Peri-implantitis: from diagnosis to therapeutics

Peri‐implantitis is an infection of the tissue around an implant, resulting in the loss of supporting bone. Risk factors for peri‐implantitis consist of a history of periodontitis, dental plaque, poor oral hygiene, smoking, alcohol consumption and diabetes. A clinical diagnosis indicates inflammatory signs including bleeding on probing with or without suppuration and a peri‐implant pocket depth ≥5 mm. A radiograph shows images of marginal bone loss ≥2 mm. A differential diagnosis of peri‐implant mucositis, occlusal overload, retrograde peri‐implantitis and inflammatory implant periapical lesions suggests the appropriate treatment in each case. The non‐surgical treatment of peri‐implantitis, including a mechanical treatment alone or combined with antiseptics or antibiotics can improve clinical parameters in the short term but residual defects may still persist. Surgical treatment such as guided bone regeneration results in a gain of clinical attachment level and bone reconstruction in the long term. The limited effect of laser‐assisted therapy needs to be further evaluated. The concept of prevention based on early detection and regular maintenance plays a principal role in reducing the occurrence of peri‐implantitis.     

Management of peri‐implant mucositis and peri‐implantitis

Peri‐implant diseases are defined as inflammatory lesions of the surrounding peri‐implant tissues and include peri‐implant mucositis (an inflammatory lesion limited to the surrounding mucosa of an implant) and peri‐implantitis (an inflammatory lesion of the mucosa that affects the supporting bone with resulting loss of osseointegration). This review aims to describe the different approaches to manage both entities and to provide a critical evaluation of the evidence available on their efficacy. Therapy of peri‐implant mucositis and nonsurgical therapy of peri‐implantitis usually involve mechanical debridement of the implant surface using curettes, ultrasonic devices, air‐abrasive devices or lasers, with or without the adjunctive use of local antibiotics or antiseptics. The efficacy of these therapies has been demonstrated for mucositis: controlled clinical trials show an improvement in clinical parameters, especially in bleeding on probing. For peri‐implantitis, the results are limited, especially in terms of probing pocket‐depth reduction. Surgical therapy of peri‐implantitis is indicated when nonsurgical therapy fails to control the inflammatory changes. Selection of the surgical technique should be based on the characteristics of the peri‐implant lesion. In the presence of deep circumferential and intrabony defects, surgical interventions should aim to provide thorough debridement, implant‐surface decontamination and defect reconstruction. In the presence of defects without clear bony walls or with a predominant suprabony component, the aim of the surgical intervention should be the thorough debridement and the repositioning of the marginal mucosa to enable the patient to perform effective oral‐hygiene practices, although this aim may compromise the esthetic result of the implant‐supported restoration.     

Outcome of surgical treatment of peri-implantitis: results from a 2-year prospective clinical study in humans

Aim: The aim of the present study was to evaluate the outcome of a surgical procedure based on pocket elimination and bone re‐contouring for the treatment of peri‐implantitis. Material and methods: The 31 subjects involved in this study presented clinical signs of peri‐implantitis at one or more dental implants (i.e. ≥6 mm pockets, bleeding on probing and/or suppuration and radiographic evidence of ≥2 mm bone loss). The patients were treated with a surgical procedure based on pocket elimination and bone re‐contouring and plaque control before and following the surgery. At the time of surgery, the amount of bone loss at implants was recorded. Results: Two years following treatment, 15 (48%) subjects had no signs of peri‐implant disease; 24 patients (77%) had no implants with a probing pocket depth of ≥6 mm associated with bleeding and/or suppuration following probing. A total of 36 implants (42%) out of the 86 with initial diagnosis of peri‐implantitis presented peri‐implant disease despite treatment. The proportion of implants that became healthy following treatment was higher for those with minor initial bone loss (2–4 mm bone loss as assessed during surgery) compared with the implants with a bone loss of ≥5 mm (74% vs. 40%). Among the 18 implants with bone loss of ≥7 mm, seven were extracted. Between the 6‐month and the 2‐year examination, healthy implants following treatment tended to remain stable, while deepening of pockets was observed for those implants with residual pockets. Conclusion: The results of this study indicated that a surgical procedure based on pocket elimination and bone re‐contouring and plaque control before and following surgery was an effective therapy for treatment of peri‐implantitis for the majority of subjects and implants. However, complete disease resolution at the site level seems to depend on the initial bone loss at implants. Implants with no signs of peri‐implantitis following treatment tended to remain healthy during the 2‐year period, while a tendency for disease progression was observed for the implants that still showed signs of peri‐implant disease following treatment. To cite this article:
Serino G, Turri A. Outcome of surgical treatment of peri‐implantitis: results from a 2‐year prospective clinical study in humans.
Clin. Oral Impl. Res. 22 , 2011; 1214–1220.
doi: 10.1111/j.1600‐0501.2010.02098.x     

