidence of progressive peri-implant bone loss beyond the initial physiologic bone remodeling that occurred following implant place- ment (Fig. 1). Sites with periimplantitis, on the other hand, exhibit progressive peri- implant bone loss following the initial physiologic bone remodeling that occurred after implant placement as the inflammatory lesion progresses in both the mucosa and bone (Fig. 2). As the discriminating feature is progressive bone loss beyond physio- logic bone remodeling, it is, thus, important to establish baseline peri-implant bone levels, which is recommended to best occur at the time of prosthesis installation. Changes in bone levels from the time of implant placement to prosthesis installation are considered the result of physiologic bone remodeling or early implant failure. Therefore, it is challenging to determine the baseline peri-implant bone levels for immediately loaded implants, as time is not allowed for physiologic bone remodeling.
Diagnosis
Based on the abovementioned definitions, peri-implant mucositis is diagnosed by the presence of bleeding on probing, which is a key clinical parameter that indicates gingival inflammation. In addition, the presence of suppuration and/or increase in probing pocket depth (eg, ≥4 mm) are also used to detect peri-implant mucositis. Periimplantitis often presents with similar clinical signs as peri-implant mucositis but with progressive bone loss as the main feature that distinguishes periimplantitis from peri-implant mucositis. Baseline and follow-up radiographs are needed to detect changes in peri-implant bone levels over time, however, these are only useful for assessing the interproximal regions. Changes in buccal or lingual bone levels can be determined by probing depths or recession of the peri-implant mucosa resulting in exposure of the implant threads. When the baseline peri-implant bone levels cannot be accurately determined, for example, in immediately loaded implants or when base- line radiographs are not taken, it is recommended to consider 2-mm vertical bone loss from the expected bone level as a threshold for the diagnosis of periimplantitis. In addition, marginal peri-implant bone loss of more than 0.44 mm per year has been suggested to be an indication of progressive bone loss. Clinical detection of mobility of the implant fixture signifies failure of the implant restoration, which is the end point of peri-implant diseases.
Classification
A newly proposed classification schema for periimplantitis has attempted to catego- rize periimplantitis into early, moderate, and advanced based on the percentage of bone loss, which is differentiated as less than 25%, 25% to 50%, and greater than 50% of the implant length (Fig. 3) and the probing depth of 4 mm or greater, 6 mm or greater, and 8 mm or greater with the presence of bleeding or suppuration on prob- ing, respectively. This classification hopes to provide a standardized method for cli- nicians and researchers to better share information relevant to the management of periimplantitis. Considering different defect configurations, several investigators have endeavored to categorize the pattern of peri-implant bone loss. In a human and dog comparative model, peri-implant bone defects were divided into well- defined intrabony defects (class Ia–e) and horizontal bone loss (class II). Circumferen- tial bone loss with buccal and lingual dehiscences was the most common defect configuration. Another classification system described the radiographic presenta- tion of peri-implant bone loss as 5 main types, namely, saucer-shaped, wedge- shaped, flat, undercut, and slitlike defects. It was found that the saucer-shaped defects were the most common. This finding is important because the defect config- uration may impact the chosen treatment approach.
Epidemiology
Epidemiologic studies on peri-implant diseases often report varying prevalence rates because of the distinct differences in the disease case definitions, sample size, sam- ple population, and follow-up periods. In particular, the different case definitions resulted only in an average agreement (52%) among examiners. Table 1 clearly demonstrates the wide variation in the prevalence of peri-implant mucositis and peri- implantitis from epidemiologic studies published from 2011 to 2015. In attempt to reduce the effects of confounders, the 11th European Workshop on Periodontology recently published a meta-analysis of the current epidemiology of peri-implant dis- eases. An estimated weighted mean prevalence of 43% (range: 19%–65%) for peri-implant mucositis was reported in a European, South American, and North Amer- ican sample population consisting of 4209 implants in 1196 patients. For periimplan- titis, it was 22% (range: 1%–47%) in a similar ethnic sample population of 8893 implants in 2131 patients. These values seemed to concur with those reported by the American Academy of Periodontology.
