Clinical Senior Lecturer/Consultant in Restorative Dentistry, Newcastle School of Dental Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4BW, UK
Unfortunately, peri-implant disease is a common clinical finding in patients with dental implants. Whilst preventive and supportive regimens are best practice, many patients still present with signs of peri-implant disease. Treatment options include non-surgical or surgical approaches but there does not appear to be a consensus for management of these challenging conditions. This paper discusses the current management options of peri-implant mucositis and peri-implantitis.
CPD/Clinical Relevance: This paper discusses the management of peri-implant diseases placing emphasis on regular supportive care and follow up.
Article
Peri-implant diseases are recognized as being polymicrobial, biofilm-associated inflammatory lesions.1 Peri-implant mucositis is inflammation of peri-implant tissues without associated bone loss, whereas in peri-implantitis there is also loss of supporting clinical attachment and bone. The prevalence of peri-implantitis is reported to affect 10% of implants and 20% of patients over a minimum of 5 years,2 but might range from 6.6%−36.6% of implants and 11.2%−47.1% of patients.3 The prevalence of peri-implant mucositis is higher than that of peri-implantitis, occurring in about 50% of implants and just under 80% of patients.4 Despite this, there does not appear to be any consensus in the treatment approaches for peri-implant diseases.5 This article discusses management options for peri-implant diseases.
Supportive therapy
Following placement and restoration of any implant-supported prosthesis, patients should be enrolled on a supportive maintenance programme of regular reviews. The aim of this programme is to prevent and allow early detection and management of inflammatory lesions occurring in the peri-implant tissues.5,6
Peri-implant mucositis has been a common finding in patients not adhering to regular supportive care6,7,8 in comparison to those attending,9 and regular supportive care appears to be essential in identifying destructive peri-implant disease at an early stage, when treatment is potentially easier and outcomes more predictable.10 Over 5 years, the incidence of peri-implantitis has been shown to be lower in subjects who are enrolled on a regular maintenance programme (18%) compared to those patients without regular maintenance care (43.9%).3,7,11
Signs and symptoms of peri-implant inflammation/disease should be recorded as well as plaque scores, pocket depths, bleeding indices, mobility, presence or absence of suppuration and assessment of crestal bone levels through radiographs, when appropriate. Risk assessment of factors, including poor plaque control, history or activity of periodontal or previous peri-implant disease, uncontrolled diabetes, and smoking status should be recorded and recommendations given. This patient contact, furthermore, provides the opportunity for professional prophylaxis through the removal of plaque and calculus by supra and submucosal instrumentation.
There continues to be no consensus on the frequency of recall visits for patients who have implants; typically patients will be placed on recall intervals of 3, 6 or 12 months subject to their perceived risk of developing peri-implant disease by their dentist. It has also been suggested that the more complex the implant prosthesis, the greater the risk from systemic, personal or genetic factors, and therefore the more frequent the recall rate should be.9,12
Peri-implant mucositis
Peri-implant mucositis describes inflammation in the peri-implant tissues without loss of supporting alveolar bone and it is a precursor of peri-implantitis.10 Management of peri-implant mucositis therefore should be considered as a preventive measure for the onset of peri-implantitis. Interventions are concentrated on improving daily oral hygiene practices, adapting instructions for each patient to their individual needs, modifying or removing any local factors, such as excess cement,13 adjusting bulky prostheses or submucosal margins, which prevent access for hygiene, and supporting the patient to address risk factors where possible.14
Mechanical decontamination consists of the physical removal of hard- and soft-tissue deposits on the contaminated exposed implant surface. Mechanical debridement around dental implants encounters some specific characteristics different from the natural gingival sulcus: the absence of periodontal ligament; a rough/smooth metallic implant surface; and different designs of abutment connection.