Surgical treatment of peri‐implantitis: Prognostic indicators of short‐term results

Aim

To evaluate the clinical and radiographic short‐term (6 months) effect of surgical treatment of peri‐implantitis, and to identify prognostic indicators affecting the outcome using a multilevel statistical model.

Materials & Methods

A total of 143 implants (45 patients) with a diagnosis of progressive peri‐implantitis (progressive bone loss (PBL) ≥2.0 mm and bleeding on probing (BoP)/suppuration) received surgical treatment. Clinical and radiographic parameters were assessed 6 months postoperatively. Potential prognostic indicators on subject, implant and site level prior to surgery were analysed to evaluate the effect on individual and composite outcomes using multilevel logistic regression analysis.

Results

At the 6‐month evaluation, none of the implants demonstrated PBL and 14% of the implants were registered with the absence of bleeding and no pocket probing depth ≥6 mm. Multilevel regression analysis identified, among others, suppuration, pocket probing depth >8 mm, bone loss >7 mm and the presence of plaque as criteria associated with the outcome.

Conclusion

Resective peri‐implantitis surgery seemed to reduce the amount of peri‐implant inflammation. However, most of the sites continued to have BoP/suppuration. Thus, long‐term maintenance and evaluation is warranted. The effect of treatment was reduced by some prognostic indicators such as the presence of suppuration prior to interception and peri‐implant bone loss exceeding 7 mm.     

Diagnostic accuracy of clinical parameters to monitor peri‐implant conditions: A matched case‐control study

1 Background

The aim of this case‐control study was to estimate the diagnostic accuracy of the standard clinical parameters in diagnosing healthy peri‐implant tissues, peri‐implant mucositis, and peri‐implantitis.

2 Methods

A case‐control study was designed to compare the clinical parameters used in the diagnosis of peri‐implant diseases such as: probingdepth (PD), bleeding on probing (BOP), mucosal redness (MR), suppuration (SUP), and plaque index (PI). Furthermore, the influence of patient‐ (sex, age) and implant‐related variables (implant neck configuration, time in function after loading) were evaluated to investigate the association with the clinical findings. The inferential analysis consisted of estimation by generalized estimating equations (GEE) of multilevel logistic regression models.

3 Results

In total, 1,572 sites were evaluated around 262 implants from 141 patients. Sites with implant mucositis showed significant levels of BOP (OR = 3.56), MR (OR = 7.66) and PD (OR = 1.48) compared to healthy sites. The specificity was 90.3% while the sensitivity was only 43.6%. Likewise, sites exhibiting peri‐implantitis showed significant levels of BOP (OR = 2.32), MR (OR = 7.21), PD (OR = 2.43) and SUP (OR = 6.81) compared to healthy sites. Again, the multiple logistic regressions showed high specificity (92.1%) but modest sensitivity (52.5%). PD was the only diagnostic marker displaying significance comparing peri‐implant mucositis and peri‐implantitis sites (OR = 1.76). Moreover, tissue‐level compared to bone‐level implants were less associated with SUP+ (OR = 0.20), and PI (OR = 0.36) and demonstrated statistical significance. In addition, age, sex, and function time significantly influenced the tested clinical parameters.