Goals of Treatment
The progression of peri-implant diseases is assumed to be similar to that of periodontal diseases, whereby healthy peri-implant mucosa under persistent inflammatory challenge can transform into peri-implant mucositis and eventually periimplantitis. Therefore, the primary goal of the management of peri-implant disease is clearly to eradicate the inflammatory lesions so that healthy and stable peri-implant tissues can be achieved in the long-term. The secondary goals are the elimination of poten- tial contributing factors to prevent recurrence of disease and the reestablishment of function and esthetics, so that long-term clinical success can be acheived.
CONTROL OF CONTRIBUTING FACTORS
Several contributing factors that were thought to facilitate the initiation and progres- sion of peri-implant disease have been identified, and they can be broadly categorized into patient- and implant-related factors (Table 2).
Patient-Related Factors
Smoking
Numerous studies have demonstrated that smoking is associated with increased implant failure rates and periimplantitis, with an odds ratio of 3.6 to 4.6. This finding may be attributed to the increased levels of inflammatory cytokines in the peri-implant crevicular fluids in smokers compared with nonsmokers, thus leading to an increased rate of peri-implant bone loss of 0.164 mm per year and compro- mised midfacial and interproximal soft tissue remodeling adversely affecting the long-term functional and esthetic stability of the implant restoration. Some recent studies showed that smoking did not exert a significant effect on the risk of periimplan- titis. A recent patient-based meta-analysis reported that smoking had no signifi- cant effect on the risk of periimplantitis (risk ratio of 1.7). However, an implant-based analysis showed that smoking significantly increased the risk of periimplantitis (risk ra- tio of 2.1). The conflicting results might be caused by heterogeneous case definitions for smoking and periimplantitis, small study sample sizes, and inferior patient compliance to regular periodontal maintenance. Future studies in this area are required.
Periodontal status
Longitudinal studies, systematic reviews, and meta-analyses have stressed that the history of treated periodontitis is a major risk factor in the develop- ment of periimplantitis leading to implant loss. Patients with compromised periodontal status were more susceptible to peri-implant diseases compared with periodontally healthy patients with an odds ratio of 3.1 to 4.7 and a risk ratio of 2.17. A recent systematic review reported that plaque accumulation around the implant restoration initiates the development of peri-implant mucositis, presaging periimplantitis Pa- tients with poor plaque control were associated with an increased risk of periimplan- titis (odds ratio of 14.1). Those with a full-mouth plaque score of less than 25% had only 5% of their implants with periimplantitis compared with 23% in patients with a full-mouth plaque score of 25% or greater. Patients with residual probing depths and noncompliance to a strict periodontal maintenance program are at risk of devel- oping peri-implant diseases, with a lower 10-year implant survival rate of 92.1% and approximately 3-times greater marginal peri-implant bone loss over time. In contrast, patients who adhered to a periodontal maintenance program had a 2.5-times lower risk of periimplantitis. Therefore, the value of good periodontal health before implant placement and after prosthetic installation is paramount to long-term implant success; this can be achieved by stringent periodontal maintenance.
Implant-Related Factors Implant position
In order to achieve a stable functional and esthetic restoration for the long-term, the dental implant has to be placed in a prosthetically driven position. This position will ensure that the restoration has an appropriate emergence profile and occlusal loading so that maintenance of healthy peri-implant tissues is feasible. In addition, implant placement is governed by rules so thatadjacent anatomic tissues are not violated. Mesiodistally, there shouldbe at least 1.5 mm of space between implant and adjacent teeth. This dimension may be increased to 3 mm in the posterior region in order to accommodate the emer- gence profile of the restoration. It is recommended that at least 3 mm of space be kept between 2 implants. These dimensions allow for proper bone remodeling and osseointe- gration with minimal risk of damage to adjacent teeth or implant. Buccolingually, the implant shoulder should be about 1.5 to 2.0 mm palatal to the buccal plate to compensate for buccal bone remodeling and to provide support for the overlying soft tissue. Implants that are buccally placed have a 3-times greater risk of esthetic complications, such as midfacial mucosal recession. In general, the implant platform should be placed 2 mm below the expected cementoenamel junction or the midfacial gingival margin. However, in the esthetic zone, it may be prudent to place the implant shoulder 0.5 to 1.0 mm subcrestal so that a proper emergence profile can be achieved. Recent litera- ture also found that subcrestal placement of the microgap and the presence of a plat- form switch aid in the preservation of the marginal bone level and, therefore, can be a useful feature in the anterior region where the implant can be placed slightly subcrestal. If the implant is placed too shallow, esthetic complications, such as poor contours of the restoration and visible metal margins, may ensue. Also, any physiologic bone and soft tissue remodeling may result in exposure of the implant threads to the oral environment, leading to increased plaque accumulation and subsequent peri-implant bone and soft tis- sue loss. If the implant is placed too deep, the peri-implant sulcular depth will increase, thus favoring the growth of anaerobic microbiota, which will facilitate peri-implant tissue breakdown.