Pumice slurry and polishing cups have been used for supramucosal plaque removal. Calculus, however, can be more difficult to remove and titanium scalers or ultrasonic devices have been generally advised.15 Curettes made of metal that is harder than titanium increase the likelihood of damage, leaving deep scratches in the implant in which bacteria can stagnate. Therefore, instruments, for example curettes, made of materials softer than titanium, including gold-plated, carbon-fibre, teflon or plastic have been used.3 These instruments are not themselves without problems, tending to be less efficient in removing submucosal deposits and having a higher risk of breakage. Plastic curettes in particular are fragile and risk leaving small fragments of blades in the peri-implant sulcus. Similarly, soft polyether-etherketone tips have been advised for ultrasonic scalers, but again their effectiveness is considered to be reduced in comparison to standard tips used on natural teeth.3
Adjuncts to mechanical debridement, such as local or systemic antibiotics15,16,17,18 or antimicrobials such as chlorhexidine, have not demonstrated any significant impact on treatment outcomes.10,19,20,21,22 Alternative methods of physical biofilm disruption and removal, such as air-abrasive devices, other ultrasonic devices, and lasers, have been used to enhance cleaning efficacy but there is little or no evidence for them enhancing standard protocols of care in the longer term.17,22,23,24,25,26
Peri-implantitis: non-surgical management
Similar to the management of periodontal diseases, non-surgical therapy might be performed as part of the initial phase therapy. This stage has been shown to aid the reduction of peri-implant inflammation and allows the clinician to evaluate the healing response of the tissues and the patient's ability to perform effective oral hygiene measures.27 However, non-surgical treatment has been reported to have only a modest efficacy in the management of peri-implantitis lesions.28,29,30 It is thought that the geometry of the implant threads and surface roughness may complicate decontamination of the implant below the mucosal margin. Moreover, the gram-negative anaerobic microbiota associated with peri-implantitis, similar to that found in the advanced stages of periodontitis, might also be less responsive to non-surgical therapy alone.31,32
Peri-implantitis: surgical management
Surgical techniques may offer more predictable outcomes compared to non-surgical management,33 having demonstrated successful outcomes after 5 years.34,35 A surgical approach might improve access for implant surface decontamination, enables pocket elimination through resective procedures, and provides opportunity for regeneration.36 These procedures will be discussed further below.
Flap procedures
Access flap
Access flap surgery is a surgical approach to decontaminate the implant surface while maintaining the soft tissues around the affected implant. The aim is to maintain the soft tissue height around the implant, and it is recommended when bone loss is minimal, or in aesthetic regions when minimal soft tissue removal is necessary. This technique aims to maintain the pre-operative position of the soft-tissue margin around the implant neck. This can only be used when the peri-implant bone loss is shallow.37
The procedure uses an inverse bevel incision that facilitates flap elevation and preserves soft tissue. Following removal of the soft-tissue collar from the infected tissue around the implant, mechanical decontamination, to remove plaque and mineralized deposits from the implant surface, is performed. The granulation tissue is then curetted, usually with titanium curettes, to expose the remaining bony architecture.
Apically repositioned flap
Apically repositioned flaps have been suggested to be used in regions that are not of high aesthetic priority, when peri-implant defects are predominantly suprabony, with an aim to enhance self-managed oral hygiene and reduce the pockets around the affected implants.20,37,38 An inverse bevelled incision with vertical relief is undertaken prior to raising mucoperiostal flaps, both buccally and palatally/lingually. Thorough implant decontamination is performed and ostectomy and osteoplasty is often required before finally closing and suturing the flaps in an apical position, leaving the previously affected surface of the implant exposed to the oral cavity. Removal of the exposed implant threads has been performed, being described as an implantoplasty procedure. This has been undertaken with burs and stones under copious irrigation, to leave a smooth implant surface which, it is hoped, is less plaque retentive.19
Implant surface decontamination
Following surgical access and mechanical debridement, implant surface decontamination should be performed. The aim of surface decontamination is to remove the biofilm to create a surface suitable for re-osseointegration. Several agents including saline, citric acid, hydrogen perioxide, abrasive pumice, chlorhexidine, air-powder abrasive, lasers and antimicrobials might be used to enhance decontamination. Whilst application of these agents are thought to have a beneficial impact upon re-osseointegration, no single method has been shown to be superior.22,37,39,40,41,42