4 Conclusions

The diagnosis of peri‐implant diseases cannot rely solely upon individual clinical parameters but rather require a combination of criteria. The clinical parameters, particularly probing depth, might accurately discern between diagnoses among peri‐implant conditions. Nevertheless, the specificity of the clinical parameters surpasses the sensitivity in the detection of peri‐implant diseases, validating its potential use as a diagnostic tool.     

Randomized clinical trial of the effects of azithromycin use in the treatment of peri‐implantitis

Background

The aim of this clinical trial was to establish a proof of concept that the adjunctive use of systemic azithromycin (AZM) in conjunction with mechanical debridement has an increased benefit in reducing soft tissue inflammation in the treatment of peri‐implantitis.

Methods

In a randomized, double‐blind, clinical trial, the treatment group (nine patients) received AZM as well as mechanical debridement in a single course of treatment, whereas the control group (eight patients) received a placebo and mechanical debridement. The primary outcome variables studied were bleeding on probing, suppuration, pocket probing depth and gingival recession. The secondary variables studied were gingival index, plaque index, microbiological and interleukin‐1β status. The observation period was 6 months.

Results

Over the 6 months’ observation period, the treatment patients showed a consistently greater reduction of gingival inflammation and an improvement in soft tissue healing than the control patients.

Conclusions

The adjunctive use of a single course of systemic azithromycin can assist in the control of peri‐implant mucositis in the treatment of peri‐implantitis.     

The evaluation of peri‐implant sulcus fluid osteocalcin,osteopontin, and osteonectin levels in peri‐implant diseases

1 Background

Peri‐implant mucositis is an inflammation of the soft tissues surrounding an implant. Peri‐implantitis refers to a process characterized by peri‐implant bone loss along with an inflammation of the soft tissues. Osteocalcin, osteopontin, and osteonectin proteins are related to bone remodeling. The aim of the present study was to investigate peri‐implant sulcus fluid (PISF) osteocalcin, osteopontin, and osteonectin levels in peri‐implant mucositis and peri‐implantitis.

2 Methods

Fifty‐two implants with peri‐implantitis, 46 implants with peri‐implant mucositis, and 47 control implants were included in the study. Clinical parameters including probing depth, modified sulcus bleeding index and modified plaque index were recorded. PISF osteocalcin, osteopontin, and osteonectin levels were analyzed by ELISA kits.

3 Results

There were no significant differences in PISF osteocalcin, osteopontin, and osteonectin total amounts between healthy controls, peri‐implant mucositis and peri‐implantitis groups (P > 0.05). Probing depths were not correlated with PISF osteocalcin, osteopontin, and osteonectin levels in the study groups (P > 0.05).

4 Conclusions

Soft tissue inflammation around dental implants does not cause a change in osteocalcin, osteopontin, and osteonectin levels in PISF. Also, peri‐implantitis does not seem to give rise to an increase in PISF levels of osteocalcin, osteopontin, and osteonectin.     

Possible impact of inflammatory status on C‐telopeptide pyridinoline cross‐links of Type I collagen and osteocalcin levels around oral implants with peri‐implantitis: a controlled clinical trial