Prosthetic considerations
Although peri-implant tissue response around screw-retained restorations seems to be more favorable compared with that around cement-retained restorations, a recent systematic review and meta-analysis found no difference in peri-implant mar- ginal bone loss around cement- and screw-retained implant restorations. Studies have shown that, in the presence of excess cement at the crown-abutment interface, peri- implant mucosal inflammation or bone loss occurs 80% to 85% of the time. The use of certain cement, for example, methacrylate-based cement, is associated with increased residual cement and consequently a higher prevalence for peri-implant dis- eases because they are less viscous and also more susceptible to bacterial in- vasion. In contrast, zinc oxide eugenol–containing cements are more viscous, thus, easier to remove and can inhibit biofilm growth at the crown-abutment interface. Customized abutments that bring the restorative margins coronally or screw- retained restorations may be considered if the restorative margins are located more subgingivally, as it is technically more challenging to remove excess cement around such restorations.
The ability to clean around the implant restoration plays a role in the development of peri-implant diseases. A poor emergence profile impedes proper plaque control and, thus, expedites the progression of peri-implant diseases. A clinical trial demonstrated a 12-times reduction in prevalence of peri-implants in patients who were able to effectively clean their implant restorations (4%) as compared with those who could not maintain good plaque control (48%).
Bone formation can result from mild occlusal overloading of 1500 to 3000 micro- strain. When the strain in bone exceeds 3000 microstrain, bone resorption occurs. However, most studies have not measured or defined the amount of occlusal overload on implant restorations. It is thought that bacterial plaque is the main causative factor of peri-implant bone loss. However, a recent case report demonstrated that occlusal overloading in the absence of peri-implant mucosal inflammation resulted in bone loss along the implant surface without affecting marginal bone levels. In addition, reos- seointegration occurred after removal of the heavy occlusal forces. Therefore, it might be possible to have peri-implant bone loss along the implant surface and not on the crestal region in the absence of mucosal inflammation. On the other hand, if there is peri-implant mucosal inflammation, marginal bone loss will ensue. More clinical trials are needed to investigate the effect of occlusal overloading on dental im- plants as current systematic reviews showed limited and conflicting results.
THERAPEUTIC OPTIONS AND THEIR CLINICAL OUTCOMES
Similar to the treatment of periodontal diseases, the management of periimplantitis can be categorized into nonsurgical and surgical interventions (Table 3). Frequently, the nonsurgical interventions, also known as antiinfective measures, are also used in combination with surgical interventions to eliminate biofilm on the implant and restore peri-implant tissue health. An ideal treatment outcome will include a shallow probing sulcular depth of less than 5 mm with no bleeding on probing and stable peri-implant bone and soft tissue levels. Alternative treatment outcomes that are re- ported in the literature include implant loss, persistent or recurrent periimplantitis, changes in bleeding on probing, and diminished peri-implant mucosal level and mar- ginal bone level. Various therapeutic options used in the management of peri- implant diseases are discussed next.
Nonsurgical Interventions
Antiinfective measures
Mechanical debridement Bacterial challenge within the peri-implant tissues is the main cause of peri-implant diseases. Therefore, the main aim of mechanical debride- ment is the restitution of peri-implant tissue health with the removal of peri-implant bio- film from the implant and/or abutment surface. This procedure can be achieved by using specific instruments that are softer than titanium to avoid damage to the implant and abutment surfaces, which would otherwise promote bacterial colonization. These instruments can be coated with titanium, carbon fiber, polytetrafluoroethylene, plastic, polyetheretherketone, or silicon. Ultrasonic tips or polishing cups coated with carbon fiber or plastic ultrasonic and/or air abrasive systems that use low abrasive amino acid glycine powder are also useful. In general, instruments that are softer than the implant fixture are recommended for mechanical debridement to minimize damage to the implant surface. However, as these instruments have often been found to be ineffective, the use of stainless steel curettes and an air-powder abrasive system are advocated for the debridement of rough implant surfaces, as any resultant implant surface modification will not increase the susceptibility of the surfaces to bacterial adhesion. The effectiveness of mechanical debridement in recent randomized clin- ical trials is summarized in Table 4.