Regeneration procedures
Regenerative surgical approaches aim to modify tissue responses and dimensions during the healing process and avoid recession of the mucosa interfacing the implant and abutment surface. The success of these procedures are heavily dependent upon the complete mechanical and chemical decontamination of the implant surface as a prerequisite for success.19,43 The decision for whether a regeneration procedure is advisable appears to depend upon the nature of the defect, which may be intrabony or suprabony. Intrabony defects are categorized by the configuration of the bony walls.28,44 The most common configuration around implants has been shown to be circumferential bone loss and occurs with maintenance of the buccal and lingual crestal bone plates. These closed, well contained, ‘doughnut-shaped’ defects are thought to have greatest potential for successful regeneration of tissues compared to open defects where the lingual or buccal plate has been lost.28,38,44,45
Intracrevicular incisions are made to maintain the greatest amount of peri-implant soft tissues. Following flap access, removal of granulation tissue and decontamination of the implant surface is completed. Following this, a graft is placed around the implant into the intrabony component of the defect. Grafts may be either autologous, xenograft bone or bone substitute. The graft area might be covered with a resorbable or a non-resorbable membrane before repositioning and suturing the flaps.46 Furthermore, the use of a connective tissue graft with a bone graft has been thought to be advantageous aesthetically, in an effort to gain more keratinized mucosa and improve mucosal thickness.47
Tension-free primary wound closure is thought to be important for regeneration procedures and, in some cases, it is thought to be ideal if the implant suprastructures are deconstructed, to allow the implant and regenerative sites to remain submerged and to heal undisturbed.28 However, this is not always seen to be essential, especially in cases where deconstruction of the suprastructure would require its destruction, for example a cemented restoration that has to be cut away.27
Antibiotics and surgery
Professional mechanical interventions have been shown to result in significant reductions in peri-implant tissue inflammation and bleeding on probing scores, independently of any additional use of antimicrobials.37,48 There does not appear to be strong evidence that the effects of systemic antibiotics are sustained in the longer term,16,20,49,50,51 and antimicrobial resistance has been demonstrated in peri-implant biofilms, suggesting that antimicrobials should be used cautiously.52,53
Success
The measurement of successful outcome after management of peri-implant disease has focused on the absence of bleeding/suppuration on probing during the follow-up period after treatment and this has been shown to have a high predictive value for a reduction of further bone loss.20 Despite receiving regular supportive care, some patients may require retreatment, adjunctive therapies and/or implant removal due to disease progression or recurrence.1 At present, it remains challenging to understand and predict fully the cases that will not respond to currently accepted therapies.
Treatment protocols
Contemporary approaches to managing peri-implant disease involve a sequence of procedures and have been described as a ‘treatment ladder’ approach. The approach adopted depends on the severity and extent of the lesion to be managed.54,55 As management progresses, if not initially successful, the treatment options become increasing complex. The ladder begins at modification of plaque control and biofilm management by the patient, through non-surgical mechanical therapy, to surgical therapy with or without the use of adjunctive therapies, including antimicrobials as the severity of disease increases. As the case progresses up the ladder, there appears to be an associated reduction in prognosis.12 It should be noted, however, that there is limited evidence to recommend any particular comprehensive protocol. The concept of a staged treatment protocol, however, appears sensible, where management is an accumulation of approaches leading to a tailored regimen.38
Summary
Peri-implant diseases are common, pathological inflammatory conditions occurring in tissues around dental implants. At the outset, risk factors, such as plaque control, smoking and periodontitis, need to be addressed in patients considering implant treatments. Non-surgical approaches with thorough mechanical debridement appear to be effective for peri-implant mucositis, but outcomes are more guarded in the management of peri-implantitis. Surgical therapy with resective or regenerative procedures are a further treatment option, primarily for peri-implantitis, and the approach taken appears to be dependent on the implant site and nature of the defect. Adjuvant treatments may give benefits in the short term but the evidence base for long-term outcomes is lacking. A graded treatment protocol approach to managing peri-implant disease is recommended but, above all, patient engagement with a supportive care programme, including regular monitoring and early detection of peri-implant disease, appears to be central for long-term success.