Summary Detection of progression level of peri‐implantitis may help in the prevention of oral implant failure. C‐telopeptide pyridinoline crosslinks of Type I collagen (ICTP) and osteocalcin (OC) are specific markers of bone turnover and bone degradation. Determination of the ICTP and OC levels in the peri‐implant sulcus fluid (PISF) may predict the metabolic and/or inflammatory changes in the peri‐implant bone. The aim of this clinical study was to evaluate ICTP and OC levels in the PISF for oral implants with and without peri‐implant bone destruction and correlate these levels with the traditional clinical peri‐implant parameters (probing depth, plaque index, gingival index and gingival bleeding time index) and radiographic bone level measurements. Fifteen patients with 30 peri‐implant sites with bone destruction (radiographic bone loss) and health were included. Clinical parameters were measured and PISF was collected from the sites. Peri‐implant sulcus fluid ICTP and OC levels were detected by radioimmunoassay technique from PISF samples. All clinical parameters demonstrated a significant increase in peri‐implantitis sites compared with healthy sites. The PISF volume of the peri‐implantitis sites was also significantly higher than of the healthy peri‐implant sites. Although not statistically significant, a trend of increase was demonstrated in ICTP PISF samples sampled from peri‐implantitis sites compared with healthy sites. A significant increase was noticed for OC PISF level in peri‐implantitis sites compared with healthy ones. As well as peri‐implant clinical measurements, volumetric changes at PISF may be counted as an important clinical parameter to distinguish the bone destruction sites from healthy sites around oral implants.     

Clinical evaluation of an implant maintenance protocol for the prevention of peri-implant diseases in patients treated with immediately loaded full-arch rehabilitations

To cite this article:
Int J Dent Hygiene 9 , 2011; 216–222
DOI: 10.1111/j.1601‐5037.2010.00489.x
Corbella S, Del Fabbro M, Taschieri S, De Siena F, Francetti L. Clinical evaluation of an implant maintenance protocol for the prevention of peri‐implant diseases in patients treated with immediately loaded full‐arch rehabilitations. Abstract: Objective: The aim of this prospective study was to assess the outcomes of an implant maintenance protocol for implants supporting a full‐arch rehabilitation. Materials and methods: Sixty‐one patients (28 women and 33 men) treated with immediately loaded full‐arch rehabilitation, both mandibular and maxillary, supported by a combination of two tilted and two axial implants, were included in the study. Patients were scheduled for follow‐up visits every 6 months for +2 years, then yearly up to 4 years. Each patient received professional oral hygiene treatment and detailed oral hygiene instructions. During each visit, modified plaque index, bleeding index and probing depth were assessed. The presence of peri‐implant tissue inflammation was also evaluated. Results: Mean observation time, considering both mandible and maxilla, was 18.3 months ranging from 6 months to 5 years. Both plaque and bleeding indexes frequency decreased over time. Probing depth was stable (2.46 ± 0.5 mm at 4 years). Only three implants were lost due to peri‐implantitis (1.4% at 12 months), whereas the incidence of peri‐implant mucositis was less than 10% in each considered period. Conclusions: The adoption of a systematic hygienic protocol is effective in keeping low the incidence of peri‐implant mucositis as well as in controlling plaque accumulation and clinical attachment loss.     

Correlation between different genotypes of human cytomegalovirus and Epstein-Barr virus and peri-implant tissue status

Background: The purpose of this study was to estimate the prevalence of different genotypes of human cytomegalovirus (HCMV) and Epstein‐Barr virus (EBV) in peri‐implantitis and mucositis sites, and to evaluate the correlation between herpesvirus presence and clinical parameters. Methods: A total of 80 dental implants (mean time of loading, 4.16 ± 1.8 years) were evaluated during the course of the study (30 peri‐implantitis, 25 mucositis and 25 healthy peri‐implant sites). The following clinical parameters were assessed: visible plaque index, bleeding on probing, suppuration and probing depth. A polymerase chain reaction (PCR) assay was used to identify the presence of different HCMV and EBV genotypes in peri‐implant tissue plaque samples. Results: HCMV‐2 was detected in 53.3% and EBV‐1 in 46.6% of the 30 peri‐implantitis sites evaluated. By contrast, HCMV‐2 was not detected in healthy periodontal sites and EBV‐1 was detected in one healthy site. A statistically significant correlation was found between the presence of HCMV‐2 and EBV‐1 genotypes and clinical parameters of peri‐implantitis. Conclusions: The results from the present study confirmed the high prevalence of HCMV‐2 and EBV‐1 in the peri‐implant tissue plaque of peri‐implantitis sites and suggests a possible active pathogenic role of the viruses in peri‐implantitis.     