Chemotherapeutics Chemotherapeutics can be used adjunctively to mechanical debridement. They can be categorized into antiseptics, which are germicides used on skin or living tissues to inhibit or destroy microorganisms, and antibiotics, which can inhibit or kill selective bacteria by affecting their metabolic processes. In both cases, the aim is to eliminate invasive pathogens and prevent recolonization of these pathogens in the peri-implant tissues so that long-term peri-implant health is sus- tained. The main types of antiseptics used are topically applied essential oils, triclosan, and chlorhexidine. Antibiotics can be delivered either locally or systemically. Locally delivered antibiotics are typically minocycline microspheres or doxycycline hyclate gel. Systemic antibiotics are typically from the penicillin, erythromycin, or tetracycline classes. Other agents that have been used in implant surface decontam- ination are saline, citric acid, and hydrogen peroxide. The effectiveness of these agents in recent randomized clinical trials is summarized in Table 5.
Lasers The use of lasers in dentistry has gained popularity in recent years. The commonly used lasers for the decontamination of the implant surface are Nd:YAG (2940 nm), erbium:yttrium-aluminium-garnet (Er:YAG) (2940 nm), diode (660 nm), and carbon dioxide (10600 nm) lasers. Both the Nd:YAG and Er:YAG lasers have high bactericidal potential on implant surfaces at low-energy density, but there may be some titanium surface alterations if the power settings for the Er:YAG laser are greater than 300 mJ/10 Hz. Thus, it is recommended to use 100 mJ/10 Hz for not more than 2 minutes to decontaminate the implant surface safely. It was reported that ablation of the titanium surface occurs easily regardless of the power settings for the Nd:YAG laser. In addition, the Nd:YAG, diode, and carbon dioxide lasers are less effective in removing calculus compared with the Er:YAG laser. A recent case report demonstrated that the Er:YAG laser could remove the bacterial-contaminated titanium oxide layer, thus promoting reosseointegration and healthy soft tissue adaptation around a failing implant. Consequently, the Er:YAG laser seems to be the laser of choice in the management of peri-implant disease.
The laser-assisted periimplantitis protocol is a variation of the laser-assisted new attachment protocol. In this technique, the Nd:YAG laser is used to remove inflamed peri-implant tissues and decontaminate the implant surface during mechanical debridement. However, this application is still in its infancy as no clinical trial has been reported.
Photodynamic therapy involves the use of a specific wavelength of light (630– 700 nm) to activate photosensitive dyes that are placed at the site of interest, for example, periodontal pockets. The activation of these dyes, such as toluidine blue O, causes the release of oxygen radicals that will decimate periodontal pathogens. The effectiveness of lasers and photodynamic therapy in recent randomized clinical trials is summarized in Table 6.
Summary Nonsurgical interventions, such as mechanical debridement with good oral hygiene practices, are effective in reducing bleeding on probing and mucosal inflam- mation in peri-implant mucositis. The use of a powered toothbrush and adjunctive use of chemotherapeutics or lasers required further validation. Also, as there is no one superior reagent or methodology, additional well-designed randomized clinical trials are needed to validate the effectiveness of various methodologies used in the surface decontamination of dental implants.
Surgical Interventions
Nonsurgical treatment of periimplantitis shows limited improvement in clinical param- eters with no particular treatment having superior performance than mechanical debridement alone. It is, thus, ineffective in arresting disease progression, achieving disease resolution, and preventing disease recurrence. Therefore, similar to the treatment of chronic periodontitis, surgical interventions are needed to gain access to the peri-implant defect in an attempt to debride the implant surface and promote reosseointegration or soft tissue reattachment.