Treatment Outcome in Patients With Peri‐Implantitis in a Periodontal Clinic: A Retrospective Study

Background: The number of placed implants has grown during the past decade, and the prevalence of peri‐implantitis has increased. The purpose of the present study is to investigate the treatment outcome of peri‐implantitis and to identify factors influencing the treatment success rate. Methods: The study was conducted as a retrospective longitudinal study on a referral population. The material included 382 implants with peri‐implantitis in 150 patients. Peri‐implantitis was defined as presence of pocket depths ≥5 mm, bleeding at probing and/or suppuration, and the presence of implant radiographic bone loss ≥3 mm or bone loss comprising at least three threads of the implant. Variance analyses, χ² analyses, and logistic regression analysis were used for data analyses. Results: The mean age of the participants at baseline was found to be 64 years (range: 22 to 87 years). The mean ± SD follow‐up time was 26 ± 20 months, and the mean time between implant installation and baseline was 6.4 years (range: 1 to 20 years). Periodontal flap surgery with osteoplasty was the most common type of therapy (47%), and regenerative surgery procedures with bone substitute materials were chosen in 20% of the cases. The mean success rate at patient level was 69%. The results of the logistic regression analyses showed that the success rate was significantly lower for individuals with the diagnosis of severe periodontitis, severe marginal bone loss around the implants, poor oral hygiene, and low compliance. Conclusion: The effectiveness of the peri‐implantitis therapy was impaired by severe periodontitis, severe marginal bone loss around the implants, poor oral hygiene, and low compliance.     

Anti-infective treatment of peri-implant mucositis: a randomised controlled clinical trial

Aim: To compare the effectiveness of two anti‐infective protocols for the treatment of peri‐implant mucositis. Materials and methods: Twenty‐nine patients with one implant diagnosed with peri‐implant mucositis (bleeding on probing [BOP] with no loss of supporting bone) were randomly assigned to a control or test group. Following an assessment of baseline parameters (probing depth, BOP, suppuration, presence of plaque), all patients received non‐surgical mechanical debridement at the implant sites and were instructed to brush around the implant twice daily using a gel provided for a period of 4 weeks. The test group (15 patients) received a chlorhexidine gel (0.5%), and the control group (14 patients) received a placebo gel. The study was performed double blind. After 4 weeks, patients were instructed to discontinue using the gel and to continue with routine oral hygiene at the implant sites. Baseline parameters were repeated at 1 and 3 months. Results: At 1 month, there was a statistically significant reduction in the mean number of sites with BOP and mean probing depth measurements at implants in both groups. There were also some statistically significant changes in these parameters from 1 to 3 months. However, there were no statistically significant differences between test and control groups. One month following treatment, 76% of implants had a reduction in BOP. Complete resolution of BOP at 3 months was achieved in 38% of the treated implants. The presence of a submucosal restoration margin resulted in significantly lower reductions in probing depth following treatment. Conclusions: Non‐surgical debridement and oral hygiene were effective in reducing peri‐implant mucositis, but did not always result in complete resolution of inflammation. Adjunctive chlorhexidine gel application did not enhance the results compared with mechanical cleansing alone. Implants with supramucosal restoration margins showed greater therapeutic improvement compared with those with submucosal restoration margins. To cite this article:
Heitz‐Mayfield LJA, Salvi GE, Botticelli D, Mombelli A, Faddy M, Lang NP, On Behalf of the Implant Complication Research Group (ICRG). Anti‐infective treatment of peri‐implant mucositis: a randomised controlled clinical trial.
Clin. Oral Impl. Res. 22 , 2011; 237–241.
doi: 10.1111/j.1600‐0501.2010.02078.x     

General genetic and acquired risk factors,and prevalence of peri‐implant diseases – Consensus report of working group 1

For decades, oral implants have been used successfully for the replacement of missing teeth. Nevertheless, peri‐implant diseases have become an increasingly important issue in daily practice. In this working group, the prevalence of peri‐implant mucositis and peri‐implantitis, as well as different general risk factors and their impact on the onset and progression of peri‐implant diseases, were discussed based on reviews reflecting the current state of evidence. The influence of smoking on the peri‐implant bone‐healing process and its association with peri‐implantitis has been explored in the current literature, demonstrating that smoking is an important risk indicator for the development of peri‐implantitis and implant loss. Compared with non‐smokers, smokers have a higher potential for pathological peri‐implant bone loss, which is also influenced by poor oral hygiene. Despite the fact that a growing number of genetic polymorphisms have been identified and related to periodontal diseases, there are still no genetic patterns that could act as adjuncts to clinical diagnostics in order to identify patients at higher risk of peri‐implant diseases. Long‐term medications, such as bisphosphonate therapy (> 3 years), may have an impact on implant loss. A higher incidence of implant failure was reported in patients using selective serotonin reuptake inhibitors in anti‐depression therapy. Alcoholism (defined as more than 5 units a day) has been associated with implant loss in retrospective and case–control studies, as well as in animal studies.     

Association of Preventive Maintenance Therapy Compliance and Peri‐Implant Diseases: A Cross‐Sectional Study

Background: This study aims to investigate association between peri‐implant maintenance therapy (PIMT) and the frequency of peri‐implant diseases and to further identify factors that contribute to failure of PIMT compliance. Methods: A cross‐sectional study on patients who were healthy and partially edentulous was conducted. They were grouped in the following categories according to PIMT compliance: 1) regular compliers (RC) (≥2 PIMT/year); 2) erratic compliers (EC) (<2 PIMT/year); and 3) non‐compliers (NC) (no PIMT). Radiographic and clinical analyses were carried out including probing depth (PD), plaque index (PI), bleeding on probing (BOP), mucosal redness (MR), suppuration (SUP), keratinized mucosa dimension, and marginal bone loss. A multiple logistic regression model was estimated at implant and patient level to obtain adjusted odds ratios (ORs) and to control possible confounding effects among variables. Results: Overall, 206 implants in 115 patients fulfilled inclusion criteria. At patient level, it was shown that association between compliance and peri‐implant condition was statistically significant (P = 0.04). Compliance was associated with 86% fewer conditions of peri‐implantitis. The probability of PIMT compliance was substantially associated with frequency of peri‐implantitis (OR = 0.13, P = 0.01). Patients with a history of periodontal disease multiplied their probability of being EC (versus NC) 4.23 times with respect to not having a history of periodontal disease (P = 0.02). Moreover, light smokers significantly resulted to be NC compared with RC (P = 0.04) and EC (P = 0.02). Nevertheless, mucositis was not found to be statistically associated with level of compliance. In addition, PD, PI, BOP, MR, and SUP varied significantly according to PIMT compliance and peri‐implant condition. Conclusions: Peri‐implant maintenance compliance ≥2 PIMT/year seems to be crucial to prevent peri‐implantitis in healthy patients. Furthermore, history of periodontal disease and disease severity, as well as its extent and a smoking habit, appear to be factors that influence the compliance risk profile (NCT02789306).     