Access flap
The objective of the access flap is to gain contact to the supracrestal but submucosal implant surface for debridement and decontamination (Fig. 4). Debridement can be achieved with the use of curettes, ultrasonic tips, and air abrasive systems. A recent multicentered clinical trial evaluated the effectiveness of an antiinfective protocol in the management of periimplantitis defects. The protocol involved elevation of full- thickness mucoperiosteal flaps at the implants with periimplantitis, debridement of the implant surface with titanium coated or carbon fiber curettes, and decontamina- tion using copious sterile saline irrigation and rubbing the implant surface with saline-soaked sterile gauze before replacing and suturing the flap. Patients were also given postoperative antimicrobial and antiseptic mouth rinses. The results of this trial demonstrated reduction in probing depths, bleeding on probing, and suppu- ration on probing from baseline to 1 year after surgery. Bone levels were stable, but there was significant facial mucosal recession of 1 mm. Therefore, the investigators concluded that periimplantitis could be successfully managed with this specific anti- infective protocol. The advantage of this protocol is that it is straightforward, safe, and economical and yet delivered sustainable clinical outcomes.
Resective and regenerative
Treatment of teeth with horizontal bone loss and deep probing depths involves an access flap or apically positioned flap with osseous bone recontouring to achieve a biologically compatible and maintainable periodontal architecture. Likewise for the management of periimplantitis defects with horizontal bone loss and deep probing depths, which are categorized as class II defects,11 an apically positioned flap with osseous recontouring is a treatment option. However, in order to facilitate optimal pla- que control around the exposed roughened implant surface, implantoplasty is recom- mended. Implantoplasty is a resective procedure that involves the smoothening of the roughened implant surface or threads with a high-speed diamond or tungsten carbide bur to create a polished implant surface that is not plaque retentive (Fig. 5). A 3-year clinical trial reported that implants treated with implantoplasty had a higher implant survival rate compared with those that were treated with an apically positioned flap only.
Regenerative surgical techniques have been proposed for the management of the intrabony component of peri-implant defects (Fig. 6). Its aim is to regenerate lost peri-implant bone and increase the chance of reosseointegration. Diverse antiinfective methods have been proposed, but no one superior method has been described. Likewise, different grafting materials and barrier membranes have been used. A recent clinical trial found that the additional use of a barrier membrane did not improve the clinical outcomes as both groups demonstrated similar bone fill and reductions in probing depth and bleeding on probing. This finding concurred with the reported re- sults from a review on surgical therapy for the management of periimplantitis. Also, the defect configuration may influence the regenerative potential of the site. Defects that were noncontained, such as class Ib, Ie, and II, tend to have lesser probing depth reduction and clinical attachment gain.
Recently, a combination treatment approach comprising implantoplasty (resective) and guided bone regeneration (regenerative) demonstrated favorable clinical out- comes in terms of probing depth reduction, resolution of inflammation, and defect fill. Therefore, this approach was suggested in the management of periimplan- titis defects with suprabony and intrabony components. Unfortunately there is paucity of current literature comparing the effectiveness of various surgical techniques and grafting materials to treat periimplantitis. In addition, a recent systematic review found that there was only partial bone regeneration in most studies; thus, it is uncertain if guided bone regeneration is superior to other nonsurgical or surgical methods for treating periimplantitis.
Summary Surgical interventions are more effective in the management of periimplan- titis compared with nonsurgical interventions. Periimplantitis defects can be managed conservatively with an access flap and an antiinfective protocol. Alter- natively, regenerative procedures are recommended for periimplantitis defects that have an intrabony component. Through a network meta-analysis, it was found that guided bone regeneration with nonresorbable membranes or resorbable membranes had 3.52 mm and 2.40 mm greater probing depth reduction compared with nonsur- gical therapy, respectively. Recent systematic reviews and meta-analyses showed a weighted mean probing depth reduction of 2.97 mm (2.04 mm [33.4%] for surgical resection and 3.16 mm [48.2%] for guided bone regeneration), clinical attachment level gain of 1.65 mm, bleeding on probing reduction of 45.8%, and a weighted mean radiographic bone fill of 2.1 to 2.17 mm for guided bone regeneration. It is important to realize that there are several limitations associated with the analyses, such as inclusion of case series and cohort studies, a limited number of high-quality studies available, and vast heterogeneity in the study designs and treatment modal- ities. Therefore, further validation of the various surgical techniques is necessary.