Surgical treatment of peri‐implantitis – Consensus report of working group 4

The following consensus report is based on four background reviews (Keeve et al., Implant Dent 2019 28(2): 177–186; Ramanauskaite et al., Implant Dent 2019 28(2): 187–209; Koo et al., Implant Dent 2019 28(2): 173–176; Sculean et al., Implant Dent 2019 210–216). The surgical treatment of peri‐implantitis is indicated in the cases where the first choice of treatment, the non‐surgical one, failed with recurrence of bleeding and suppuration. The aim of this review was to systematically screen the literature for possible surface decontamination techniques and material during surgical treatment, the surgical regenerative and non‐regenerative treatments of peri‐implantitis, radiological and clinical outcomes, the importance of the presence of fixed and or keratinised peri‐implant gingiva, and to determine predictable therapeutic options for the clinical surgical management of peri‐implantitis lesions. Existent clinical, radiographic and microbiological data do not favour any decontamination approaches and fail to show the influence of a particular decontamination protocol on surgical therapy. Using implantoplasty in surgical non‐regenerative treatment leads to a significant decrease in bleeding on probing and probing depth, and may result in improvement of clinical and radiographic parameters, up to 3 years after surgery compared with mechanical debridement alone. Surgical augmentative peri‐implantitis therapy resulted in improved clinical and radiographic treatment outcomes compared with the baseline in the majority of studies with 6 months to 7–10 years of follow‐up. There is no evidence to support the superiority of a specific material, product or membrane in terms of long‐term clinical benefits. The best treatment modality to improve the width of keratinised attached mucosa and bleeding and plaque scores, and to sustain the peri‐implant marginal bone level, is the use of an apically positioned flap combined with a free gingival graft.     

Reliability of periodontal diagnostic tools for monitoring peri‐implant health and disease

The prevalence, causes and consequences of crestal bone loss at dental implants are a matter of debate. In recent years, a high prevalence of peri‐implant soft‐tissue inflammation, associated with peri‐implant bone loss, has been reported and the need for treatments similar to those offered for natural teeth affected by periodontitis has been proposed. This suggestion is based on the assumption that periodontal indices, such as probing pocket depth and bleeding on probing, are reliable indicators of the peri‐implant tissue conditions and good predictors of future bone loss. However, based on a critical review of the literature in the present paper, it is concluded that periodontal indices are not reliable either for identifying peri‐implant disease or for predicting future risk for peri‐implant crestal bone loss and implant failure. The long‐term experiences with dental implants, presented in the literature, indicate that the presence of bleeding on probing, probing pocket depths much larger than 4 mm and some bone loss seem to reflect, in most instances, normal conditions of well‐functioning dental implants, bearing in mind that healing of dental implants is the result of a foreign body reaction with the formation of scar tissue. Therefore, the use of probing pocket depth and bleeding on probing assessments may lead to over‐diagnosis and possibly to over‐treatment of assumed biofilm‐mediated peri‐implantitis lesions. It is the opinion of the authors of this review that a treatment should only be initiated when a clinical problem is present based on patient's symptoms (discomfort, pain), the presence of swelling, redness and pus, and significant crestal bone loss over time (as verified with radiographs). The treatment should aim at resolving the infection, which could include removal of the implant.     

Patient compliance as a risk factor for the outcome of implant treatment

Peri‐implantitis can be explained using a multicausality model. Many factors are involved in the etiology of peri‐implantitis, but patient compliance also plays a key role. Oral hygiene, attending recall visits, smoking behavior, and therapy comprehension are relevant factors that contribute to peri‐implant health. The clinician should create the most optimal conditions for patients to facilitate adequate oral self‐care and to help patients improve their oral hygiene skills. Implementation of a supportive periodontal therapy program is mandatory to control inflammation and plaque accumulation, as well as to keep the incidence of peri‐implant diseases low. Patient compliance, including plaque control and dental follow‐up, must be optimal. Consequently, precautions must be taken with patients treated with dental implants.     

Radiographic evaluation of modern oral implants with emphasis on crestal bone level and relevance to peri‐implant health

Implant stability and maintenance of stable crestal bone level are prerequisites for the successful long‐term function of oral implants, and continuous crestal bone loss constitutes a threat to the longevity of implant–supported prosthetic constructions. The prevalence/incidence and reasons for crestal bone loss are under debate. Some authors regard infection (i.e. peri‐implantitis) as the cause for virtually all bone loss, while others see crestal bone loss as an unavoidable phenomenon following surgery and implant loading. Irrespective of the cause of continuous crestal bone loss, correct usage and scientifically sound interpretation of radiographs are of utmost importance for evaluation of oral implants. The periapical radiographic technique is currently the preferred method for evaluating implant health based on bone loss, and digital radiographs allow easy standardization of the image contrast. It is suggested that baseline radiographs should be taken at the time the transmucosal part pierces the mucosal tissues and annually thereafter. The number of unreadable radiographs should be presented in scientific publications to give insights into the quality of the radiographic examination. It is suggested that not only mean values, but also the range of bone levels, should be presented to describe the proportion of implants that show continuous crestal bone loss. In the absence of other clinical symptoms, bleeding on probing around implants seems to be a weak indicator of ongoing or future loss of crestal bone. According to recent longitudinal studies on modern implant surfaces peri‐implantitis defined as ‘infection with suppuration associated with clinically significant progressing crestal bone loss’ occurs with a prevalence of less than 5 % in implants with 10 years in function.     

Composition of supra- and subgingival biofilm of subjects with healthy and diseased implants

Objectives: The purpose of this study was to compare the microbial composition of supra‐ and subgingival biofilm in subjects with and without peri‐implantitis. Material and methods: Forty‐four subjects (mean age 48.9 ± 13.51 years) with at least one implant restored and functional for at least 2 years were assigned to two groups: a peri‐implantitis group (n=22), consisting of subjects presenting peri‐implant sites with radiographic defects >3 mm, bleeding on probing and/or suppuration; and a control group (n=22), consisting of subjects with healthy implants. The clinical parameters evaluated were plaque index, gingival bleeding, bleeding on probing, suppuration, probing depth and clinical attachment level. Supra‐ and subgingival biofilm samples were taken from the deepest sites of each implant and analyzed for the presence of 36 microorganisms by checkerboard DNA–DNA hybridization. Results: Higher mean counts of Porphyromonas gingivalis, Treponema denticola and Tannerella forsythia were observed in the peri‐implantitis group, both supra‐ and subgingivally (P<0.05). The proportions of the pathogens from the red complex were elevated, while host‐compatible beneficial microbial complexes were reduced in diseased compared with healthy implants. The microbiological profiles of supra‐ and subgingival environments did not differ substantially within each group. Conclusion: Marked differences were observed in the composition of supra‐ and subgingival biofilm between healthy and diseased implants. The microbiota associated with peri‐implantitis was comprised of more periodontal pathogenic bacterial species, including the supragingival biofilm.     

Estimation of Bone Loss Biomarkers as a Diagnostic Tool for Peri‐Implantitis

Background: The aims of this study are to estimate the profile of bone loss biomarkers in peri‐implant tissues and to identify potential prognostic biomarkers of peri‐implantitis. Methods: Peri‐implant crevicular fluid samples collected from 164 participants (52 patients with peri‐implantitis, 54 with mucositis, and 58 with healthy peri‐implant tissues) were analyzed using enzyme‐linked immunosorbent assays to evaluate concentrations of the receptor activator of nuclear factor‐κB (RANK), soluble RANK ligand (sRANKL), osteoprotegerin (OPG), cathepsin‐K, and sclerostin. Results: Concentrations of RANK, sRANKL, OPG, and sclerostin were significantly increased in patients with peri‐implantitis compared with patients with healthy peri‐implant tissues. Comparisons between peri‐implantitis and mucositis demonstrated significantly higher values of sclerostin in peri‐implantitis samples. Comparisons between mucositis and healthy peri‐implant tissues showed significantly increased levels of RANK and cathepsin‐K in mucositis. Conclusion: These results are suggestive of a role of sRANKL, OPG, and sclerostin as prognostic biomarkers in peri‐implantitis.