PROPOSED WORKFLOW
Based on the available evidence and consensus statement, the authors proposed the following workflow for the management of peri-implant diseases (Fig. 7) as a guide to clinicians. Similar to conventional periodontal therapy, the management of peri- implant diseases should start with the initial therapy, which involves the identification of disease and elimination or reduction of etiologic and contributing factors. This step is crucial in achieving predictable and stable long-term clinical outcomes. Therefore, in the management of peri-implant diseases, the first step is to determine the nature of the disease and identify, remove, or correct the causative and contributing factors, such as bacterial plaque, smoking, and undesirable prosthetic designs. Subsequently, patients should go through mechanical debridement with or without the adjunctive use of chemotherapeutics or lasers. Evaluation of disease resolution, that is, elimination or reduction in mucosal inflammation, probing depths, suppuration on probing and bleeding on probing, presence of clinical attachment gain, and/or mucosal recession and no bone loss, should be performed 2 to 4 weeks after therapy. At sites with periimplantitis, mechanical debridement alone is generally unable to eradicate the disease progression; further surgical interventions are commonly necessary. Clinicians can decide on the surgical intervention based on the degree of peri-implant bone loss. In advanced cases, whereby there is greater than 50% bone loss or if the implant is mobile, explantation and implant site development with guided bone regeneration for future implant placement is recommended. The rationale is to remove the existing inflammation early and prevent further bone loss, especially in the vertical dimension, so that future prosthetic rehabilitation is possible. At sites with early (<25% bone loss) or moderate (25%–50% bone loss), the defect configuration will aid in the selection of the surgical intervention. When there is horizontal peri-implant bone loss, an access flap or implantoplasty with an apically positioned flap can be performed to debride the exposed implant surfaces and promote soft tissue readhesion. Sites with an intrabony defect can be managed with guided bone regeneration to promote reosseointegration and soft tissue read- hesion. Combination defects that have both suprabony and intrabony components can be treated with implantoplasty on the supracrestal exposed implant surface and guided bone regeneration in the intrabony component. This combined approach will facilitate good plaque control and reosseointegration. Surgical interventions are accompanied by postoperative antiinfective approaches that may include antibiotics and/or antimicrobial mouth rinses. Patients are subsequently reviewed for disease resolution, which, in cases of periimplantitis, includes radiographic examination to ensure that there is no further peri-implant bone loss. Consequently, patients who have regained healthy peri-implant tissues will, thus, be enrolled into a strict peri- odontal maintenance program.
SUMMARY
Systematic reviews and meta-analyses concluded that
● Mechanical plaque control, either professionally or home care, should be the goal in the management of peri-implant mucositis and the prevention of the development of periimplantitis. Therefore, strict adherence to periodontal main- tenance is of paramount importance.
● The evidence to support the use of systemic or locally delivered antibiotics in the management of peri-implant diseases is inconclusive.
● The use of locally delivered antibiotics (minocycline or doxycycline hyclate), Er:YAG laser treatment, or submucosal air polishing with glycine powder together with mechanical debridement using curettes show greater reductions in probing depth and bleeding on probing compared with adjunctive submucosal chlorhexidine irrigation.
● The use of lasers for nonsurgical debridement in the management of periimplan- titis offered no additional benefits over conventional mechanical debridement with curettes.
● There is no single superior antiinfective method available.
● Surgical interventions achieved greater probing depth reduction and clinical attachment gain compared with nonsurgical interventions.
● Access flap surgery shows resolution in only 58% of the lesions.
● The combination of resective and regenerative surgical techniques seemed to have favorable treatment outcomes in the management of periimplantitis.
● Reosseointegration of a previously contaminated implant surface is possible but highly variable and unpredictable.
The question posed for the paper was as follows: Can periimplantitis be treated? Based on the available evidence, the authors have found that periimplantitis could be treated to a certain extent; but the treatment outcome is not always successful or predictable, as indicated by favorable short-term treatment outcomes and further progression or recurrence of the disease. A mean patient-based success rate of 69% was reported, with periodontal access flap surgery being the most frequently performed procedure (47%) compared with regenerative therapy (20%). Also, the success rate was significantly reduced in patients with severe peri- odontitis, severe marginal bone loss, poor oral hygiene, and low compliance. Therefore, it is best to prevent peri-mucositis, which is the precursor of periimplan- titis. This prevention can be achieved by eliminating bacterial plaque through metic- ulous oral hygiene practices and professional mechanical debridement. In addition, other contributing factors, such as unfavorable implant position, poor pa- tient selection, and presence of residual cement or probing depths, should be erad- icated. Patients who maintained excellent oral hygiene standards and are enrolled in a strict periodontal maintenance program exhibited stable peri-implant tissues over time.
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